检索结果-南通市图书馆

Water Science and Engineering 2023年第4期16卷 419-428页

作者： Qin Ke Ming-chao Li Qiu-bing Ren Wen-chao Zhao State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300350China Bei Fang Investigation Design&Research Co.LtdTianjin 300222China

Numerical simulation of concrete-faced rockfill dams(CFRDs)considering the spatial variability of rockfill has become a popular research topic in recent *** order to determine uncertain rockfill properties efficiently and reliably,this study developed an uncertainty inversion analysis method for rockfill material parameters using the stacking ensemble strategy and Jaya *** comprehensive implementation process of the proposed model was described with an illustrative CFRD ***,the surrogate model method using the stacking ensemble algorithm was used to conduct the Monte Carlo stochastic finite element calculations with reduced computational cost and improved ***,the Jaya algorithm was used to inversely calculate the combination of the coefficient of variation of rockfill material *** optimizer obtained higher accuracy and more significant uncertainty reduction than traditional ***,the developed model effectively identified the random parameters of rockfill *** study provided scientific references for uncertainty analysis of *** addition,the proposed method can be applied to other similar engineering structures.

关键词： CFRD Uncertainty inversion analysis Stochastic finite element Surrogate model Stacking ensemble Jaya algorithm

Parameter identification theory of a complex model based on global optimization method

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) 2008年第11期51卷 1722-1732页

作者： QU Jie1, JIN QuanLin2 & XU BingYe3 1 College of Automotive Engineering, South China University of Technology, Guangzhou 510640, China 2 Beijing research Institute of Mechanical and Electrical Technology, Beijing 100083, China 3 Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China College of Automotive Engineering South China University of Technology Guangzhou China Beijing research Institute of Mechanical and Electrical Technology Beijing China Department of Engineering Mechanics Tsinghua University Beijing China

With the development of computer technology and numerical simulation technology, computer aided engineering (CAE) technology has been widely applied to many fields. One of the main obstacles, which hinder the further application of CAE technology, is how to successfully identify the parameters of the selected model. An elementary framework for parameter identification of a complex model is provided in this paper. The framework includes the construction of objective function, the design of the optimization method and the evaluation of the identified results, etc. The parameter identification process is described in this framework, taking the parameter identification of the superplastic constitutive model considering grain growth for Ti-6Al-4V at 927°C as an example. The objective function is the weighted quadratic sums of the difference between the experimental and computational data for the stress-strain relationship and the grain growth relationship; the designed optimization method is a hybrid global optimization method, which is based on the feature of the objective function and incorporates the strengths of genetic algorithm (GA), the Levenberg-Marquardt algorithm and the augmented Gauss-Newton algorithm. The reliability evaluation of parameter identification result is made through the comparison between the calculated and experimental results and between the theoretical values of the parameters and the identified ones.

关键词： constitutive model parameter identification theory inverse analysis global optimization

Synthesis,Crystal Structure and Photophysical Property of 2-(9H-carbazol-9-yl)-3-(2-(2,4,5-tri-(9H-carbazol-9-yl)-3,6-dicyanophenoxy)phenoxy)dibenzo[b,e][1,4]dioxine-1,4-dicarbonitrile

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2018年第9期37卷 1433-1439页

作者：董亚芳余荣民卢灿忠 College of Chemistry Fuzhou University CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

