The excessive demand for phosphorus-based fertilizers is contributing to the undesired byproduct of phosphogypsum(PG),typically found in large quantities in phosphoric acid industry.Without proper management,this indu...The excessive demand for phosphorus-based fertilizers is contributing to the undesired byproduct of phosphogypsum(PG),typically found in large quantities in phosphoric acid industry.Without proper management,this industrial waste poses a significant environmental pollution risk.Current technologies are struggle to effectively handle the volume of PG produced,but one promising solution is its conversion into hemihydrate gypsum(CaSO_(4)·0.5 H_(2)O,HH).HH can exist in two phases,α-HH andβ-HH,withα-hemihydrate gypsum(α-HH)being preferred for its complete crystal structure and lower water requirement for hydration.The morphology ofα-HH gypsum is crucial for its material applications,and controlling crystal morphology is possible through the use of suitable crystal modifiers.This review explores various aspects of crystal modifiers and highlights their role in the preparation ofα-HH from PG.It suggests that leveraging the interfacial properties of PG could lead to innovative applications.Additionally,the review outlines future directions for PG development and identifies challenges to be addressed in the next steps.展开更多
Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementi...Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementitious components, such as dicalcium silicate (C2S) and tricalcium silicate (C3S) (Waligora et al., 2010). However, blended cements with steelmaking slag show low early hydration activity, low compressive strength and bad durability because steel slag generates above 1600 ℃ with the tense and large grain size crystals, consisting of low content of C2S and C3S and high proportions of f-CaO and f-MgO compared with cement clinker.展开更多
The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were expl...The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.展开更多
Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alu...Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.展开更多
Detection of target analytes at low concentrations is significant in various fields,including pharmaceuticals,healthcare,and environmental protection.Theophylline(TP),a natural alkaloid used as a bronchodilator to tre...Detection of target analytes at low concentrations is significant in various fields,including pharmaceuticals,healthcare,and environmental protection.Theophylline(TP),a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma,bronchitis,and emphysema,has a narrow therapeutic window with a safe plasma concentration ranging from 55.5-111.0μmol·L^(-1)in adults.Accurate monitoring of TP levels is essential because too low or too high can cause se-rious side effects.In this regard,non-enzymatic electrochemical sensors offer a practical solution with rapidity,portability,and high sensitivity.This article aims to provide a comprehensive review of the recent developments of non-enzymatic electrochemical sensors for TP detection,highlighting the basic principles,electro-oxidation mechanisms,catalytic effects,and the role of modifying materials on electrode performance.Carbon-based electrodes such as glassy carbon electrodes(GCEs),carbon paste electrodes(CPEs),and carbon screen-printed electrodes(SPCEs)have become the primary choices for non-enzymatic sensors due to their chemical stability,low cost,and flexibility in modification.This article identifies the sig-nificant contribution of various modifying materials,including nanomaterials such as carbon nanotubes(CNTs),graphene,metal oxides,and multi-element nanocomposites.These modifications enhance sensors’electron transfer,sensitivity,and selectivity in detecting TP at low concentrations in complex media such as blood plasma and pharmaceutical samples.The electro-oxidation mechanism of TP is also discussed in depth,emphasizing the hydroxyl and carbonyl reaction pathways strongly influenced by pH and electrode materials.These mechanisms guide the selection of the appropriate electrode ma-terial for a particular application.The main contribution of this article is to identify superior modifying materials that can improve the performance of non-enzymatic electrochemical sensors.In a recent study,the combination of multi-element nanocomposites based on titanium dioxide(TiO_(2)),CNTs,and gold nanoparticles(AuNPs)resulted in the lowest detection limit of 3×10^(-5)μmol·L^(-1),reflecting the great potential of these materials for developing high-performance electrochemical sensors.The main conclusion of this article is the importance of a multidisciplinary approach in electrode material design to support the sensitivity and selectivity of TP detection.In addition,there is still a research gap in understanding TP’s more detailed oxidation mechanism,especially under pH variations and complex environments.Therefore,further research on electrode modification and analysis of the TP oxidation mechanism are urgently needed to improve the accuracy and sta-bility of the sensor while expanding its applications in pharmaceutical monitoring and medical diagnostics.By integrating various innovative materials and technical approaches,this review is expected to be an essential reference for developing efficient and affordable non-enzymatic electrochemical sensors.展开更多
