检索结果-南通市图书馆

Numerical analysis of thermal-hydraulic behavior of supercritical water in vertical upward/downward flow channels

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2008年第3期19卷 178-186页

作者： GU Hanyang yu Yiqi cheng Xu liu Xiaojing School of Nuclear Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

Investigations on the thermal-hydraulic behavior in the SCWR fuel assembly have obtained a significant attention in the international SCWR community. However, there is still a lack of understanding of the heat transfer behavior of supercritical fluids. In this paper, the numerical analysis is carried out to study the thermal-hydraulic behaviour in vertical sub-channels cooled by supercritical water. Remarkable differences in characteristics of secondary flow are found, especially in square lattice, between the upward flow and downward flow. The turbulence mixing across sub-channel gap for downward flow is much stronger than that for upward flow in wide lattice when the bulk temperature is lower than pseudo-critical point temperature. For downward flow, heat transfer deterioration phenomenon is suppressed with respect to the case of upward flow at the same conditions.

关键词：传热理论热转换数字分析水力行为

The research of DPA attacks against AES implementations

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2008年第4期15卷 101-106页

作者： HAN yu ZOU Xue-cheng liu Zheng-lin CHEN Yi-cheng Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

This article examines vulnerabilities to power analysis attacks between software and hardware implementations of cryptographic algorithms. Representative platforms including an Atmel 89S8252 8-bit processor and a 0.25 um 1.8 v standard cell circuit are proposed to implement the advance encryption standard （AES）. A simulation-based experimental environment is built to acquire power data, and single-bit differential power analysis （DPA）, and multi-bit DPA and correlation power analysis （CPA） attacks are conducted on two implementations respectively. The experimental results show that the hardware implementation has less data-dependent power leakages to resist power attacks. Furthermore, an improved DPA approach is proposed. It adopts hamming distance of intermediate results as power model and arranges plaintext inputs to differentiate power traces to the maximal probability. Compared with the original power attacks, our improved DPA performs a successful attack on AES hardware implementations with acceptable power measurements and fewer computations.

关键词： AES implementation side-channel leakage DPA CPA power model power trace

ECG quality assessment based on a kernel support vector machine and genetic algorithm with a feature matrix

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第7期15卷 564-573页

作者： Ya-tao ZHANG cheng-yu liu Shou-shui WEI Chang-zhi WEI Fei-fei liu School of Control Science and Engineering Shandong University School of Mechanical Electrical & Information Engineering Shandong University Institute of Cellular Medicine Newcastle University

We propose a systematic ECG quality classification method based on a kernel support vector machine(KSVM) and genetic algorithm(GA) to determine whether ECGs collected via mobile phone are acceptable or not. This method includes mainly three modules, i.e., lead-fall detection, feature extraction, and intelligent classification. First, lead-fall detection is executed to make the initial classification. Then the power spectrum, baseline drifts, amplitude difference, and other time-domain features for ECGs are analyzed and quantified to form the feature matrix. Finally, the feature matrix is assessed using KSVM and GA to determine the ECG quality classification results. A Gaussian radial basis function(GRBF) is employed as the kernel function of KSVM and its performance is compared with that of the Mexican hat wavelet function(MHWF). GA is used to determine the optimal parameters of the KSVM classifier and its performance is compared with that of the grid search(GS) method. The performance of the proposed method was tested on a database from PhysioNet/Computing in Cardiology Challenge 2011, which includes 1500 12-lead ECG recordings. True positive(TP), false positive(FP), and classification accuracy were used as the assessment indices. For training database set A(1000 recordings), the optimal results were obtained using the combination of lead-fall, GA, and GRBF methods, and the corresponding results were: TP 92.89%, FP 5.68%, and classification accuracy 94.00%. For test database set B(500 recordings), the optimal results were also obtained using the combination of lead-fall, GA, and GRBF methods, and the classification accuracy was 91.80%.

