The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lack...The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lacking for hilly red soil region of southern China. Experiments were conducted in the hilly red soil region of southern China for seven years in three rtmoffplots, each of which represented different SWC forest-grass measures. Principal component analysis and multiple regression techniques were used to relate the aboveground biomass （representing soil productivity） to soil properties. Based on the final regression equations, soil organic carbon content （Sot） is significantly correlated with soil productivity under the condition of forest-grass measures, whereas pH value and cation exchange capacity （Cee） are the main factors for soil productivity without SWC. Therefore, SWC plays an important role in sequestering Soc and improving soil productivity.展开更多
In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were appli...In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were applied to study optimization design of herringbone multilateral well.According to the characteristics of herringbone multilateral well,by using pressure superposition and mirror image reflection theory,the coupled model of herringbone multilateral well was developed on the basis of a three-dimensional pseudo-pressure distribution model for horizontal wells.The model was formulated in consideration of friction loss,acceleration loss of the wellbore and mixed loss at the confluence of main wellbore and branched one.After mathematical simulation on productivity of the herringbone multilateral well with the coupled model,the effects of well configuration on productivity were analyzed.The results show that lateral number is the most important factor,length of main wellbore and length of branched wellbore are the secondary ones,angle between main and branched one has the least influence.展开更多
Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in...Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in the alternate cotton-peanut intercropping,specifically focusing on its yield benefits,environmental impacts,and the underlying mechanisms.In addition,we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment,pest management options,and the mechanisms of root-canopy interactions.This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.展开更多
Improving crop water productivity is necessary for ensuring food security. To quantify the water utilization in grain production from multiple perspectives, gross inflow water productivity(WPg), generalized agricultur...Improving crop water productivity is necessary for ensuring food security. To quantify the water utilization in grain production from multiple perspectives, gross inflow water productivity(WPg), generalized agricultural water productivity(WPa), evapotranspiration water productivity(WPET) and irrigation water productivity(WPI) were examined in this study. This paper calculated and analyzed the temporal and spatial variation in these water productivity(WP) indices in the irrigated land of Heilongjiang Province. The results showed that almost all of the municipal WP indices increased from 2007 to 2015. The four indices showed large differences in scientific connotation and numerical performance, and their degrees of spatial variation were ranked as WPI>WPa>WPg>WPET. The spatial patterns of WP indices in different years were similar; the central and southern regions on the Songnen Plain and the eastern region had high WP values, while those of the northern region were low. Each WP index was used to evaluate the relationship between the input of water resources and the output of grain between different regions. Most cities had the potential to improve WP by reducing the input of irrigation water. Furthermore, the results provided recommendations to decision makers to plan for efficient use of water resources in different cities.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(202...This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(2022)who established global existence and boundedness of classical solution under the parameter constraintsµ_(1)µ_(2)a_(2)≥χ1(4+µ_(2)^(2)a _(2)^(2)),µ_(1)µ_(2)a_(1)≥χ2(4+µ_(1)^(2)a_(1)^( 2)).Our main contribution demonstrates that these technical conditions can be significantly relaxed toµ1≥5χ_(1),µ2≥5χ_(2),thereby expanding the admissible parameter space for solution boundedness.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_...Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.展开更多
