检索结果-南通市图书馆

Chinese Herbal Medicines 2022年第3期14卷 464-469页

作者： Dan Li Yuetao Liu Xuemei Qin Modern Research Center for Traditional Chinese Medicine Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of EducationShanxi UniversityTaiyuan 030006China Shanxi Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine Taiyuan 030006China

Objective:Astragali Radix(AR)is one of the most widely used traditional Chinese medicines(TCMs)for tonic,which can be divided into wild-simulated and cultivated AR according to its cultivation ***,whether cultivated AR can replace wild-simulated AR has always been a ***:In this study,a rapid,highly sensitive and specific analytical method using ultra-high performance liquid chromatography tandem mass spectrometry(UHPLC-MS)was developed to quantitatively measure 12 chemical constituents of AR in the different cultivation ***:AR samples were analyzed with a good linear regression relationship(R2,0.9983–0.9995),precisions(relative standard deviation(RSD),1.31%-2.36%),repeatability(RSD,2.65%-4.92%),stability(RSD,1.50%-4.05%),and recovery(95.13%-106.52%).Through the determination of AR samples,we found the components of favonoids in wild-simulated AR were higher than cultivated AR,the saponins in cultivated AR were higher,the ratio of saponins/favonoids in cultivated AR was higher than wildsimulated ***:Based on this research,it could provide guidance for the quality control of AR.

关键词： Astragali Radix chemical constituent cultivation method quantification UHPLC-MS

A data selection method for matrix effects and uncertainty reduction for laser-induced breakdown spectroscopy

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2023年第7期25卷 82-89页

作者：龙杰宋惟然侯宗余王哲 State Key Laboratory of Power System Operation and Control Systems International Joint Laboratory on Low Carbon Clean Energy InnovationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan 030032People’s Republic of China

Severe matrix effects and high signal uncertainty are two key bottlenecks for the quantitative performance and wide applications of laser-induced breakdown spectroscopy(LIBS).Based on the understanding that the superposition of both matrix effects and signal uncertainty directly affects plasma parameters and further influences spectral intensity and LIBS quantification performance,a data selection method based on plasma temperature matching(DSPTM)was proposed to reduce both matrix effects and signal *** selecting spectra with smaller plasma temperature differences for all samples,the proposed method was able to build up the quantification model to rely more on spectra with smaller matrix effects and signal uncertainty,therefore improving final quantification *** applied to quantitative analysis of the zinc content in brass alloys,it was found that both accuracy and precision were improved using either a univariate model or multiple linear regression(MLR).More specifically,for the univariate model,the root-mean-square error of prediction(RMSEP),the determination coefficients(R^(2))and relative standard derivation(RSD)were improved from 3.30%,0.864 and 18.8%to 1.06%,0.986 and 13.5%,respectively;while for MLR,RMSEP,R^(2)and RSD were improved from 3.22%,0.871 and 26.2%to 1.07%,0.986 and 17.4%,*** results prove that DSPTM can be used as an effective method to reduce matrix effects and improve repeatability by selecting reliable data.

关键词： laser-induced breakdown spectroscopy(LIBS) quantification uncertainty univariate/multivariate analysis matrix effects temperature matching

Quantifying growth and breakage of agglomerates in fluid-particle flow using discrete particle method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第5期26卷 914-921页

作者： Lingfeng Zhou Junwu Wang Wei Ge Shiwen Liu Jianhua Chen Ji xu Limin Wang Feiguo Chen Ning Yang Rongtao Zhou Lin Zhang Qi Chang Philippe Ricoux Alvaro Fernandez State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Tianjin University Tianjin 300072 China TOTALSA - R&D Groupe Paris 92069 France Total Research & Technology Feluy Belgium Germany

The cohesive solids in liquid flows are featured by the dynamic growth and breakage of agglomerates, and the difficulties in the development, design and optimization of these systems are related to this significant *** this paper, discrete particle method is used to simulate a solid–liquid flow system including millions of cohesive particles, the growth rate and breakage rate of agglomerates are then systematically investigated. It was found that the most probable size of the agglomerates is determined by the balance of growth and breakage of the agglomerates the cross point of the lines of growth rate and breakage rate as a function of the particle numbers in an agglomerate, marks the most stable agglomerate size. The finding here provides a feasible way to quantify the dynamic behaviors of growth and breakage of agglomerates, and therefore offers the possibility of quantifying the effects of agglomerates on the hydrodynamics of fluid flows with cohesive particles.

