To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conduct...To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.展开更多
Sedimentary basins are where the products or erosion of the related reliefs accumulate.The sedimentary records preserved in the basins offer the possibility of quantifying the paleotopography z(x,y,t) at each point( x...Sedimentary basins are where the products or erosion of the related reliefs accumulate.The sedimentary records preserved in the basins offer the possibility of quantifying the paleotopography z(x,y,t) at each point( x,y )of a given region at any time t in the past by using methods of mass balanced reconstruction(Hay et al.,1989,Métivier and Gaudemer,1997),The importance of paleotopography is on that atmospheric circulation models and the ocean circulation models which depend on them require knowledge of the topography of the land as an important input boundary condition which strongly affects the model output(Barron and Washington,1984,Ruddiman et al.,1997).Thus,a first step towards establishing paleoelevations is to reconstitute the history of sedimentary basins in terms of mass accumulation(Hay et al.,1989).This work reconstructs the space\|time depositional history and estimates the mass stored in the Hoh Xil basin,northern Tibet.The Hoh Xil basin,with an area of 101000km\+2 and an average elevation of over 5000m,is the largest Cenozoic sedimentary basin in the hinterland of the Tibetan plateau.From the Early Eocene to the Early Miocene,a sediment pile of approximately 5 4km thick of fluvial mudstone,sandstone,and conglomerate and 0 3km thick of limestone was formed in the basin (Liu and Wang,2000;Liu et al.,2000).the mass estimate is derived from 21 measured field cross\|sections,with total thickness of 13479 3m.The results show that the Hoh Xil basin has undergone 7 stages of evolution from the Early Eocene to the Early Oligocene,with a period of no sedimentation during the Late Oligocene.The Fenghuoshan Group was formed from the first four stages as 56 0～52 0,52 0～46 7,46 7～39 7,and 39 7～33 2Ma ago,with the depocenter moving eastward and northward.The Yaxicuo Group was formed from the two next stages as 33 2～32 2 and 33 2～30 2Ma ago.The Wudaoliang Group spread the entire basin during the last stage of ca.23 0～16 0Ma ago,with its depocenter in the northern part.The strata of the Fenghuoshan and Yaxicuo Groups have undergone strong deformation mainly during 30 0 to ca.23 0Ma,whereas only minor tilting has occurred in the Wudaoliang Group later.The space\|time evolution indicates that the Hoh Xil basin could be formed by the collision between Indi and Asia during the Early Eocene,and that its filling processes were controlled by early uplift and crustal shortening of the Tibetan plateau.The sedimentation budget is estimated as 297 15×10 12 t for the Cenozoic sediments deposited in the Hoh Xil basin.The accumulation rate curve shows that the value rises suddenly to around 800t/(m\+2 Ma -1 )during 32 2～30 0Ma ago from around 400t/(m\+2·Ma -1 )during 56～32 2Ma ago.The sudden increase of accumulation rate could be produced by early uplift of the Tibetan plateau.展开更多
In order to improve the understanding of the fundamental mechanism of rainfall infiltration induced landslides in accumulation slope and to clarify some important characteristics of slope performance,artificial rainfa...In order to improve the understanding of the fundamental mechanism of rainfall infiltration induced landslides in accumulation slope and to clarify some important characteristics of slope performance,artificial rainfall simulation tests and field synthetic monitoring were carried out on a typical accumulation slope of Shangrui Freeway in Guizhou Province,China.The monitoring results show that the most accumulation landslides caused by rainfall infiltration are shallow relaxation failure,whose deformation zone lies within the top 0-4 m soil layer.The deformation of slope gradually reduces from the surface,where the greatest deformation lies in,to the deep part of slope.The average percentage of infiltration during the first 2 h is 86%,and then it reduces gradually with time because of the increase of the surface runoff.The average percentage of infiltration drop to a relatively stable value(50%)after 6 h.Rainfall infiltration causes obvious increase of pore-water pressure,which may result in a reduction of shear strength due to a decrease in effective stress and wetting-induced softening.The double-effect of rainfall infiltration is the main reason of rainfall infiltration induced landslides in accumulation slope.展开更多
Based on the collaborative exploitation of deep mineral resources and geothermal resources, the thermal accumulation process of cemented tailings backfill(CTB) was studied by numerical simulation. The effects of therm...Based on the collaborative exploitation of deep mineral resources and geothermal resources, the thermal accumulation process of cemented tailings backfill(CTB) was studied by numerical simulation. The effects of thermal accumulation time, slurry proportions and temperature conditions on the thermal accumulation of backfill are analyzed, the influence of the heat conduction between backfill and surrounding rock, the heat convection between backfill and airflow on thermal accumulation were compared simultaneously. The results show that the total thermal accumulation capacity increases by approximately 85% within 10-90 d. The influence of surrounding rock temperature and initial temperature on total thermal accumulation capacity is more significant and it is approximately 2 times of the influence of slurry proportions under the conditions of this study. It is clear that the rise of surrounding rock temperature and the decrease of initial temperature can improve the thermal accumulation capacity more effectively. Moreover, the heat conduction accounts for a considerable proportion in the process of thermal accumulation, the average heat conduction capacity is approximately 25 times of the heat convection capacity. This study can provide the theoretical basis and application reference for the optimization of thermal accumulation process of CTB in the exploitation of geothermal resources.展开更多
In this paper, a Euler-Lagrangian particle/fluid film/VOF coupled multiphase flow model is presented. Numerical simulations are conducted, and the rainwater accumulation and flow characteristics over two types of wind...In this paper, a Euler-Lagrangian particle/fluid film/VOF coupled multiphase flow model is presented. Numerical simulations are conducted, and the rainwater accumulation and flow characteristics over two types of windshields are studied based on the presented model. The results show that an uneven water film is formed over the windshield, with rain water accumulation occurring for the concave windshield but not for the convex windshield. At low speeds, the average fluid-film thickness for a concave windshield is larger than that of a convex windshield;however, a minor difference occurs between these two values at high speeds, and a critical velocity is observed for the two types of windshields. When the train velocity is less than the critical velocity, the fluid film at the lower part of the windshield and the train nose flows downward, and beyond the critical velocity, the fluid film over the entire windshield and train nose flows upward.展开更多