With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a c...With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.展开更多
Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,gr...Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.展开更多
Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decom...Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decomposition of lithium-based oxides at the air cathode,which not only lead to a low cathode catalytic efficiency but also restrict the electrochemical reversibility and cause side reaction problems.Carbon materials are considered key to solving these problems due to their conductivity,functional flexibility,and adjustable pore structure.This paper considers the research progress on carbon materials as air cathode catalytic materials for LABs,focusing on their structural characteristics,electrochemical behavior,and reaction mechanisms.Besides being used as air cathodes,carbon materials also show potential for being used as protective layers for metal anodes or as anode materials for LABs.展开更多
The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce t...The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.展开更多
CAB is a binder commonly utilized in CL-20-based mixed explosives.Based on the requirements of CL-20-based polymer bonded explosives in formability,safety,and detonation energy,we explored a hightoughness and low dosa...CAB is a binder commonly utilized in CL-20-based mixed explosives.Based on the requirements of CL-20-based polymer bonded explosives in formability,safety,and detonation energy,we explored a hightoughness and low dosage CAB binder system.CAB was subjected to different toughening modifications and the effects of the modified CAB binders on the bonding and coating of CL-20 crystals,as well as the formability,safety,and mechanical properties of CL-20-based polymer bonded explosive molding powder(MP)were evaluated.The changes in glass transition temperature(Tg)and mechanical properties of the modified binders were investigated using the molecular dynamics simulation at first.A series of modified binders with different molecular weights were then synthesized and characterized by FTIR,1H NMR,^(13)C NMR and SEC.The T_(g) and cross-sectional morphologies of the binder membranes were determined by DSC and SEM.The tensile properties of the binder membranes with different molecular weights and their mixtures with the plasticizer were evaluated at different temperature.With the optimized modified binder,CL-20/CAB and CL-20/CAB-g-PCL-3 MPs with the same plasticizer ratio and Cl-20/CAB-g-PCL-3 MP with a lower plasticizer ratio and higher CL-20 content were prepared and evaluated for the bonding and coating effects,crystal form,mechanical sensitivity and specific heat capacity(C_(p))by SEM,XRD,sensitivity testing and DSC,respectively.Their compressive strengths and splitting tensile strengths were measured at different temperature using a universal testing machine.Our work has provided a high-toughness and low-dosage binder system for CL-20-based MPs and offers a novel strategy to improve the formability,safety,and energy of CL-20 based polymer bonded explosives.展开更多
Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis r...Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis remain significant challenges.This research aims to develop an effective computational method for analyzing the free vibration of functionally graded(FG)microplates under high temperatures while resting on a Pasternak foundation(PF).This formulation leverages a new thirdorder shear deformation theory(new TSDT)for improved accuracy without requiring shear correction factors.Additionally,the modified couple stress theory(MCST)is incorporated to account for sizedependent effects in microplates.The PF is characterized by two parameters including spring stiffness(k_(w))and shear layer stiffness(k_(s)).To validate the proposed method,the results obtained are compared with those of the existing literature.Furthermore,numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates.These factors include the length scale parameter(l),geometric dimensions,material properties,and the presence of the elastic foundation.The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the results of this research will have great potential in military and defense applications such as components of submarines,fighter aircraft,and missiles.展开更多
