检索结果-南通市图书馆

Potassium bromide or sodium chloride catalyzed acetoxyselenenylation of alkenes with diselenides and mCPBA

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2015年第9期26卷 1117-1120页

作者： Hong-wei shi Chen Yu Jie Yan College of Chemical Engineering Zhejiang University of Technology

KBr or NaCl is found to be a good catalyst in Se-Se bond cleavage of diselenides in the present of the oxidant *** electrophilic addition of the in situ generated reactive electrophilic selenium species PhSeX（X = Br,Cl） to alkenes in AcOH provides a convenient access to *** with other catalysts,KBr or NaCl is less expensive and more environment-friendly.

关键词： Acetoxyselenenylation Diselenide Alkene Catalysis

Photoluminescence in fluorescent 4H-SiC single crystal adjusted by B,Al,and N ternary dopants

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第1期28卷 532-536页

作者： shi-Yi Zhuo Xue-Chao Liu wei Huang Hai-Kuan Kong Jun Xin Er-wei shi Shanghai Institute of Ceramics Chinese Academy of Sciences

This paper reports the sensitive effect of photoluminescence peak intensity and transmittance affected by B, Al, and N dopants in fluorescent 4H-SiC single crystals. The crystalline type, doping concentration, photoluminescence spectra,and transmission spectra were characterized at room temperature. It is found that the doped 4H-SiC single crystal emits a warm white light covering a wide range from 460 nm to 720 nm, and the transmittance increases from ~10% to ~60%with the fluctuation of B, Al, and N ternary dopants. With a parameter of C_(D-A), defined by B, Al, and N concentration, the photoluminescence and transmittance properties can be adjusted by optimal doping regulation.

关键词： photoluminescence property luminescence adjustment N–B–Al codoped 4H-SiC

Engineering practice of seismic isolation and energy dissipation structures in China

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2012年第11期55卷 3036-3046页

作者： PAN Peng YE LiePing shi wei CAO HaiYun Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil EngineeringTsinghua Univer-sityBeijing 100084China

The concepts of seismic isolation and energy dissipation structures emerged in the early *** China,the first seismic isolation structure was finished in 1993,and the first energy dissipation structure was built at about the same *** to 2007,China had more than 600 seismic isolation and about 100 energy dissipation building *** 2008,the huge Wenchuan earthquake hit the southwest of China,which triggered a bloom of new seismic isolation and energy dissipation *** paper presents the development history and representative applications of seismic isolation and energy dissipation structures in China,reviews the state-of-the-practice of Chinese design,and discusses the challenges in the future *** findings are as follows:Basic design procedures are becoming standardized after more than ten years of experiences,which mainly involve determination of design earthquake forces,selection of ground motions,modeling and time-history analyses,and performance *** time-history analyses using multiple ground motions are the characteristic of the design of seismic isolation and energy dissipation ***,standardization and quality control of devices,balance between performance and cost,comparison with real responses,and regular inspection are identified as the issues that should be improved to further promote the application of seismic isolation and energy dissipation structures in China.

关键词： seismic isolation structure energy dissipation structure development history design practice regulatory environment

Inhibition of Eukaryotic Initiating Factor eIF4E Overcomes Abemaciclib Resistance in Gastric Cancer

在线全文

学校读者我要写书评

暂无评论

Current Medical Science 2023年第5期43卷 927-934页

作者： Huo-long ZHA wei CHEN wei shi Ying-ying LIAO Department of Gastroenterology Renmin HospitalHubei University of MedicineShiyan 442000China Department of Critical Care Medicine Taihe HospitalHubei University of MedicineShiyan 442000China

