检索结果-南通市图书馆

Identifying the critical phosphorus balance for optimizing phosphorus input and regulating soil phosphorus effectiveness in a typical winter wheat-summer maize rotation system in North China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2023年第12期22卷 3769-3782页

作者： XU Meng-ze WANG Yu-hong NIE Cai-e SONG Gui-pei xin su-ning LU Yan-li BAI You-lu ZHANG Yin-jie WANG Lei State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Plant Nutrition and Fertilizer of Ministry of Agriculture and Rural Affairs Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China College of Resources and Environment Henan Agricultural UniversityZhengzhou 450002P.R.China

Phosphorus(P)is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop *** P fertilizer application is widespread in agricultural production,which not only wastes phosphate resources but also causes P accumulation and groundwater ***,we hypothesized that the apparent P balance of a crop system could be used as an indicator for identifying the critical P input in order to obtain a high yield with high phosphorus use efficiency(PUE).A 12-year field experiment with P fertilization rates of 0,45,90,135,180,and 225 kg P_(2)O_(5)ha^(-1)was conducted to determine the crop yield,PUE,and soil Olsen-P value response to P balance,and to optimize the P *** yield stagnation occurred when the P fertilizer application exceeded a certain level,and high yield and PUE levels were achieved with annual P fertilizer application rates of 90-135 kg P_(2)O_(5)ha^(-1).A critical P balance range of 2.15-4.45 kg P ha^(-1)was recommended to achieve optimum yield with minimal environmental *** critical P input range estimated from the P balance was 95.7-101 kg P_(2)O_(5)ha^(-1),which improved relative yield(>90%)and PUE(90.0-94.9%).In addition,the P input-output balance helps in assessing future changes in Olsen-P values,which increased by 4.07 mg kg^(-1)of P for every 100 kg of P ***,the P balance can be used as a critical indicator for P management in agriculture,providing a robust reference for limiting P excess and developing a more productive,efficient and environmentally friendly P fertilizer management strategy.

关键词： yield of winter wheat and summer maize phosphorus balance phosphorus use efficiency Olsen-P critical phosphorus application rate

Ablation behaviour and mechanical performance of ZrB_(2)-ZrC-SiC modified carbon/carbon composites prepared by vacuum infiltration combined with reactive melt infiltration

在线全文

学校读者我要写书评

暂无评论

新型炭材料（中英文） 2024年第4期39卷 633-644页

作者： ZHANG Jia-ping su Xiao-xuan LI xin-gang WANG Run-ning FU Qian-gang Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials Northwestern Polytechnical UniversityXi’an 710072China

The development of advanced aircraft relies on high performance thermal-structural materials,and carbon/carbon com-posites(C/C)composited with ultrahigh-temperature ceramics are ideal ***,the traditional routes of compositing are either inefficient and expensive or lead to a non-uniform distribution of ceramics in the *** with the traditional C/C-ZrC-SiC composites prepared by the reactive melt infiltration of ZrSi_(2),C/C-ZrB_(2)-ZrC-SiC composites prepared by the vacuum infiltration of ZrB_(2) combined with reactive melt infiltration have the higher content and more uniform distribution of the introduced ceramic *** mass and linear ablation rates of the C/C-ZrB_(2)-ZrC-SiC composites were respectively 68.9%and 29.7%lower than those of C/C-ZrC-SiC composites prepared by reactive melt *** ablation performance was improved because the volatilization of B_(2)O_(3),removes some of the heat,and the more uniformly distributed ZrO_(2),that helps produce a ZrO2-SiO2 continu-ous protective layer,hinders oxygen infiltration and decreases ablation.

关键词： C/C composites ZrB_(2)-ZrC-SiC Vacuum filtration Reactive melt infiltration Ablation.

Numerical study of the influence of the atmospheric pressure on the thermal environment in the passenger cabin

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第2期17卷 253-265页

作者： xin su Yu Guo Zhengwei Long Yi Cao Tianjin Key Lab.of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin300072China Shanghai Aircraft Design and Research Institute Jinke RoadPudong DistrictShanghai201210China

The cabin air pressure remains lower than the horizontal atmospheric pressure when the airplane is in *** pressure is one of the parameters that must be taken into consideration while studying the thermal environment of an airplane *** are still no reference values for aircraft cabins despite the fact that numerous studies on low pressure heat transfer have demonstrated the connection between convective heat transfer coefficient(CHTC)and air *** this paper,a correction method for CHTC under low pressure conditions was established by using the dummy heat dissipation in the low-pressure cabin *** this basis,a thermal environment simulation model was developed,then was applied to the simulation of a seven-row aircraft cabin containing 42 passengers,and the CHTC and heat loss of dummy surface in the cabin were ***,the results of PMV calculated by using heat dissipation and air parameters at sampling points were *** results show that the modified CHTC can accurately reflect the cabin thermal environment under low pressure conditions,and the correction of CHTC can be realized by adjusting the turbulent Prandtl number,which is nonlinear correlated with the *** simulation results of the thermal environment in the seven-row cabin show that the CHTC changes by about 42%before and after *** air pressure decreases during take-off,which reduces the average CHTC of the crew surface from 5.09 W/(m^(2)·K)to 4.56 W/(m^(2)·K),but the air temperature rises by about 0.2°C as a *** deviation of PMV results calculated by using simulated heat loss data and using air parameters of measuring points in space is up to 0.5,but the latter is representative for calculating the thermal comfort level of the whole cabin.

