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CAPACITIVE DROP ANALYSER FOR MEASURING PHYSICAL PROPERTIES OF LIQUIDS
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作者 王春海 张国雄 《Transactions of Tianjin University》 EI CAS 1999年第2期19-24,共6页
A new instrument called capacitive drop analyser (CDA) for measuring the physical properties of liquid is developed.A delivery head with a specialized wetting design was constructed for forming drops.The capacitive tr... A new instrument called capacitive drop analyser (CDA) for measuring the physical properties of liquid is developed.A delivery head with a specialized wetting design was constructed for forming drops.The capacitive transducer uses the delivery head as one of its plates and a cylindrical ring plate.Excellent linearity is achieved by optimising the design,with an accuracy of drop volume measurement of approximately 2 μL.It is suitable for measuring both drops in equilibrium and those in the process of growing.Its capability of real time measurement makes it particularly useful for volatile liquids,in which instance the measurement of drop volume using a flowmeter or a pump is no longer reliable.The CDA can also be used to determine concentration.It is found that concentration curve is linear for aqueous glycerol solutions although not so for aqueous ethanol solution.The CDAs capability of measuring surface tension is also explored and experimental results are presented. 展开更多
关键词 capacitive drop analyser LIQUID DROPS
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Development of x-ray scintillator functioning also as an analyser grating used in grating-based x-ray differential phase contrast imaging 被引量:4
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作者 雷耀虎 刘鑫 +2 位作者 郭金川 赵志刚 牛憨笨 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第4期222-227,共6页
In order to push the grating-based phase contrast imaging system to be used in hospitM and laboratories, this paper designs and develops a novel structure of x-ray scintillator functioning also as an analyser grating,... In order to push the grating-based phase contrast imaging system to be used in hospitM and laboratories, this paper designs and develops a novel structure of x-ray scintillator functioning also as an analyser grating, which has been proposed for grating-based x-ray differential phase contrast imaging. According to this design, the scintillator should have a periodical structure in one dimension with the pitch equaling the period of self-image of the phase grating at the Talbot distance, where one half of the pitch is pixellated and is made of x-ray sensitive fluorescent material, such as CsI(T1), and the remaining part of the pitch is made of x-ray insensitive material, such as silicon. To realize the design, a deep pore array with a high aspect ratio and specially designed grating pattern are successfully manufactured on 5 inch silicon wafer by the photo-assisted electrochemical etching method. The related other problems, such as oxidation-caused geometrical distortion, the filling of CsI(T1) into deep pores and the removal of inside bubbles, have been overcome. Its pixel size, depth and grating pitch are 3 p.m^7.5 ~m, 150 p^m and 3 Ixm, respectively. The microstructure of the scintillator has been examined microscopically and macroscopically by scanning electron microscope and x-ray resolution chart testing, respectively. The preliminary measurements have shown that the proposed scintillator, also functioning as an analyser grating, has been successfully designed and developed. 展开更多
关键词 scintillator screen pore arrays oxidation CsI(T1) analyser grating
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Lie algebraic analysis for the beam transport in the spherical electrostatic analyser 被引量:1
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作者 吕建钦 张卓 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第5期1280-1284,共5页
This paper uses the Lie algebraic method to analyse the charged particle trajectories in the spherical electrostatic analyser, and obtains the nonlinear solutions. The results show that the focusing abilities both in ... This paper uses the Lie algebraic method to analyse the charged particle trajectories in the spherical electrostatic analyser, and obtains the nonlinear solutions. The results show that the focusing abilities both in the x and y directions of the analyser are almost the same. Moreover, there exist dispersion effects in the x direction, and no dispersion effects in the y direction. 展开更多