Objective Aberrant activating mutations in cyclin-dependent kinases 4 and 6(CDK4/6)are common in various cancers,including gastroesophageal *** CDK4/6 inhibitors,such as abemaciclib and palbociclib,have been approved for breast cancer treatment,their effectiveness as a monotherapy remains limited for gastroesophageal *** present study explored the underlying mechanism of abemaciclib *** Abemaciclib-resistant gastric cancer cell lines were generated,and the phospho-eukaryotic translation initiation factor 4E(p-eIF4E)and eIF4E expression was compared between resistant and parental cell *** order to analyze the role of eIF4E in cell resistance,siRNA knockdown was *** effectiveness of ribavirin alone and its combination with abemaciclib was evaluated in the gastric cancer xenograft mouse *** The upregulation of eIF4E was a common feature in gastric cancer cells exposed to prolonged abemaciclib *** cancer cells with increased eIF4E levels exhibited a better response to eIF4E inhibition,especially those that were resistant to ***,which is an approved anti-viral drug,significantly improved the efficacy of abemaciclib,both in vitro and in vivo,by inhibiting ***,ribavirin effectively suppressed the abemaciclib-resistant gastric cancer growth in mice without causing *** These findings suggest that targeting eIF4E can enhance the abemaciclib treatment for gastric cancer,proposing the potential combination therapy of CDK4/6 inhibitors with ribavirin for advanced gastric cancer.

关键词： eIF4E CDK4/6 ribavirin gastric cancer resistance

A new look at roles of the cryosphere in sustainable development

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

Advances in Climate Change Research 2019年第2期10卷 124-131页

作者： WANG Xiaoming LIU shi-wei ZHANG Jing-Lin State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190 China

While the cryosphere may bring in adverse impacts on natural and built environment, it may also provide benefits resulting from cryosphere services. By looking into the effect of the cryosphere on human-being, the study develops a unified approach in the analysis of cryospheric risks and services, with one focusing on the adverse impacts by cryospheric hazards and another emphasizing on the benefits that people can obtain from the natural capitals in the cryosphere. Meanwhile, climate change could further alter and complicate the roles of the cryosphere, not only by the changes in risks to cryospheric hazards, but also the changes in services that could potentially add more risks. The study further proposed a risk-based approach for the development of climate adaptation in the cryosphere. The approach essentially takes options to reduce exposure and vulnerability of societies to cryospheric hazards, and to better manage natural capitals and demands together with enhancing utility of the cryosphere, so as to maintain the benefit of cryosphere services in a sustainable way. The study further addresses the role of cryosphere services in strengthening sustainable development in terms of its relation with the sustainable development goals (SDGs), and provides a preliminary results on how the services contributes to SDGs. Overall, the approach developed in this study creates a new way to comprehensively assess the effect of cryosphere changes on our society and identify measures to maximize the benefit while minimizing the risk in relation to the cryosphere.

关键词： Cryosphere Cryospheric science Cryosphere service Cryosphere change Climate change impact Climate change adaptation Risk management

Atlas Compatibility Transformation:A Normal Manifold Learning Algorithm

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

International Journal of Automation and computing 2015年第4期12卷 382-392页

作者： Zhong-Hua Hao shi-wei Ma Fan Zhao School of Mechatronic Engineering and Automation Shanghai Key Laboratory of Power Station Automation TechnologyShanghai University

Over the past few years,nonlinear manifold learning has been widely exploited in data analysis and machine *** paper presents a novel manifold learning algorithm,named atlas compatibility transformation(ACT),It solves two problems which correspond to two key points in the manifold definition:how to chart a given manifold and how to align the patches to a global coordinate space based on *** the first problem,we divide the manifold into maximal linear patch(MLP) based on normal vector field of the *** the second problem,we align patches into an optimal global system by solving a generalized eigenvalue *** with the traditional method,the ACT could deal with noise datasets and fragment ***,the mappings between high dimensional space and low dimensional space are *** on both synthetic data and real-world data indicate the effection of the proposed algorithm.

关键词： Nonlinear dimensionality reduction manifold learning normal vector field maximal linear patch ambient space.