通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based...通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based range query)域查询处理算法,能够引入搜索区域进行预裁剪以减少查询精炼阶段所需代价偏高的积分计算.实验仿真表明,采用MP_BBRQ算法的TPU-tree概率查询性能极大地优于传统的TPR-tree索引,且更新性能与传统索引大致相当,具有良好的实用价值.展开更多
为实现牛粪与水稻秸秆资源化利用,采用批式试验,分别研究了预处理剂种类(H_2O_2、H_2SO_4、NaOH)、预处理剂浓度(2%、4%、6%)及牛粪与水稻秸秆物料比(1∶1、2∶1、4∶1)对牛粪与水稻秸秆混合厌氧发酵产气效果的影响。结果表明,采用2%H2...为实现牛粪与水稻秸秆资源化利用,采用批式试验,分别研究了预处理剂种类(H_2O_2、H_2SO_4、NaOH)、预处理剂浓度(2%、4%、6%)及牛粪与水稻秸秆物料比(1∶1、2∶1、4∶1)对牛粪与水稻秸秆混合厌氧发酵产气效果的影响。结果表明,采用2%H2O_2预处理剂,物料配比控制在1∶1,系统平均原料产气率为398.0 m L·g^(-1),发酵效果最佳。动力学研究发现,一级动力学模型与Modified Gompertz方程均可较为准确地对牛粪与水稻秸秆混合厌氧发酵产气过程进行动态模拟,其中,Modified Gompertz方程的模拟效果更优。展开更多
Composite solid propellants(CSPs) have widely been used as main energy source for propelling the rockets in both space and military applications. Internal ballistic parameters of rockets like characteristic exhaust ve...Composite solid propellants(CSPs) have widely been used as main energy source for propelling the rockets in both space and military applications. Internal ballistic parameters of rockets like characteristic exhaust velocity, specific impulse, thrust, burning rate etc., are measured to assess and control the performance of rocket motors. The burn rate of solid propellants has been considered as most vital parameter for design of solid rocket motors to meet specific mission requirements. The burning rate of solid propellants can be tailored by using different constituents, extent of oxidizer loading and its particle size and more commonly by incorporating suitable combustion catalysts. Various metal oxides(MOs),complexes, metal powders and metal alloys have shown positive catalytic behaviour during the combustion of CSPs. These are usually solid-state catalysts that play multiple roles in combustion of CSPs such as reduction in activation energy, enhancement of rate of reaction, modification of sequences in reaction-phase, influence on condensed-phase combustion and participation in combustion process in gas-phase reactions. The application of nanoscale catalysts in CSPs has increased considerably in recent past due to their superior catalytic properties as compared to their bulk-sized counterparts. A large surface-to-volume ratio and quantum size effect of nanocatalysts are considered to be plausible reasons for improving the combustion characteristics of propellants. Several efforts have been made to produce nanoscale combustion catalysts for advanced propellant formulations to improve their energetics. The work done so far is largely scattered. In this review, an effort has been made to introduce various combustion catalysts having at least a metallic entity. Recent developments of nanoscale combustion catalysts with their specific merits are discussed. The combustion chemistry of a typical CSP is briefly discussed for providing a better understanding on role of combustion catalysts in burning rate enhancement. Available information on different types of combustion nanocatalysts is also presented with critical comments.展开更多
基金Project(2022YFC3902703)supported by the National Key R&D Program of ChinaProject(KF22028)supported by the Special Project for High Quality Development of the Ministry of Industry and Information Technology of China+1 种基金Project(62004143)supported by the National Natural Science Foundation of ChinaProject(2022BAA084)supported by the Key R&D Program of Hubei Province,China。
文摘The excessive demand for phosphorus-based fertilizers is contributing to the undesired byproduct of phosphogypsum(PG),typically found in large quantities in phosphoric acid industry.Without proper management,this industrial waste poses a significant environmental pollution risk.Current technologies are struggle to effectively handle the volume of PG produced,but one promising solution is its conversion into hemihydrate gypsum(CaSO_(4)·0.5 H_(2)O,HH).HH can exist in two phases,α-HH andβ-HH,withα-hemihydrate gypsum(α-HH)being preferred for its complete crystal structure and lower water requirement for hydration.The morphology ofα-HH gypsum is crucial for its material applications,and controlling crystal morphology is possible through the use of suitable crystal modifiers.This review explores various aspects of crystal modifiers and highlights their role in the preparation ofα-HH from PG.It suggests that leveraging the interfacial properties of PG could lead to innovative applications.Additionally,the review outlines future directions for PG development and identifies challenges to be addressed in the next steps.