关键词： ECG quality assessment Kernel support vector machine Genetic algorithm Power spectrum Cross validation

Determination of Sparfloxacin Concentrations in Chicken Serums and Residues in Chicken Tissues and Manures Using Self-Ordered Ring Fluorescence Microscopic Imaging Technique

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2012年第10期32卷 2759-2764页

作者： DONG cheng-yu liu yuan-yuan liu Yin College of Life and Environmental Sciences Minzu University of China Beijing 100081 China

Based on the self-ordered ring(SOR) fluorescence microscopic imaging technique on a hydrophobic glass slide with Zn 2+ and cetyltrimethyl ammonium bromide(CTMAB) as sensitizer,and poly(vinyl alcohol)-124(PVA-124) and NH 3-NH 4 Cl(pH 10.00) as the medium,a method has been developed for determining sparfloxacin(SPFX) concentrations in chicken serum and residues in chicken tissues and *** the droplet volume was 0.20 μ L,SPFX was determined in the range of 1.38×10-13 ～2.03×10-12 ***-1(or 6.90×10-7 ～1.02×10-5 mol.L-1),and the limit of detection(LOD) was ***-1(or 6.90× 10-8 mol.L-1).The recoveries of SPFX at all different spiked levels are in the range of 90.74%～106.61% when the methanol or acetonitrile were used as extracting agent,respectively,and the relative standard deviations(RSDs) are less than 3.0%.This study expands the applied fields of SOR technique in drug concentrations and residues determination.

关键词：光谱学光谱分析研究发展

Large eddy simulation of cavitating flows with dynamic adaptive mesh refinement using OpenFOAM

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2020年第2期32卷 398-409页

作者： Lin-min Li Dai-qing Hu yu-cheng liu Bi-tao Wang Chen Shi Jun-jie Shi Chang Xu College of Energy and Electrical Engineering Hohai UniversityNanjing211100China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Anhui Jinzhai Pumped Storage Power Co. LtdLu’an237300China

Cavitating flows are dominated by large gradients of physical properties and quantities containing complicated interfacial structures and lots of multi-scale eddies that need to be accurately characterized using a high-resolution *** present work,within OpenFOAM,proposes an effective modeling framework using the large eddy simulation(LES)approach along with the volume of fluid(VOF)method to simulate the two-phase flow system and applies the Schnerr-Sauer model to calculate the mass-transfer rate between water and *** adaptive mesh refinement(AMR)which is a powerful tool for allocating high-resolution grids only to the region of the greatest concern is adopted for improving the solution of interfacial *** effect of grid size is firstly investigated and the time-averaged quantities are verified against the experimental data,and then simulations of cavitating flows are successfully achieved to precisely characterize the features of cavitation with automatically and dynamically refining the *** the refinement only takes place in the interfacial region,high-precision simulations can be achieved with limited computational resources,and the method shows promising prospects for modeling of the multi-scale,time-critical and computationally intensive cavitating flows.

关键词： Cavitating flows large eddy simulation(LES) multi-scale adaptive mesh refinement(AMR) OpenFOAM

Development and validation of a machine learning-based early prediction model for massive intraoperative bleeding in patients with primary hepatic malignancies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第1期16卷 90-101页

作者： Jin Li yu-Ming Jia Zhi-Lei Zhang cheng-yu liu Zhan-Wu Jiang Zhi-Wei Hao Li Peng Department of Hepatological Surgery The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina Department of General Surgery II Baoding First Central HospitalBaoding 071000Hebei ProvinceChina

BACKGROUND Surgical resection remains the primary treatment for hepatic malignancies,and intraoperative bleeding is associated with a significantly increased risk of ***,accurate prediction of intraoperative bleeding risk in patients with hepatic malignancies is essential to preventing bleeding in advance and providing safer and more effective *** To develop a predictive model for intraoperative bleeding in primary hepatic malignancy patients for improving surgical planning and *** The retrospective analysis enrolled patients diagnosed with primary hepatic malignancies who underwent surgery at the Hepatobiliary Surgery Department of the Fourth Hospital of Hebei Medical University between 2010 and *** regression analysis was performed to identify potential risk factors for intraoperative bleeding.A prediction model was developed using Python programming language,and its accuracy was evaluated using receiver operating characteristic(ROC)curve *** Among 406 primary liver cancer patients,16.0%(65/406)suffered massive intraoperative *** regression analysis identified four variables as associated with intraoperative bleeding in these patients:ascites[odds ratio(OR):22.839;P<0.05],history of alcohol consumption(OR:2.950;P<0.015),TNM staging(OR:2.441;P<0.001),and albumin-bilirubin score(OR:2.361;P<0.001).These variables were used to construct the prediction *** 406 patients were randomly assigned to a training set(70%)and a prediction set(30%).The area under the ROC curve values for the model’s ability to predict intraoperative bleeding were 0.844 in the training set and 0.80 in the prediction *** The developed and validated model predicts significant intraoperative blood loss in primary hepatic malignancies using four preoperative clinical factors by considering four preoperative clinical factors:ascites,history of alcohol consumption,TNM staging,and albumin-bilirubin ***