The shifting landscape of China’s fuel market,characterized by a declining diesel-to-gasoline ratio and the rigorous enforcement of China VI diesel standards,has intensified the challenge of optimizing light cycle oi...The shifting landscape of China’s fuel market,characterized by a declining diesel-to-gasoline ratio and the rigorous enforcement of China VI diesel standards,has intensified the challenge of optimizing light cycle oil(LCO)utilization.The trend of diesel overcapacity coincides with a growing supply-demand imbalance in key petrochemical building blocks,namely benzene,toluene,and xylene(BTX).In this context,hydrocracking(HYC)is increasingly recognized as a pivotal upgrading technology to address both issues simultaneously:alleviating the diesel surplus while selectively producing high-value BTX aromatics.This review provides a systematic analysis of contemporary technologies for the catalytic transformation of LCO into BTX.We delve into the fundamental reaction mechanisms,including hydrogenation,ring-opening,and dealkylation,which govern the selectivity towards light aromatics.A particular focus is placed on recent advancements in bifunctional catalyst design,in which the delicate balance between metal function and zeolite acidity is critical for directing the reaction pathway.Furthermore,we critically analyze the oftenoverlooked aspect of mass transfer and diffusion limitations within catalyst particles and zeolite micropores.A profound understanding of molecular diffusion is paramount for the rational design of next-generation catalysts,ultimately enabling the highly efficient and selective conversion of low-value LCO into premium BTX products via hydrocracking.展开更多
[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previo...[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previous studies have demonstrated that cultivating perennial biomass crops on marginal lands significantly impacts regional climate change and food production.However,these investigations did not fully consider the interactive feedback between plant growth and climate change,leading to slightly insufficient reliability of the result.[Methods]To address the limitations of earlier studies,the coupled model CWRF-BioCro was employed to comprehensively consider the interactive feedback between plant growth and climate change,and to analyze changes in regional precipitation patterns and their physical mechanisms under two scenarios in the United States:cultivation of perennial biomass crops on marginal lands and maintenance of existing vegetation cover.[Results]The result showed that after cultivating perennial biomass crops on marginal lands,the regional total average daily precipitation increased by 6.33 mm/day(0.01%),with most of the increase occurring during spring,summer,and autumn in the central and western regions and during autumn and winter in the eastern region.This was primarily due to the significant enhancement of water vapor transport and latent heat flux in the region.The regional maximum daily precipitation decreased by 2.1 mm(4.39%),mainly in the central and eastern regions,Resulting from a significant decrease in sensible heat flux in these regions.Meanwhile,the frequency of precipitation events with an average daily precipitation greater than 50 mm/d decreased in the central and eastern regions,with the most pronounced reduction of 31 days(0.24%)observed in events in the range of 50.0~99.9 mm/day.[Conclusion]In summary,planting perennial biomass crops on marginal lands can increase regional precipitation and reduce extreme precipitation.These findings highlight the critical role of biophysical feedback mechanisms in regulating regional climate and provide a scientific foundation for developing climate-adaptive land management strategies.展开更多
Food Science of Animal Products(ISSN:2958-4124,e-ISSN:2958-3780)is a peer-reviewed,open access international journal that publishes the latest research findings in the field of animal-origin foods,involving food mater...Food Science of Animal Products(ISSN:2958-4124,e-ISSN:2958-3780)is a peer-reviewed,open access international journal that publishes the latest research findings in the field of animal-origin foods,involving food materials such as meat,aquatic products,milk,eggs,animal offals and edible insects.展开更多
To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesize...To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.展开更多
This work aimed to(i)understand conventional and pulse gas tungsten arc welding(GTAW)of AZ31B,and(ii)explore high frequency welding(100 Hz-1500 Hz).GTA welding with alternating current(AC)and direct current electrode ...This work aimed to(i)understand conventional and pulse gas tungsten arc welding(GTAW)of AZ31B,and(ii)explore high frequency welding(100 Hz-1500 Hz).GTA welding with alternating current(AC)and direct current electrode positive(DCEP)polarities yielded crack-free partial penetration welds for6 mm thick AZ31B alloy sheet.Welding under direct current electrode negative(DCEN)polarity with identical parameters as that for AC and DCEP resulted in full penetration welds that had microcracks.Defect-free full-penetration welds could be accomplished with pulse GTA welding using DCEN polarity at a pulse frequency of 1 Hz with a pulse duration ratio of 1:1.The resultant DCEN P 1:1 weld metal had a microstructure finer than the conventional DCEN weld.Welds produced with pulse duration ratios of 1:2and 1:4 lacked penetration but had a much finer microstructures because of the lower heat input.The arc constriction by the high frequency pulsing in the Activ Arc■-High frequency(AA-HF)mode welding was responsible for deeper penetration.Welds produced under DCEN pulsing and AA-HF conditions had hardness higher than conventional DCEN,DCEP and AC GTA welds,attributed to the finer microstructure.AA-HF GTA welding produced defect free deeper penetration welds with good microstructural features/mechanical properties and also gave an advantage of 50%enhanced productivity when welded at1500 Hz.展开更多