Nitrogen（N） is considered as an important yield and quality-determining factor in soybean production.The objective of the current experiment was to determine the regularity of N accumulation and its simulation among...Nitrogen（N） is considered as an important yield and quality-determining factor in soybean production.The objective of the current experiment was to determine the regularity of N accumulation and its simulation among different varieties.This work was conducted with frame tests（pot without bottom）,and three cultivars,HH41,SN14,HN40,and one feed soybean variety MSD was used as materials.The results showed that the regularity of N accumulation in four varieties with the same tendency increased during the whole growth period,which was up to the maximum when the plant was harvested.The longer growth period was,the higher N accumulation of cultivars was,HN40〉SN14〉HH41,N accumulation of MSD was the highest because of the property for feed soybean.Regularity of N accumulation in plants could be accurately described by the Logistic equation.During the growth there was a period when N accumulation in the whole plant occurred at an intense rate.The time of onset and its duration varied with different varieties.The maximum daily N accumulation was on seed filling stage,pod bearing stage,seed filling stage and pod bearing stage in HH41,SN14,HN40 and MSD,respectively.展开更多
Physiological studies of soybean [Glycine max(L.)Merr.]genotypes with wide differences in seed protein concentration may permit detection of important yield related processes.In order to research the law of protein a...Physiological studies of soybean [Glycine max(L.)Merr.]genotypes with wide differences in seed protein concentration may permit detection of important yield related processes.In order to research the law of protein accumulation and the characteristics of N accumulation and translocation,we did an experiment with three soybean cultivars which have different protein content and the similar phase in pot culture.The results showed that the laws of protein accumulation of three soybean cultivars are similar in the course of seeding;protein content descended in the early stage,and increased steadily in the middle period,then increased quickly in the later period.But the speed of protein accumulation in soybean seeds was difference in different period.In addition,high protein cultivar (Dongnong 42) and intermediate protein cultivar (Dongnong 7819) were more than those of low protein cultivar (Dongnong 434),including nitrogen contents in leaf and petiole,stem and pod,peak value of nitrogen accumulation of the whole plant,value of nitrogen translocation,its efficiency.展开更多
Based on the drilling,cores,logs,seismic,laboratory analysis and so on,reservoir characteristics and hydrocarbon accumulation of Carboniferous volcanic weathered crust in Zhongguai high area are studied.Volcanic rocks...Based on the drilling,cores,logs,seismic,laboratory analysis and so on,reservoir characteristics and hydrocarbon accumulation of Carboniferous volcanic weathered crust in Zhongguai high area are studied.Volcanic rocks were formed in an island arc environment.The lithology is mainly andesite and tuff;Reservoir spaces are mainly secondary pore,fracture and their combination forms,fractures have a better effect on reservoir seepage;There are four layer structures of volcanic weathered crust,weathered clay layer,strongly weathered zone,weakly weathered zone and unweathered zone and strongly weathered zone is the best,which is the main reservoir development zone;The development of reservoir is mainly affected by weathering-leaching,lithology and lithofacies,and fault(fracture);Effective reservoirs could reach to 480 m thickness(high quality reservoirs are within 240 m).Carboniferous volcanic reservoirs are distributed along three zones,which are near the fault zone,high structural part,favorable lithofacies development zone,and one plane,which is near the unconformity.展开更多
The micromigration of oil-drive-water and gas-drive-water in oil and gas fields was studied,by using core slices and micro-experimental technology,and the migration processes and characteristics of oil and gas in pore...The micromigration of oil-drive-water and gas-drive-water in oil and gas fields was studied,by using core slices and micro-experimental technology,and the migration processes and characteristics of oil and gas in pores and throats were observed,as well as entry pressures of oil/gas migration.Research shows that entry pressures of both oil-drive-water and gas-drive-water increase obviously as porosity decreases,and the statistical regularity observes the power function variation.However,there is a complex changing relationship between porosity and different entry pressure values of the two replacement processes,forming three curve sections,each representing a different accumulation significance.When the porosity is over 10%-12%,the difference between oil-drive-water and gas-drive-water entry pressures is small.Both oil and gas can migrate and accumulate in this kind of reservoir.The probabilities of oil and gas reservoir formation are nearly equal,forming conventional oil/gas pools.When porosity is between 5% and 10%-12%,the difference between the two is obvious,which indicates that this kind of reservoir can seal oil,but can also be a reservoir for gas,easily forming unconventional hydrocarbon pools(deep-basin gas pools).When porosity is less than 5%,the difference is indistinct and the entry capillary pressures show the same sealing function for oil and gas.In this condition,both oil and gas pools are difficult to form.Experimental results give a rational explanation for the difference of accumulation probability between deep-basin gas and deep-basin oil,and also for the mechanism of tight sand acting as cap rock.展开更多
