检索结果-南通市图书馆

Theoretical studies of vibrationally resolved absorption and emission spectra: From a single chromophore to multichromophoric oligomers/aggregates

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第2期53卷 297-309页

作者： gao fang LIANG WanZhen ZHAO Yi Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry Xiamen UniversityXiamen 361005China

Absorption and photoluminescence spectroscopies are useful tools to study the photo-physical properties of materials. The theoretical methods for calculation of the spectra of molecules/supermolecules and aggregates, whose structures can differ significantly, are reviewed from the viewpoint of computational efficiency. Several model compounds/multimers are taken as examples for the spectral calculations. The numerical results achieve a satisfactory agreement between the theory and experiment.

关键词： vibrationally resolved absorption and photoluminescence spectroscopies single chromophore multichromophoric oligomers aggregates time-dependent density functional theory(TD-DFT)

Longitudinal Vibration Analysis of Marine Riser During Installation and Hangoff in Ultra Deepwater

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2016年第4期111卷 357-373页

作者： Yanbin Wang Deli gao Jun fang MOE Key Laboratory of Petroleum Engineering China University of PetroleumBeijing102249China

This paper is concerned with the problem of longitudinal vibration of a 3,000 m long disconnected drilling riser during installation and hangoff *** natural frequency,amplitude of vibration displacement and vibration force of longitudinal vibration have been determined with consideration of the damping effect of the sea *** show the natural frequency of riser under these two situations are both decrease with the increase of water *** natural frequency of riser in installation operation is bigger than that in hangoff *** vibration displacement in hangoff configuration is bigger than that in installation while the vibration force in hangoff configuration is smaller than that in installation *** the condition of resonance,the vibration displacement increase along riser from top end to the bottom end while the vibration force increase along riser from riser bottom end to the top end.

关键词： Marine riser Installation Hangoff Longitudinal vibration

Minimum best success probability by classical strategies for quantum pseudo-telepathy

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(Physics,Mechanics & Astronomy) 2014年第7期57卷 1244-1249页

作者： gao Fei fang Wei WEN QiaoYan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

Quantum pseudo-telepathy(QPT)is a new type of game where the quantum team can win with certainty while the classical one *** means the advantages of quantum participants over classical ones in ***,there has been no systematic and formal analysis on the QPT game *** we present the formal description of the QPT game and the definition of the most simplified *** on the above definitions,we simplify a famous QPT game,*** Cabllo ***,according to some instances,we analyze the minimum best success probability by classical strategies of the two-player QPT,which reflects the advantage of the quantum ***,we prove the best success probability by classical strategies for the most simplified QPT is totally related to the number of all possible question combinations.

关键词： quantum game pseudo-telepathy quantum strategy

Serum ferritin levels in children with attention deficit hyperactivity disorder and tic disorder

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第22期10卷 7749-7759页

作者： Cai-yun Tang fang Wen Department of Psychiatry Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China

BACKGROUND Iron plays an important role in neurodevelopmental functions in the *** ferritin levels are different in children with attention deficit hyperactivity disorder and tic disorder than in healthy *** To explore the current status of iron deficiency in children with neurodevelopmental disorders and its sex and age *** A total of 1565 children with attention deficit hyperactivity disorder(ADHD),1694 children with tic disorder(TD),93 children with ASD and 1997 healthy control children were included between January 1,2020,and December 31,2021 at Beijing Children's *** describe the differences in age levels and ferritin levels between different disease groups and their sex *** differences between the sexes in each disease were analyzed using the t *** incidence rate of low serum ferritin was used to describe the differences between different diseases and different age groups.A chi-square test was used to analyze the difference in the incidence of low serum ferritin between the disease group and the control *** of variance was used for comparisons between subgroups,and regression analysis was used for confounding factor *** A total of 1565 ADHD patients aged 5-12 years were included in this study,and the average serum ferritin levels of male and female children were 36.82±20.64μg/L and 35.64±18.56μg/L,respectively.A total of 1694 TD patients aged 5-12 years were included in this study,and the average serum ferritin levels of male and female children were 35.72±20.15μg/L and 34.54±22.12μg/L,*** age increased,the incidence of low serum ferritin in ADHD and TD first decreased and then increased,and 10 years old was the turning point of rising *** incidence of ADHD with low serum ferritin was 8.37%,the incidence of TD with low serum ferritin was 11.04%,and the incidence of the healthy control group with low serum ferritin was 8.61%,among which male children with TD accounte

关键词： Iron deficiency Attention deficit hyperactivity disorder Tic disorder Serum ferritin levels Retrospective study

Thermodynamics and kinetics of cadmium adsorption onto oxidized granular activated carbon

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

Journal of Environmental Sciences 2007年第11期19卷 1287-1292页

作者： HUANG Xin gao Nai-yun ZHANG Qiao-li State Key Laboratory of PoUution Control and Resource Reuse Tongji University Shanghai 200092 China

Cadmium sorption behavior of granular activated carbon oxidized with nitric acid was systematically studied by sets of the equilibrium and time-based experiments under various conditions. The cadmium adsorption capacity of oxidized granular activated carbon enlarged with an increase in pH, and reduced with an increase in ionic strength. Experimental data were evaluated to find out kinetic characteristics. Adsorption processes were found to follow pseudo-second order rate equation. Adsorption isotherms correlate well with the Langmuir isotherm model and the maximum sorption capacity of cadmium evaluated is 51.02 μmol/g. Thermodynamic parameters were calculated based on Van＇t Hoff equation. Equilibrium constant Kd was evaluated from Freundlich isotherm model constants, Langmuir isotherm model constants, and isotherms, respectively. The average change of standard adsorption heat ΔH^0 was -25.29 kJ/mol. Negative ΔH^0 and ΔG^0 values indicate the adsorption process for cadmium onto the studied activated carbon is exothermic and spontaneous. The standard entropy ΔS^0 was also negative, which suggests a decrease in the freedom of the system.

