全文获取类型
收费全文 | 4535篇 |
免费 | 507篇 |
国内免费 | 136篇 |
专业分类
电工技术 | 197篇 |
综合类 | 250篇 |
化学工业 | 1847篇 |
金属工艺 | 265篇 |
机械仪表 | 70篇 |
建筑科学 | 68篇 |
矿业工程 | 29篇 |
能源动力 | 106篇 |
轻工业 | 230篇 |
水利工程 | 2篇 |
石油天然气 | 70篇 |
武器工业 | 18篇 |
无线电 | 596篇 |
一般工业技术 | 1294篇 |
冶金工业 | 56篇 |
原子能技术 | 7篇 |
自动化技术 | 73篇 |
出版年
2024年 | 26篇 |
2023年 | 110篇 |
2022年 | 100篇 |
2021年 | 151篇 |
2020年 | 164篇 |
2019年 | 164篇 |
2018年 | 179篇 |
2017年 | 165篇 |
2016年 | 192篇 |
2015年 | 181篇 |
2014年 | 238篇 |
2013年 | 238篇 |
2012年 | 356篇 |
2011年 | 333篇 |
2010年 | 234篇 |
2009年 | 277篇 |
2008年 | 239篇 |
2007年 | 273篇 |
2006年 | 266篇 |
2005年 | 223篇 |
2004年 | 196篇 |
2003年 | 147篇 |
2002年 | 132篇 |
2001年 | 103篇 |
2000年 | 100篇 |
1999年 | 86篇 |
1998年 | 85篇 |
1997年 | 57篇 |
1996年 | 51篇 |
1995年 | 38篇 |
1994年 | 22篇 |
1993年 | 18篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有5178条查询结果,搜索用时 15 毫秒
971.
为提高铜浆料的导电性能,利用微胶囊技术对铜粉表面做改性处理,添加碳纳米管为导电增强相,制备碳纳米管-微胶囊铜复合浆料。利用四探针测试仪、扫描电子显微镜(SEM) 等研究了微胶囊铜粉的抗氧化性能及碳纳米管的参数、添加量对铜浆料导电性能的影响,分析其导电机理并建立导电相连接模型。研究结果表明:微胶囊化的铜粉具有较好的抗氧化性和导电性。当碳纳米管与铜粉的质量比为4∶[KG-2mm]96时,采用管径1~2 nm,长度5~30 nm的碳纳米管制备的复合浆料的电阻率达到最小值6.05 mΩ·cm,与纯铜浆料相比降低了89.39%。以碳纳米管-铜复合浆料与铜浆料分别制得导电膜,两者相比,前者更平坦、更致密,导电相间的接触更紧密,大量的碳纳米管覆盖在铜粉颗粒表面或填充铜粉颗粒间隙,同时碳纳米管之间相互“吸引”,形成致密的网状结构,在铜粉颗粒之间建立起大量的导电“桥梁”,从而改善了复合浆料的导电性能。 相似文献
972.
A new approach for making stable, flexible, and conductive hollow fibres of poly (acrylonitrile) using dry-jet-wet spinning technique is investigated, wherein the inner walls of the poly (acrylonitrile) hollow fibres are deposited with silver nanowires using their dispersion in the bore fluid. The bore fluid plays a crucial role in determining the morphology and flexibility of the hollow fibres and entrapment of long silver nanowires on the inner walls. Fibres with AgNW layer having high conductivity of ~104 Scm−1 are obtained with the use of ~2 wt% of silver nanowires. The conducting fibres are successfully assembled into coaxial configuration to yield highly stable, flexible supercapacitors with capacitance value of 128 Fcm−3. The unique morphology of these conductive hollow fibres opens the possibility of making flexible and stable devices for wearable electronics. 相似文献
973.
974.
Chen Wang Stanislav S. Rubakhin Michael J. Enright Jonathan V. Sweedler Ralph G. Nuzzo 《Advanced functional materials》2021,31(14):2010246
Electrically conductive 3D periodic microscaffolds are fabricated using a particle-free direct ink writing approach for use as neuronal growth and electrophysiological recording platforms. A poly (2-hydroxyethyl methacrylate)/pyrrole ink, followed by chemical in situ polymerization of pyrrole, enables hydrogel printing through nozzles as small as 1 µ m. These conductive hydrogels can pattern complex 2D and 3D structures and have good biocompatibility with test cell cultures ( ≈ 94.5% viability after 7 days). Hydrogel arrays promote extensive neurite outgrowth of cultured Aplysia californica pedal ganglion neurons. This platform allows extracellular electrophysiological recording of steady-state and stimulated electrical neuronal activities. In summation, this 3D conductive ink printing process enables the preparation of biocompatible and micron-sized structures to create customized in vitro electrophysiological recording platforms. 相似文献
975.
Zhanrong Jia Jinglei Gong Yan Zeng Jinhui Ran Jin Liu Kefeng Wang Chaoming Xie Xiong Lu Jun Wang 《Advanced functional materials》2021,31(19):2010461
Ideal epidermal bioelectronics can be used not only for long-term detection of physiological signals for disease diagnosis but also for chronic disease treatment. Silk, an animal-derived fiber with good biocompatibility and skin-affinity, is widely used in flexible bioelectronics. However, silk fibers are insulating. In this study, ultralong conductive silk microfibers (mSFs) are fabricated by extracting mSF from raw silk using a bioinspired extraction-protection process with the assistance of polydopamine, followed by deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) on its surface. The conductive mSFs are produced and used to fabricate a conductive flexible silk fibroin patch, which is used as a conformable bioelectronic for monitoring physiological signals. In addition, as the conductive mSF possessed anti-oxidative activity, the patch exhibits excellent performance in chronic diabetic wound healing by reducing inflammation and regulating oxidative stress. Thus, this bioinspired strategy produces conductive silk fibers that can be used as biocompatible building blocks, opening new avenues for employing passive silk as an active component in the design of epidermal wound repair biomaterials and next-generation flexible epidermal bioelectronics. 相似文献
976.