In order to explore the response of maize phosphorus absorption to the appropriate proportion of organic fertilizer substitution for reduced chemical fertilizer,a field experiment with eight treatments was conducted i...In order to explore the response of maize phosphorus absorption to the appropriate proportion of organic fertilizer substitution for reduced chemical fertilizer,a field experiment with eight treatments was conducted in 2018.The eight treatments in the trial were:(1)CK;(2)M0+F;(3)M1+F1;(4)M1+F2;(5)M2+F1;(6)M2+F2;(7)M3+F1 and(8)M3+F2.In these treatments,M0,M1,M2 and M3 were organic fertilization of 0,15(low),30(medium)and 45(high)m3•hm-2,respectively.F1 and F2 indicated 20%and 40%reduction of conventional chemical fertilization.The soil nutrient content,phosphorus accumulation,dry weight,yield and yield components of maize were analyzed.The results showed that the phosphorus accumulation of maize stalks and leaves were 3.30%-43.17%and 10.98%-84.95%higher in M3+F1 treatment(20%reduction of chemical fertilizer with organic fertilizer of 45 m3•hm-2)than those in the conventional treatment(M0+F)during the maize reproductive period.At R2 stage,stalk and shoot P accumulation of M3+F1 treatment were 24.67%-43.18%and 20.34%-25.19%higher than other treatments,respectively.At V12 stage,leaf P accumulation of M3+F1 increased by 84.95%compared with other treatments.The maize yield of M3+F1 was significantly higher than that of other treatments,even though the partial productivity of the total phosphorus fertilizer of M3+F2 was the highest in the treatments.It could be found that the substitution of organic fertilizer for chemical fertilizer improved crop yield,phosphorus fertilizer efficiency and accumulation.M3+F1 treatment had the most positive effects on improving maize phosphorus accumulation and yield.展开更多
The lower Ordovician mid-assemblage Formations in the central Ordos Basin of China host prolific gas resources,and most hydrocarbon reserves are stored in naturally-fractured reservoirs.Thus,fracture pathway systems m...The lower Ordovician mid-assemblage Formations in the central Ordos Basin of China host prolific gas resources,and most hydrocarbon reserves are stored in naturally-fractured reservoirs.Thus,fracture pathway systems may have a significant impact on reservoir performance.This article focuses on the core-and laboratory-based characterization of fractures.Through the developmental degrees,extended scale,output state and filling characteristics of various types of fractures,the results show that there are three distinct fracture types:1)nearly vertical fractures,2)oblique fractures,and 3)horizontal fractures.Based on a systematic study of the characterization of reservoir space,the main geologic setting of natural gas accumulation and the regional tectonic background,type 1 is mainly driven by the tectonic formation mechanism,and type 3 and parts of low-angle fractures in type 2 are induced by the diagenetic formation mechanism.While recovered paleopressure for methane-rich aqueous inclusions trapped in fracture-filling cement indicates that the fracture opening and growth are consistent with gas maturation and charge and such high-angle fractures in type 2 are caused by the compound formation mechanism.The fractures to hydrocarbon accumulation may play a more significant role in improving the quality of reservoir porosity.Furthermore,connected fractures,dissolved pores and cavities together constitute the three-dimensional pore-cave-fracture network pathway systems,with faults serving as the dominant charge pathways of highly pressurized gas in the study area.Our results demonstrate that protracted growth of a pervasive fracture system is not only the consequence of various formation mechanisms but also intrinsic to quasi-continuous accumulation reservoirs.展开更多
The creep behaviors of granite residual soil with pre-stress of 100 kPa was investigated by a series of small size creep tests. Three different types of strain curves were obtained at different stress levels. Based on...The creep behaviors of granite residual soil with pre-stress of 100 kPa was investigated by a series of small size creep tests. Three different types of strain curves were obtained at different stress levels. Based on creep characteristics of the granite residual soil under different stress levels, a creep model of the granite residual soil was established by rheological theory, and related parameters of the model were determined according to the experimental data at the same time. Further on, based on the established creep model, a theoretical model of dynamic stress accumulation in the granite residual soil under cyclic loading was deduced. It is found that there is a threshold of dynamic stress accumulation in this theoretical model. The dynamic stress accumulation laws of the granite residual soil are different under different cyclic loading stress. Finally, with the dynamic stress accumulation laws in the small-size samples of granite residual soil under different cycle loading studied and the experimental results comparing with the theoretical results, it verifies the validity of the theoretical model.展开更多
Salt-induced osmotic pressure has been drawing increasing attention in the field of microalgal biomechanics because it can enhance the lipids accumulation of microalgae.Studies have shown that osmotic stress can affec...Salt-induced osmotic pressure has been drawing increasing attention in the field of microalgal biomechanics because it can enhance the lipids accumulation of microalgae.Studies have shown that osmotic stress can affect the synthesis of phospholipids by activating different phospholipid signaling pathways.However,there is little research about the mechanism of action of osmotic stress in neutral lipids synthesis.In this work,the effects of different salt-induced osmotic pressure on oil synthesis and potential mechanismwere studied.First,effect of various salt4nduced osmotic pressure of 64,112,191,453 and 1304 mOsm/kg on Chlorella pyrenoidosa oil synthesis were studied and optimal salt-induced osmotic pressure of 453 mOsm/kg was acquired.Then the content of key signaling chemicals in the Cyclic Adenosine monophosphate(cAMP)signaling pathway and the key enzyme activities in the lipid synthesis pathway were determined under salt-induced osmotic pressure of 453 mOsm/kg.It was found that the cAMP signaling pathway were up-regulated under salt osmotic pressure conditions of 453 mOsm/kg;in addition,the key enzymes related to lipid synthesis increased,while those related to protein synthesis decreased,enabling the increase of the lipid content.Finally,the effects of inhibitor atropine and promoter IBMX of cAMP signal pathway were also investigated.Results showed that atropine inhibits the cAMP signaling pathway and the lipid contents decreased;in contrast,IBMX activated thecAMP signaling pathway and the lipids content increased.These observations further confirm that salt-induced osmotic pressure had the same function as the signal promoter to regulate lipid synthesis by adjusting cAMP signaling pathway regulating lipid synthesis.This study preliminarily revealed the mechanism that salt-induced osmotic pressure affected lipid synthesis pathway through cAMP signaling pathway to regulate lipid synthesis in microalgae.展开更多