关键词： cadmium granular activated carbon thermodynamics kinetics adsorption

Atmospheric Test and Numerical Models Assessment of Annular Combustor on ZK2000 Gas Turbine

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2018年第6期27卷 516-526页

作者： WANG Weihao HUANG Weiguang CAO yun gao Chuang Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China University of Chinese Academy of Sciences Beijing 100049 China ShanghaiTech University Shanghai 201210 China Helan Turbines Co. Ltd Shanghai 210815 China

ZK2000 is a newly developed 2 MW all radial gas turbine with an annular combustor. In this paper, the authors present the atmospheric test results of the combustor on test rig. Evaluation of several RANS turbulence models and reaction models were used in order to determine which model was the most appropriate combination for comparison with the test results. FGM with SST were selected because of the better agreement with test results in terms of combustor temperature rise, primary zone temperature, liner metal temperature, and NO_x emission predictions.

关键词： lean premixed annular combustor low emission atmospheric test flamelet generated manifold

Transonic buffet control research with two types of shock control bump based on RAE2822 airfoil

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2017年第5期30卷 1681-1696页

作者： yun TIAN Shiqi gao Peiqing LIU Jinjun WANG National Lab for Aeronautics and Astronautics Beihang University Beijing 100191 China School of Aeronautic Science and Engineering Beihang University Beijing 100191 China

Current research shows that the traditional shock control bump（SCB） can weaken the intensity of shock and better the transonic buffet performance. The author finds that when SCB is placed downstream of the shock, it can decrease the adverse pressure gradient. This may prevent the shock foot separation bubble to merge with the trailing edge separation and finally improve the buffet performance. Based on RAE2822 airfoil, two types of SCB are designed according to the two different mechanisms. By using Reynolds-averaged Navier-Stokes（RANS） and unsteady Reynolds-averaged Navier-Stokes（URANS） methods to analyze the properties of RAE2822 airfoil with and without SCB, the results show that the downstream SCB can better the buffet performance under a wide range of freestream Mach number and the steady aerodynamics characteristic is similar to that of RAE2822 airfoil. The traditional SCB can only weaken the intensity of the shock under the design condition. Under the off-design conditions, the SCB does not do much to or even worsen the buffet performance. Indeed, the use of backward bump can flatten the leeward side of the airfoil, and this is similar to the mechanism that supercritical airfoil can weaken the recompression of shock wave.

关键词： Aerodynamics Buffet control RAE2822 airfoil Shock control bump Transonic

Designing and Optimization of an Off-line Programming System for Robotic Belt Grinding Process

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2011年第4期24卷 647-655页

作者： WANG Wei yun Chao ZHANG Ling gao Zhihui Robotics Institute Beihang University Beijing 100191 China State Key Laboratory for Manufacturing Systems Engineering Xi＇an Jiaotong University Xi＇an 710049 China

Off-line programming （OLP） system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification （IGES） file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton＇s iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.

关键词： off-line programming robotic belt grinding path generation tool optimization

一种新型的含筛孔八棱锥内构件泡沫分离设备的构建及其应用

在线全文

学校读者我要写书评

暂无评论

食品工业科技 2025年第1期46卷 104-113页

作者：薛静丽方思含张才亮韩娟吴嘉聪王蕾王赟江苏大学食品与生物工程学院江苏镇江212013 江苏大学化学化工学院江苏镇江212013

目的:本研究设计了一种新型的含筛孔八棱锥内构件,用以强化泡沫排液,提高泡沫分离效率。方法:以重组β-葡萄糖苷酶(Glu-linker-ELP50-GB,GLEGB)发酵液为模型,考察内构件的结构参数(个数、间距、筛孔直径)和泡沫分离实验参数(温度、初始... 详细信息

目的:本研究设计了一种新型的含筛孔八棱锥内构件,用以强化泡沫排液,提高泡沫分离效率。方法:以重组β-葡萄糖苷酶(Glu-linker-ELP50-GB,GLEGB)发酵液为模型,考察内构件的结构参数(个数、间距、筛孔直径)和泡沫分离实验参数(温度、初始蛋白浓度、气体流速、装液量)对GLEGB富集比和回收率的影响。此外,基于弹性蛋白样多肽(elastin-like polypeptides,ELPs)的温敏性,对重组β-葡萄糖苷酶泡沫液进一步纯化,并通过圆二色光谱仪(CD)、紫外-可见分光光度计(UV-vis)和傅里叶-红外光谱仪(FT-IR)对纯化后GLEGB的结构进行分析。结果:在内构件数量为5、间距为78 mm、筛孔直径为2 mm、蛋白质初始浓度为0.3 mg/mL、温度为45℃、气体流速为200 mL/min、装液量为100 mL的最佳条件下,GLEGB的蛋白富集比为2.46±0.10是对照柱的1.33倍,对重组β-葡萄糖苷酶泡沫液进一步纯化后GLEGB的纯化倍数为37.25±0.60,此外,结果证明纯化过程不会影响GLEGB的结构。结论:本研究设计的含筛孔八棱锥内构件可以有效地提高从发酵液中分离GLEGB的富集比,为泡沫分离设备的设计、研究及工艺优化提供了新的研究思路。

关键词：泡沫分离富集比重组 β-葡萄糖苷酶内构件