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101.
102.
酒钢不锈钢冷轧二期大冷线基础分9块,全长270 m,底部标高最深为7.6 m。基础螺栓标高大致分三层近千根,由于设备安装精度要求高,螺栓相对尺寸及总尺寸的安装精度同样要求十分严格。为了保证螺栓的安装精度,从测量控制、螺栓固定架安装、螺栓安装、混凝土浇筑等几个方面进行了严格的控制。特别是定位控制,采用长短线相结合的方法,利用全站仪进行有效的控制,满足了规范的相关规定。 相似文献
103.
《Ergonomics》2012,55(11):1551-1557
Abstract This paper examines (1) the responses of participants in specific indoor sports to questions regarding their self-perceived health and fitness, and (2) the relation betweeen these responses and body composition. A representative sample of indoor sports participants (n = 4308; 2938 male and 1370 female) from six cities in the United Kingdom responded to a questionnaire concerned with their self-perception of health and fitness. Height and weight was established from self-report and a body mass index (BMI) was calculated. Seventy eight percent of males and 85% of females reported their health as ‘good’ or ‘excellent’. Less than 2% of the sample reported their health as ‘poor’ or ‘very poor’. However, only 67% of males and 67% of females reported their fitness as ‘good’ or ‘excellent’. Again, the proportion of the sample reporting ‘poor’ or ‘very poor’ fitness was low; less than 4%. The question on health was compared with a recent general population survey and this yielded markedly more ‘unfavourable’ results; only 72% of males and 70% of females reported their health as being ‘good’ or ‘excellent’. A comparison of the response category groups for BMI showed significant differences between the ‘poor’ and ‘fair’ groups but not between the ‘good’ and ‘excellent’ groups. It is concluded that: (1) indoor sports participants regard their health and fitness highly, but their fitness less so than their health; (2) adiposity tends to be associated with poorer perceptions of health and fitness; (3) women sports participants perceive their health more highly than others of the same age compared with men, yet the reverse is true of fitness. 相似文献
104.
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106.
Nanoparticle assembly and colloidal processing are two techniques with the goal to fabricate materials and devices from preformed particles. While colloidal processing has become an integral part of ceramic processing, nanoparticle assembly is still mainly limited to academic interests. It typically starts with the precise synthesis of building blocks, which are generally not only considerably smaller than those used for colloidal processing, but also better defined in terms of size, shape, and size distribution. Their arrangement into 1D, 2D, and 3D architectures is performed with great accuracy well beyond what is achieved by colloidal processing. At the same time, the final assembly is not sintered such that the intrinsic, nanospecific properties of the initial building blocks are preserved or even lead to collective behavior. However, in contrast to colloidal processing the structures accessible by nanoparticle assembly are often limited to a small length scale. The review presents selected examples of nanoparticle assembly and colloidal processing with the goal to reveal the capabilities of these two techniques to fabricate novel materials from preformed building blocks, and also to demonstrate the immense opportunities that would arise if the two methods could be combined with each other. 相似文献
107.
Louis Frentzel-Beyme Pascal Kolodzeiski Kai Terlinden Sebastian Henke 《Advanced functional materials》2023,33(36):2302033
Porous framework materials are of major importance for a wide range of technologies. Nevertheless, many of these materials lack processibility as they are typically synthesized under rather harsh conditions and obtained as microcrystalline powders that cannot easily be coated or deposited from solution. Herein, a new approach to water-processable metal–organic framework materials is presented. The materials are based on amphiphilic organic building blocks consisting of polar carboxylate groups and non-polar alkyl chains connected to a rigid aromatic core. The amphiphilic building blocks assemble to porous framework structures via bonding to kinetically labile sodium ions from concentrated aqueous solution. The obtained crystalline materials, termed amphiphile salt frameworks , are thermally and mechanically stable (some derivatives up to 365 °C and up to at least 4000 bar hydrostatic pressure), exhibit persistent microporous channels accessible to several gases (N2, CO2, propane, propylene, n-butane), and can be reversibly assembled/disassembled by crystallization from or dissolution in water. Systematic variation of the hydrophobic side chains of the amphiphile building blocks allows extracting structure-property relationships and first design rules for this new class of water-processable microporous framework materials. 相似文献
108.