关键词 Lie algebraic method spherical electrostatic analyser optical properties NONLINEARITY
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Rheological Behaviour for Polymer Melts and Concentrated Solutions Part Ⅰ:A New Multiple Reptation Model to Predict the Nonlinear Visco-elasticity with Nagai Chain Constraints in Entangled Polymer Melts 被引量:2
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作者 Mingshi SONG and Sizhu WU(Dept. of Polymer Science, Beijing University of Chemical Technology Beijing, 100029, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第1期15-30,共16页
An approach of stochastically statistical mechanics and a unified molecular theory of nonlinear viscoelasticity with constraints of Nagai chain entanglement for polymer melts have been proposed. A multimode model stru... An approach of stochastically statistical mechanics and a unified molecular theory of nonlinear viscoelasticity with constraints of Nagai chain entanglement for polymer melts have been proposed. A multimode model structure for a single polymer chain with n tail segments and N reversible entanglement sites on the test polymer chain is developed. Based on the above model structure and the mechanism of molecular flow by the dynamical reorganization of entanglement sites, the probability distribution function of the end-to-end vectr for a single polymer chain at entangled state and the viscoelastic free energy of deformation for polymer melts are calculated by using the method of the stochastically statistical mechanics. The four types of stress-strain relation and the memory function are derived from this thery. The above theoretical relations are verified by the experimentaf data for various polymer melts. These relations are found to be in good agreement with the experimental results 展开更多
关键词 Rheological Behaviour for Polymer Melts and Concentrated Solutions Part A New Multiple Reptation Model to Predict the Nonlinear visco-elasticity with Nagai Chain Constraints in Entangled Polymer Melts
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HEMORRHEOLOGY, VISCO-ELASTICITY AND THIXOTROPY IN CEREBRAL THROMBOSIS
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作者 杨景文 乐忠庆 +3 位作者 林杰 赵梅金 戚华铭 徐济民 《Medical Bulletin of Shanghai Jiaotong University》 CAS 1992年第2期71-74,共4页
In this study, we used blood rheometer type HT-I to determine blood viscosity, plasma viscosity, hematocrit, blood red cell visco-elasticity and thixotropy in 70 cases with cerebral thrombosis, compared with normal co... In this study, we used blood rheometer type HT-I to determine blood viscosity, plasma viscosity, hematocrit, blood red cell visco-elasticity and thixotropy in 70 cases with cerebral thrombosis, compared with normal control group in order to study the relationship between their alteration and cerebral thrombosis blood and plasma viscosity were higher in the patients than in normal control. Hysteresis loop analysis showed that the red blood cell’s visco-elasticity, thixotropy and deformity decrease. 展开更多
关键词 visco-elasticity THIXOTROPY BLOOD VISCOSITY
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Multi-scale Modeling and Finite Element Analyses of Thermal Conductivity of 3D C/SiC Composites Fabricating by Flexible-Oriented Woven Process
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作者 Zheng Sun Zhongde Shan +5 位作者 Hao Huang Dong Wang Wang Wang Jiale Liu Chenchen Tan Chaozhong Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期275-288,共14页
Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale pr... Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC composites.An entirely new process is introduced to weave the preform with three-dimensional orthogonal architecture.The 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary conditions.Three RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the microscale.Besides,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix models.The prediction results at the mesoscale correspond closely to the experimental values.The effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into consideration.The multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures. 展开更多
关键词 3D C/SiC composites Finite element analyses Multi-scale modeling Thermal conductivity
