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91.
我县小水电事业起步早、发展快,素有“小水电之乡”之称。全县电站数量众多、星罗棋布,共有水电站56座,总装机为14.4万kW。但电站装机容量都比较小,普遍选用0.4kV低压机组。现结合我县小水电的实际,谈谈水电站低压机组的设备改造及运行情况。 相似文献
92.
通过对近距离煤层开采高瓦斯综采工作面瓦斯涌出量的分析,指出工作面上隅角瓦斯涌出量大而治理难度也大,通过采取瓦斯的综合治理等措施,提高了瓦斯抽放率,提高了工作面单产,取得了较好的经济效益。 相似文献
93.
一种针对高维决策空间的进化多目标优化方法 总被引:2,自引:1,他引:1
进化算法可并行处理多个解的特性使得它特别适合解决多目标优化问题。针对高维决策空间,将基因表达式编程引入多目标优化,设计了新的个体结构和操作,提出了一个进化多目标优化算法EMOGEP。实验结果表明,新算法在低维决策空间是可行和有效的;在高维决策空间中,表现出了比传统进化多目标优化算法更好的性能;多模态情况下,新算法能很好的逼近理论Pareto前沿。 相似文献
94.
研究了在盐酸介质中,蜜胺树脂对铑的吸附行为及其影响因素,将实验结果与在硝酸,硫酸中的吸附进行比较,对其吸附机理作了初步探讨。 相似文献
95.
CHEN TianRan YU KeFu SHI Qi LI Shu Gilbert J. Price WANG Rong ZHAO MeiXia CHEN TeGu ZHAO JianXin 《科学通报(英文版)》2009,54(12):2107-2117
Coral reefs worldwide are becoming increasingly and detrimentally impacted upon by a variety of factors including significant climate changes, such as global warming and increased El Nino-Southern Oscillation activity. Generally, the persistence of coral reefs, especially at low-latitudes, is governed, in part, by sea surface temperatures not exceeding the critical limit (-30℃) at which mass mortality can occur. Thus, it is thought that corals living at high-latitudes (i.e., currently cooler sea surface temperatures) will likely respond more favourably to hypothesized future temperature increases than corals living at low-latitudes (i.e., currently warmer sea surface temperatures). Consequently, high-latitude coral communities may have the potential to act as regions of refugia for many coral species in the face of potential future global warming. The Daya Bay (22°31′--22°50′N), northern South China Sea, contains several high-latitude non-reefal coral communities and represents one of the most northerly distributions of scleractinian corals within the region. Significantly, Daya Bay has experienced dramatic warming in both air and sea surface temperatures throughout the past 50 years. In this paper, we analyze 25 years of change in the Daya Bay coral communities, based both on historic surveys and our latest 2006--2008 regional ecological surveys. Our results suggest that, contrary to predictions, there have been significant declines in coral cover within the Daya Bay during the past 25 years (i.e., 76.6% coral cover in 1983/1984 to only 15.3% coral cover by 2008). Such changes also reflect a significant shift in the most abundant coral species, from Acropora pruinosa to Favites abdita. Most of the modern coral communities became established between 15 and 30 years ago, corresponding to a period of increased winter sea surface temperature. However, very few colonies have become established within the last 15 years, despite a more intense period of warming. By taking into account additional factors, we hypothesize that direct anthropogenic impacts, rather than climatic events, have both restricted the development, and drove the decline, of Daya Bay coral communities in the last 15 years. The Daya Bay has also been subjected to occasional extreme cold events during the past 50 years, with the most recent occurring in early 2008 (13 January-13 February). During the 2008 cold event, the lowest air temperature reaches only 6.6℃, and the mean sea surface temperature for February fall to 〈 14℃, including six continuous days at 12.3℃. Significantly, the sea surface temperatures fall below the hypothesized critical lower temperature threshold (-13℃) that commonly leads to mass mortality in scleractinian coral communities. Surprisingly, our coral community surveys, conducted both before (August 2007) and after (late February 2008) the extreme 2008 cold event, demonstrate that the Daya Bay coral ecosystems are barely impacted upon during the cold period. Those observations suggest that the Daya Bay scleractinian coral communities have developed adaptations to low sea surface temperatures. Overall, our data support the hypothesis that high-latitude coral communities, such as Daya Bay, have the potential to act as areas of refugia for scleractinian corals in the advent of potential future global warming. 相似文献
96.
97.
DESIGN METHODOLOGY OF NETWORKED SOFTWARE EVOLUTION GROWTH BASED ON SOFTWARE PATTERNS 总被引:4,自引:1,他引:4
Keqing HE Rong PENG Jing LIU Fei HE Peng LIANG Bing LI 《系统科学与复杂性》2006,19(2):157-181
Recently,some new characteristics of complex networks attract the attentions of scientistsin different fields,and lead to many kinds of emerging research directions.So far,most of the researchwork has been limited in discovery of complex network characteristics by structure analysis in large-scalesoftware systems.This paper presents the theoretical basis,design method,algorithms and experiment results ofthe research.It firstly emphasizes the significance of design method of evolution growth for networktopology of Object Oriented(OO)software systems,and argues that.the selection and modulationof network models with various topology characteristics will bring un-ignorable effect on the processof design and implementation of OO software systems.Then we analyze the similar discipline of“negation of negation and compromise”between the evolution of network models with different topologycharacteristics and the development of software modelling methods.According to the analysis of thegrowth features of software patterns,we propose an object-oriented software network evolution growthmethod and its algorithms in succession.In addition,we also propose the parameter systems for OOsoftware system metrics based on complex network theory.Based on these parameter systems,it cananalyze the features of various nodes,links and local-world,modulate the network topology and guidethe software metrics.All these can be helpful to the detailed design,implementation and performanceanalysis.Finally.we focus on the application of the evolution algorithms and demonstrate it by a casestudy.Comparing the results from our early experiments with methodologies in empirical software engi-neering,we believe that the proposed software engineering design method is a computational softwareengineering approach based on complex network theory.We argue that this method should be greatlybeneficial for the design,implementation,modulation and metrics of functionality,structure and per-formance in large-scale OO software complex system. 相似文献
98.
XIE Rong HE Zhishui LIU Fanghua ZOU Huasong ZHU Jiabi YU Guanqiao 《科学通报(英文版)》2006,51(17):2087-2094
Under limited nitrogen conditions, rhizobia are ableto induce the formation of nitrogen-fixing root nodules on their leguminous plant host. This organogenetic process is triggered by a complex exchange of molecu- lar signals between the host plant and bac… 相似文献
99.
BI Chuanxing CHEN Xinzhao ZHOU Rong CHEN Jian 《科学通报(英文版)》2006,51(11):1374-1380
In the past twenty years, nearfield acoustic holography (NAH) has become an efficient tool for noise source identification, noise source localization and acoustic field visualization. By measuring the complex pressure or particle velocity on a hologram su… 相似文献
100.
LIU Rong GUO Chunyan JIANG Yang 《科学通报(英文版)》2006,51(12):1467-1475
Working memory refers to temporary storage and manipulation of “on-line” information in the brain,which is central to a large range of cognitive capabili- ties[1]. Visual working memory involves processes such as maintaining, updating and manipulating b… 相似文献