Nanpu sag lies in the northwest part of the Bohai bay basin.Laoyemiao structural zone is located in the northwest part of the sag,to the north bound by basin-bounding master fault-Xi’nanzhuang fault (XNZF).This paper...Nanpu sag lies in the northwest part of the Bohai bay basin.Laoyemiao structural zone is located in the northwest part of the sag,to the north bound by basin-bounding master fault-Xi’nanzhuang fault (XNZF).This paper aims to gain insight into Laoyemiao tectonic features and set up its tectonic -hydrocarbon accumulation model by展开更多
As a structural protein, the physiological function of tau proteins is to promote microtu-bule assembly and maintain the stability of the microtubules, so that to build up the tracks for axonal transport of the neuron...As a structural protein, the physiological function of tau proteins is to promote microtu-bule assembly and maintain the stability of the microtubules, so that to build up the tracks for axonal transport of the neurons. Recent studies suggest that tau is also actively involved in regulation of cell viability and enzymatic reaction. In Alzheimer disease (AD) and other tauopathies, tau proteins are abnormally hyperphosphorylated or cleaved, or the gene mutated, which result in intracellular tau accumulation and formation of neurofibrillary tangles in the degenerated neurons. In addition to hyperphosphorylation, many other types of tau posttranslational modifications have been identified in the brains of AD patients and/or the transgenic mouse models. To date, it is not clear how the abnormality of tau causes neurodegeneration and memory deficits. By overexpressing human full-length wildtype tau to mimic tau abnormality as seen in the brain of sporadic AD patients, we found that tau accumulation activated JAK2 to phosphorylate STAT1 at Tyr701 leading to STAT1 dimerization, nuclear translocation and its activation. STAT1 activation suppressed expression of NMDAR through direct binding to the specific GAS element of Glu N1, Glu N2A and Glu N2B promoters, while knockdown STAT1 by AAV-Cre in STAT1 flox/flox mice or expressing dominant negative Y701F-STAT1 efficiently rescued tau-induced suppression of NMDAR expression with amelioration of synaptic functions and memory performance.These findings indicate that tau accumulation impairs synaptic plasticity through JAK2/STAT1-induced suppression of NMDAR expression, which reveals a novel mechanism for tau-associated synapse and memory deficits in AD and other tauopathies.展开更多
The northern type Longtan Formation of the Late Permian in central Hunan is dominated by an assemblage of greyish black mudstone,siltstone, sandy mudstone,fine sandstone and coals,and contains a variety of sedimentary...The northern type Longtan Formation of the Late Permian in central Hunan is dominated by an assemblage of greyish black mudstone,siltstone, sandy mudstone,fine sandstone and coals,and contains a variety of sedimentary structures such as thin sandstone-mudstone interbedded bedding,flaser beddings,lenticular beddings,horizontal展开更多
Fault controlling petroleum accumulation is mainly reflected in hydrocarbon migration and sealing in accumulation periods.By fault activity rate analysis and fuzzy comprehensive sealing evaluation in different places ...Fault controlling petroleum accumulation is mainly reflected in hydrocarbon migration and sealing in accumulation periods.By fault activity rate analysis and fuzzy comprehensive sealing evaluation in different places of Linshang Fault Zone(LFZ),LFZ controlling petroleum accumulation shows a lot of spatiotemporal differences:(1) main branch of展开更多
The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the me...The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.展开更多
In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developi...In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developing seeds. The objective of this study was to provide the changes of various fatty acid accumulations in seed oil obtained from the seeds of three pumpkin varieties belonging to the species Cucurbita maxima and Cucurbita pepo. Unsaturated acids(oleic and linoleic) were dominant in various fatty acids, which constituted 38.9%-49.1% and 29.4%-42.7% of the total fatty acids at seed maturity for three pumpkin varieties, respectively, while other fatty acid concentrations except for palmitic acid all did not reach 10%. Different varieties exhibited greater effect on various fatty acid contents and the total fatty acid contents in the seeds of pumpkin rather than the species. On the whole, palmitic acid profiles of the seed oil in three varieties all followed the fluctuant decrease during all the stages of seed development, but palmitoleic acid and the total fatty acid profiles of the seed oil in three varieties were just the opposite. Stearic, oleic and linoleic acid profiles of the seed oil in three varieties all experienced the third pattern that fluctuated during all the stages of seed development, but no significant differences in these three fatty acid concentrations were found from the beginning to the end. Linolenic acid concentrations of three varieties were on the decline and ultimately close to zero. Myristic and arachidic acid profiles of the seed oil followed different trends in three varieties. Among them, myristic and arachidic acid profiles of the seed oil of Yinhui-1 fluctuated downward all the time until seed maturity, but those of 0238-1 and Jinhui-2 completely changed oppositely.展开更多
In the present study,microstructural evolution,mechanical and creep properties of Al/SiC/Cu composite stripsfabricated via accumulative roll bonding(ARB)process were studied.The obtained results showed the formation o...In the present study,microstructural evolution,mechanical and creep properties of Al/SiC/Cu composite stripsfabricated via accumulative roll bonding(ARB)process were studied.The obtained results showed the formation of anatomic diffusion layer with thickness of about 17μm at the interface during the ARB under three creep loadingconditions namely 30 MPa at 225℃,35 MPa at 225℃,and 35 MPa at 275℃.An generated intermetallic compoundresulted in a 40%increase of interface thickness near Al.The stress level decreased by 13%at constant temperature withno signi fi cant effect on the interface thickness,and the creep failure time declined by 44%.It was observed that atconstant temperatures,the second slope of the creep curve reached to 39%with increasing stress level,then,it dropped to2%with a little temperature rising.After creep test under 35 MPa at 275℃,the sample displays the presence of 60%Aland 40%Cu,containing brittle Al_(2)Cu intermetallic compound at the interface.Applied temperature and stress had effecton the creep properties,specially increasing the slope of creep curves with higher stresses.展开更多
文摘To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.