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Meta databases of steel frame buildings for surrogate modelling and machine learning-based feature importance analysis 被引量:1
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作者 Delbaz Samadian Imrose B.Muhit +1 位作者 Annalisa Occhipinti Nashwan Dawood 《Resilient Cities and Structures》 2024年第1期20-43,共24页
Traditionally,nonlinear time history analysis(NLTHA)is used to assess the performance of structures under fu-ture hazards which is necessary to develop effective disaster risk management strategies.However,this method... Traditionally,nonlinear time history analysis(NLTHA)is used to assess the performance of structures under fu-ture hazards which is necessary to develop effective disaster risk management strategies.However,this method is computationally intensive and not suitable for analyzing a large number of structures on a city-wide scale.Surrogate models offer an efficient and reliable alternative and facilitate evaluating the performance of multiple structures under different hazard scenarios.However,creating a comprehensive database for surrogate mod-elling at the city level presents challenges.To overcome this,the present study proposes meta databases and a general framework for surrogate modelling of steel structures.The dataset includes 30,000 steel moment-resisting frame buildings,representing low-rise,mid-rise and high-rise buildings,with criteria for connections,beams,and columns.Pushover analysis is performed and structural parameters are extracted,and finally,incorporating two different machine learning algorithms,random forest and Shapley additive explanations,sensitivity and explain-ability analyses of the structural parameters are performed to identify the most significant factors in designing steel moment resisting frames.The framework and databases can be used as a validated source of surrogate modelling of steel frame structures in order for disaster risk management. 展开更多
关键词 Surrogate models Meta database Pushover analysis Steel moment resisting frames Sensitivity and explainability analyses Machine learning
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Thermodynamic,Economic,and Environmental Analyses and Multi-Objective Optimization of Dual-Pressure Organic Rankine Cycle System with Dual-Stage Ejector
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作者 Guowei Li Shujuan Bu +5 位作者 Xinle Yang Kaijie Liang Zhengri Shao Xiaobei Song Yitian Tang Dejing Zong 《Energy Engineering》 EI 2024年第12期3843-3874,共32页
A novel dual-pressure organic Rankine cycle system(DPORC)with a dual-stage ejector(DE-DPORC)is proposed.The system incorporates a dual-stage ejector that utilizes a small amount of extraction steam from the highpressu... A novel dual-pressure organic Rankine cycle system(DPORC)with a dual-stage ejector(DE-DPORC)is proposed.The system incorporates a dual-stage ejector that utilizes a small amount of extraction steam from the highpressure expander to pressurize a large quantity of exhaust gas to performwork for the low-pressure expander.This innovative approach addresses condensing pressure limitations,reduces power consumption during pressurization,minimizes heat loss,and enhances the utilization efficiency of waste heat steam.A thermodynamic model is developed with net output work,thermal efficiency,and exergy efficiency(W_(net,ηt,ηex))as evaluation criteria,an economicmodel is established with levelized energy cost(LEC)as evaluation index,anenvironmentalmodel is created with annual equivalent carbon dioxide emission reduction(AER)as evaluation parameter.A comprehensive analysis is conducted on the impact of heat source temperature(T_(S,in)),evaporation temperature(T_(2)),entrainment ratio(E_(r1),E_(r2)),and working fluid pressure(P_(5),P_(6))on system performance.It compares the comprehensive performance of the DE-DPORC system with that of the DPORC system at TS,in of 433.15 K and T2 of 378.15 K.Furthermore,multi-objective optimization using the dragonfly algorithm is performed to determine optimal working conditions for the DE-DPORC system through the TOPSIS method.The findings indicate that the DEDPORC system exhibits a 5.34%increase inWnet andηex,a 58.06%increase inηt,a 5.61%increase in AER,and a reduction of 47.67%and 13.51%in the heat dissipation of the condenser andLEC,compared to theDPORCsystem,highlighting the advantages of this enhanced system.The optimal operating conditions are TS,in=426.74 K,T_(2)=389.37 K,E_(r1)=1.33,E_(r2)=3.17,P_(5)=0.39 MPa,P_(6)=1.32 MPa,which offer valuable technical support for engineering applications;however,they are approaching the peak thermodynamic and environmental performance while falling short of the highest economic performance. 展开更多
