检索结果-南通市图书馆

The role of botanical gardens in scientific research, conservation, and citizen science

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2018年第4期40卷 181-188页

作者： gao chen Weibang Sun Kunming Botanical Garden Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 Yunnan China Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Kunming 650204 China Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 Yunnan China

Plant diversity is currently being lost at an unprecedented rate, resulting in an associated decrease in ecosystem services. About a third of the world＇s vascular plant species face the threat of extinction due to a variety of devastating activities, including, over-harvesting and over exploitation, destructive agricul- tural and forestry practices, urbanization, environmental pollution, land-use changes, exotic invasive species, global climate change, and more. We therefore need to increase our efforts to develop integrative conservation approaches for plant species conservation. Botanical gardens devote their resources to the study and conservation of plants, as well as making the world＇s plant species diversity known to the public. These gardens also play a central role in meeting human needs and providing well-being. In this minireview, a framework for the integrated missions of botanical gardens, including scientific research, inJex situ conservation, plant resource utilization, and citizen science are cataloged. By reviewing the history of the development of Kunming Botanical Garden, we illustrate successful species conservation approaches （among others, projects involving Camellia, Rhododendron, Magnolia, Begonia, Alliurn, Ne- penthes, medicinal plants, ornamental plants, and Plant Species with Extreme Small Populations）, as well as citizen science, and scientific research at Kunming Botanical Garden over the past 80 years. We emphasize that Kunming Botanical Garden focuses largely on the ex situ conservation of plants from Southwest China, especially those endangered, endemic, and economically important plant species native to the Yunnan Plateau and the southern Hengduan Mountains. We also discuss the future chal- lenges and responsibilities of botanical gardens in a changing world, including： the negative effects of outbreeding and/or inbreeding depression; promoting awareness, study, and conservation of plant species diversity; accelerating global access t

关键词： Botanical gardens Citizen science Conservation biology Endangered plants Germplasm Horticulture

On the Largest Prime Factor of Shifted Primes

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2017年第3期33卷 377-382页

作者： Feng Juan chen Yong gao chen School of Mathematical Sciences Soochow University School of Mathematical Sciences and Institute of Mathematics Nanjing Normal University

For any integer n ≥ 2, let P（n） be the largest prime factor of n. In this paper, we prove 1 This that the number of primes p 〈 x with P（p- 1） ≥ pC is more than （1 -c＋o（1））π（x） for 0 〈 c 〈 1/2 extends... 详细信息

关键词： Prime factor shifted prime

Design and operation strategies of the system for destroying time-sensitive target based on system effectiveness

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2008年第6期19卷 1151-1156页

作者： chen Jun gao Xiaoguang Ding Lin School of Electronics and Information Northwestern Polytechnical Univ. Xi'an 710072 P. R. China

To improve the effect of destroying time-sensitive target （TST）, a method of operational effectiveness evaluation is presented and some influential factors are analyzed based on the combat flow of system for destroying TST. Considering the possible operation modes of the system, a waved operation mode and a continuous operation mode are put forward at first. At the same time, some relative formulas are modified. In examples, the influential factors and operation modes are analyzed based on the system effectiveness. From simulation results, some design and operation strategies of the system for destroying time sensitive targets are concluded, which benefit to the improvement of the system effectiveness.

关键词： effectiveness evaluation time-sensitive target waved operation mode continuous operation mode

Five Consecutive Positive Odd Numbers None of Which Can Be Expressed as a Sum of Two Prime Powers Ⅱ

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2008年第11期24卷 1883-1890页

作者： Yong gao chen Min TANG Department of Mathematics Nanjing Normal University Nanjing 210097 P. R. China Department of Mathematics Anhui Normal University Wuhu 241000 P. R. China

In this paper, we find two integers k0, m of 159 decimal digits such that if k ≡ k0 （mod m）, then none of five consecutive odd numbers k, k - 2, k - 4, k - 6 and k - 8 can be expressed in the form 2^n ± p^α, wher... 详细信息

关键词： Erdos problems covering systems odd numbers sums of prime powers

A 3-DOF Pseudo-Rigid-Body Model for Tension-Based Compliant Bistable Mechanisms

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2010年第2期23卷 149-153页

作者： chen Guimin gao Hongwei JIA Jianyuan School of Mechatronics Xidian University Xi ＇an 710071 China

Compliant bistable mechanisms, devices with two distinct stable equilibrium positions, are used in a variety of applications, such as switches, clasps, and valves. Many kinds of compliant bistable mechanisms were proposed and studied during the past decade. Among them, tension-based compliant bistable mechanisms, that incorporate tension pivots as their flexible members, feature in short travel distance and low power consuming. So far, the design of this kind of bistable mechanisms is done using finite element method through trial and error, thus is time-consuming. By treating the tension pivots as fixed-guided segments and their elongation as a spring, we developed a novel three degree-of-freedom （3-DOF） pseudo-rigid-body model （PRBM） for this kind of bistable mechanisms. The principle of virtual work is used to derive the force-deflection relationship of the PRBM model. The comparison between the PRBM results and the experimental results of the force-deflection characteristics shows that the PRBM can predict not only the bistable behavior of the tension-based bistable mechanisms, but also their soft spring-like post-bistable behavior and the spring-like force-deflection characteristics when pulling in the reverse direction from the as-fabricated position, which is called reverse behavior. The 3-DOF PRBM can be used to design and identify tension-based bistable mechanisms. Using the PRBM instead of the trial-and-error method can greatly reduce the development time of this kind of bistable mechanisms.

