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Tsinghua science and Technology 2007年第4期12卷 394-399页

作者：申佳孟甄苏慧邢东明丁怡杜力军 Laboratory of Pharmaceutical sciences Department of Biological Sciences and Biotechnology Tsinghua University

The objective of this study is to quantify the puerarin in rat plasma following oral administration of TZ18 and compare the pharmacokinetics characteristics of puerarin in normal rats with that in depression model rats. A high performance liquid chromatography method was used to quantify the puerarin due to its good selectivity and linearity （coefficient correlation, r^2 = 0.9991） within the tested range （0.028-0.889 μg·mL^-1）- Intra- and inter-day precision coefficients of variation and accuracy bias were acceptable （Maximum coefficient of variation was 5.74% for intra-day and 3.09% for inter-day） over the entire range. The recoveries were found to be 98.3%, 101.4%, and 103.4% for concentrations of 0.028, 0.222, and 0.444 μg · mL^-1, respectively. The concentration-time curves for both normal rats and depression model rats were fit to a twocompartment model with the first order absorption. The results show significant differences in the main pharmacokinetic parameters of peak time, peak concentration, and the area under the concentration-time curve between the two kinds of rats.

关键词： puerarin depression rat model pharmacokinetics

Machine Learning‑Enhanced Flexible Mechanical sensing

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Nano-Micro Letters 2023年第4期15卷 190-222页

作者： Yuejiao Wang Mukhtar Lawan Adam Yunlong Zhao Weihao Zheng Libo Gao Zongyou Yin Haitao Zhao Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China Materials Interfaces Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361102People’s Republic of China school of Mechano‑Electronic Engineering Xidian UniversityXi’an 710071People’s Republic of China Research school of Chemistry Australian National UniversityCanberraACT 2601Australia

To realize a hyperconnected smart society with high productivity,advances in flexible sensing technology are highly ***,flexible sensing technology has witnessed improvements in both the hardware performances of sensor devices and the data processing capabilities of the device’s *** research efforts have been devoted to improving materials,sensing mechanism,and configurations of flexible sensing systems in a quest to fulfill the requirements of future ***,advanced data analysis methods are being developed to extract useful information from increasingly complicated data collected by a single sensor or network of *** learning(ML)as an important branch of artificial intelligence can efficiently handle such complex data,which can be multi-dimensional and multi-faceted,thus providing a powerful tool for easy interpretation of sensing *** this review,the fundamental working mechanisms and common types of flexible mechanical sensors are firstly *** how ML-assisted data interpretation improves the applications of flexible mechanical sensors and other closely-related sensors in various areas is elaborated,which includes health monitoring,human-machine interfaces,object/surface recognition,pressure prediction,and human posture/motion ***,the advantages,challenges,and future perspectives associated with the fusion of flexible mechanical sensing technology and ML algorithms are *** will give significant insights to enable the advancement of next-generation artificial flexible mechanical sensing.

关键词： Flexible mechanical sensors Machine learning Artificial intelligence Data processing

A novel procedure for pollen-based quantitative paleoclimate reconstructions and its application in China

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science China Earth sciences 2017年第11期60卷 2059-2066页

作者： CHEN JianHui LV FeiYa HUANG XiaoZhong H.John B.BIRKs Richard J.TELFORD ZHANG shengRui XU QingHai ZHAO Yan WANG HaiPeng ZHOU AiFeng HUANG Wei LIU JianBao WEI GuoYing Key Laboratory of West China's Environmental system(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Department of Biology and Bjerknes Centre for Climate Research University of BergenN-5020 BergenNorway Institute of Nihewan Archaeology Research Hebei Normal UniversityShijiazhuang 050024China Institute of Geographic science and Natural Resources Research Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of sciences Beijing 100049China

Traditionally, the evaluation of pollen-based quantitative paleoclimate reconstructions focuses on the ability of calibration sets to infer present climatic conditions and/or the similarity between fossil and modem assemblages. Objective criteria for choosing the most appropriate climate parameter（s） to be reconstructed at a specific site are thus lacking. Using a novel approach for testing the statistical significance of a quantitative reconstruction using random environmental data, in combination with the advantageous large environmental gradients, abundant vegetation types and comprehensive modem pollen databases in China, we describe a new procedure for pollen-based quantitative paleoclimatic reconstructions. First, the most significant environmental variable controlling the fossil pollen assemblage changes is identified. second, a calibration set to infer changes in this targeted variable is built up, by limiting the modem ranges of other environmental variables. Finally, the pollen-based quantitative reconstruction is obtained and its statistical significance assessed. This novel procedure was used to reconstruct the mean annual precipitation （Pann） from Gonghai Lake in the Lvliang Mountains, and Tianchi Lake in the Liupan Mountains, on the eastern and western fringe of the Chinese Loess Plateau, respectively. Both Pann. reconstructions are statistically significant （p〈0.001）, and a sound and stable correlation relationship exists in their common period, showing a rapid precipitation decrease since 3300 cal yr BP. Thus, we propose that this procedure has great potential for reducing the uncertainties associated with pollen-based quantitative paleoclimatic reconstructions in China.