关键词： Agglomerate Growth and breakage quantification Discrete particle method

StudyonMathematicalModeofquantification Performance-to-Price Ratio

在线全文

学校读者我要写书评

暂无评论

科技经济市场 2007年第8期 40-41页

作者：裴兰华史德战王冠吉林大学管理学院 130025 吉林大学管理学院130025 吉林大学管理学院130025

Nowadays, consumers often compare the same kind of commodities and decide what to pick out when they purchase merchandise including the service. The paper discusses the mathematical mode of quantification performance-... 详细信息

关键词： performance-to-price ratio quantification mathematical mode

Analytical methods and environmental processes of nanoplastics

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 2020年第8期32卷 88-99页

作者： Peng Li Qingcun Li Zhineng Hao Sujuan Yu Jingfu Liu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

The degradation of plastic debris may result in the generation of nanoplastics(NPs).Their high specific surface area for the sorption of organic pollutions and toxic heavy metals and possible transfer between organisms at different nutrient levels make the study of NPs an urgent ***,there is very limited understanding on the occurrence,distribution,abundant,and fate of NPs in the environment,partially due to the lack of suitable techniques for the separation and identification of NPs from complex environmental *** this review,we first overviewed the state-of-the-art methods for the extraction,separation,identification and quantification of NPs in the *** of them have been successfully applied for the field determination of NPs,while some are borrowed from the detection of microplastics or engineered *** the possible fate and transport of NPs in the environment are thoroughly *** great efforts have been made during the recent years,large knowledge gaps still exist,such as the relatively high detection limit of existing method failing to detect ultralow masses of NPs in the environment,and spherical polystyrene NP models failing to represent the various compositions of NPs with different irregular shapes,which needs further investigation.

关键词： Nanoplastics Separation Identification quantification Fate

Mechanical force drives the polarization and orientation of cells

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第2期35卷 275-288页

作者： Shijie He Xiaomeng Li Baohua Ji Center for Engineering in Medicine Massachusetts General Hospital Harvard Medical School Boston MA 02114 USA Department of Applied Mechanics School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Department of Engineering Mechanics Zhejiang University Hangzhou 310027 China

Collective cells are organized to form specific patterns which play important roles in various physiological and pathological processes, such as tissue morphogenesis, wound healing, and cancer invasion. Compared to single cell behaviors, which has been intensively studied from many aspects (cell migration, adhesion, polarization, proliferation, etc.) and at various scales (molecular, subcellular, and cellular), the multiple cell behaviors are relatively less understood, particularly in a quantitative manner. In this paper, we will present our recent studies of collective polarization and orientation of multiple cells through both experimental measurement and theoretical modeling, including those cell behaviors on/in 2D and 3D substrate/tissue. We find that the collective cell behaviors, including polarization, alignment and migration are closely related to local stress states in cell layer or tissue, which demonstrate the crucial roles of mechanical forces in the living organisms. Specifically, the cells prefer to polarize and align along the maximum principal stress in the cell layer, and the aspect ratio of cell increases with the in-plane maximum shear stress, suggesting that the maximum shear stress is the underlying driving force of cell polarization and orientation. This theory of stress-driven cell behaviors of polarization and orientation provides a new perspective for understanding cell behaviors in living organisms and the guideline for tissue engineering in biomedical applications.

关键词： Collective cell behaviors Cell polarization Cell alignment quantification Cell mechanosensing

Advance of research on modern soil phytolith

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 Earth Sciences 2018年第9期61卷 1169-1182页

作者： Changhui WEN Houyuan LU Xinxin ZUO Yong GE Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Center for Excellence in Tibetan Plateau Earth Science Chinese Academy of Sciences Beijing 100101 China School of Geography Science Fujian Normal University Fuzhou 350007 China Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044 China

Phytolith study is a new branch of micropaleontology with an increasingly important role in geology, archaeology, and plant taxonomy. Phytoliths have several advantages considering their characteristics of small particle size, high production, wide distribution, anti-decomposition, in situ deposition, distinctive morphologies, and element sequestrating capacity. Phytolith assemblages in modem soil have been found to be closely related to modem vegetation types and climate conditions, which forms the basis for the quantitative study of paleoecology, paleoclimate, and bio-geochemical cycles. At present, phytolith studies generally focus on the following four aspects：（1） Morphology： about 260 unduplicated types of phytoliths have been identified in modem soil, of which 110 types are from grasses, 50 types from ferns, woody plants and other angiosperms, whereas the origin plants of the remaining 100 types are still under investigation. （2） Soil phytolith assemblages and vegetation： phytolith assemblages from the topsoil have been used to distinguish surface vegetation types including different forests and grasslands over a typical region. This model has been applied to restore past vegetation conditions and monitor the dynamic evolution of specific vegetation types at different temporal and spatial scales. （3） Soil phytolith assemblages and climate： quantitative and semi-quantitative relationships between phytolith assemblages and a series of climate parameters, such as annual mean temperature, annual mean precipitation and altitude, have been established through mathematical analysis. In this manner, quantitative reconstruction of paleoclimatic parameters has been achieved through the phytolith-climate transfer function model. （4） Soil phytolith and its sequestered elements： in this topic, the content of soil PhytOC （Phytolith-occluded Organic Carbon） and the importance of PhytOC in the bio-geochemical cycle have been the focus. The study of modem soil phytoliths has