关键词： low pressure aircraft cabin simulation heat dissipation convective heat transfer coefficient

Effect of solvent on the initiation mechanism of living anionic polymerization of styrene:A computational study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第5期69卷 135-142页

作者： Shen Li Yin-ning Zhou Zhong-xin Liu Zheng-Hong Luo School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

For living anionic polymerization(LAP),solvent has a great influence on both reaction mechanism and *** this work,by using the classical butyl lithium-styrene polymerization as a model system,the effect of solvent on the mechanism and kinetics of LAP was revealed through a strategy combining density functional theory(DFT)calculations and kinetic *** terms of mechanism,it is found that the stronger the solvent polarity,the more electrons transfer from initiator to solvent through detailed energy decomposition analysis of electrostatic interactions between initiator and solvent ***,we also found that the stronger the solvent polarity,the higher the monomer initiation energy barrier and the smaller the initiation rate ***,initiation is more favorable at lower temperatures based on the calculated results ofΔG_(TS).Finally,the kinetic characteristics in different solvents were further examined by kinetic *** is found that in benzene and n-pentane,the polymerization rate exhibits first-order ***,slow initiation and fast propagation were observed in tetrahydrofuran(THF)due to the slow free ion formation rate,leading to a deviation from first-order kinetics.

关键词： Living anionic polymerization Solvent effect Reaction kinetics Computational chemistry Mathematical modeling Kinetic modeling

Exosomes from umbilical cord mesenchymal stromal cells promote the collagen production of fibroblasts from pelvic organ prolapse

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2024年第6期16卷 708-727页

作者： Lei-Mei Xu xin-xin Yu ning Zhang Yi-Song Chen Department of Gynecology Obstetrics and Gynecology Hospital of Fudan UniversityShanghai 200011China Department of Gynecology Shanghai Key Laboratory of Female Reproductive Endocrine-related DiseasesShanghai 200011China

BACKGROUND Pelvic organ prolapse(POP)involves pelvic organ herniation into the vagina due to pelvic floor tissue laxity,and vaginal structure is an essential *** POP,the vaginal walls exhibit abnormal collagen distribution and decreased fibroblast levels and *** intricate etiology of POP and the prohibition of trans-vaginal meshes in pelvic reconstruction surgery present challenges in targeted therapy *** umbilical cord mesenchymal stromal cells(hucMSCs)present limitations,but their exosomes(hucMSC-Exo)are promising therapeutic tools for promoting fibroblast proliferation and extracellular matrix *** inflammation in POP group fibroblasts,stimulated primary fibroblast growth,and elevated collagen I(Col1)production in ***-throughput RNA-seq of fibroblasts treated with hucMSC-Exo and miRNA sequencing of hucMSC-Exo revealed that abundant exosomal miRNAs downregulated matrix metalloproteinase 11(MMP11)*** HucMSC-Exo normalized the growth and function of primary fibroblasts from patients with POP by promoting cell growth and Col1 expression in *** miRNAs in hucMSC-Exo targeted and downregulated MMP11 ***-Exo-based therapy may be ideal for safely and effectively treating POP.

关键词： Pelvic organ prolapse Exosomes Fibroblasts Human umbilical cord mesenchymal stromal cells Extracellular matrix Collagen I

Restraining growth of Zn dendrites by poly dimethyl diallyl ammonium cations in aqueous electrolytes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3735-3747页

作者： Xiang-xin Zhang Yuan-Qiang Chen Chang-xin Lin Yuan-Sheng Lin Guo-Lin Hu Yong-Chuan Liu Xi-Lai Xue su-Jing Chen Zhan-Lin Yang Bai-Sheng Sa Yi-ning Zhang Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Helmholtz Institute Ulm(HIU) 89081 UlmGermany Karlsruhe Institute of Technology(KIT) 76021 KarlsruheGermany College of Materials Science and Engineering Fuzhou UniversityFuzhou350108China

Metallic zinc is an excellent anode material for Zn-ion batteries,but the growth of Zn dendrite severely hinders its practical ***,an efficient and economical cationic additive,poly dimethyl diallyl ammonium(PDDA) was reported,used in aqueous Zn-ion batteries electrolyte for stabilizing Zn *** growth of zinc dendrites can be significantly restrained by benefiting from the pronounced electrostatic shielding effect from PDDA on the Zn metal ***,the PDDA is preferentially absorbed on Zn(002) plane,thus preventing unwanted side reactions on Zn *** to the introduction of a certain amount of PDDA additive into the common ZnSO_(4)-based electrolyte,the cycle life of assembled Zn‖Zn cells(1 mA·cm^(-2) and 1 mAh·cm^(-2)) is prolonged to more than 1100 *** response to the perforation issue of Zn electrodes caused by PDDA additives,the problem can be solved by combining foamy copper with zinc *** real application,Zn-ion hybrid supercapacitors and MnO_(2)‖Zn cells were assembled,which exhibited excellent cycling stability with PDDA *** work provides a new solution and perspective to cope with the dendrite growth problem of Zn anode.

