检索结果-南通市图书馆

A Novel Sparse Penalty for Singular Value Decomposition

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2017年第2期26卷 306-312页

作者： WANG Caihua LIU Juan min wenwen QU Aiping The State Key Laboratory of Software Engineering School of ComputerWuhan University

Singular value decomposition(SVD) is a tool widely used in data denoising,matrix approximation,recommendation system,text mining and computer vision.A ma jority of applications prefer sparse singular vectors to capture inherent structures and patterns of the input data so that the results are *** present a novel penalty for SVD to achieve *** with the traditional penalties,the proposed penalty is scale,dimensional insensitive and bounded between 0 and 1,which are in favor of controlling *** by the penalty,we provide an efficient algorithm to pro ject a vector onto a given sparse level in O(n) expected *** efficient pro jection algorithm serve as a drudge for sparse SVD(SSVD).In experiments,SSVD is efficient and could capture the latent structures and patterns of the input data.

关键词： Sparse controllable projection(SCP) Sparse singular value decomposition(SSVD) Sparse low rank matrix approximation(SLRMA)

Analysis of EET on Ca increasing the melting point of Mg_(17)Al_(12) phase

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第13期47卷 1082-1086页

作者： min Xuegang, DU wenwen, XUE Feng & SUN YangshanDepartment of Material Science and Engineering, Southeast University, Nanjing 210096, China Department of Material Science and Engineering Southeast University Nanjing China

The present investigation showed that the additions of Ca to the alloy AZ91 were mainly dissolved into the Mg17Al12 phase and increased its melting point and thermal stability, which would have great effects on the high-temperature properties of AZ91 alloy. The empirical electron theory (EET) of solid and molecules was used to calculate the valence electron structures (VES) of Mg17Al12 intermetallic compound with and without Ca addition. The results showed that Ca dissolving in Mg17Al12 phase increased the strength of bonds that control the thermal stability of Mg17Al12 phase. Additions of Ca also made the distribution of the valence electrons on the dominant bond network more uniform in the whole unit cell of Mg17Al12. The theoretical conclusions well account for the experimental results.

关键词： melting point Mg17Al12 intermetallic compound Ca empirical electron theory (EET) valence electron structure (VES).

Nondestructive determination of nutritional information in oilseed rape leaves using visible/near infrared spectroscopy and multivariate calibrations

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2011年第3期54卷 598-608页

作者： LIU Fei, NIE PengCheng, HUANG min, KONG wenwen & HE Yong College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, China 1. College of Biosystems Engineering and Food Science Zhejiang University Hangzhou 310029 China

Nitrogen, phosphorus and potassium content are the three most important nutritional parameters for growing oilseed rape. We investigated visible and near infrared (Vis/NIR) spectroscopy combined with chemometrics for the fast and nondestructive determination of nutritional information in oilseed rape leaves. A total of 154 leaf samples were collected, with 104 randomly selected as the calibration set, and the remaining 50 samples used as the validation set. The performance of eight different preprocessing methods was compared in partial least squares (PLS) models. Some effective wavelengths selected by a successive projections algorithm (SPA) were also used to develop linear SPA-PLS, nonlinear back propagation neural network (BPNN), and nonlinear least squares-support vector machine (LS-SVM) models to determine nutritional information. The best prediction models were DOSC-PLS for nitrogen with r=0.9743 and RMSEP=0.1459, DOSC-SPA-BPNN for phosphorus with r=0.7054 and RMSEP=0.0594, and DOSC-SPA-BPNN for potassium with r=0.9380 and RMSEP=0.1788. The prediction precision for nitrogen and potassium determinations was acceptable for further practical applications, whereas further studies are needed to improve the prediction precision for phosphorus. The results indicated that Vis/NIR spectroscopy is feasible for nondestructive determination of nutritional information in oilseed rape leaves. It also provided an alternative technique for detecting other growth information about oilseed rape leaves.

关键词： visible and near infrared spectroscopy oilseed rape nutritional information successive projections algorithm direct orthogonal signal correction chemometrics

有机燃料与氧化剂的化学计量比对La_(0.8)Sr_(0.2)CoO_3催化剂性能的影响

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

石油化工 2007年第11期36卷 1093-1098页

作者：刘伟罗来涛闵雯雯南昌大学应用化学研究所江西南昌330031

以D,L-丙氨酸为有机燃料,采用溶液燃烧法制备了钙钛矿型复合氧化物La0.8Sr0.2CoO3催化剂,研究了有机燃料与氧化剂的化学计量比(φ)对催化剂结构和性能的影响,考察了催化剂的甲烷燃烧活性,并对催化剂进行了表征。实验结果表明,La0.8Sr0.2... 详细信息