基金Supported by the National Key Technologies R&D Program of China (NO. 2011BAB03B05)
文摘Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementitious components, such as dicalcium silicate (C2S) and tricalcium silicate (C3S) (Waligora et al., 2010). However, blended cements with steelmaking slag show low early hydration activity, low compressive strength and bad durability because steel slag generates above 1600 ℃ with the tense and large grain size crystals, consisting of low content of C2S and C3S and high proportions of f-CaO and f-MgO compared with cement clinker.
文摘The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.
文摘Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.
基金the funding from Lembaga Penelitian dan Pengabdian Masyarakat(LPPM)Universitas Indonesia,by Riset Kolaborasi Indonesia(RKI)-World Class University(WCU)Program with grant number NKB-1067/UN2-RST/HKP.05.00/2023 and NKB-781/UN2.RST/HKP.05.00/2024.
文摘Detection of target analytes at low concentrations is significant in various fields,including pharmaceuticals,healthcare,and environmental protection.Theophylline(TP),a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma,bronchitis,and emphysema,has a narrow therapeutic window with a safe plasma concentration ranging from 55.5-111.0μmol·L^(-1)in adults.Accurate monitoring of TP levels is essential because too low or too high can cause se-rious side effects.In this regard,non-enzymatic electrochemical sensors offer a practical solution with rapidity,portability,and high sensitivity.This article aims to provide a comprehensive review of the recent developments of non-enzymatic electrochemical sensors for TP detection,highlighting the basic principles,electro-oxidation mechanisms,catalytic effects,and the role of modifying materials on electrode performance.Carbon-based electrodes such as glassy carbon electrodes(GCEs),carbon paste electrodes(CPEs),and carbon screen-printed electrodes(SPCEs)have become the primary choices for non-enzymatic sensors due to their chemical stability,low cost,and flexibility in modification.This article identifies the sig-nificant contribution of various modifying materials,including nanomaterials such as carbon nanotubes(CNTs),graphene,metal oxides,and multi-element nanocomposites.These modifications enhance sensors’electron transfer,sensitivity,and selectivity in detecting TP at low concentrations in complex media such as blood plasma and pharmaceutical samples.The electro-oxidation mechanism of TP is also discussed in depth,emphasizing the hydroxyl and carbonyl reaction pathways strongly influenced by pH and electrode materials.These mechanisms guide the selection of the appropriate electrode ma-terial for a particular application.The main contribution of this article is to identify superior modifying materials that can improve the performance of non-enzymatic electrochemical sensors.In a recent study,the combination of multi-element nanocomposites based on titanium dioxide(TiO_(2)),CNTs,and gold nanoparticles(AuNPs)resulted in the lowest detection limit of 3×10^(-5)μmol·L^(-1),reflecting the great potential of these materials for developing high-performance electrochemical sensors.The main conclusion of this article is the importance of a multidisciplinary approach in electrode material design to support the sensitivity and selectivity of TP detection.In addition,there is still a research gap in understanding TP’s more detailed oxidation mechanism,especially under pH variations and complex environments.Therefore,further research on electrode modification and analysis of the TP oxidation mechanism are urgently needed to improve the accuracy and sta-bility of the sensor while expanding its applications in pharmaceutical monitoring and medical diagnostics.By integrating various innovative materials and technical approaches,this review is expected to be an essential reference for developing efficient and affordable non-enzymatic electrochemical sensors.