关键词 Dual-pressure ORC dual-stage ejector performance analyses multi-objective optimization steam waste heat recovery
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Heart abnormality associates with a wide spectrum of psychiatric disorders:Evidence from Mendelian randomization analyses
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作者 Xue-Shi Chen Zi-Yan Song +2 位作者 Xuan-Long Chen Yi-Ming Bo Li-Liang Li 《World Journal of Psychiatry》 SCIE 2024年第12期1988-1991,共4页
Psychiatric disorders and heart abnormality are closely interconnected.Previous knowledge has been well-established that psychiatric disorders can lead to increased cardiovascular morbidity and even sudden cardiac dea... Psychiatric disorders and heart abnormality are closely interconnected.Previous knowledge has been well-established that psychiatric disorders can lead to increased cardiovascular morbidity and even sudden cardiac death.Conversely,whether heart abnormality contributes to psychiatric disorders remains rarely studied.The work by Zhang et al pointed out that chronic heart failure had effects on the anxiety and depression(AD)severity,and indices including left ventricular ejection fraction,N-terminal pro-brain natriuretic peptide and interleukin-6 were independent risk factors for AD severity.In addition to the aforementioned AD,we herein find that heart failure might additionally impact the development of autism spectrum disorder and post-traumatic stress disorder(albeit P>0.05),and significantly protects against the presence of attention deficit hyperactivity disorder(ADHD),[odds ratio(OR)=0.61,P=0.0071]by using a Mendelian randomization analysis.Bradycardia is also a protective factor for ADHD(OR=0.61,P=0.0095),whereas hypertrophic cardiomyopathy is a mild risk factor for schizophrenia(OR=1.02,P=0.032).These data suggest a wide spectrum of psychiatric disorders secondary to heart abnormality,and we highlight more psychiatric care that should be paid to patients with heart abnormality. 展开更多
关键词 Psychiatric disorders SCHIZOPHRENIA Heart abnormality Heart failure Mendelian randomization analyses
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Design,preparation,application of advanced array structured materials and their action mechanism analyses for high performance lithium-sulfur batteries
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作者 Nanping Deng Xiaofan Feng +7 位作者 Yongbing Jin Zhaozhao Peng Yang Feng Ying Tian Yong Liu Lu Gao Weimin Kang Bowen Cheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期266-303,I0007,共39页
Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely comme... Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB. 展开更多
关键词 Array structured materials Preparation methods and structural designs Action mechanism analyses Advanced Li-S batteries Excellent electrochemical performances and safety
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In silico prospective analysis of the medicinal plants activity on the CagA oncoprotein from Helicobacter pylori
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作者 Rafaela Viana Vieira Gabrielle Caroline Peiter +2 位作者 Fabrício Freire de Melo Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira 《World Journal of Clinical Oncology》 2024年第5期653-663,共11页
BACKGROUND Colonization with Helicobacter pylori(H.pylori)has a strong correlation with gastric cancer,and the virulence factor CagA is implicated in carcinogenesis.Studies have been conducted using medicinal plants w... BACKGROUND Colonization with Helicobacter pylori(H.pylori)has a strong correlation with gastric cancer,and the virulence factor CagA is implicated in carcinogenesis.Studies have been conducted using medicinal plants with the aim of eliminating the pathogen;however,the possibility of blocking H.pylori-induced cell differentiation to prevent the onset and/or progression of tumors has not been addressed.This type of study is expensive and time-consuming,requiring in vitro and/or in vivo tests,which can be solved using bioinformatics.Therefore,prospective computational