关键词： Pollen Quantitative reconstructions statistical significance Marginal areas of the Asian summer monsoon

Molecular Phylogeny of Parapenaeopsis Alcock, 1901(Decapoda: Penaeidae) Based on Chinese Materials and 16s rDNA and COI sequence

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Journal of Ocean University of China 2014年第1期13卷 104-114页

作者： LI Xinzheng XU Yan KOU Qi Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of sciences

The phylogenetic relationship among Chinese Parapenaeopsis species was studied by comparing 16s rDNA and COI gene sequence. The results showed that Parapenaeopsis hardwickii(Miers, 1878) and P. cultrirostris Alcock, 1906 identified from Chinese samples were the same species. Parapenaeopsis cornuta(Kishinouye, 1900), P. incisa Liu and Wang, 1987, and P. sinica Liu and Wang, 1987 were different species. However, their systematic relationship were closer than those of other species, and they formed an advanced branch in the phylogenetic trees. Additionally, the systematic position of P. hardwickii(Miers, 1878), P. hungerfordi Alcock, 1905, and P. tenella(Bate, 1888) were not stable in the phylogenetic trees. More genetic markers such as 18s rDNA and 28s rDNA were supposed to be used to confirm the phylogenic relationship of Parapenaeopsis species.

关键词： Parapenaeopsis Decapoda Crustacea phylogeny 16s rDNA COI

sOME NONLINEAR APPROXIMATIONs FOR MATRIX-VALUED FUNCTIONs

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Journal of Computational Mathematics 2003年第6期21卷 801-814页

作者： Guo-liang Xu(Academy of Mathematics and system sciences, Chinese Academy of sciences,Beijing 100080, China) Academy of Mathematics and system sciences Chinese Academy of Sciences 北京 100080

some nonlinear approximants, i.e., exponential-sum interpolation with equal distance or at origin, (0,1)-type, (0,2)-type and (1,2)-type fraction-sum approximations, for matrix-valued functions are introduced. All these approximation problems lead to a same form system of nonlinear equations. solving methods for the nonlinear system are discussed. Conclusions on uniqueness and convergence of the approximants for certain class of functions are given.

关键词： Matrix-valued function Nonlinear approximation Interpolation.

Acid Hydrolytic Method for Determination of Ginkgo Biloba Total Flavonoids in Rat Plasma by HPLC for Pharmacokinetic studies

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Tsinghua science and Technology 2010年第4期15卷 452-459页

作者：胡珺赵玉男马超王伟聿邢东明杜力军 Laboratory of Pharmaceutical sciences Department of Biological Sciences and Biotechnology Tsinghua University

A simple, reliable, economical method was developed using HPLC with a diode-array detector for determination of total flavonoids in plasma after introvenous administration of ginkgo biloba extract. The method simultaneously detects quercetin, kaempferol, and isorhamnetin after acid hydrolysis and recalcula- tion. The hydrolysis and extraction conditions were optimized in an orthogonal test. The specificity was tested by comparing the retention time, UV spectra, and peak purity indices with standards. The detection limits were 20 ng/mL for quercetin, 20 ng/mL for kaempferol, and 50 ng/mL for isorhamnetin. The calibration curve ranges were 75-2400, 71-2280, and 70-2240 ng/mL. The pharmacokinetic characteristics of ginkgo biloba flavonoids after venous administration of 50 mg/kg ginkgo biloba extract to rats were analyzed using a two-compartment model. The initial plasma concentration was 171.22 μg/mL. The half-life of flavonoids in the first compartment （distribution） was 0.07 h and at the second compartment （elimination） was 4.51 h, while the AUC（0-∞） was 1711.06 Iag-min/mL. The apparent volume of distribution was 0.11 L/kg. The total body clearance is 10.52 mL/（***）. The result shows the method is suitable for pharmacokinetic studies.