以D,L-丙氨酸为有机燃料,采用溶液燃烧法制备了钙钛矿型复合氧化物La0.8Sr0.2CoO3催化剂,研究了有机燃料与氧化剂的化学计量比(φ)对催化剂结构和性能的影响,考察了催化剂的甲烷燃烧活性,并对催化剂进行了表征。实验结果表明,La0.8Sr0.2CoO3催化剂具有钙钛矿型结构,催化剂的结构和性能随φ的不同而变化,当φ=1.52时所制备的催化剂活性最高,甲烷转化率达到50%和100%时的反应温度分别为460,540℃。该催化剂的平均晶粒度(12.32nm)较小,晶格畸变率(4.66×10-3)和比表面积(21.40m2/g)较大,表面和氧空穴处的化学吸附氧更容易移动,表观活化能(62.54kJ/mol)较低。

关键词：有机燃料氧化剂化学计量比溶液燃烧法 D,L-丙氨酸镧-锶-钴复合氧化物钙钛矿型结构甲烷催化燃烧

Congruent Feature Selection Method to Improve the Efficacy of Machine Learning-Based Classification in Medical Image Processing

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2025年第1期142卷 357-384页

作者： Mohd Anjum Naoufel Kraiem Hong min Ashit Kumar Dutta Yousef Ibrahim Daradkeh Department of Computer Engineering Aligarh Muslim UniversityAligarh202002India College of Computer Science King Khalid UniversityAbha61413Saudi Arabia School of Computing Gachon UniversitySeongnam13120Republic of Korea Department of Computer Science and Information Systems College of Applied SciencesAlMaarefa UniversityRiyadh13713Saudi Arabia Department of Computer Engineering and Information College of Engineering in Wadi AlddawasirPrince Sattam bin Abdulaziz UniversityAl-Kharj16273Saudi Arabia

Machine learning(ML)is increasingly applied for medical image processing with appropriate learning *** applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for *** primary concern of ML applications is the precise selection of flexible image features for pattern detection and region *** of the extracted image features are irrelevant and lead to an increase in computation ***,this article uses an analytical learning paradigm to design a Congruent Feature Selection Method to select the most relevant image *** process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel *** similarity between the pixels over the various distribution patterns with high indexes is recommended for disease ***,the correlation based on intensity and distribution is analyzed to improve the feature selection ***,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the ***,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of ***,the probability of feature selection,regardless of the textures and medical image patterns,is *** process enhances the performance of ML applications for different medical image *** proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected *** mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset.

关键词： Computer vision feature selection machine learning region detection texture analysis image classification medical images

C-X-C chemokine receptor type 5+CD8+T cells as immune regulators in hepatitis Be antigen-positive chronic hepatitis B under interferonalpha treatment

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

World Journal of Gastroenterology 2025年第3期31卷 73-83页

作者： Zhen-Yu Xu Zhong-Shang Dai Guo-Zhong Gong min Zhang Department of Infectious Diseases Second Xiangya HospitalCentral South UniversityChangsha 410011Hunan ProvinceChina Institute of Hepatology and Department of Infectious Diseases The Second Xiangya HospitalCentral South UniversityChangsha 410011Hunan ProvinceChina

BACKGROUND C-X-C chemokine receptor type 5(CXCR5)+CD8+T cells represent a unique immune subset with dual roles,functioning as cytotoxic cells in persistent viral infections while promoting B cell *** their importance,the specific role of CXCR5+CD8+T cells in chronic hepatitis B(CHB),particularly during interferon-alpha(IFN-α)treatment,is not fully *** study aims to elucidate the relationship between CXCR5+CD8+T cells and sustained serologic response(SR)in patients undergoing 48 weeks of pegylated IFN-α(peg-IFN-α)treatment for *** To elucidate the relationship between CXCR5+CD8+T cells and sustained SR in patients undergoing 48 weeks of peg-IFN-αtreatment for *** This study enrolled 60 patients with hepatitis Be antigen(HBeAg)-positive CHB undergoing 48 weeks of peg-IFN-α*** were assessed for eligibility based on criteria such as persistent HBsAg-positive status for at least six months,HBeAb-negative,hepatitis B virus DNA levels exceeding 2×104 copies/mL,and alanine aminotransferase(ALT)levels between 2 and 10 times the upper limit of *** samples were collected at baseline and at weeks 12,24,48,and a 24-week treatment-free follow-up(week 72)to measure serum interleukin(IL)-21 concentration via ELISA and to analyze CXCR5 and programmed death-ligand 1(PD-L1)expression on CD8+T cells by flow cytometry,CXCR5 is a chemokine receptor that directs immune cells to specific tissues,while PD-L1 is a protein that regulates immune responses by inhibiting T cell *** Patients with CHB exhibited significantly lower levels of circulating CXCR5+CD8+T cells compared to healthy controls(Pminently expressed in patients who achieved sustained SR compared to non-SR(NSR).A significant correlation was observed between CXCR5 and PD-L1 expression(r=-0.189,P=0.002).However,there was no significant correlation between serum IL-21 levels and CXCR5+CD8+lymphocytes(r=-0.03,P=0.62

关键词： C-X-C chemokine receptor type 5 Programmed death-ligand 1 Interleukin-21 Pegylated interferon-alpha Chronic hepatitis B

不同施工机械碾压下矿区复垦土壤物理性质的变化

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

山东国土资源 2017年第3期33卷 64-72页

作者：张雯雯闵祥宇孙晓明郑加刚烟台市征地办公室山东烟台264003 山东农业大学资源与环境学院山东泰安271018 烟台市不动产登记中心山东烟台264003 烟台市土地储备中心山东烟台264003