analyses were conducted to assess the feasibility of interaction between phenolic compounds from medicinal plants and the CagA oncoprotein.AIM To perform a computational prospecting of the interactions between phenolic compounds from medicinal plants and the CagA oncoprotein of H.pylori.METHODS In this in silico study,the structures of the phenolic compounds(ligands)kaempferol,myricetin,quercetin,ponciretin(flavonoids),and chlorogenic acid(phenolic acid)were selected from the PubChem database.These phenolic compounds were chosen based on previous studies that suggested medicinal plants as non-drug treatments to eliminate H.pylori infection.The three-dimensional structure model of the CagA oncoprotein of H.pylori(receptor)was obtained through molecular modeling using computational tools from the I-Tasser platform,employing the threading methodology.The primary sequence of CagA was sourced from GenBank(BAK52797.1).A screening was conducted to identify binding sites in the structure of the CagA oncoprotein that could potentially interact with the ligands,utilizing the GRaSP online platform.Both the ligands and receptor were prepared for molecular docking using AutoDock Tools 4(ADT)software,and the simulations were carried out using a combination of ADT and AutoDock Vina v.1.2.0 software.Two sets of simulations were performed:One involving the central region of CagA with phenolic compounds,and another involving the carboxy-terminus region of CagA with phenolic compounds.The receptor-ligand complexes were then analyzed using PyMol and BIOVIA Discovery Studio software.RESULTS The structure model obtained for the CagA oncoprotein exhibited high quality(C-score=0.09)and was validated using parameters from the MolProbity platform.The GRaSP online platform identified 24 residues(phenylalanine and leucine)as potential binding sites on the CagA oncoprotein.Molecular docking simulations were conducted with the three-dimensional model of the CagA oncoprotein.No complexes were observed in the simulations between the carboxy-terminus region of CagA and the phenolic compounds;however,all phenolic compounds interacted with the central region of the oncoprotein.Phenolic compounds and CagA exhibited significant affinity energy(-7.9 to-9.1 kcal/mol):CagA/kaempferol formed 28 chemical bonds,CagA/myricetin formed 18 chemical bonds,CagA/quercetin formed 16 chemical bonds,CagA/ponciretin formed 13 chemical bonds,and CagA/chlorogenic acid formed 17 chemical bonds.Although none of the phenolic compounds directly bound to the amino acid residues of the K-Xn-R-X-R membrane binding motif,all of them bound to residues,mostly positively or negatively charged,located near this region.CONCLUSION In silico,the tested phenolic compounds formed stable complexes with CagA.Therefore,they could be tested in vitro and/or in vivo to validate the findings,and to assess interference in CagA/cellular target interactions and in the oncogenic differentiation of gastric cells. 展开更多
关键词 CagA oncoprotein Phenolic compounds Helicobacter pylori In silico analyses Medicinal plants Prospective analysis
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谐和与有界噪声联合参激作用下的Visco-Elastic系统 被引量:3
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作者 徐伟 戎海武 方同 《应用数学和力学》 CSCD 北大核心 2003年第9期963-972,共10页
 研究了带visco_elastic项的非线性系统,在谐和与有界噪声联合参激作用下的响应和稳定性问题· 用多尺度法分离了系统的快变项,并求出了系统的最大Liapunov指数和稳态概率密度函数,根据最大Liapunov指数可得系统解稳定的充分必...  研究了带visco_elastic项的非线性系统,在谐和与有界噪声联合参激作用下的响应和稳定性问题· 用多尺度法分离了系统的快变项,并求出了系统的最大Liapunov指数和稳态概率密度函数,根据最大Liapunov指数可得系统解稳定的充分必要条件· 讨论了系统的visco_elastic项对系统阻尼项和刚度项的贡献。 展开更多
关键词 参数主共振 visco-elastic项 多尺度法 最大Liapunov指数 分岔
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1992-2022年菜子湖流域景观格局变化分析
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作者 路彤 赵素婷 +1 位作者 周存宇 孙君瑶 《湖北大学学报(自然科学版)》 CAS 2025年第1期63-74,共12页
通过分析1992—2022年7期土地利用遥感影像,使用ArcGIS和Fragstats软件评估菜子湖流域30年间景观格局的变化。研究旨在揭示流域景观演变的特征与趋势,及其对生态系统健康和服务功能的潜在影响。结果表明,菜子湖流域的土地利用情况在研... 通过分析1992—2022年7期土地利用遥感影像,使用ArcGIS和Fragstats软件评估菜子湖流域30年间景观格局的变化。研究旨在揭示流域景观演变的特征与趋势,及其对生态系统健康和服务功能的潜在影响。结果表明,菜子湖流域的土地利用情况在研究期间整体保持稳定,耕地为流域内最主要的土地利用类型,建筑用地的增长趋势则尤为显著。研究发现耕地的破碎化程度较高,表明农业用地正在分割和转变,可能影响区域生态连通性和生物多样性。相比之下,水体斑块的破碎化有所减少,显示出流域水生态系统的一定恢复或改善。林地破碎化的缓和趋势及草地和裸地变化的不显著性,反映了人类管理措施和自然恢复力量的共同作用。菜子湖流域中部地区范围的优势斑块具有良好的连接性。流域东北自西南一带景观受到一种或少数几种优势斑块类型所支配,30年间景观呈现多样化发展。尽管菜子湖流域的景观稳定性显示出积极的增长趋势,但整体水平仍处于较低状态,这表明该流域的生态系统面临来自不断变化的人类活动和自然条件的持续压力,尤其是人口密度对研究区景观格局变化影响较大。本研究强调了对菜子湖流域内景观格局动态变化规律的深入理解,以及其对维护生态系统健康和服务功能的重要性。 展开更多