关键词： ginkgo biloba flavonoids quercetin kaempferol isorhamnetin acid hydrolysis orthogonal test

Joint fit of Warm Absorbers in COs and HETG spectra of NGC 3783

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Research in Astronomy and Astrophysics 2017年第9期17卷 71-80页

作者： Xiao-Dan Fu shui-Nai Zhang Wei sun shu Niu Li Ji Purple Mountain Observatory Chinese Academy of Sciences shanghai Astronomical Observatory Chinese Academy of Sciences

Warm Absorbers （WAs）, as an important form of AGN outflows, show absorption in both the UV and X-ray bands. Using XsTAR generated photoionization models, for the first time we present a joint fit to the simultaneous observations of HsT/COs and Chandra/HETG on NGC 3783. A total of five WAs explain well all absorption features from the AGN outflows, which are spread over a wide range of parameters： ionization parameter log~ from 0.6 to 3.8, column density logNH from 19.5 to 22.3 cm-2, velocity v from 380 to 1060 km s-1, and covering factor from 0.33 to 0.75. Not all the five WAs are consistent in pressure. Two of them are likely different parts of the same absorbing gas, and two of the other WAs may be smaller discrete clouds that are blown out from the inner region of the torus at different periods. The five WAs suggest a total mass outflowing rate within the range of 0.22-4.1 solar mass per year.

关键词： galaxies individual (NGC 3783) - quasars absorption lines - ultraviolet galaxies - X-ray galaxies

Recent advances in ultrathin materials and their applications in e-skin

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InfoMat 2023年第8期5卷 1-36页

作者： Wenchao Gao Jiaoya Huang Jiang He Runhui Zhou Zemin Li Ziyu Chen Yufei Zhang Caofeng Pan CAs Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijingthe People's Republic of China Center on Nanoenergy Research School of Physical Science and TechnologyGuangxi UniversityNanningthe People's Republic of China

Intelligent technologies based on artificial intelligence and big data hold great potential for health monitoring and human–machine capability ***,electronics must be connected to the human body to realize this ***,tissue or skin-like electronics with high stretchability and low stiffness mechanical properties are highly *** materials have attracted significant attention from the research community and the industry because of their high performance and *** the past few years,considerable progress has been made in flexible ultrathin sensors and devices based on ultrathin ***,we review the developments in this area and examine representative research progress in ultrathin materials fabrication and device *** for the fabrication of stretchable ultrathin materials and devices are *** relationship between the thin-film structure and performance is emphasized and ***,the current capabilities and limitations of ultrathin devices were explored.

关键词： e-skin flexible electronics ultrathin devices ultrathin materials wearable devices

Pfaffian graphs embedding on the torus

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science China Mathematics 2013年第9期56卷 1957-1964页

作者： ZHANG LianZhu WANG Yan LU FuLiang school of Mathematical sciences Xiamen University school of sciences Linyi University

An orientation of a graph G with even number of vertices is Pfaffian if every even cycle C such that G-V(C) has a perfect matching has an odd number of edges directed in either direction of the cycle. The significance of Pfaffian orientations stems from the fact that if a graph G has one, then the number of perfect matchings of G can be computed in polynomial time. There is a classical result of Kasteleyn that every planar graph has a Pfaffian orientation. Little proved an elegant characterization of bipartite graphs that admit a Pfaffian orientation. Robertson, seymour and Thomas (1999) gave a polynomial-time recognition algorithm to test whether a bipartite graph is Pfaffian by a structural description of bipartite graphs. In this paper, we consider the Pfaffian property of graphs embedding on the orientable surface with genus one (i.e., the torus). some sufficient conditions for Pfaffian graphs on the torus are obtained. Furthermore, we show that all quadrilateral tilings on the torus are Pfaffian if and only if they are not bipartite graphs.

关键词： Pfaffian graph perfect matching crossing orientation

Potential simplification of Charge and the Coulomb Force without Affecting Predictions

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Journal of Applied Mathematics and Physics 2022年第10期10卷 3003-3015页

作者： Espen Gaarder Haug Norwegian University of Life sciences &#197 s Norway

We are taking a deeper look at charge and the Coulomb force and other electric properties. There is an embedded 10-7 in the Coulomb constant that we will claim is “only” needed to cancel out an embedded 107 in the c... 详细信息

We are taking a deeper look at charge and the Coulomb force and other electric properties. There is an embedded 10sup>-7sup> in the Coulomb constant that we will claim is “only” needed to cancel out an embedded 10sup>7sup> in the charge squared. We suggest three alternatives to redefine the charge and the Coulomb constant that give considerable simplification. The Coulomb constant is not needed as a separate constant as, in the new suggested framework, it can be replaced with simply the speed of light without affecting predicted output values. We also point out potential issues with the 2019 redefinition of the Coulomb constant and elementary charge. This is not meant conclusive but to open up for further discussion on how one potential can simplify parts of physics.

关键词： Coulomb Law Coulomb Constant Elementary Charge Planck Charge Planck Voltage Electric Units