文摘Sedimentary basins are where the products or erosion of the related reliefs accumulate.The sedimentary records preserved in the basins offer the possibility of quantifying the paleotopography z(x,y,t) at each point( x,y )of a given region at any time t in the past by using methods of mass balanced reconstruction(Hay et al.,1989,Métivier and Gaudemer,1997),The importance of paleotopography is on that atmospheric circulation models and the ocean circulation models which depend on them require knowledge of the topography of the land as an important input boundary condition which strongly affects the model output(Barron and Washington,1984,Ruddiman et al.,1997).Thus,a first step towards establishing paleoelevations is to reconstitute the history of sedimentary basins in terms of mass accumulation(Hay et al.,1989).This work reconstructs the space\|time depositional history and estimates the mass stored in the Hoh Xil basin,northern Tibet.The Hoh Xil basin,with an area of 101000km\+2 and an average elevation of over 5000m,is the largest Cenozoic sedimentary basin in the hinterland of the Tibetan plateau.From the Early Eocene to the Early Miocene,a sediment pile of approximately 5 4km thick of fluvial mudstone,sandstone,and conglomerate and 0 3km thick of limestone was formed in the basin (Liu and Wang,2000;Liu et al.,2000).the mass estimate is derived from 21 measured field cross\|sections,with total thickness of 13479 3m.The results show that the Hoh Xil basin has undergone 7 stages of evolution from the Early Eocene to the Early Oligocene,with a period of no sedimentation during the Late Oligocene.The Fenghuoshan Group was formed from the first four stages as 56 0～52 0,52 0～46 7,46 7～39 7,and 39 7～33 2Ma ago,with the depocenter moving eastward and northward.The Yaxicuo Group was formed from the two next stages as 33 2～32 2 and 33 2～30 2Ma ago.The Wudaoliang Group spread the entire basin during the last stage of ca.23 0～16 0Ma ago,with its depocenter in the northern part.The strata of the Fenghuoshan and Yaxicuo Groups have undergone strong deformation mainly during 30 0 to ca.23 0Ma,whereas only minor tilting has occurred in the Wudaoliang Group later.The space\|time evolution indicates that the Hoh Xil basin could be formed by the collision between Indi and Asia during the Early Eocene,and that its filling processes were controlled by early uplift and crustal shortening of the Tibetan plateau.The sedimentation budget is estimated as 297 15×10 12 t for the Cenozoic sediments deposited in the Hoh Xil basin.The accumulation rate curve shows that the value rises suddenly to around 800t/(m\+2 Ma -1 )during 32 2～30 0Ma ago from around 400t/(m\+2·Ma -1 )during 56～32 2Ma ago.The sudden increase of accumulation rate could be produced by early uplift of the Tibetan plateau.
基金Project(50678175)supported by the National Natural Science Foundation of China
文摘In order to improve the understanding of the fundamental mechanism of rainfall infiltration induced landslides in accumulation slope and to clarify some important characteristics of slope performance,artificial rainfall simulation tests and field synthetic monitoring were carried out on a typical accumulation slope of Shangrui Freeway in Guizhou Province,China.The monitoring results show that the most accumulation landslides caused by rainfall infiltration are shallow relaxation failure,whose deformation zone lies within the top 0-4 m soil layer.The deformation of slope gradually reduces from the surface,where the greatest deformation lies in,to the deep part of slope.The average percentage of infiltration during the first 2 h is 86%,and then it reduces gradually with time because of the increase of the surface runoff.The average percentage of infiltration drop to a relatively stable value(50%)after 6 h.Rainfall infiltration causes obvious increase of pore-water pressure,which may result in a reduction of shear strength due to a decrease in effective stress and wetting-induced softening.The double-effect of rainfall infiltration is the main reason of rainfall infiltration induced landslides in accumulation slope.
基金Projects(51974225,51674188,51874229,51904224,51904225,51704229)supported by the National Natural Science Foundation of ChinaProject(2018KJXX-083)supported by the Shaanxi Innovative Talents Cultivate Program-New-Star Plan of Science and Technology,China+2 种基金Projects(2018JM5161,2018JQ5183,2015JM-074)supported by the Natural Science Basic Research Plan of Shaanxi Province,ChinaProject(19JK0543)supported by the Scientific Research Program funded by Education Department of Shaanxi Province,ChinaProject(2018YQ201)supported by the Outstanding Youth Science Fund of Xi’an University of Science and Technology,China。
文摘Based on the collaborative exploitation of deep mineral resources and geothermal resources, the thermal accumulation process of cemented tailings backfill(CTB) was studied by numerical simulation. The effects of thermal accumulation time, slurry proportions and temperature conditions on the thermal accumulation of backfill are analyzed, the influence of the heat conduction between backfill and surrounding rock, the heat convection between backfill and airflow on thermal accumulation were compared simultaneously. The results show that the total thermal accumulation capacity increases by approximately 85% within 10-90 d. The influence of surrounding rock temperature and initial temperature on total thermal accumulation capacity is more significant and it is approximately 2 times of the influence of slurry proportions under the conditions of this study. It is clear that the rise of surrounding rock temperature and the decrease of initial temperature can improve the thermal accumulation capacity more effectively. Moreover, the heat conduction accounts for a considerable proportion in the process of thermal accumulation, the average heat conduction capacity is approximately 25 times of the heat convection capacity. This study can provide the theoretical basis and application reference for the optimization of thermal accumulation process of CTB in the exploitation of geothermal resources.