关键词 土地利用 景观格局指数 景观稳定性 驱动力分析
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Electronic structure and ultraviolet spectra of p-C_(6)H_(4)-C_(20)
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作者 CHEN Xin 《原子与分子物理学报》 CAS 北大核心 2025年第3期21-28,共8页
Geometry optimization of p-C_(6)H_(4)-connected cyclo[20]carbon(p-C_(6)H_(4)-C_(20))was carried out at M062X/6-311G(d,p)level,three kinds of bond orders(Mayer,Laplacian,and Wiberg),electron-hole distributions,localize... Geometry optimization of p-C_(6)H_(4)-connected cyclo[20]carbon(p-C_(6)H_(4)-C_(20))was carried out at M062X/6-311G(d,p)level,three kinds of bond orders(Mayer,Laplacian,and Wiberg),electron-hole distributions,localized orbital locators(LOL),and infrared(IR)spectrum were also performed at the same level.Based on TD-DFT M062X/6-311G(d,p)method,the first 20 excited states and ultraviolet(UV)spectra of p-C_(6)H_(4)-C_(20) were calculated.Calculation results of π-electron delocalization analyses prove thatπ-electron delocalization of p-C_(6)H_(4)-C_(20) is more likely to occur on shorter C-C bonds rather than longer C-C bonds,and inside/outside of the ring plane rather than above/below the ring plane.Two absorption peaks of p-C_(6)H_(4)-C_(20) locate at about 319 nm and 236 nm,respectively. 展开更多
关键词 p-C_(6)H_(4)-C_(20) Bone orders UV spectrum Electron-hole analyses π-electron delocalization analyses
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VALIDATION AND ANALYSES OF THE SIMPLE METHOD FOR DETERMINING rm OF APHIDS AND MITES
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作者 况荣平 R. Fleming 《Zoological Research》 CAS CSCD 1992年第1期37-46,共10页
This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. T... This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. The value of rm can be estimated by the simple equation: rm=0.74ln (Md)/d, where d is the time from birth to first reproduction; Md is the number of female offspring produced per original female in 2d. This method was developed by Wyatt and White. We reached the following conclusions from our study: When the parameter, Md is less than 1, this equation is not appropriate for estimating rm of populations; When the parameter, Md is larger than 1 and about 70% or more of the reproductive contribution to the rm is achieved in 2d, the equation is appropriate for calculatng the rm of aphids and mites.As Md decreases, the required reproductive contribution to the rm in 2d corresponding to the constant 0.74 will increase. However, whether 70% or more of reproductive contribution to rm is achieved in 2d still is a problem for whole taxa of aphids and mites. Therefore, further siudy on reproductive distribution will be required for practical application of this method. 展开更多
关键词 Intrinsic rate of increase APHIDS MITES Simple calculation VALIDATION analysES
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Reevaluating health metrics:Unraveling the limitations of disabilityadjusted life years as an indicator in disease burden assessment
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作者 Ariel Beresniak Dominique Bremond-Gignac +1 位作者 Danielle Dupont Gerard Duru 《World Journal of Methodology》 2025年第1期14-19,共6页
In 1993,the World Bank released a global report on the efficacy of health promotion,introducing the disability-adjusted life years(DALY)as a novel indicator.The DALY,a composite metric incorporating temporal and quali... In 1993,the World Bank released a global report on the efficacy of health promotion,introducing the disability-adjusted life years(DALY)as a novel indicator.The DALY,a composite metric incorporating temporal and qualitative data,is grounded in preferences regarding disability status.This review delineates the algorithm used to calculate the value of the proposed DALY synthetic indicator and elucidates key methodological challenges associated with its application.In contrast to the quality-adjusted life years approach,derived from multi-attribute utility theory,the DALY stands as an independent synthetic indicator that adopts the assumptions of the Time Trade Off utility technique to define Disability Weights.Claiming to rely on no mathematical or economic theory,DALY users appear to have exempted themselves from verifying whether this indicator meets the classical properties required of all indicators,notably