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891.
课程实验是环境工程专业实践教学体系中不可或缺的重要环节。在分析湖北师范学院环境工程专业课程实验开设现状的基础上,进一步提出针对实验内容、考核方式和教学手段的优化思路,以促进本专业的实验教学改革。 相似文献
892.
发育模型是目前具有自主认知能力的发育机器人研究的热点,为解决发育模型问题,定义了发育机器人的体系结构,以及信息处理流程中的算法问题,并针对现有模型不能解决机器人“诱拐”问题,给出了一个任务驱动的发育模型。该模型结构将具有自主环境感知能力的发育机器人结构分为3层:物理层、信号处理层以及发育层。其中,物理层由传感系统、执行机构以及机器人本体组成;信号处理层主要负责实现传感信号的处理;发育层是发育机器人的核心,由特征提取与发育体组成,特征提取可以将大量的传感数据压缩到很少的几维以方便处理,发育体是整个系统的决策机构,负责感知与动作的匹配。 相似文献
893.
894.
薛华清 《西南师范大学学报(自然科学版)》2013,38(8):119-124
西南土石山区高速公路地形地质复杂,环境影响因素多,环保选线难度大,有必要对山区高速公路的路线方案比选进行深入的研究.以梁黔高速公路(梁平至忠县段)为例,对高速公路环保选线过程进行了研究,对初选方案的工程与环境两方面进行了深入比选,提出了环保推荐方案,使高速公路建设与环境保护协调统一. 相似文献
895.
建立了以加速度作为路面激励输入信号,且不考虑非悬置质量的履带车辆单自由度磁流变阻尼控制实验台动力学模型.选定状态变量,推导出悬挂系统状态方程和振动微分方程.依据现代控制理论,分别采用滑移模态控制和极点配置控制算法实现实验台动力学模型的仿真计算,对比分析了在三种不同采样频率下,两种不同控制算法的控制效果,并与被动控制效果进行比较.结果表明,两种算法都能很好地控制车体相对位移、相对速度和加速度,滑移模态控制效果更好.滑移模态控制不仅适用线性问题而且适用非线性问题,因此比极点配置更实用.最后分析确定了最佳仿真采样频率,为控制算法的实验台调试奠定了基础. 相似文献
896.
三维曲面柔性卷板成形技术及其数值模拟 总被引:1,自引:0,他引:1
介绍三维曲面柔性卷板成形技术,并与传统卷板成形和多点成形进行了对比. 对柔性卷板成形装置进行研究并开发出相应的实验装置. 建立柔性卷板成形的有限元模型,并对其成形过程进行数值模拟,得到了较好的模拟结果. 模拟了两种不同材料板材的成形效果,分析了其产生不同成形效果的原因. 相似文献
897.
This paper presents a multi-proxy reconstruction of the climate change in Caotanhu wetland using pollen, phytolith and charcoal records, and the data of loss of ignition (LOI), grain size analysis, and susceptibility. Results reveal that between 4550 and 2500 cal. a BP, a dry climatic condition was not favorable for the accumulation of peat. Since 2500 cal. a BP, the climate became humid and the wetland developed with abundant freshwater aquatic plants, which contributed to peat accumulation. Never-theless, alternate periods of rain and dry climate occurred during that period. Between 2500 and 1810 cal. a BP (550 BC-140 AD), the climate was more humid than at present. A lot of emerged plants, such as Phragmites, Typha and Sparganium, and freshwater green algae grew in the wetland which was sur-rounded by desert-steppe vegetation composed mainly of Chenopodiaceae, Artemisia, Compositae and Thalictrum. However, from 1810 to 1160 cal. a BP (140--790 AD), the water level started to decrease and hydrophyte species reduced greatly, but some Phragmites still grew in the wetland and around it was desert vegetation with high proportion of Chenopodiaceae and Artemisia. Then from 1160 to 650 a BP (790--1300 AD), it entered a period of desert-steppe with abundant mesic and xerophytic plants. And a lot of aquatic plants prevailed in the wetland. Here, what is noticeable is that percentages of arboreal pollen, consisting mainly of Betula and Picea, increased greatly and reached a maximal value of 27.2%, in which, Betula percentages rose to 23.2%. Hence, it is reasonable to conclude that Betula grew in the highland of the wetland, or Picea timberline shifted downward resulting in the increase of percentages of Betula and Picea pollen, which were transported into the wetland by flood or wind. But since 650 cal. a BP, desert vegetation prevailed around the wetland again with dominant Chenopodiaceae and Artemisia, and the climate was similar to modern one. Despite some aquatic plants still growing in the wetland at 相似文献
898.
On the basis of GC and GC-MS analyses, the seasonal variation of leaf lipids is observed in five plant species in Qingjiang in Hubei Province. The CPI values (carbon preference index) of n-alkanes decrease gradually from May to November, though the carbon number distributions and the predominant carbon number in an individual species keep unchanged. The declined CPI values might be caused by the leaf fading, which is further supported by a comparison of the defoliated leaves with the fresh leaves. This observation infers the CPI values of n-alkanes in Quaternary sediments can be used as a tool to index the humification, and thus the climatic and the environmental conditions. The plants analyzed here show a remarkable difference in n-alkanes abundance, suggesting their differential contribution to the n-alkanes identified in sediments. The abundance and the compound species of the n-alkenes detected in the plant leaves change greatly with the seasons due to the influence of temperature, with the least compounds being identified in August. 相似文献
899.
An endpoint damage oriented model for life cycle environmental impact assessment of buildings in China 总被引:2,自引:0,他引:2
The midpoint impact assessment methodology and several weighting methods that are currently used by most building Life cycle assessment (LCA) researchers in China, still have some shortcomings. In order to make the evaluation results have better temporal and spatial applicability, the endpoint impact assessment methodology was adopted in this paper. Based on the endpoint damage oriented concept, four endpoints of resource exhaustion, energy exhaustion, human health damage and ecosystem damage were selected according to the situation of China and the specialties of the building industry. Subsequently the formula for calculating each endpoint, the background value for normalization and the weighting factors were defined. Following that, an endpoint damage oriented model to evaluate the life cycle environmental impact of buildings in China was established. This model can produce an in- tegrated indicator for environmental impact, and consequently provides references for directing the sustainable building design. 相似文献
900.
优化大型仪器设备管理,保障实验教学科研质量 总被引:2,自引:0,他引:2
大型仪器设备为高校进行教学科研活动提供了先进的科学技术手段,有力地促进了学科建设的发展。结合工作实践,针对高校大型仪器设备的使用和管理现状进行探讨,提出了几点建议和措施。 相似文献