关键词： compliant bistable mechanism pseudo-rigid-body model tension pivot

Data and knowledge-driven named entity recognition for cyber security

在线全文

学校读者我要写书评

暂无评论

Cybersecurity 2021年第1期4卷 123-135页

作者： chen gao Xuan Zhang Hui Liu School of Software Yunnan University650091 YunnanChina Key Laboratory of Software Engineering of Yunnan Province 650091 YunnanChina Engineering research center of cyberspace 650091 YunnanChina

Named Entity Recognition(NER)for cyber security aims to identify and classify cyber security terms from a large number of heterogeneous multisource cyber security *** the field of machine learning,deep neural networks automatically learn text features from a large number of datasets,but this data-driven method usually lacks the ability to deal with rare *** et *** a deep learning method for named entity recognition in the field of cyber security,and achieved good results,reaching an F1 value of 82.8%.But it is difficult to accurately identify rare entities and complex words in the *** cope with this challenge,this paper proposes a new model that combines data-driven deep learning methods with knowledge-driven dictionary methods to build dictionary features to assist in rare entity *** addition,based on the data-driven deep learning model,an attentionmechanism is adopted to enrich the local features of the text,better models the context,and improves the recognition effect of complex *** results show that our method is better than the baseline *** model is more effective in identifying cyber security *** Precision,Recall and F1 value reached 90.19%,86.60%and 88.36%respectively.

关键词： Cyber security Named entity recognition Attention mechanism Dictionary Deep learning

Global impact of RNA splicing on transcriptome remodeling in the heart

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

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第8期13卷 603-608页

作者： chen gao Yibin WANG Molecular Biology Institute University of California Los Angeles California 90095 USA

In the eukaryotic transcriptome, both the numbers of genes and different RNA species produced by each gene contribute to the overall complexity. These RNA species are generated by the utilization of different transcriptional initiation or termination sites, or more commonly, from different messenger RNA (mRNA) splicing events. Among the 30 000+ genes in human genome, it is estimated that more than 95% of them can generate more than one gene product via alternative RNA splicing. The protein products generated from different RNA splicing variants can have different intracellular localization, activity, or tissue-distribution. Therefore, alternative RNA splicing is an important molecular process that contributes to the overall complexity of the genome and the functional specificity and diversity among different cell types. In this review, we will discuss current efforts to unravel the full complexity of the cardiac transcriptome using a deep-sequencing approach, and highlight the potential of this technology to uncover the global impact of RNA splicing on the transcriptome during development and diseases of the heart.

关键词： Alternative RNA splicing Transcriptome,Gene regulation Heart RNA-seq

Decode protein-metabolite regulatory network: one MIDAS at a time

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2023年第9期8卷 3896-3898页

作者： Tian Liu chen gao Department of Pharmacology and Systems Physiology University of CincinnatiCincinnatiOHUSA

In a recent study published in Science,Hicks et *** Mass spectrometry integrated with equilibrium dialysis for the discovery of allostery systematically(MIDAS)to explore protein-metabolite interactome and have revealed previously unknown regulation for lactate dehydrogenase.1 This report brings an exciting new approach to address a long-standing challenge in *** functions are orchestrated by an interactive network of molecular constituents,the physical interactions between proteins and other molecular entities,such as DNA,RNA,and *** basic vocabulary for the book of life,these interactions are the fundamental mechanisms for complex physiology and diseases.

关键词： network such she

Moderate deviations and central limittheorem for small perturbationWishart processes

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

Frontiers of Mathematics in China 2014年第1期9卷 1-15页

作者： Lei chen Fuqing gao Shaochen WANG School of Mathematics and Statistics Wulhan University Wuhan 430072 China

Let X^ε be a small perturbation Wishart process with values in the set of positive definite matrices of size m, i.e., the process X^ε is the solution of stochastic differential equation with non-Lipschitz diffusion coefficient： dXt^ε = √εXt^εtdBt＇＋ dBt＇√εXt^ε ＋ ρImdt, X0 = x, where B is an rn x m matrix valued Brownian motion and B＇ denotes the transpose of the matrix B. In this paper, we prove that { （Xt^ε-Xt^0）/√εh^2（ε）,ε 〉 0} satisfies a large deviation principle, and （Xt^ε - Xt^0）/√ε converges to a Gaussian process, where h（ε） → ＋∞ and √ε h（ε） →0 as ε →0. A moderate deviation principle and a functional central limit theorem for the eigenvalue process of X^ε are also obtained by the delta method.

关键词： Large deviation moderate deviation central limit theorem Wishart vprocess eigenvalue