A purely organic compound 2-（9 H-carbazol-9-yl）-3-（2-（2,4,5-tri-（9 H-carbazol-9-yl）-3,6-dicyanophenoxy）phenoxy）dibenzo[b,e][1,4]dioxine-1,4-dicarbonitrile, C76 H40 N8 O4, was synthesized and characterized by NMR, UV-Vis, photoluminescenceand X-ray single-crystal structure analysis. The compound crystallizes in monoclinic system, space group P21/n with a = 11.6537（3）, b = 34.9738（8）, c = 15.5053（3）？, β =101.992（2）°, V = 6181.6（2）？3, Z = 4, Mr= 1129.18 g/mol, Dc =1.396 g/cm3, F（000） =2672, μ = 2.239 mm–1, GOOF = 1.019, the final R = 0.0577 and wR= 0.1559 for 11925 observed reflections with I 〉2σ（I）. The UV-vis absorption and fluorescence of the compound were discussed. The compound exhibitsyellow-green luminescence with maximum emission peak at 538 nm, and quantum yields of ф = 0.25 and 0.48 in air-equilibrated and degassed toluene at room temperature. Transient decay spectral studies show that compound 1 displays two component decay fashions with a short decay lifetime of 23 ns for the prompt fluoresce anda long decay lifetime of 3.8ms for thermally activated delayed fluorescence. In air-equilibrated toluene, only a short decay lifetime of 17 ns was *** experimental and computational results show thatthe emission of the compound originates from the CT excited states.

关键词： purely organic compound synthesis crystal structure luminescence DFT calculation

Protective effects of astragaloside in rats with adriamycin nephropathy and underlying mechanism

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2016年第4期14卷 270-277页

作者： WANG Na WEI Ri-Bao LI Qing-Ping YANG Xi CHEN Xiang-Mei Department of Nephrology Chinese PLA General Hospital Chinese PLA Institute of NephrologyState Key Laboratory of Kidney DiseasesNational Clinical Research Center for Kidney DiseasesBeijingChina 100853

The present study was designed to determine the mechanism underlying the treatment of nephrotic syndrome using astragaloside by observing the effects of astragaloside on the expression of nephrin and podocin proteins and genes in kidneys of rats with adriamycin nephropathy. The rats were injected with adriamycin and, after successful model establishment, randomly divided into a model group, a Methylprednisolone(MP) group, and an astragaloside group. The 24-h complete urine samples were collected. Biochemical indicators were monitored, and kidney tissues were collected for pathological analysis using light microscopy and electron microscopy. The m RNA expression of nephrin and podocin was measured in the kidney tissues using the real-time q PCR, and the protein expression levels of nephrin and podocin were detected using Western blot analysis. At the end of 12 weeks of drug intervention, the urinary protein level was lower in the MP and astragaloside groups than that in the model group(P = 0.008 and P = 0.01, respectively). Serum albumin was higher in the MP and astragaloside groups than in the model group(P group were nearly normal, and fusion of podocytes in the astragaloside group was significantly less than that in the control group. The nephrin and podocin m RNA and protein expression levels in the intervention groups were higher(P group. Due to the increased expression of podocyte-related nephrin and podocin proteins, astragaloside maintained slit diaphragm integrity and decreased the level of proteinuria in rats with adriamycin nephropathy.

关键词： Astragaloside Adriamycin nephropathy Podocyte Nephrin Podocin

Long-term survival outcomes of video-assisted thoracic surgery for patients with non-small cell lung cancer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer research 2014年第4期26卷 391-398页

作者： Wenlong Shao Xinguo Xiong Hanzhang Chen Jun Liu Weiqiang Yin Shuben Li Xin Xu Xin Zhang Jianxing He Department of Thoracic Surgery the First Affiliated Hospital of Guangzhou Medical University Department of Thoracic Surgery Guangzhou Institute of Respiratory Diseases Key cite of National Clinical research Center for Respiratory Diseases

Background： Video-assisted thoracic surgery （VATS） has been shown to be a safe alternative to conventional thoracotomy for patients with non-small cell lung cancer （NSCLC）. However, popularization of this relatively novel technique has been slow, partly due to concerns about its long-term outcomes. The present study aimed to evaluate the long-term survival outcomes of patients with NSCLC after VATS, and to determine the significant prognostic factors on overall survival. Methods： Consecutive patients diagnosed with NSCLC referred to one institution for VATS were identified from a central database. Patients were treated by either complete-VATS or assisted-VATS, as described in previous studies. A number of baseline patient characteristics, clinicopathologic data and treatment-related factors were analyzed as potential prognostic factors on overall survival. Results： Between January 2000 and December 2007, 1,139 patients with NSCLC who underwent VATS and fulfilled a set of predetermined inclusion criteria were included for analysis. The median age of the entire group was 60 years, with 791 male patients （69%）. The median 5-year overall survival for Stage Ⅰ, Ⅱ, Ⅲ and Ⅳ disease according to the recently updated TNM classification system were 72.2%, 47.5%, 29.8% and 28.6%, respectively. Female gender, TNM stage, pT status, and type of resection were found to be significant prognostic factors on multivariate analysis. Conclusions： VATS offers a viable alternative to conventional open thoracotomy for selected patients with clinically resectableNSCLC