基金Projects(2016YFB1200602-11,2016YFB1200602-12)supported by the National Key R&D Plan of China
文摘In this paper, a Euler-Lagrangian particle/fluid film/VOF coupled multiphase flow model is presented. Numerical simulations are conducted, and the rainwater accumulation and flow characteristics over two types of windshields are studied based on the presented model. The results show that an uneven water film is formed over the windshield, with rain water accumulation occurring for the concave windshield but not for the convex windshield. At low speeds, the average fluid-film thickness for a concave windshield is larger than that of a convex windshield;however, a minor difference occurs between these two values at high speeds, and a critical velocity is observed for the two types of windshields. When the train velocity is less than the critical velocity, the fluid film at the lower part of the windshield and the train nose flows downward, and beyond the critical velocity, the fluid film over the entire windshield and train nose flows upward.
基金Supported by China's National Key Technology R&D Programs (2007BAD88B01-05 2007BAD89B05)
文摘Nitrogen（N） is considered as an important yield and quality-determining factor in soybean production.The objective of the current experiment was to determine the regularity of N accumulation and its simulation among different varieties.This work was conducted with frame tests（pot without bottom）,and three cultivars,HH41,SN14,HN40,and one feed soybean variety MSD was used as materials.The results showed that the regularity of N accumulation in four varieties with the same tendency increased during the whole growth period,which was up to the maximum when the plant was harvested.The longer growth period was,the higher N accumulation of cultivars was,HN40〉SN14〉HH41,N accumulation of MSD was the highest because of the property for feed soybean.Regularity of N accumulation in plants could be accurately described by the Logistic equation.During the growth there was a period when N accumulation in the whole plant occurred at an intense rate.The time of onset and its duration varied with different varieties.The maximum daily N accumulation was on seed filling stage,pod bearing stage,seed filling stage and pod bearing stage in HH41,SN14,HN40 and MSD,respectively.
基金Research wassubsidized by thegrandtechnology- surm ounted research items of the National Science Committee ofthe Tenth five- year plan:the research and demonstration of the technology for good- quality soybean
文摘Physiological studies of soybean [Glycine max(L.)Merr.]genotypes with wide differences in seed protein concentration may permit detection of important yield related processes.In order to research the law of protein accumulation and the characteristics of N accumulation and translocation,we did an experiment with three soybean cultivars which have different protein content and the similar phase in pot culture.The results showed that the laws of protein accumulation of three soybean cultivars are similar in the course of seeding;protein content descended in the early stage,and increased steadily in the middle period,then increased quickly in the later period.But the speed of protein accumulation in soybean seeds was difference in different period.In addition,high protein cultivar (Dongnong 42) and intermediate protein cultivar (Dongnong 7819) were more than those of low protein cultivar (Dongnong 434),including nitrogen contents in leaf and petiole,stem and pod,peak value of nitrogen accumulation of the whole plant,value of nitrogen translocation,its efficiency.
基金Project (51674211) supported by the National Natural Science Foundation of ChinaProject (51534006) supported by the Key Projects of the Natural Science Foundation,ChinaProject (2017ZX05036003-003) supported by the National Science and Technology Project of China
文摘Based on the drilling,cores,logs,seismic,laboratory analysis and so on,reservoir characteristics and hydrocarbon accumulation of Carboniferous volcanic weathered crust in Zhongguai high area are studied.Volcanic rocks were formed in an island arc environment.The lithology is mainly andesite and tuff;Reservoir spaces are mainly secondary pore,fracture and their combination forms,fractures have a better effect on reservoir seepage;There are four layer structures of volcanic weathered crust,weathered clay layer,strongly weathered zone,weakly weathered zone and unweathered zone and strongly weathered zone is the best,which is the main reservoir development zone;The development of reservoir is mainly affected by weathering-leaching,lithology and lithofacies,and fault(fracture);Effective reservoirs could reach to 480 m thickness(high quality reservoirs are within 240 m).Carboniferous volcanic reservoirs are distributed along three zones,which are near the fault zone,high structural part,favorable lithofacies development zone,and one plane,which is near the unconformity.
基金Projects(4067208740472073) supported by the National Natural Science Foundation of China
文摘The micromigration of oil-drive-water and gas-drive-water in oil and gas fields was studied,by using core slices and micro-experimental technology,and the migration processes and characteristics of oil and gas in pores and throats were observed,as well as entry pressures of oil/gas migration.Research shows that entry pressures of both oil-drive-water and gas-drive-water increase obviously as porosity decreases,and the statistical regularity observes the power function variation.However,there is a complex changing relationship between porosity and different entry pressure values of the two replacement processes,forming three curve sections,each representing a different accumulation significance.When the porosity is over 10%-12%,the difference between oil-drive-water and gas-drive-water entry pressures is small.Both oil and gas can migrate and accumulate in this kind of reservoir.The probabilities of oil and gas reservoir formation are nearly equal,forming conventional oil/gas pools.When porosity is between 5% and 10%-12%,the difference between the two is obvious,which indicates that this kind of reservoir can seal oil,but can also be a reservoir for gas,easily forming unconventional hydrocarbon pools(deep-basin gas pools).When porosity is less than 5%,the difference is indistinct and the entry capillary pressures show the same sealing function for oil and gas.In this condition,both oil and gas pools are difficult to form.Experimental results give a rational explanation for the difference of accumulation probability between deep-basin gas and deep-basin oil,and also for the mechanism of tight sand acting as cap rock.