The sea cucumber is a highly esteemed source of nourishment,recognized as one of the“Eight Treasures of the Sea.”The bioactive compounds derived from sea cucumbers exhibit diverse physiological activities,including ...The sea cucumber is a highly esteemed source of nourishment,recognized as one of the“Eight Treasures of the Sea.”The bioactive compounds derived from sea cucumbers exhibit diverse physiological activities,including anti-tumor,antioxidant,anti-coagulation,anti-viral,anti-fatigue,immune enhancement,cognitive improvement,and metabolic regulation.Notably,within the skincare sector,these compounds demonstrate significant anti-aging,moisturizing,whitening,wrinkle reduction,repair and inhibition of melanin production properties.This article assesses the current state of sea cucumber aquaculture in China and the utilization of its bioactive ingredients in skincare formulations.The objective is to furnish additional raw materials and semi-finished products for China’s skincare and pharmaceutical industries,to advance the integration of sea cucumber bioactive components within these sectors,and to invigorate the rapid development of the tropical sea cucumber breeding industry.展开更多
A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffr...A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.展开更多
采用2011—2012年全国实测水稻、小麦、玉米、大豆、油菜、棉花6种作物的生物量获得的干燥系数(DC)、收获指数(HI)和根冠比(R/S),结合2010年以县为单位的农业统计数据估算了2010年中国农作物产生的净初级生产力(NPP)。2010年中国农作物...采用2011—2012年全国实测水稻、小麦、玉米、大豆、油菜、棉花6种作物的生物量获得的干燥系数(DC)、收获指数(HI)和根冠比(R/S),结合2010年以县为单位的农业统计数据估算了2010年中国农作物产生的净初级生产力(NPP)。2010年中国农作物产生的NPP为596 Tg C,其中地上NPP为517 Tg C,地下NPP为80 Tg C。NPP空间分布不平衡,主要集中在东北的松嫩三江平原、黄淮海平原、长江中下游平原、西南的四川盆地和华南的珠江流域。单位面积农作物产生的NPP介于9—2094g C m^(-2)a^(-1)之间,平均密度为519 g C m^(-2)a^(-1)。NPP密度(NPPD)较高的地区主要分布在中国的东部的湿润、半湿润地区以及内陆灌溉条件较好的地区。9个农业区中,黄淮海区农作物产生的NPP最多,东北区NPPD最高,青藏区农作物NPPD最低,产生的NPP也最少。作物种植面积能解释98%农业区之间NPP差异。通过对每个区域内县域NPPD与气候因子和化肥因子做相关分析,发现化肥施用量、日照时数、气温和降水均对NPPD的空间分异有影响,但是9个区域的主导因素不同。展开更多
基金Project(40971170) supported by the National Natural Science Foundation of ChinaProject(NCET-09-330) supported by the Program for New Century Excellent Talents in University of China
文摘The effects of soil and water conservation （SWC） on soil properties are well documented. However, definitive and quantitative information of SWC and its interactions with soil properties on soil productivity is lacking for hilly red soil region of southern China. Experiments were conducted in the hilly red soil region of southern China for seven years in three rtmoffplots, each of which represented different SWC forest-grass measures. Principal component analysis and multiple regression techniques were used to relate the aboveground biomass （representing soil productivity） to soil properties. Based on the final regression equations, soil organic carbon content （Sot） is significantly correlated with soil productivity under the condition of forest-grass measures, whereas pH value and cation exchange capacity （Cee） are the main factors for soil productivity without SWC. Therefore, SWC plays an important role in sequestering Soc and improving soil productivity.
基金Project(12521044) supported by Scientific and Technological Research Program of Heilongjiang Provincial Education Department,China
文摘In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were applied to study optimization design of herringbone multilateral well.According to the characteristics of herringbone multilateral well,by using pressure superposition and mirror image reflection theory,the coupled model of herringbone multilateral well was developed on the basis of a three-dimensional pseudo-pressure distribution model for horizontal wells.The model was formulated in consideration of friction loss,acceleration loss of the wellbore and mixed loss at the confluence of main wellbore and branched one.After mathematical simulation on productivity of the herringbone multilateral well with the coupled model,the effects of well configuration on productivity were analyzed.The results show that lateral number is the most important factor,length of main wellbore and length of branched wellbore are the secondary ones,angle between main and branched one has the least influence.
基金National Natural Science Foundation of China(32101844)Shandong Provincial Natural Science Foundation(ZR2021QC188 and ZR2022MC103).
文摘Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in the alternate cotton-peanut intercropping,specifically focusing on its yield benefits,environmental impacts,and the underlying mechanisms.In addition,we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment,pest management options,and the mechanisms of root-canopy interactions.This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.