基金the Experimental Technology Research Project of Zhejiang University(SYB202138)National Natural Science Foundation of China(32000195)。
文摘With the approval of more and more genetically modified(GM)crops in our country,GM safety management has become more important.Transgenic detection is a major approach for transgenic safety management.Nevertheless,a convenient and visual technique with low equipment requirements and high sensitivity for the field detection of GM plants is still lacking.On the basis of the existing recombinase polymerase amplification(RPA)technique,we developed a multiplex RPA(multi-RPA)method that can simultaneously detect three transgenic elements,including the cauliflower mosaic virus 35S gene(CaMV35S)promoter,neomycin phosphotransferaseⅡgene(NptⅡ)and hygromycin B phosphotransferase gene(Hyg),thus improving the detection rate.Moreover,we coupled this multi-RPA technique with the CRISPR/Cas12a reporter system,which enabled the detection results to be clearly observed by naked eyes under ultraviolet(UV)light(254 nm;which could be achieved by a portable UV flashlight),therefore establishing a multi-RPA visual detection technique.Compared with the traditional test strip detection method,this multi-RPA-CRISPR/Cas12a technique has the higher specificity,higher sensitivity,wider application range and lower cost.Compared with other polymerase chain reaction(PCR)techniques,it also has the advantages of low equipment requirements and visualization,making it a potentially feasible method for the field detection of GM plants.
基金supported by Gansu Provincial Science and Technology Plan(23CXGA0195)Longnan Science and Technology Plan(2024CX03)。
文摘Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.
文摘Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decomposition of lithium-based oxides at the air cathode,which not only lead to a low cathode catalytic efficiency but also restrict the electrochemical reversibility and cause side reaction problems.Carbon materials are considered key to solving these problems due to their conductivity,functional flexibility,and adjustable pore structure.This paper considers the research progress on carbon materials as air cathode catalytic materials for LABs,focusing on their structural characteristics,electrochemical behavior,and reaction mechanisms.Besides being used as air cathodes,carbon materials also show potential for being used as protective layers for metal anodes or as anode materials for LABs.
基金National Natural Science Foundation of China(12161013)Research Projects of Guizhou University of Commerce in 2024。
文摘The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.
基金supported by"the Fundamental Research Funds for the Central Universities".
文摘CAB is a binder commonly utilized in CL-20-based mixed explosives.Based on the requirements of CL-20-based polymer bonded explosives in formability,safety,and detonation energy,we explored a hightoughness and low dosage CAB binder system.CAB was subjected to different toughening modifications and the effects of the modified CAB binders on the bonding and coating of CL-20 crystals,as well as the formability,safety,and mechanical properties of CL-20-based polymer bonded explosive molding powder(MP)were evaluated.The changes in glass transition temperature(Tg)and mechanical properties of the modified binders were investigated using the molecular dynamics simulation at first.A series of modified binders with different molecular weights were then synthesized and characterized by FTIR,1H NMR,^(13)C NMR and SEC.The T_(g) and cross-sectional morphologies of the binder membranes were determined by DSC and SEM.The tensile properties of the binder membranes with different molecular weights and their mixtures with the plasticizer were evaluated at different temperature.With the optimized modified binder,CL-20/CAB and CL-20/CAB-g-PCL-3 MPs with the same plasticizer ratio and Cl-20/CAB-g-PCL-3 MP with a lower plasticizer ratio and higher CL-20 content were prepared and evaluated for the bonding and coating effects,crystal form,mechanical sensitivity and specific heat capacity(C_(p))by SEM,XRD,sensitivity testing and DSC,respectively.Their compressive strengths and splitting tensile strengths were measured at different temperature using a universal testing machine.Our work has provided a high-toughness and low-dosage binder system for CL-20-based MPs and offers a novel strategy to improve the formability,safety,and energy of CL-20 based polymer bonded explosives.