Jaeyoung Jang Sooji Nam Kyuhyun Im Jaehyun Hur Seung Nam Cha Jineun Kim Hyung Bin Son Hwansoo Suh Marsha A. Loth John E. Anthony Jong‐Jin Park Chan Eon Park Jong Min Kim Kinam Kim 《Advanced functional materials》2012,22(5):1005-1014
The preparation of uniform large‐area highly crystalline organic semiconductor thin films that show outstanding carrier mobilities remains a challenge in the field of organic electronics, including organic field‐effect transistors. Quantitative control over the drying speed during dip‐coating permits optimization of the organic semiconductor film formation, although the kinetics of crystallization at the air–solution–substrate contact line are still not well understood. Here, we report the facile one‐step growth of self‐aligning, highly crystalline soluble acene crystal arrays that exhibit excellent field‐effect mobilities (up to 1.5 cm V?1 s?1) via an optimized dip‐coating process. We discover that optimized acene crystals grew at a particular substrate lifting‐rate in the presence of low boiling point solvents, such as dichloromethane (b.p. of 40.0 °C) or chloroform (b.p. of 60.4 °C). Variable‐temperature dip‐coating experiments using various solvents and lift rates are performed to elucidate the crystallization behavior. This bottom‐up study of soluble acene crystal growth during dip‐coating provides conditions under which one may obtain uniform organic semiconductor crystal arrays with high crystallinity and mobilities over large substrate areas, regardless of the substrate geometry (wafer substrates or cylinder‐shaped substrates). 相似文献
109.
为了使温度循环试验在有效提高电子组件的可靠性方面得以广泛应用,基于温度循环试验的机理,对电子组件温度循环试验的关键参数(温度范围、循环次数、保持时间、温变速率、风速)进行了探讨,给出了这些参数的工程经验选取值。在此基础上,借助热分析软件分析了温变速率、保持时间和风速三个参数对试验过程的影响并定性分析了三个参数间的关系。最后,提出了进行温度循环试验时应注意的问题,强调科学、正确地执行温度循环试验的重要性。 相似文献
110.
Lifeng Huang Naresh Eedugurala Anthony Benasco Song Zhang Kevin S. Mayer Daniel J. Adams Benjamin Fowler Molly M. Lockart Mohammad Saghayezhian Hamas Tahir Eric R. King Sarah Morgan Michael K. Bowman Xiaodan Gu Jason D. Azoulay 《Advanced functional materials》2020,30(24)
Conductive polymers largely derive their electronic functionality from chemical doping, processes by which redox and charge‐transfer reactions form mobile carriers. While decades of research have demonstrated fundamentally new technologies that merge the unique functionality of these materials with the chemical versatility of macromolecules, doping and the resultant material properties are not ideal for many applications. Here, it is demonstrated that open‐shell conjugated polymers comprised of alternating cyclopentadithiophene and thiadiazoloquinoxaline units can achieve high electrical conductivities in their native “undoped” form. Spectroscopic, electrochemical, electron paramagnetic resonance, and magnetic susceptibility measurements demonstrate that this donor–acceptor architecture promotes very narrow bandgaps, strong electronic correlations, high‐spin ground states, and long‐range π‐delocalization. A comparative study of structural variants and processing methodologies demonstrates that the conductivity can be tuned up to 8.18 S cm?1. This exceeds other neutral narrow bandgap conjugated polymers, many doped polymers, radical conductors, and is comparable to commercial grades of poly(styrene‐sulfonate)‐doped poly(3,4‐ethylenedioxythiophene). X‐ray and morphological studies trace the high conductivity to rigid backbone conformations emanating from strong π‐interactions and long‐range ordered structures formed through self‐organization that lead to a network of delocalized open‐shell sites in electronic communication. The results offer a new platform for the transport of charge in molecular systems. 相似文献