基金Supported by National Natural Science Foundation of China(51479032)National Key R&D Plan(2017YFC0406002)
文摘Improving crop water productivity is necessary for ensuring food security. To quantify the water utilization in grain production from multiple perspectives, gross inflow water productivity(WPg), generalized agricultural water productivity(WPa), evapotranspiration water productivity(WPET) and irrigation water productivity(WPI) were examined in this study. This paper calculated and analyzed the temporal and spatial variation in these water productivity(WP) indices in the irrigated land of Heilongjiang Province. The results showed that almost all of the municipal WP indices increased from 2007 to 2015. The four indices showed large differences in scientific connotation and numerical performance, and their degrees of spatial variation were ranked as WPI>WPa>WPg>WPET. The spatial patterns of WP indices in different years were similar; the central and southern regions on the Songnen Plain and the eastern region had high WP values, while those of the northern region were low. Each WP index was used to evaluate the relationship between the input of water resources and the output of grain between different regions. Most cities had the potential to improve WP by reducing the input of irrigation water. Furthermore, the results provided recommendations to decision makers to plan for efficient use of water resources in different cities.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金Supported by the National Natural Science Foundation of China(12301631)the Natural Science Foundation of Qinghai Province(2023-ZJ-949Q)。
文摘This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(2022)who established global existence and boundedness of classical solution under the parameter constraintsµ_(1)µ_(2)a_(2)≥χ1(4+µ_(2)^(2)a _(2)^(2)),µ_(1)µ_(2)a_(1)≥χ2(4+µ_(1)^(2)a_(1)^( 2)).Our main contribution demonstrates that these technical conditions can be significantly relaxed toµ1≥5χ_(1),µ2≥5χ_(2),thereby expanding the admissible parameter space for solution boundedness.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
文摘Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.
文摘The shifting landscape of China’s fuel market,characterized by a declining diesel-to-gasoline ratio and the rigorous enforcement of China VI diesel standards,has intensified the challenge of optimizing light cycle oil(LCO)utilization.The trend of diesel overcapacity coincides with a growing supply-demand imbalance in key petrochemical building blocks,namely benzene,toluene,and xylene(BTX).In this context,hydrocracking(HYC)is increasingly recognized as a pivotal upgrading technology to address both issues simultaneously:alleviating the diesel surplus while selectively producing high-value BTX aromatics.This review provides a systematic analysis of contemporary technologies for the catalytic transformation of LCO into BTX.We delve into the fundamental reaction mechanisms,including hydrogenation,ring-opening,and dealkylation,which govern the selectivity towards light aromatics.A particular focus is placed on recent advancements in bifunctional catalyst design,in which the delicate balance between metal function and zeolite acidity is critical for directing the reaction pathway.Furthermore,we critically analyze the oftenoverlooked aspect of mass transfer and diffusion limitations within catalyst particles and zeolite micropores.A profound understanding of molecular diffusion is paramount for the rational design of next-generation catalysts,ultimately enabling the highly efficient and selective conversion of low-value LCO into premium BTX products via hydrocracking.
文摘[Objective]With increasing energy demand and growing concerns about climate change,the rational utilization of marginal lands for cultivating biomass energy crops has emerged as a research focus in recent years.Previous studies have demonstrated that cultivating perennial biomass crops on marginal lands significantly impacts regional climate change and food production.However,these investigations did not fully consider the interactive feedback between plant growth and climate change,leading to slightly insufficient reliability of the result.[Methods]To address the limitations of earlier studies,the coupled model CWRF-BioCro was employed to comprehensively consider the interactive feedback between plant growth and climate change,and to analyze changes in regional precipitation patterns and their physical mechanisms under two scenarios in the United States:cultivation of perennial biomass crops on marginal lands and maintenance of existing vegetation cover.[Results]The result showed that after cultivating perennial biomass crops on marginal lands,the regional total average daily precipitation increased by 6.33 mm/day(0.01%),with most of the increase occurring during spring,summer,and autumn in the central and western regions and during autumn and winter in the eastern region.This was primarily due to the significant enhancement of water vapor transport and latent heat flux in the region.The regional maximum daily precipitation decreased by 2.1 mm(4.39%),mainly in the central and eastern regions,Resulting from a significant decrease in sensible heat flux in these regions.Meanwhile,the frequency of precipitation events with an average daily precipitation greater than 50 mm/d decreased in the central and eastern regions,with the most pronounced reduction of 31 days(0.24%)observed in events in the range of 50.0~99.9 mm/day.[Conclusion]In summary,planting perennial biomass crops on marginal lands can increase regional precipitation and reduce extreme precipitation.These findings highlight the critical role of biophysical feedback mechanisms in regulating regional climate and provide a scientific foundation for developing climate-adaptive land management strategies.