关键词： PDDA Electrostatic shielding effect Zn anode Zn dendrites

Investigation of the quality of life,mental status in patients with gynecological cancer and its influencing factors

在线全文

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2024年第7期14卷 1053-1061页

作者： Hai-Xia Shang Wen-Ting ning Jin-Fen sun Nan Guo xin Guo Jan-Nan Zhang Hong-xin Yu su-Hui Wu Department of Gynaecology and Obstetrics The Third Hospital of Shanxi Medical UniversityShanxi Bethune HospitalShanxi Academy of Medical SciencesTongji Shanxi HospitalTaiyuan 030032Shanxi ProvinceChina

BACKGROUND Having a gynecological tumor or undergoing treatment can be a traumatic experience for women,as it affects their self-image and sexual relationships and can lead to psychological *** adjustment following cancer occurrence remains a key issue among the *** To examine the current status of quality of life(QoL),anxiety,and depression in patients with gynecological cancer and to analyze the factors associated with *** Data for 160 patients with gynecological malignancies treated at Shanxi Bethune Hospital from June 2020 to June 2023 were collected and analyzed ***’QoL was assessed using the European Organization for Research on Treatment of Cancer Quality of Life Questionnaire Core 30 and the Functional Assessment of Cancer Therapy-General *** emotional status was evaluated using the Self-Rating Anxiety/Depression *** associated factors of anxiety and depression were *** The overall QoL score of the patients 6 months after surgery was 76.39±3.63 *** included low levels of social and emotional function and severe fatigue and *** scores for physiological,functional,emotional,social,and family well-being exhibited an upward trend following surgery compared with those before *** month after surgery,some patients experienced anxiety and depression,with an incidence of 18.75%and 18.13%,*** analysis revealed that good sleep was a protective factor against anxiety and depression in patients with gynecological tumors,whereas physical pain was a risk *** Patients with gynecological malignancies often experience anxiety and *** analyzing the factors that affect patients’QoL,effective nursing measures can be administered.

关键词： Gynecological Tumors Quality of life Anxiety Depression

Multiplicity of solutions for the semilinear subelliptic Dirichlet problem

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第3期67卷 475-504页

作者： Hua Chen Hong-Ge Chen Jin-ning Li xin Liao School of Mathematics and Statistics Wuhan UniversityWuhan 430072China Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

In this paper,we study the semilinear subelliptic equation{−△Xu=f(x,u)+g(x,u)inΩ,u=0 on∂Ω,where△X=−∑m i=1 Xi∗Xi is the self-adjoint Hormander operator associated with the vector fields X=(X_(1),X_(2),...,X_(m))satisfying the Hormander's condition,f(x,u)∈C(Ω×R),g(x,u)is a Carathéodory function onΩ×R,andΩis an open bounded domain in R~n with smooth *** the perturbation from the symmetry method with the approaches involving the eigenvalue estimate and the Morse index in estimating the minimax values,we obtain two kinds of existence results for multiple weak solutions to the problem ***,we discuss the difference between the eigenvalue estimate approach and the Morse index approach in degenerate *** with the classical elliptic cases,both approaches here have their own strengths in the degenerate *** new phenomenon implies that the results in general degenerate cases would be quite different from the situations in classical elliptic cases.

关键词： degenerate elliptic equations Hormander operators perturbation method Morse index

Reorientation and obstacle avoidance control of free-floating modular robots using sinusoidal oscillator

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 262-275页

作者： Zhiyuan YANG Mingzhu LAI Jian QI ning ZHAO xin suI Jie ZHAO Yanhe ZHU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

This paper presents that a serpentine curve-based controller can solve locomotion control problems for articulated space robots with extensive flight phases,such as obstacle avoidance during free floating or attitude adjustment before *** proposed algorithm achieves articulated robots to use closed paths in the joint space to accomplish the above *** snakes,which can shuttle through gaps and adjust their landing posture by swinging their body during gliding in jungle environments,inspired the design of two *** first maneuver generates a rotation of the system by varying the moment of inertia between the joints of the robot,with the magnitude of the net rotation depending on the controller *** maneuver can be repeated to allow the robot to reach arbitrary *** second maneuver involves periodic undulations,allowing the robot to avoid collisions when the trajectory of the global Center of Mass(CM)passes through the *** maneuvers are based on the improved serpenoid curve,which can adapt to redundant systems consisting of different numbers of ***,the simulation illustrates that combining the two maneuvers can help a free-floating chain-type robot traverse complex *** proposed algorithm can be used with similar articulated robot models.

关键词： Collision avoidance Modularrobots Reorientation Free-floating space robots Nonholonomic systems Biologically inspired controllers Serpenoid curve