content validity,reliability,specificity,and sensitivity.The DALY concept emerged primarily to facilitate comparisons of the health impacts of various diseases globally within the framework of the Global Burden of Disease initiative,leading to numerous publications in international literature.Despite widespread adoption,the DALY synthetic indicator has prompted significant methodological concerns since its inception,manifesting in inconsistent and non-reproducible results.Given the substantial diffusion of the DALY indicator and its critical role in health impact assessments,a reassessment is warranted.This reconsideration is imperative for enhancing the robustness and reliability of public health decisionmaking processes. 展开更多
关键词 Disability adjusted life years Cost-utility analyses Outcome research Public health Burden of disease
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Analyses on Marketing Strategies of Penglai's Tourism
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作者 徐宜华 《海外英语》 2013年第7X期285-288,共4页
Although tourism marketing has made great progress in recent years,researches on it are far from enough.Current re searches on tourism marketing at home and abroad lack pertinence and mostly provide theoretical basis ... Although tourism marketing has made great progress in recent years,researches on it are far from enough.Current re searches on tourism marketing at home and abroad lack pertinence and mostly provide theoretical basis for tourism development within a wide range.The researches on tourism marketing of Penglai are few and far between.Based on previous studies and the status quo of tourism marketing strategy,the below statements tries to find out existing problems of Penglai's tourism,put for ward countermeasures and propose feasible marketing patterns suitable for its tourism development.It subsequently concludes that it can make contribution to the sustainable development of Penglai's tourism and provide other county-level tourism cities with reference for marketing tourism marketing strategies. 展开更多
关键词 Penglai TOURISM MARKETING STRATEGY analysES
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Effect of kidney transplantation on sexual dysfunction in patients with end stage renal disease:A systematic review
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作者 Jaydeep Jain Mahendra Singh +6 位作者 Shashank Kumar Om Kumar Yadav Ankit Shettar Shiv Charan Navriya Deepak Prakash Bhirud Gautam Ram Choudhary Arjun Singh Sandhu 《World Journal of Nephrology》 2025年第1期127-137,共11页
BACKGROUND End-stage renal disease(ESRD)is associated with a multitude of physical,psychological,and social health challenges,including a profound impact on sexual and reproductive health.Among males with ESRD,erectil... BACKGROUND End-stage renal disease(ESRD)is associated with a multitude of physical,psychological,and social health challenges,including a profound impact on sexual and reproductive health.Among males with ESRD,erectile dysfunction(ED)is highly prevalent due to factors such as underlying comorbidities,including diabetes and hypertension,and the physiological effects of long-term dialysis.Kidney transplantation(KTx)has been proposed as a potential intervention to mitigate the effects of ED by restoring renal function and improving hormonal balance.However,the evidence surrounding the effectiveness of KTx in improving sexual function,specifically erectile function(EF),remains inconclusive.This systematic review and meta-analysis aim to evaluate the effects of KTx on sexual dysfunction(SexDys),particularly ED,in male ESRD patients.AIM To evaluate the benefits and potential harms of KTx compared to other forms of renal replacement therapy in improving EF in adult males with ESRD,assessed using the international index of EF(IIEF),to survey the prevalence of SexDys in this population,and to assess the correlation between various factors and SexDys through regression analysis.METHODS A systematic search of PubMed,EMBASE,Cochrane Library,Scopus,Clinical-Trials.gov,and Google Scholar was conducted,following the PRISMA 2020 guidelines.Prospective and retrospective cohort studies,as well as cross-sectional studies assessing EF pre-and post-transplantation,were included.These studies used validated tools such as the IIEF to measure EF.Meta-analyses were performed using a random-effects model to estimate standardized