关键词： Non-small cell lung cancer (NSCLC) video-assisted thoracoscopic surgery (VATS) overall survival

analysis of the temporal and spatial distribution of water quality in China＇s major river basins, and trends between 2005 and 2010

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2015年第3期9卷 463-472页

作者： Jinjian LI Xiaojie MENG Yan ZHANG Juan LI Linlin XIA Hongmei ZHENG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China Chinese research Academy of Environmental Sciences Beijing 100012 China

In this study, based on environmental quality monitoring data on 22 pollutants from 490 control sections, we analyzed the spatial distribution and temporal changes of water quality in ten Chinese river basins （watersheds） to reveal the trends from 2005 to 2010. We used a comprehensive water pollution index （WPI） and the proportions of this index accounted for by the three major pollutants to analyze how economic development has influenced water quality. Higher values of the index represent more serious pollution. We found that WPI was much higher for the Hai River Basin （1.83 to 5.60 times the averages in other regions）. In the Yangtze River Basin, WPI increased from upstream to downstream. The indices of some provinces toward the middle of a basin, such as Hebei Province in the Hal River Basin, Shanxi Province in the Yellow River Basin, and Anhui Province in the Huai River Basin, were higher than those of upstream and downstream provinces. In the Songhua, Liao, and South- east river basins, WPI decreased during the study period： in 2010, it decreased by 33.9%, 44.3%, and 67.2%, respectively, compared with the 2005 value. In the Pearl River, Southwest, and Inland river basins, WPI increased by 23.1%, 47.7%, and 38.5% in 2010, compared with 2005. A comparison of WPI with the GDP of each province showed that the water pollution generated by economic development was lightest in northwestern, southwestern, and northeastern China, and highest in central and eastern China, and that the water environment in some coastal regions were improving. However, some provinces （e.g., Shanxi Province） were seriously polluted.

关键词： water environment temporal changes spatial

1B Specific LMW-GS Primers Cloned a 1D Located Gene from Wheat Cultivar Xiaoyan 22

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

Agricultural Sciences in China 2009年第12期8卷 1419-1428页

作者： YU Xu GAO Xiang CHEN Qi-jiao WU Dan DONG Jian ZHAO Wan-chun PANG Hong-xi LI Zhe-qing College of Agronomy Northwest A&F University Yangling 712100 P.R.China Wheat Engineering research Center of Shaanxi Province Yangling 712100 P.R. China

In the present study, one unique low-molecular-weight glutenin subunit （LMW-GS） gene. LMWXY22-2 （GenBank no. FJ028810）, was isolated from wheat cultivar Xiaoyan 22 （Triticum aestivum L.） by a pair of genomic specific PCR primers for 1B chromosome. Sequence analysis revealed that LMWXY22-2 was composed of 1 364 bp nucleotides, including a 317 bp promotion region and a 1 047 bp coding region which could be translated into a mature protein of 349 amino acids. In spite of a few minor mutations, the sequence of 5＇ untranslated region （UTR）, the coding region, the deduced N- and Cterminus comparisons indicated that LMWXY22-2 belonged to the reported subunits of LMW-m type and type lII group 5, respectively. Inner gene markers for 1D chromosome together with the phylogenetic analysis revealed that this gene was classified into Glu-D3, which was not in agreement with the I B locus-specific primers for LMW genes completely.

