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91.
Tianxi Sun Zhiguo Liu Yude Li Guangpu Wang Guanghua Zhu Qing Xu Xiaoyan Lin Hui Liu Ping Luo Qiuli Pan Yuepeng Teng Xunliang Ding 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(24):3554-3560
A laboratory micro X-ray fluorescence spectrometer based on a special polycapillary X-ray lens (PXRL) was used to carry out the source apportionment of aerosol particles. In the curve of the distribution of the X-ray intensity in the focal spot of the special PXRL, there was a plateau with a diameter of 21.3 μm in which the distribution of the X-ray intensity was homogeneous. The gain in flux density in the plateau of the PXRL is 1490. The uniformity of this plateau was 2.9%. This was helpful for the quantitative X-ray fluorescence analysis of a single aerosol particle with smaller size than that of the plateau of the PXRL. The fingerprint database of aerosol particles with given sizes from various air pollution sources was established with the single particle analysis method. The size-resolved source apportionment of aerosol particles in haze in Beijing city was performed with this fingerprint database. 相似文献
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94.
Jintuo Zhu Xinjian He Liang Wang Xiaoxue Liao Guangping Teng Pengli Jing 《矿业科学技术学报(英文版)》2022,32(1):215-224
High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners.This paper aims at quantitatively evaluating the respirators used in deep coal mines and providing scientific guidance for the respiratory protection of miners.Based on the self-designed in-situ PM2.5collector,controllable PM2.5generator,human breathing simulator,and respirator simulation testing system,under the simulated deep mine working ... 相似文献
95.
Dingfang Liu Zheng Teng John J. Sansalone Frank K. Cartledge 《Canadian Metallurgical Quarterly》2001,127(10):879-888
Most current control strategies for storm water treatment utilize fixed or filter-bed media with specific gravity (ρs) greater than 1.0. In contrast to Part I, Part II focuses on such higher density (ρs > 1.0) manganese-oxide-coated media that can be used in combined unit operations and processes for in-situ treatment of storm water. Methods were developed to coat manganese oxides onto sand and cementitious media for storm water treatment. With respect to manganese, coatings of ramsdellite produced a point of zero charge (PZC) of 5.2, while mixtures of birnessite and cryptomelane produced a PZC of 2.6 Manganese oxide increased the specific surface area (SSA) of sand and cementitious media. Manganese-oxide-coated sand (MOCS) produced a larger SSA (2.48-m2∕g), as compared with birnessite-coated media (BCM) (1.51 m2∕g), while the two have a similar surface charge (PZC = 6.4). Manganese-oxide-coated cementitious media (MOCM) produced a significantly larger SSA (19.49 m2∕g), as compared with coated sand, and SEM analyses indicated the surface contained manganese oxide and calcite of thickness 10–30 μm. Based on the results, coated cementitious media provided surface characteristics that can significantly enhance filtration and adsorption of heavy metal in storm water, in comparison to sand. 相似文献
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97.
马腾 《Canadian Metallurgical Quarterly》2011,10(2)
儒法思想之融通,在历史渊源上呈现为"儒法同宗"的命题.管仲的思想是其实质依据,后来稷下学官的<管子>将其文本化.李悝、吴起师儒而任法,开"儒家"向"法家"转变之先河."杂家"尸佼曾为商鞅之师,其思想以儒家思想为主体,杂以法家思想,亦体现了儒法思想的融通."转关人物"的思想不但从学术源流上印证了法家出于儒家的命题,且揭示了法家的"政治家"本质,蕴涵了对传统政治法律文化中人物思想矛盾性的解释. 相似文献
98.
开展65 nm高速大容量静态随机存取存储器(SRAM)大气中子单粒子效应特性及试验评价技术研究,基于4 300 m高海拔地区大面积器件阵列实时测量试验,突破效应甄别、智能远程测控等关键技术,在153 d的试验时间内共观测到错误43次,其中器件内单粒子翻转39次,多单元翻转(MCU)在单粒子翻转中占比23%,最大的MCU为9位。对高能中子、热中子和封装α粒子的贡献比例进行了分析,并基于多地中子通量数据,推演得到北京地面和10 km高空应用时的单位翻转(SBU)和MCU失效率(FIT)。发现地面处软错误的主要诱因为封装α粒子,随着海拔的增高,大气中子对软错误的贡献比例明显增大;MCU全部由高能中子引起,北京10 km高空处的MCU FIT值明显增大,其占比由地面的8%增大至26%。结合器件版图布局,对MCU产生机理进行了深入分析。最后,提出一种目标导向的存储器软错误加固策略优化方法。 相似文献
99.
Finding clusters in data is a challenging problem. Given a dataset, we usually do not know the number of natural clusters hidden in the dataset. The problem is exacerbated when there is little or no additional information except the data itself. This paper proposes a general stochastic clustering method that is a simplification of nature-inspired ant-based clustering approach. It begins with a basic solution and then performs stochastic search to incrementally improve the solution until the underlying clusters emerge, resulting in automatic cluster discovery in datasets. This method differs from several recent methods in that it does not require users to input the number of clusters and it makes no explicit assumption about the underlying distribution of a dataset. Our experimental results show that the proposed method performs better than several existing methods in terms of clustering accuracy and efficiency in majority of the datasets used in this study. Our theoretical analysis shows that the proposed method has linear time and space complexities, and our empirical study shows that it can accurately and efficiently discover clusters in large datasets in which many existing methods fail to run. 相似文献
100.
针对嵌入式实时系统在系统负载模型不确定的情况下系统的实时任务错过率过高以及调度稳定性差的问题,提出了一个基于反馈控制的调度模型.该模型主要由改进的多级队列调度器和3个控制器(准入控制器、执行等级控制器、比例积分微分(PID)控制器)组成.任务的错过率偏差反馈到PID控制器,产生相应的调整量并作用于其他两个控制器,对实时任务的执行等级进行调整, 经过调整的任务被调度器调度执行.在对模型中每个部件进行了一些结构调整和改进设计之后,将该调度模型应用于嵌入式可配置操作系统(eCos)中.实验结果表明,该模型降低了任务的时限错过率,同时解决了系统频频超载的问题. 相似文献