mean differences(SMD)and hazard ratios(HR)with 95%confidence intervals(CI).Heterogeneity was assessed using the I²statistic,and publication bias was evaluated with a funnel plot and the Egger’s test.RESULTS A total of 2419 studies were identified,with 362 abstracts screened and 193 full-text articles reviewed.Ultimately,11 studies were included for qualitative analysis and 7 for quantitative synthesis.The random effects model for SMD yielded a combined estimate of 0.43(95%CI:-0.20-1.07),indicating a small but non-significant improvement in EF post-transplantation.The heterogeneity across studies was substantial(I²=90%),reflecting significant variability in outcomes.Subgroup analysis showed greater improvements in EF among living-donor transplant recipients compared to those receiving organs from deceased donors.Despite this trend,the overall result for changes in EF was not statistically significant(P=0.15).Additionally,the combined HR from the meta-analysis was 2.87(95%CI:1.76-4.69),suggesting that KTx significantly increases the likelihood of improved EF,though variability between studies persisted(I²=63%).CONCLUSION While KTx offers some promise for improving EF in male ESRD patients,the overall evidence remains inconclusive due to high heterogeneity between studies and a lack of statistical significance in the combined results.Despite this,individual studies suggest that KTx may lead to significant improvements in EF for certain subgroups,particularly living-donor recipients.Future research should focus on larger,well-designed cohort studies with standardized outcome measures to provide more definitive conclusions.Addressing SexDys as part of routine care for ESRD patients undergoing KTx is crucial to improving their overall quality of life.However,adjunct therapies such as phosphodiesterase type 5 inhibitors may be necessary for those who do not experience adequate improvements post-transplantation. 展开更多
关键词 Kidney transplantation Sexual dysfunction Erectile dysfunction International index of erectile function Syste-matic review Meta analyses
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Entransy analyses of heat–work conversion systems with inner irreversible thermodynamic cycles 被引量:9
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作者 程雪涛 梁新刚 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期259-264,共6页
In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influenc... In this paper, we try to use the entransy theory to analyze the heat–work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat–work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat–work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed.Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied. 展开更多
关键词 entransy loss heat–work conversion inner irreversible thermodynamic cycle analysES
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Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L 被引量:5
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作者 Laila Salim Al Hashmi Mohammad Amzad Hossain +2 位作者 Afaf Mohammed Weli Qasim Al-Riyami Jamal Nasser Al-Sabahi 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2013年第1期69-73,共5页
Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(T.vulgaris)by gas chromatography-mass spectrometry(GC-MS).Methods:The shad... Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(T.vulgaris)by gas chromatography-mass spectrometry(GC-MS).Methods:The shade dried leaves powder was extracted with methanol by using Soxhlet extractor.Methanol crude extracts of T.vulgaris and the derived fractions of hexane,chloroform,ethyl acetate and butanol were obtained.Results:Qualitative analyses of various organic crude extracts of T.vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds.Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important.Further,the T.vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation.The crude extracts were prepared from the powder leaves of T.vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis.Conclusions:All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T.vulgaris are biologically active molecules.Thus the identification of a good number of compounds in various crude extracts of T.vulgaris might have some ecological role. 展开更多
关键词 THYMUS VULGARIS L Preparation CRUDE extracts SOXHLET EXTRACTOR GC-MS analyses
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