Lijuan Diao Qianli Ma Wensheng Yu Guixia Liu Jinxian Wang Xiangting Dong 《大分子材料与工程》2021,306(6):2100052
Novel flexible anisotropic conductive film with light-controllable property is designed and constructed. The film is composed of electrospun polymeric nanobelts array loaded with TiO2 nanoparticles. The products are characterized by scanning electron microscopy, X-ray diffractometry, thermal gravimetric analysis, and ultraviolet–visible absorption spectroscopy. The conductivity of the materials along two perpendicular directions of the film surface is investigated under dark and light irradiation conditions. The results reveal that the film is insulative in all directions under dark condition. Under irradiation, the light resistance along the length direction of the nanobelts is three orders of magnitude lower than the dark resistance, and the light resistance along the length direction of the nanobelts is two orders of magnitude lower than that along the perpendicular direction on the film surface. The effects of loading quantity of TiO2 nanoparticles and ratio of polyethylene oxide (PEO) to polymethylmethacrylate (PMMA) on the properties of the products are studied, and the influencing mechanism is proposed. This kind of anisotropic conductive film with new characteristics has broad application prospects in controllable flexible circuits and other fields. 相似文献
977.
Samira Agbolaghi 《Polymer International》2019,68(8):1516-1523
Reduced graphene oxide nanosheets modified by conductive polymers including polythiophene (GPTh), polyaniline (GPANI) and polypyrrole (GPPy) were prepared using the graphene oxide as both substrate and chemical oxidant. UV–visible and Raman analyses confirmed that the graphene oxide simultaneously produced the reduced graphene oxide and polymerized the conjugated polymers. The prepared nanostructures were subsequently electrospun in mixing with poly(3‐hexylthiophene) (P3HT)/phenyl‐C71‐butyric acid methyl ester (PC71BM) and poly[bis(triisopropylsilylethynyl)benzodithiophene‐bis(decyltetradecylthien)naphthobisthiadiazole] (PBDT‐TIPS‐DTNT‐DT)/PC71BM components and embedded in the active layers of photovoltaic devices to improve the charge mobility and efficiency. The GPTh/PBDT‐TIPS‐DTNT‐DT/PC71BM devices demonstrated better photovoltaic features (Jsc = 11.72 mA cm?2, FF = 61%, Voc = 0.68 V, PCE = 4.86%, μh = 8.7 × 10?3 cm2 V–1 s?1 and μe = 1.3 × 10?2 cm2 V–1 s?1) than the GPPy/PBDT‐TIPS‐DTNT‐DT/PC71BM (Jsc = 10.30 mA cm?2, FF = 60%, Voc = 0.66 V, PCE = 4.08%, μh = 1.4 × 10?3 cm2 V–1 s?1 and μe = 8.9 × 10?3 cm2 V–1 s?1) and GPANI/PBDT‐TIPS‐DTNT‐DT/PC71BM (Jsc = 10.48 mA cm?2, FF = 59%, Voc = 0.65 V, PCE = 4.02%, μh = 8.6 × 10?4 cm2 V–1 s?1 and μe = 7.8 × 10?3 cm2 V–1 s?1) systems, assigned to the greater compatibility of PTh in the nano‐hybrids and the thiophenic conjugated polymers in the bulk of the nanofibers and active thin films. Furthermore, the PBDT‐TIPS‐DTNT‐DT polymer chains (3.35%–5.04%) acted better than the P3HT chains (2.01%–3.76%) because of more complicated conductive structures. © 2019 Society of Chemical Industry 相似文献
978.
Syamak Farajikhah Rebecca Van Amber Sepidar Sayyar Sajjad Shafei Cormac D. Fay Stephen Beirne Mohammad Javadi Xungai Wang Peter C. Innis Brett Paull Gordon G. Wallace 《大分子材料与工程》2019,304(3)
The demand for wearable electronics has resulted in an increasing interest in the development of functional fibers, with a specific focus upon the development of electrically conductive fibers incorporable into garments. However, the production of thermally conductive fibers for heat dissipation has been largely neglected. Owing to the very rapid development of miniaturized wearable electronics, there is an increasing need for the development of thermally conductive fibers as heat sinks and thermal management processes. In this study, thermally conductive but electrically insulating boron nitride nanopowder (BNNP) fillers are used to effectively enhance the thermal conductivity and mechanical properties of elastomeric polyurethane fibers. Thermal conductivity enhancement of more than 160% is achieved at very low loadings of BNNP (less than 5 wt%) with an improvement in the mechanical properties of the unmodified fiber. These thermally conductive fibers are also incorporated into 3D textile structures as a proof of processability. 相似文献
979.
Coolnise导热排湿纬编针织产品的开发 总被引:2,自引:1,他引:1
介绍了Coolnise涤纶纤维的性能,简述了它的导热排湿针织产品的形成方法和在生产中需注意的问题。 相似文献
980.