以国家自然科学基金为依托建立模拟实验区,探究不同施工机械和碾压次数下的土壤物理指标(压实度、容重、孔隙度、含水量、电导率和温度)的变化。研究结果表明:随土层深度的增加,压实度、容重和电导率逐渐递增,孔隙度、含水量和温度逐渐... 详细信息

以国家自然科学基金为依托建立模拟实验区,探究不同施工机械和碾压次数下的土壤物理指标(压实度、容重、孔隙度、含水量、电导率和温度)的变化。研究结果表明:随土层深度的增加,压实度、容重和电导率逐渐递增,孔隙度、含水量和温度逐渐递减;随碾压次数的增加,压实度和容重逐渐递增,孔隙度逐渐递减,土壤含水量、电导率和温度先增加后降低,其中使用自卸汽车时,3次碾压指标值最高,使用履带式推土机时,5次碾压指标值最高,而使用履带式推土机的处理效果要好于使用自卸汽车;通过对各处理与对照间的拟合度分析发现,使用履带式推土机碾压5次的土壤中各指标与对照拟合度最高,表明采用"履带式推土机×碾压5次"的组合,复垦土壤中物理性质与正常土壤最为接近。

关键词：施工机械碾压次数复垦土壤物理性质

Porous Organic Cage‑Based Quasi‑Solid‑State Electrolyte with Cavity‑Induced Anion‑Trapping Effect for Long‑Life Lithium Metal Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 376-386页

作者： Wei-min Qin Zhongliang Li Wen‑Xia Su Jia‑min Hu Hanqin Zou Zhixuan Wu Zhiqin Ruan Yue‑Peng Cai Kang Li Qifeng Zheng School of Chemistry South China Normal UniversityGuangzhou 510006People’s Republic of China Key Laboratory of Functional Metal‑Organic Compounds of Hunan Province College of Chemistry and Material ScienceHengyang Normal UniversityHengyang 421008People’s Republic of China Guangzhou Key Laboratory of Energy Conversion and Energy Storage Materials Guangzhou 510006People’s Republic of China

Porous organic cages(POCs)with permanent porosity and excellent host–guest property hold great potentials in regulating ion transport behavior,yet their feasibility as solid-state electrolytes has never been testified in a practical ***,we design and fabricate a quasi-solid-state electrolyte(QSSE)based on a POC to enable the stable operation of Li-metal batteries(LMBs).Benefiting from the ordered channels and cavity-induced anion-trapping effect of POC,the resulting POC-based QSSE exhibits a high Li+transference number of 0.67 and a high ionic conductivity of 1.25×10^(−4) S cm^(−1) with a low activation energy of 0.17 *** allow for homogeneous Li deposition and highly reversible Li plating/stripping for over 2000 *** a proof of concept,the LMB assembled with POC-based QSSE demonstrates extremely stable cycling performance with 85%capacity retention after 1000 ***,our work demonstrates the practical applicability of POC as SSEs for LMBs and could be extended to other energy-storage systems,such as Na and K batteries.

关键词： Porous organic cage Cavity-induced anion-trapping Quasi-solid-state electrolyte Homogeneous Li+flux Lithium metal battery

Calibration of GRACE on-board accelerometers for thermosphere density derivation

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2022年第1期25卷 74-87页

作者： min Li Zhuo Lei wenwen Li Kecai Jiang Youcun Wang Qile Zhao GNSS Research Center Wuhan UniversityWuhanChina Collaborative Innovation Center of Geospatial Technology Wuhan UniversityWuhanChina

Low Earth Orbit satellite on-board accelerometers play an important role in improving our understanding of thermosphere density;however,the accelerometer-derived densities are subject to accelerometer calibration *** this study,two different dynamic calibration schemes,the accelerometer parameter-incorporated orbit fitting and precise orbit determination(POD),are investigated with the Gravity Recovery And Climate Experiment(GRACE)satellite accelerometers for thermosphere density derivation during years 2004–2007(inclusive).We show that the GRACE accelerometer parametrization can be optimized by fixing scale coefficients and estimating biases every 60 min so that the orbit fitting and POD precision can be improved from 10 cm to 2 cm in the absence of empirical acceleration compensations and as a result the integrity of calibration parameters may be *** orbit-fitting scheme demonstrates similar calibration precision with respect to *** bias estimates in the along-track and cross-track components exhibit an offset within 0.1%and a standard deviation(STD)less than 0.3%.Correspondingly,a bias of 2.20%and a STD of 5.75%exists between their thermosphere density *** orbit-fitting and POD-derived thermosphere densities are validated through the comparison against the results published by other *** comparison shows that either of them can achieve a precision level at 6%.To derive thermosphere density from the rapid-increasing amount of on-board accelerometer data sets,it is suggested to take full advantage of the orbit-fitting scheme due to its high efficiency as well as high precision.

关键词： GRACE accelerometer calibration thermosphere density precise orbit determination orbit fit