基金Supported by the National Key Research and Development Plan Project(2017YFD0201803)。
文摘In order to explore the response of maize phosphorus absorption to the appropriate proportion of organic fertilizer substitution for reduced chemical fertilizer,a field experiment with eight treatments was conducted in 2018.The eight treatments in the trial were:(1)CK;(2)M0+F;(3)M1+F1;(4)M1+F2;(5)M2+F1;(6)M2+F2;(7)M3+F1 and(8)M3+F2.In these treatments,M0,M1,M2 and M3 were organic fertilization of 0,15(low),30(medium)and 45(high)m3•hm-2,respectively.F1 and F2 indicated 20%and 40%reduction of conventional chemical fertilization.The soil nutrient content,phosphorus accumulation,dry weight,yield and yield components of maize were analyzed.The results showed that the phosphorus accumulation of maize stalks and leaves were 3.30%-43.17%and 10.98%-84.95%higher in M3+F1 treatment(20%reduction of chemical fertilizer with organic fertilizer of 45 m3•hm-2)than those in the conventional treatment(M0+F)during the maize reproductive period.At R2 stage,stalk and shoot P accumulation of M3+F1 treatment were 24.67%-43.18%and 20.34%-25.19%higher than other treatments,respectively.At V12 stage,leaf P accumulation of M3+F1 increased by 84.95%compared with other treatments.The maize yield of M3+F1 was significantly higher than that of other treatments,even though the partial productivity of the total phosphorus fertilizer of M3+F2 was the highest in the treatments.It could be found that the substitution of organic fertilizer for chemical fertilizer improved crop yield,phosphorus fertilizer efficiency and accumulation.M3+F1 treatment had the most positive effects on improving maize phosphorus accumulation and yield.
基金Project (2011ZX05007-004) supported by the National Sciences and Technologies,ChinaProject (41502132) supported by the National Natural Science Foundation of China
文摘The lower Ordovician mid-assemblage Formations in the central Ordos Basin of China host prolific gas resources,and most hydrocarbon reserves are stored in naturally-fractured reservoirs.Thus,fracture pathway systems may have a significant impact on reservoir performance.This article focuses on the core-and laboratory-based characterization of fractures.Through the developmental degrees,extended scale,output state and filling characteristics of various types of fractures,the results show that there are three distinct fracture types:1)nearly vertical fractures,2)oblique fractures,and 3)horizontal fractures.Based on a systematic study of the characterization of reservoir space,the main geologic setting of natural gas accumulation and the regional tectonic background,type 1 is mainly driven by the tectonic formation mechanism,and type 3 and parts of low-angle fractures in type 2 are induced by the diagenetic formation mechanism.While recovered paleopressure for methane-rich aqueous inclusions trapped in fracture-filling cement indicates that the fracture opening and growth are consistent with gas maturation and charge and such high-angle fractures in type 2 are caused by the compound formation mechanism.The fractures to hydrocarbon accumulation may play a more significant role in improving the quality of reservoir porosity.Furthermore,connected fractures,dissolved pores and cavities together constitute the three-dimensional pore-cave-fracture network pathway systems,with faults serving as the dominant charge pathways of highly pressurized gas in the study area.Our results demonstrate that protracted growth of a pervasive fracture system is not only the consequence of various formation mechanisms but also intrinsic to quasi-continuous accumulation reservoirs.
基金Projects(41572277,41877229)supported by the National Natural Science Foundation of ChinaProject(2018B030311066)supported by the Natural Science Foundation of Guangdong Province,ChinaProject(201607010023)supported by the Science and Technology Program of Guangzhou,China
文摘The creep behaviors of granite residual soil with pre-stress of 100 kPa was investigated by a series of small size creep tests. Three different types of strain curves were obtained at different stress levels. Based on creep characteristics of the granite residual soil under different stress levels, a creep model of the granite residual soil was established by rheological theory, and related parameters of the model were determined according to the experimental data at the same time. Further on, based on the established creep model, a theoretical model of dynamic stress accumulation in the granite residual soil under cyclic loading was deduced. It is found that there is a threshold of dynamic stress accumulation in this theoretical model. The dynamic stress accumulation laws of the granite residual soil are different under different cyclic loading stress. Finally, with the dynamic stress accumulation laws in the small-size samples of granite residual soil under different cycle loading studied and the experimental results comparing with the theoretical results, it verifies the validity of the theoretical model.
基金supported by the National Natural Science Foundation of China ( 51376200)the social livelihood projects of Chongqing City ( 10 cstc2018jscx-msybX0227)
文摘Salt-induced osmotic pressure has been drawing increasing attention in the field of microalgal biomechanics because it can enhance the lipids accumulation of microalgae.Studies have shown that osmotic stress can affect the synthesis of phospholipids by activating different phospholipid signaling pathways.However,there is little research about the mechanism of action of osmotic stress in neutral lipids synthesis.In this work,the effects of different salt-induced osmotic pressure on oil synthesis and potential mechanismwere studied.First,effect of various salt4nduced osmotic pressure of 64,112,191,453 and 1304 mOsm/kg on Chlorella pyrenoidosa oil synthesis were studied and optimal salt-induced osmotic pressure of 453 mOsm/kg was acquired.Then the content of key signaling chemicals in the Cyclic Adenosine monophosphate(cAMP)signaling pathway and the key enzyme activities in the lipid synthesis pathway were determined under salt-induced osmotic pressure of 453 mOsm/kg.It was found that the cAMP signaling pathway were up-regulated under salt osmotic pressure conditions of 453 mOsm/kg;in addition,the key enzymes related to lipid synthesis increased,while those related to protein synthesis decreased,enabling the increase of the lipid content.Finally,the effects of inhibitor atropine and promoter IBMX of cAMP signal pathway were also investigated.Results showed that atropine inhibits the cAMP signaling pathway and the lipid contents decreased;in contrast,IBMX activated thecAMP signaling pathway and the lipids content increased.These observations further confirm that salt-induced osmotic pressure had the same function as the signal promoter to regulate lipid synthesis by adjusting cAMP signaling pathway regulating lipid synthesis.This study preliminarily revealed the mechanism that salt-induced osmotic pressure affected lipid synthesis pathway through cAMP signaling pathway to regulate lipid synthesis in microalgae.
