检索结果-南通市图书馆

Existence and uniqueness of positive solutions of semilinear elliptic equations

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2007年第8期50卷 1141-1156页

作者： Qiu-yi DAI yu-xia fu Yong-geng GU Department of Mathematics Hunan Normal UniversityChangsha 410081China Department of Applied Mathematics Hunan UniversityChangsha 410082China

This paper is devoted to the study of existence,uniqueness and non-degeneracy of positive solutions of semi-linear elliptic equations.A necessary and sufficient condition for the existence of positive solutions to problems is *** prove that if the uniqueness and non-degeneracy results are valid for positive solutions of a class of semi-linear elliptic equations,then they are still valid when one perturbs the differential operator a little *** consequences,some uniqueness results of positive solutions under the domain perturbation are also obtained.

关键词： semilinear elliptic equation positive solution existence uniqueness nondegeneracy 35J65

On-site variety discrimination of tomato plant using visible-near infrared reflectance spectroscopy

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第2期10卷 126-132页

作者： Hui-rong XU Peng yu xia-ping fu Yi-bin YING College of Biosystems Engineering and Food Science Zhejiang University Hangzhou 310029 China

The use of visible-near infrared (NIR) spectroscopy was explored as a tool to discriminate two new tomato plant varieties in China (Zheza205 and Zheza207). In this study, 82 top-canopy leaves of Zheza205 and 86 top-canopy leaves of Zheza207 were measured in visible-NIR reflectance mode. Discriminant models were developed using principal component analysis (PCA), discriminant analysis (DA), and discriminant partial least squares (DPLS) regression methods. After outliers detection, the samples were randomly split into two sets, one used as a calibration set (n=82) and the remaining samples as a validation set (n=82). When predicting the variety of the samples in validation set, the classification correctness of the DPLS model after optimizing spectral pretreatment was up to 93%. The DPLS model with raw spectra after multiplicative scatter cor- rection and Savitzky-Golay filter smoothing pretreatments had the best satisfactory calibration and prediction abilities (correlation coefficient of calibration (Rc)=0.920, root mean square errors of calibration=0.196, and root mean square errors of predic- tion=0.216). The results show that visible-NIR spectroscopy might be a suitable alternative tool to discriminate tomato plant varieties on-site.

关键词： Visible-NIR spectroscopy Tomato plant variety Discrimination Principal component analysis (PCA) Discriminant analysis (DA) Discriminant partial least squares (DPLS)

Prognostic role of neutrophil-lymphocyte ratio in operable esophageal squamous cell carcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2015年第18期21卷 5591-5597页

作者： Hao Duan Xu Zhang Fei-xiang Wang Mu-Yan Cai Guo-Wei Ma Hong Yang Jian-Hua fu Zi-Hui Tan yu-Qi Meng xia-yu fu Qi-Long Ma Peng Lin Department of Thoracic Oncology Sun YatSen University Cancer Center Department of Pathology Sun Yat-sen University Cancer Center Guangdong Esophageal Cancer Research Institute

AIM:To explore the relationship of clinicopathological features and the distribution of neutrophils in the t umor mic roenvironment wi t h t he prognosis of ***:Two hundred and fifty-four formalin-fixed and paraffin embedded tissue blocks were analyzed, including tissues from cholangiocarcinoma(n = 254), and tumor adjacent tissues(n = 238).Tissue sections were stained for CD15 using immunohistochemical ***15 expression was detected to identify the distribution of neutrophils in the local tumor *** neutrophil density of the tumor tissues and the adjacent tumor tissues was detected to reflect their inflammatory *** data and follow-up information of cholangiocarcinoma patients who underwent surgery from January 2004 to December 2010 were analyzed *** relationship between clinicopathological features and the distribution of neutrophils with prognosis of the patients were ***:The positive expression level of CD15 was only significantly related to the TNM ***15 expression was higher in tumor tissues than in adjacent tissues(73.6% vs 54.6%), with significant *** with high expression of CD15 had significantly shorter overall survival(OS) than those with low expression of CD15(median overall survival time 39.77 mo vs 16.87 mo, P = 0.008).Patients with high CD15 expression had significantly shorter disease free survival time(DFS) than those with low expression of CD15(median DFS 38.27 mo vs 16.83 mo, P = 0.029).COX multivariate analysis indicated that high CD15 expression in tumor tissues was an independent risk factor for predicting OS for patients with cholangiocarcinoma [P = 0.012, relative risk(RR) = 1.601], but it was not an independent risk factor for predicting DFS(P = 0.073, RR = 1.462).CONCLUSION:Patients with high CD15 expression in cancer tissues had shorter DFS and *** expression of CD15 is an independent risk factor for OS.