关键词： 1B locus-specific primers gene cloning LMW-GS transferability wheat

Ultrastructural view of colon anastomosis under propolis effect by transmission electron microscopy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第30期14卷 4763-4770页

作者： Sibel Serin Kilicoglu Bulent Kilicoglu Esra Erdemli Department of Histology and Embryology Ufuk University School of Medicine 4th General Surgery Department Ankara Training and Research Hospital Department of Histology and Embryology Ankara University School of Medicine

AIM： To evaluate the effect of propolis administration on the healing of colon anastomosis with light and transmission electron microscopes. METHODS： Forty-eight Wistar-AIbino female rats were divided into two groups and had colon resection and anastomosis. In group Ⅰ, rats were fed with standard rat chow pre- and postoperatively. The rats in group Ⅱ were fed with standard rat chow and began receiving oral supplementation of propolis 100 mg/kg per day beginning 7 d before the operation and continued until they were sacrificed. Rats were sacrificed 1, 3, 7 and 14 d after operation, and anastomotic bursting pressures measured. After the resection of anastomotic segments, histopathological examination was performed with light and transmission electron microscopes by two blinded histologists and photographed. RESULTS： The colonic bursting pressures of the propolis group were statistically significantly better than the control group. UItrastructural histopathological analysis of the colon anastomosis revealed that propotis accelerated the phases of the healing process and stimulated mature granulation tissue formation and collagen synthesis of fibroblasts. CONCLUSION： Bursting pressure measurements and ultra structural histopathological evaluation showed that administration of propolis accelerated the healing of colon anastomosis following surgical excision.

关键词： Propolis Wound healing Colon anastomosis Histopathology Transmission electron microscope

group Settling Velocity of Non-Cohesive Sediment Mixtures

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

China Ocean Engineering 2000年第4期15卷 485-494页

作者：吴华林沈焕庭朱建荣张小峰 State Key Laboratory of Estuarine and Coastal research East China Normal University Shanghai 200062 China River Engineering Department Wuhan University of Hydraulic and Electric Engineering Wuhan 430072 China

Settling velocity is a fundamental parameter in sediment transport dynamics. For uniform particles, there are abundant formulas for calculation of their settling velocities. But in natural fields, sediment consists of non-uniform particles. The interaction among particles is complex and should not be neglected. In this paper, based on the analysis of settling mechanism of non-cohesive and non-uniform particles, a theoretical model to describe settling mechanism is proposed. Besides suspension concentration and upward turbulent flow caused by other particles, collision among particles is another main factor influencing settling velocity. By introducing the collision theory, equations of fall velocity before collision, collision probability, and fall velocity after collision are established. Finally, a formula used to calculate the settling velocity of non-cohesive particles with wide grain gradation is presented, which agrees well with the experimental data.

关键词： iron-cohesive sediment group settling velocity interaction collision

Synthesis,Crystal Structure,and Magnetic Property of One 3D Nickel Coordination Polymer Based on 2-Hydroxy-5-(3',5'-terephthalic acid)Pyridine and 1,4-Bis(1-imdazoly)benzene

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2015年第10期34卷 1519-1524页

作者： TANG Pei-Qin HAO Lu-Jiang FAN Li-Ming LIU Xin-Zheng LI Bin ZHANG Xiu-Tang Advanced Material Institute of research College of Chemistry and Chemical EngineeringQilu Normal University College of Biological Engineering Qilu University of Technology State Key Laboratory of Crystal Materials Shandong University

One novel nickel coordination polymer, {[Ni（OTP）（bib）1.5（H2O）]·2H2O}n（1, H2 OTP = 2-hydroxy-5-（3＇,5＇-terephthalic acid） pyridine, bib = 1,4-bis（1-imdazoly）benzene）, has been synthesized and characterized by elemental analysis（EA）, IR, powder X-ray diffraction（PXRD）, and thermogravimetric（TG） analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860（5）, b = 13.8246（6）, c = 19.0140（8） A, β = 104.3870（1）°, V = 3128.2（2） A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F（000） = 1444 and μ（Mo Kα） = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ（I） and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni（OTP）]n chain and the 2D [Ni2（bib）3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.

关键词： 2-hydroxy-5-(3',5'-terephthalic acid)pyridine 1,4-bis(1-imdazoly)benzene nickel topology magnetic property