文摘Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis remain significant challenges.This research aims to develop an effective computational method for analyzing the free vibration of functionally graded(FG)microplates under high temperatures while resting on a Pasternak foundation(PF).This formulation leverages a new thirdorder shear deformation theory(new TSDT)for improved accuracy without requiring shear correction factors.Additionally,the modified couple stress theory(MCST)is incorporated to account for sizedependent effects in microplates.The PF is characterized by two parameters including spring stiffness(k_(w))and shear layer stiffness(k_(s)).To validate the proposed method,the results obtained are compared with those of the existing literature.Furthermore,numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates.These factors include the length scale parameter(l),geometric dimensions,material properties,and the presence of the elastic foundation.The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the results of this research will have great potential in military and defense applications such as components of submarines,fighter aircraft,and missiles.
文摘通过在U-tree中添加时间戳和速度矢量等时空因素,提出一种基于U-tree的高效率当前及未来不确定位置信息检索的索引结构TPU-tree,可以支持多维空间中不确定移动对象的索引,并提出了一种改进的基于p-bound的MP_BBRQ(modifiedp-bound based range query)域查询处理算法,能够引入搜索区域进行预裁剪以减少查询精炼阶段所需代价偏高的积分计算.实验仿真表明,采用MP_BBRQ算法的TPU-tree概率查询性能极大地优于传统的TPR-tree索引,且更新性能与传统索引大致相当,具有良好的实用价值.
文摘为实现牛粪与水稻秸秆资源化利用,采用批式试验,分别研究了预处理剂种类(H_2O_2、H_2SO_4、NaOH)、预处理剂浓度(2%、4%、6%)及牛粪与水稻秸秆物料比(1∶1、2∶1、4∶1)对牛粪与水稻秸秆混合厌氧发酵产气效果的影响。结果表明,采用2%H2O_2预处理剂,物料配比控制在1∶1,系统平均原料产气率为398.0 m L·g^(-1),发酵效果最佳。动力学研究发现,一级动力学模型与Modified Gompertz方程均可较为准确地对牛粪与水稻秸秆混合厌氧发酵产气过程进行动态模拟,其中,Modified Gompertz方程的模拟效果更优。
文摘Composite solid propellants(CSPs) have widely been used as main energy source for propelling the rockets in both space and military applications. Internal ballistic parameters of rockets like characteristic exhaust velocity, specific impulse, thrust, burning rate etc., are measured to assess and control the performance of rocket motors. The burn rate of solid propellants has been considered as most vital parameter for design of solid rocket motors to meet specific mission requirements. The burning rate of solid propellants can be tailored by using different constituents, extent of oxidizer loading and its particle size and more commonly by incorporating suitable combustion catalysts. Various metal oxides(MOs),complexes, metal powders and metal alloys have shown positive catalytic behaviour during the combustion of CSPs. These are usually solid-state catalysts that play multiple roles in combustion of CSPs such as reduction in activation energy, enhancement of rate of reaction, modification of sequences in reaction-phase, influence on condensed-phase combustion and participation in combustion process in gas-phase reactions. The application of nanoscale catalysts in CSPs has increased considerably in recent past due to their superior catalytic properties as compared to their bulk-sized counterparts. A large surface-to-volume ratio and quantum size effect of nanocatalysts are considered to be plausible reasons for improving the combustion characteristics of propellants. Several efforts have been made to produce nanoscale combustion catalysts for advanced propellant formulations to improve their energetics. The work done so far is largely scattered. In this review, an effort has been made to introduce various combustion catalysts having at least a metallic entity. Recent developments of nanoscale combustion catalysts with their specific merits are discussed. The combustion chemistry of a typical CSP is briefly discussed for providing a better understanding on role of combustion catalysts in burning rate enhancement. Available information on different types of combustion nanocatalysts is also presented with critical comments.