关键词： Cholangiocarcinoma Surgery Neutrophils CD15 Prognosis Tumor microenvironment

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

基于网管业务特征的负载均衡策略研究

计算机应用研究 2012年第3期29卷 1054-1056页

作者：徐昆夏玉福中国人民解放军理工大学指挥自动化学院南京210007 国防科学技术大学长沙410073

根据用户管理业务的组织结构提出适合网管业务特征的负载均衡策略,描述了策略的算法和实现,并在原型系统中进行测试比较,验证了算法的有效性。

关键词：网络管理服务多流程引擎负载均衡

Actively tunable electromagnetically induced transparency in hybrid Dirac-VO2 metamaterials

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年第1期21卷 13-20页

作者： DI Ke XIE Meng xia Huarong CHENG Anyu LIU yu DU Jiajia Department of Optoelectronic Engineering Chongqing University of Post and Telecommunications Chongqing Key Laboratory of Autonomous Navigation and Microsystem Chongqing University of Posts and Telecommunications Department of Automation Chongqing University of Post and Telecommunications

In this paper, we present a metamaterial structure of Dirac and vanadium dioxide（VO2） and investigate its optical properties using the finite-difference time-domain（FDTD） technique. Using the phase transition feature of VO2, the design can realize active tuning of the plasmon induced transparency（PIT） effect at terahertz frequency, thereby converting from a single PIT to a double-PIT. When VO2is in the insulating state, the structure is symmetric to obtain a single-band PIT effect. When VO2is in the metallic state, the structure turns asymmetric to realize a dual-band PIT effect. This design provides a reference direction for the design of actively tunable metamaterials. Additionally, it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship. In addition, the structure achieves superior refractive index sensitivity in the terahertz band, surpassing 1 THz/RIU. Consequently, the design exhibits encouraging potential for application in refractive index sensors and optical switches.

关键词： Transparency

Amperometric Glucose Sensor Based on Batch CuO-Modified Screen-Printed Silver-Carbon Electrodes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 35-41页

作者： xia Haiyan HUANG Yin YANG Hua WANG Xintian SHI Jianping LIU Lixia fu Yacheng QUAN Changyun LI Suyuan Cofoe Medical Technology Company Limited Changsha 410000China Institute of New Energy Hexi UniversityZhangye 734000China Chemistry and Chemical Engineering Central South UniversityChangsha 410000China

CuO nanoparticles were successfully synthesized via a two-jet electrospun method,and then screen-printed on silver-carbon electrodes,forming CuO-modified Ag-C(CuO/Ag-C)disposable strip *** natural environment condition for glucose detection,the obtained CuO/Ag-C electrodes show a high sensitivity of 540 nA·mM^(-1)·cm^(-2),and a low limit of detection(0.68 mM)in a wide linear response range of 0.68 mM and 3 mM(signal/noise=3),*** addition,the CuO/Ag-C electrodes also exhibit excellent anti-interference,air stability and *** a result,the fabrication of CuO nanoparticles via an electrospun process and the technique of screen-printed electrodes are of great significance for glucose detection.

关键词： electrochemical sensor CuO nanoparticles glucose detection screen-printing technique

Gradient‑Layered MXene/Hollow Lignin Nanospheres Architecture Design for Flexible and Stretchable Supercapacitors

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

Nano-Micro Letters 2025年第2期17卷 447-462页

作者： Haonan Zhang Cheng Hao Tongtong fu Dian yu Jane Howe Kaiwen Chen Ning Yan Hao Ren Huamin Zhai Jiangsu Provincial Key Lab of Sustainable Pulp and Paper Technology and Biomass Materials NanJing Forestry UniversityNanjing 210037People’s Republic of China Department of Chemical Engineering and Applied Chemistry University of Toronto200 College StreetTorontoON M5S 3E5Canada Department of Materials Science and Engineering University of Toronto184 College StreetTorontoON M5S 3E4Canada College of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037People’s Republic of China

With the rapid development of flexible wearable electronics,the demand for stretchable energy storage devices has *** this work,a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres(HLNPs)-intercalated two-dimensional transition metal carbide(Ti_(3)C_(2)T_(x) MXene)for fabricating highly stretchable and durable *** depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient,a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene ***,the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility,thus better utilizing the pseudocapacitive property of *** these strategies effectively enhanced the capacitive performance of the *** addition,HLNPs,which acted as a protective phase for MXene layer,enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the *** electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600%uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm^(−2)(241 F g^(−1))and 514 mF cm^(−2)(95 F g^(−1)),***,their capacitances were well preserved after 1000 times of 600%stretch-release *** study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.

关键词： Hollow lignin nanospheres MXene Gradient-layered architecture Wrinkled electrodes Stretchable supercapacitors

Cross-subcarrier precoder design for massive MIMO-OFDM downlink with symplectic optimization

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年

作者： yu-Xuan ZHANG An-An LU xiang-Gen xia Xi-Qi GAO National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories Department of Electrical and Computer Engineering University of Delaware

We propose a cross-subcarrier precoder design(CSPD) for massive multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) downlink. This work aims to significantly improve the channel estimation and signal detection performance by enhancing the smoothness of the frequency domain effective channel. This is accomplished by designing a few vectors known as the transform domain precoding vectors(TDPVs), which are then transformed into the frequency domain to generate the precoders for a set of subcarriers. To combat the effect of channel aging, the TDPVs are optimized under imperfect channel state information(CSI). The optimal precoder structure is derived by maximizing an upper bound of the ergodic weighted sum-rate(WSR) and utilizing the a posteriori beam-based statistical channel model(BSCM). To avoid the large-dimensional matrix inversion, we propose an algorithm with symplectic optimization. Simulation results indicate that the proposed cross-subcarrier precoder design significantly outperforms conventional methods.

关键词：

Synthetic control of chiral pore surfaces in covalent organic frameworks for enantioselective separation of chiral drugs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Shiguo fu xiaofeng Zhang Kaixuan Wang Linfeng Chen Fan xia Yong Cui Yan Liu School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3D chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. Density functional theory (DFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

关键词：