文摘Nanpu sag lies in the northwest part of the Bohai bay basin.Laoyemiao structural zone is located in the northwest part of the sag,to the north bound by basin-bounding master fault-Xi’nanzhuang fault (XNZF).This paper aims to gain insight into Laoyemiao tectonic features and set up its tectonic -hydrocarbon accumulation model by
文摘As a structural protein, the physiological function of tau proteins is to promote microtu-bule assembly and maintain the stability of the microtubules, so that to build up the tracks for axonal transport of the neurons. Recent studies suggest that tau is also actively involved in regulation of cell viability and enzymatic reaction. In Alzheimer disease (AD) and other tauopathies, tau proteins are abnormally hyperphosphorylated or cleaved, or the gene mutated, which result in intracellular tau accumulation and formation of neurofibrillary tangles in the degenerated neurons. In addition to hyperphosphorylation, many other types of tau posttranslational modifications have been identified in the brains of AD patients and/or the transgenic mouse models. To date, it is not clear how the abnormality of tau causes neurodegeneration and memory deficits. By overexpressing human full-length wildtype tau to mimic tau abnormality as seen in the brain of sporadic AD patients, we found that tau accumulation activated JAK2 to phosphorylate STAT1 at Tyr701 leading to STAT1 dimerization, nuclear translocation and its activation. STAT1 activation suppressed expression of NMDAR through direct binding to the specific GAS element of Glu N1, Glu N2A and Glu N2B promoters, while knockdown STAT1 by AAV-Cre in STAT1 flox/flox mice or expressing dominant negative Y701F-STAT1 efficiently rescued tau-induced suppression of NMDAR expression with amelioration of synaptic functions and memory performance.These findings indicate that tau accumulation impairs synaptic plasticity through JAK2/STAT1-induced suppression of NMDAR expression, which reveals a novel mechanism for tau-associated synapse and memory deficits in AD and other tauopathies.
文摘The northern type Longtan Formation of the Late Permian in central Hunan is dominated by an assemblage of greyish black mudstone,siltstone, sandy mudstone,fine sandstone and coals,and contains a variety of sedimentary structures such as thin sandstone-mudstone interbedded bedding,flaser beddings,lenticular beddings,horizontal
文摘Fault controlling petroleum accumulation is mainly reflected in hydrocarbon migration and sealing in accumulation periods.By fault activity rate analysis and fuzzy comprehensive sealing evaluation in different places of Linshang Fault Zone(LFZ),LFZ controlling petroleum accumulation shows a lot of spatiotemporal differences:(1) main branch of
基金Nature Science Fund Project in Heilongjiang Province (C2004-10)
文摘The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.
基金Supported by the Public Welfare Industry(Agricultural)Research Special Foundation of Agricultural Ministry of China(201303112)
文摘In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developing seeds. The objective of this study was to provide the changes of various fatty acid accumulations in seed oil obtained from the seeds of three pumpkin varieties belonging to the species Cucurbita maxima and Cucurbita pepo. Unsaturated acids(oleic and linoleic) were dominant in various fatty acids, which constituted 38.9%-49.1% and 29.4%-42.7% of the total fatty acids at seed maturity for three pumpkin varieties, respectively, while other fatty acid concentrations except for palmitic acid all did not reach 10%. Different varieties exhibited greater effect on various fatty acid contents and the total fatty acid contents in the seeds of pumpkin rather than the species. On the whole, palmitic acid profiles of the seed oil in three varieties all followed the fluctuant decrease during all the stages of seed development, but palmitoleic acid and the total fatty acid profiles of the seed oil in three varieties were just the opposite. Stearic, oleic and linoleic acid profiles of the seed oil in three varieties all experienced the third pattern that fluctuated during all the stages of seed development, but no significant differences in these three fatty acid concentrations were found from the beginning to the end. Linolenic acid concentrations of three varieties were on the decline and ultimately close to zero. Myristic and arachidic acid profiles of the seed oil followed different trends in three varieties. Among them, myristic and arachidic acid profiles of the seed oil of Yinhui-1 fluctuated downward all the time until seed maturity, but those of 0238-1 and Jinhui-2 completely changed oppositely.
文摘In the present study,microstructural evolution,mechanical and creep properties of Al/SiC/Cu composite stripsfabricated via accumulative roll bonding(ARB)process were studied.The obtained results showed the formation of anatomic diffusion layer with thickness of about 17μm at the interface during the ARB under three creep loadingconditions namely 30 MPa at 225℃,35 MPa at 225℃,and 35 MPa at 275℃.An generated intermetallic compoundresulted in a 40%increase of interface thickness near Al.The stress level decreased by 13%at constant temperature withno signi fi cant effect on the interface thickness,and the creep failure time declined by 44%.It was observed that atconstant temperatures,the second slope of the creep curve reached to 39%with increasing stress level,then,it dropped to2%with a little temperature rising.After creep test under 35 MPa at 275℃,the sample displays the presence of 60%Aland 40%Cu,containing brittle Al_(2)Cu intermetallic compound at the interface.Applied temperature and stress had effecton the creep properties,specially increasing the slope of creep curves with higher stresses.