关键词： Primary liver cancer Intraoperative bleeding Machine learning Model

Lycopodine-Type Alkaloids from Lycopodium japonicum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Natural Products and Bioprospecting 2014年第4期4卷 213-219页

作者： Juan He Xing-De Wu Fei liu yu-cheng liu Li-Yan Peng yu Zhao Xiao cheng Huai-Rong Luo Qin-Shi Zhao State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Three new lycopodine-type alkaloids,4a-hydroxyanhydrolycodoline(1),4a,6a-dihydroxyanhydrolycodoline(2),and 6-epi-8b-acetoxylycoclavine(3),and an artifact,lycoposerramine G nitrate(4),along with seventeen related known compounds,were isolated from the club moss Lycopodium japonicum *** Murray(Lycopodiaceae).Their structures were elucidated by extensive spectroscopic methods as well as X-ray *** 1–4 were evaluated for their acetylcholine esterase inhibitory activity.

关键词： Lycopodium japonicum Lycopodine-type alkaloids 4a-Hydroxyanhydrolycodoline 4a,6a-Dihydroxyanhydrolycodoline 6-epi-8b-Acetoxylycoclavine Lycoposerramine G nitrate

Comprehensive Quality Evaluation of ShuXueNing Injection Employing Quantitative High-Performance Liquid Chromatography Fingerprint and Chemometrics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Traditional Chinese Medicine 2021年第1期7卷 54-62页

作者： yu Zhang Xin Xu Hua-Wen Qi yu-cheng liu Jia-Tao Dong Gui-Cai Xi Hong-Li Jin Yan-Fang liu Xin-Miao Liang Chinese Medicine Science Center Key Laboratory of Separation Science for Analytical ChemistryDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023 TCM Standardization Technology Research Group DICP‑CMC Innovation Institute of MedicineTaizhou 225300 HeiLongJiang ZBD Pharmaceutical Co. LtdHeilongjian158400China

Objective:In this study,a comprehensive and effective quality method for evaluating the efficacy of ShuXueNing injection(SXNI)was *** and Methods:Quantitative high-performance liquid chromatography fingerprint,the quantitative analysis of multicomponents by a single marker(QAMS)method,hierarchical cluster analysis(HCA),and orthogonal partial least squares discrimination analysis(OPLS-DA)were used to distinguish 53 batches of SXNI samples from 7 ***:A total of 53 batches of samples were analyzed to establish antithesis fingerprint of SXNI,and 12 peaks of the common model were collected and used for the similarity ***,six index flavonoid components were determined by the QAMS method,using rutin as internal reference *** accuracy of the QAMS method was confirmed by investigating the relative deviation between the QAMS method and the traditional external standard *** results demonstrated that there was no significant difference(RE<1%),suggesting that QAMS was a reliable and convenient method for the content determination of multiple *** HCA and OPLS-DA methods drew a similar *** 53 batches of SXNI samples from 7 manufacturers were categorized into five groups,indicating that chemometrics could reveal the quality differences of SXNI between the ***:The method established herein was efficient and successful in assessing the quality of SXNI,and that it may be potentially employed in the quality control of related products composed of Ginkgo biloba extract.

关键词： Chemometrics quantitative analysis of multicomponents by a single marker quantitative high-performance liquid chromatography fingerprint ShuXueNing injection

Carinatines A and B,Lycopodium Alkaloids from Phlegmariurus carinatus

在线全文

学校读者我要写书评

暂无评论

Natural Products and Bioprospecting 2014年第4期4卷 221-225页

作者： Fei liu yu-cheng liu Wei-Wei Jiang Juan He Xing-De Wu Li-Yan Peng Jia Su Xiao cheng Qin-Shi Zhao State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of ScienceKunming 650201People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China

Carinatine A(1),a C16N2-type Lycopodium alkaloid possessing a 5/6/6/6 ring system formed by a new C-4/C-12 bond,and carinatine B(2),the first derivative of lycojaponicumin C,along 16 known compounds,were isolated from the whole plant of Phlegmariurus *** structures were elucidated based on the spectroscopic *** two new isolates were no inhibitory activity for the acetylcholinesterase(AChE).

关键词： Lycopodium alkaloid Phlegmariurus carinatus Carinatines A and B Acetylcholinesterase(AChE)inhibitory activity