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41.
基于数据库和Internet的分布式远程多点监控系统研究 总被引:2,自引:0,他引:2
基于Internet的多监控点远程监控系统大多是单监控点系统的推广,这些多监控点系统只能对各测控点进行分时监控,不能对整个系统进行统一的调控,而且各测控点都需要固定的IP地址.为此,本文提出了一种基于数据库的Internet分布式多监控点远程监控系统解决方案.系统可对多监控点状态进行实时的监测,数据汇总、统计和分析和集中调控,各测控点不需要固定的IP地址;系统采用两级数据库实现了数据的缓存,有效解决了Internet网络数据传输不稳定的问题;系统设有Web服务器,通过WWW浏览器可对系统运行状况进行监控.本文给出了系统整体结构和系统各组成部分硬件、软件详细设计与具体实现.在校园网和城域网环境下对系统进行了实验测试.实验结果表明:系统可应用于中低速自动化监控领域,随着Internet网络数据传输速率的提高,系统监控的实时性将进一步得到提高. 相似文献
42.
密立根油滴实验数据的计算机处理 总被引:1,自引:0,他引:1
本文主要给出了利用VB编制的处理密立根油滴实验数据的程序,解决了数据处理的复杂计算的问题,利用该程序软件处理测定的电子电量值与标称值符合得较好,使该实验可以作为综合实验安排. 相似文献
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Pyrolysis of cellulose and lignin 总被引:3,自引:0,他引:3
T. Haensel A. Comouth S. I.-U. Ahmed N. Zydziak J.A. Schaefer 《Applied Surface Science》2009,255(18):8183-8189
X-ray and UV-induced photoelectron spectroscopy (XPS and UPS) and scanning electron microscopy (SEM) have been performed to characterise the pyrolysis of cellulose and lignin and their interaction with methanol. Clean highly oriented pyrolitic graphite (HOPG) was also analysed as a reference material. Asymmetric C1s core level fits and valence band XPS of the samples indicate a graphitic-like structure after the pyrolysis at 1200 °C. Due to the low polar contents in pyrolysed cellulose and lignin, an interaction with methanol under high vacuum conditions could not be identified. From a technical viewpoint a temperature of 1200 °C is attainable without high costs. Therefore, the pyrolysis of wood-based polymers containing high amounts of cellulose and lignin are potential low-cost materials for various applications. If it is possible to generate graphite in complex structures made of wood-based polymers, a cheap and energy-efficient method will become available for producing bipolar plates for fuel cells. Technical problems like form instability and foaming are discussed as well as further development and possible modifications of the ground material to achieve optimal compositions. 相似文献
45.
Lü Ling-Ling 《结构化学》2009,28(10):1226-1235
The excited-state intramolecular hydrogen abstraction reactions of butanal have been investigated using the CAS-MP2/6-311+G^*//CASSCF/6-31G^* methods. Calculated results show that the hydrogen transfer induced fluorescence quenching of the n,π^*-excited state of covalent butanal with three paths: (1) The first path corresponds to direct S0-react reconstitution, which involves the first S1 decay by partial hydrogen atom transfer. (2) The second stepwise mechanism can be viewed as a full hydrogen atom transfer followed by a partial hydrogen atom back transfer, electron transfer (near S1/S0 or S0-TS) and finally a proton transfer to S0-react. (3) On the triplet surface, the surface crossing to the singlet state would be clearly much efficient at the T1/S0 region due to the large SOC value of 8.3 cm^-1. The S0-react decay route from T1/S0 was studied with an intrinsic reaction coordinate (IRC) calculation at the CASSCF level, resulting in the S0-React minimum. 相似文献
46.
随着商场经营模式的转变,商位的出租的管理工作变得复杂,工作量大。计算机信息化管理是解决这个问题的最好的办法。论述了基于VB.NET开发平台商位出租管理系统的开发过程。本系统以SQL Server 2000为数据库,以VB.NET为开发工具,实现了出租合同管理、出租收费管理,为管理者带来极大的方便。 相似文献
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一种多通道数据采集系统设计研究 总被引:1,自引:0,他引:1
以C8051F020单片机为核心设计了多通道数据采集系统,采集系统通过USB与计算机连接,USB实现采集系统供电以及数据通信。基于VB6.0软件设计了控制界面和控制命令,采集数据以二进制文件形式保存,实现数据的多通道便携式数据采集。实际应用表明,该系统便携、操作方便,达到了设计要求。 相似文献
50.
Ordered mesoporous carbons CMK-3, CMK-1 coated with poly(methyl methacrylate)(PMMA)(CMK-3- PMMA and CMK-1-PMMA) and pristine mesoporous carbons CMK-3, CMK-1 were employed to adsorb vitamin B12(VB12) from water solution. Adsorption isotherm and kinetics of adsorption were investigated via batch experi- ments. It was found that the adsorption capacity of VB12 at 30, 40 and 50 °C can reach 688.2, 572.4 and 428.7 mg/g, respectively. The adsorption isotherm can be described by Langmuir model. The pseudo first- and second-order kinetic models were employed to fit the dynamic adsorption. It was found that the dynamic adsorption follows the pseudo second-order model. The thermodynamic equilibrium coefficients obtained at different temperatures were used to evaluate the thermodynamic constants ΔG0, ΔH0 and ΔS0. The negative value of Gibbs free energy, ΔG0 indicates that the adsorption occurred via a spontaneous process. The increase in the value of –ΔG0 with increasing temperature indicates that higher temperatures were favourable to the sorption process. The enthalpy values of ΔH040 kJ/mol(66.36 kJ/mol and 56.43 kJ/mol) for CMK-3-PMMA and CMK-1-PMMA confirm that chemisorption were involved in the adsorption process. This is consistent with the IR spectra and is another evidence for the formation of hydrogen bond between PMMA in the pore of CMK-3 and VB12. 相似文献