Tectonic evolution of the Dabashan orocline, central China: Insights from the superposed folds in the eastern Dabashan foreland

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2013年第6期4卷 729-741页

作者： wei shi Jianhua Li Mi Tian Guoli Wu Key Laboratory of Neotectonic Movement and Geohazard Ministry of Land and Resources Institute of Geomechanics Chinese Academy of Geological Sciences Wuxi Research Institute of Petroleum Geology Institute of Geology and Geophysics Chinese Academy of Sciences

The Dabashan orocline is situated in the northwestern margin of the central Yangtze block,central *** studies have defined the orthogonal superposed folds growing in its central-western segment thereby confirming its two-stage tectonic evolution *** mapping has revealed that more types of superposed folds have developed in the eastern segment of the orocline,which probably provides more clues for probing the structure and tectonic history of the Dabashan *** this paper,based on geological mapping,structural measurements and analyses of deformation,we have identified three groups of folds with different trends （***-,NE-and nearly E-trending folds） and three types of structural patterns of superposed folds in the eastern Dabashan foreland （***-axial,oblique,and conjunctional superposed folds）.In combination with geochronological data,we propose that the synaxial superposed folds are due to two stages of ～N-S shortening in the west and north of the Shennongjia massif,and that oblique superposed folds have been resulted from the superposition of the NW-and NE-trending folds onto the early ～ E-W folds in the east of the Shennongjia massif in the late Jurassic to early *** conjunctional folds are composed of the NW-and NE-trending folds,corresponding to the regional-scale dual-orocline in the eastern Sichuan as a result of the southwestward expansion of the Dabashan foreland during late Jurassic to early Cretaceous,coeval with the northwestward propagation of the Xuefengshan *** of the structure and geochronology of the belt shows that the Dabashan orocline is a combined deformation belt primarily experiencing a twostage tectonic evolution history in Mesozoic,initiation of the Dabashan orocline as a foreland basin along the front of the Qinling orogen in late Triassic to early Jurassic due to collisional orogeny,and the final formation of the Dabashan orocline owing to the southwestward propagation of th

关键词： Dabashan foreland belt Superposed folds Orocline Paleo-stress field Intra-continental orogeny Late Jurassic

Optical and SAR image registration based on improved nonsubsampled wavelet transform for sea islands

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2014年第5期33卷 86-95页

作者： shi wei SU Fenzhen WANG Ruirui LU Yongduo Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Collaborative Innovation Center of South China Sea Studies Nanjing University Beijing Forestry University National Marine Environmental Forecasting Center State Oceanic Administration

Homologous feature point extraction is a key problem in the optical and synthetic aperture radar （SAR） image registration for islands. A new feature point extraction method using a threshold shrink operator and non-subsampled wavelet transform （TSO-NSWT） for optical and SAR image registration was proposed. Moreover, the matching for this proposed feature was different from the traditional feature matching strategies and was performed using a similarity measure computed from neighborhood circles in low-frequency bands. Then, a number of reliably matched couples with even distributions were obtained, which assured the accuracy of the registration. Application of the proposed algorithm to SPOT-5 （multi-spectral） and YG-1 （SAR） images showed that a large number of accurately matched couples could be identified. Additionally, both of the root mean square error （RMSE） patterns of the registration parameters computed based on the TSO-NSWT algorithm and traditional NSWT algorithm were analyzed and compared, which further demonstrated the effectiveness of the proposed algorithm. The algorithm can supply the crucial step for island image registration and island recognition.

关键词： image registration islands South China Sea wavelet transform threshold shrink operator

Kolmogorov's ε-Entropy of Bounded Sets in Discrete Spaces and Attractors of Dissipative Lattice Systems

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2007年第2期23卷 313-320页

作者： Sheng Fan ZHOU Qiu Li JIA wei shi Department of Applied Mathematics Shanghai Normal University Department of Mathematics and Physics He'nan University of Science and Technology Department of Mathematics Shanghai University

We obtain an estimate of the upper bound for Kolmogorov＇s ε-entropy for the bounded sets with small ＂tail＂ in discrete spaces, then we present a sufficient condition for the existence of a global attractor for dissipative lattice systems in a reflexive Banach discrete space and establish an upper bound of Kolmogorov＇s ε-entropy of the global attractor for lattice systems.

关键词： Kolmogorov's ε-entropy discrete space dissipative lattice system global attractor