文摘Food Science of Animal Products(ISSN:2958-4124,e-ISSN:2958-3780)is a peer-reviewed,open access international journal that publishes the latest research findings in the field of animal-origin foods,involving food materials such as meat,aquatic products,milk,eggs,animal offals and edible insects.
文摘To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.
文摘This work aimed to(i)understand conventional and pulse gas tungsten arc welding(GTAW)of AZ31B,and(ii)explore high frequency welding(100 Hz-1500 Hz).GTA welding with alternating current(AC)and direct current electrode positive(DCEP)polarities yielded crack-free partial penetration welds for6 mm thick AZ31B alloy sheet.Welding under direct current electrode negative(DCEN)polarity with identical parameters as that for AC and DCEP resulted in full penetration welds that had microcracks.Defect-free full-penetration welds could be accomplished with pulse GTA welding using DCEN polarity at a pulse frequency of 1 Hz with a pulse duration ratio of 1:1.The resultant DCEN P 1:1 weld metal had a microstructure finer than the conventional DCEN weld.Welds produced with pulse duration ratios of 1:2and 1:4 lacked penetration but had a much finer microstructures because of the lower heat input.The arc constriction by the high frequency pulsing in the Activ Arc■-High frequency(AA-HF)mode welding was responsible for deeper penetration.Welds produced under DCEN pulsing and AA-HF conditions had hardness higher than conventional DCEN,DCEP and AC GTA welds,attributed to the finer microstructure.AA-HF GTA welding produced defect free deeper penetration welds with good microstructural features/mechanical properties and also gave an advantage of 50%enhanced productivity when welded at1500 Hz.
文摘The sea cucumber is a highly esteemed source of nourishment,recognized as one of the“Eight Treasures of the Sea.”The bioactive compounds derived from sea cucumbers exhibit diverse physiological activities,including anti-tumor,antioxidant,anti-coagulation,anti-viral,anti-fatigue,immune enhancement,cognitive improvement,and metabolic regulation.Notably,within the skincare sector,these compounds demonstrate significant anti-aging,moisturizing,whitening,wrinkle reduction,repair and inhibition of melanin production properties.This article assesses the current state of sea cucumber aquaculture in China and the utilization of its bioactive ingredients in skincare formulations.The objective is to furnish additional raw materials and semi-finished products for China’s skincare and pharmaceutical industries,to advance the integration of sea cucumber bioactive components within these sectors,and to invigorate the rapid development of the tropical sea cucumber breeding industry.
文摘A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.
文摘采用2011—2012年全国实测水稻、小麦、玉米、大豆、油菜、棉花6种作物的生物量获得的干燥系数(DC)、收获指数(HI)和根冠比(R/S),结合2010年以县为单位的农业统计数据估算了2010年中国农作物产生的净初级生产力(NPP)。2010年中国农作物产生的NPP为596 Tg C,其中地上NPP为517 Tg C,地下NPP为80 Tg C。NPP空间分布不平衡,主要集中在东北的松嫩三江平原、黄淮海平原、长江中下游平原、西南的四川盆地和华南的珠江流域。单位面积农作物产生的NPP介于9—2094g C m^(-2)a^(-1)之间,平均密度为519 g C m^(-2)a^(-1)。NPP密度(NPPD)较高的地区主要分布在中国的东部的湿润、半湿润地区以及内陆灌溉条件较好的地区。9个农业区中,黄淮海区农作物产生的NPP最多,东北区NPPD最高,青藏区农作物NPPD最低,产生的NPP也最少。作物种植面积能解释98%农业区之间NPP差异。通过对每个区域内县域NPPD与气候因子和化肥因子做相关分析,发现化肥施用量、日照时数、气温和降水均对NPPD的空间分异有影响,但是9个区域的主导因素不同。