关键词： Modem soil Phytolith Morphology Paleoenvironment quantification

A Robust Blade Design Method based on Non-Intrusive Polynomial Chaos Considering Profile Error

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2019年第5期28卷 875-885页

作者： GAO Limin MA Chi CAI Yutong School of Power and Energy Northwestern Polytechnical University Xi'an 710129 China The National Key Laboratory of Aerodynamic Design and Research Xi'an 710129 China

To weaken the influence of profile error on compressor aerodynamic performance, especially on pressure ratio and efficiency, a robust design method considering profile error is built to improve the robustness of aerodynamic performance of the blade. The characteristics of profile error are random and small-scaled, which means that to evaluate the influence of profile error on blade aerodynamic performance is a time-intensive and high-precision work. For this reason, non-intrusive polynomial chaos(NIPC) and Kriging surrogate model are introduced in this robust design method to improve the efficiency of uncertainty quantification(UQ) and ensure the evaluate accuracy. The profile error satisfies the Gaussian distribution, and NIPC is carried out to do uncertainty quantification since it has advantages in prediction accuracy and efficiency to get statistical behavior of random profile error. In the integrand points of NIPC, several surrogate models are established based on Latin hypercube sampling(LHS)+ Kriging, which further reduces the costs of optimization design by replacing calling computational fluid dynamic(CFD) repeatedly. The results show that this robust design method can significantly improve the performance robustness in shorter time(40 times faster) without losing accuracy, which is meaningful in engineering application to reduce manufacturing cost in the premise of ensuring the aerodynamic performance. Mechanism analysis of the robustness improvement samples carried out in current work can help find out the key parameter dominating the robustness under the disturbance of profile error, which is meaningful to further improvement of compressor robustness.

关键词： robust design non-intrusive polynomial chaos aerodynamic performance random profile error uncertainty quantification

The Marking Technology in Motion Capture for the Complex Locomotor Behavior of Flexible Small Animals(Gekko gecko)

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2019年第3期10卷 197-210页

作者： Zhouyi WANG Weijia ZONG Bingcheng WANG Junjie ZHU Kai QIN Zhendong DAI Institute of Bio-inspired Structure and Surface Engineering Nanjing University of Aeronautics and Astronautics29 Yudao StreetNanjing 210016JiangsuChina Shanghai Institute of Aerospace System Engineering 3888 Yuanjiang RoadShanghai 201109China

Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.

关键词： small flexible animals marking technology motion capture quantification of locomotor behavior gecko

Quantitative evaluation of long-term liver repopulation and the reconstitution of bile ductules after hepatocellular transplantation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第39期11卷 6176-6181页

作者： Yun-Wen Zheng Nobuhiro Ohkohchi Hideki Taniguchi Department of Regenerative Medicine Graduate School of Medical Science Yokohama City University Yokohama 236-0004 Japan Department of Surgery Institute of Clinical Medicine University of Tsukuba Tsukuba 305-8575 Japan Research Unit for Organ Regeneration Center for Developmental Biology RIKEN Kobe 650-0047 Japan

AIM： The treatment of liver disease is severely limited by a shortage of donor livers. In trying to address this growing problem, hepatocellular transplantation （HTx） has received much attention as an alternative to whole organ transplant. However, the expansion of transplanted cells is at low level, and the reconstitution of functional liver tissue is limited by this cellular property. We set up an animal model to better understand cell dose effect and the kinetics of liver repopulation following HTx. METHODS： Dipeptidyl peptidase Ⅳ （DPPⅣ）-deficient rats treated with retrorsine and subjected to partial hepatectomy were infused with DPPⅣ-positive hepatocytes. Rats were injected with varying numbers of donor hepatocytes down to 100 cells low, and liver repopulation was examined at different time points up to 20 mo long. Repopulation was assessed by computer-aided quantitative detection. RESULTS： Transplanted hepatocytes underwent multiple rounds of proliferation and stably repopulated the injured livers after 20 mo and at all cell doses. Transplanted cells divided 14 times within the 3-mo time period following infusion, and the liver repopulation reached a plateau between 3 and 20 too. Approximately 90% replacement occurred. Donor-derived cells also reconstituted the bile ductules of the recipients. CONCLUSION： The ability of transplanted hepatocytes to fully reconstitute injured livers strongly supports further investigation into the clinical potential of HTx. Additionally, the observation that transplanted hepatocytes also form components of the biliary system suggests that these cells may have bi-potential property of the stem cells.

关键词： Hepatocellular transplantation Hepatic stem cell Kinetics Cell dose Long-term repopulation Bile ductules quantification In viva, Therapeutic potential