全文获取类型
收费全文 | 4556篇 |
免费 | 495篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 73篇 |
综合类 | 13篇 |
化学工业 | 1177篇 |
金属工艺 | 175篇 |
机械仪表 | 290篇 |
建筑科学 | 53篇 |
矿业工程 | 16篇 |
能源动力 | 169篇 |
轻工业 | 243篇 |
水利工程 | 87篇 |
石油天然气 | 2篇 |
无线电 | 798篇 |
一般工业技术 | 1120篇 |
冶金工业 | 379篇 |
原子能技术 | 59篇 |
自动化技术 | 406篇 |
出版年
2023年 | 50篇 |
2022年 | 71篇 |
2021年 | 123篇 |
2020年 | 105篇 |
2019年 | 138篇 |
2018年 | 144篇 |
2017年 | 162篇 |
2016年 | 201篇 |
2015年 | 161篇 |
2014年 | 242篇 |
2013年 | 278篇 |
2012年 | 328篇 |
2011年 | 374篇 |
2010年 | 228篇 |
2009年 | 279篇 |
2008年 | 227篇 |
2007年 | 178篇 |
2006年 | 133篇 |
2005年 | 150篇 |
2004年 | 137篇 |
2003年 | 153篇 |
2002年 | 160篇 |
2001年 | 100篇 |
2000年 | 87篇 |
1999年 | 76篇 |
1998年 | 145篇 |
1997年 | 103篇 |
1996年 | 92篇 |
1995年 | 52篇 |
1994年 | 54篇 |
1993年 | 48篇 |
1992年 | 36篇 |
1991年 | 43篇 |
1990年 | 29篇 |
1989年 | 12篇 |
1988年 | 18篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 28篇 |
1984年 | 11篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1977年 | 7篇 |
1976年 | 12篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1970年 | 4篇 |
排序方式: 共有5060条查询结果,搜索用时 0 毫秒
81.
High‐Performance All‐Polymer Solar Cells Via Side‐Chain Engineering of the Polymer Acceptor: The Importance of the Polymer Packing Structure and the Nanoscale Blend Morphology 下载免费PDF全文
82.
Transient Electronics: Thermally Triggered Degradation of Transient Electronic Devices (Adv. Mater. 25/2015) 下载免费PDF全文
83.
Yu Ra Jeong Heun Park Sang Woo Jin Soo Yeong Hong Sang‐Soo Lee Jeong Sook Ha 《Advanced functional materials》2015,25(27):4228-4236
Stretchable electronics have recently been extensively investigated for the development of highly advanced human‐interactive devices. Here, a highly stretchable and sensitive strain sensor is fabricated based on the composite of fragmentized graphene foam (FGF) and polydimethylsiloxane (PDMS). A graphene foam (GF) is disintegrated into 200–300 μm sized fragments while maintaining its 3D structure by using a vortex mixer, forming a percolation network of the FGFs. The strain sensor shows high sensitivity with a gauge factor of 15 to 29, which is much higher compared to the GF/PDMS strain sensor with a gauge factor of 2.2. It is attributed to the great change in the contact resistance between FGFs over the large contact area, when stretched. In addition to the high sensitivity, the FGF/PDMS strain sensor exhibits high stretchability over 70% and high durability over 10 000 stretching‐releasing cycles. When the sensor is attached to the human body, it functions as a health‐monitoring device by detecting various human motions such as the bending of elbows and fingers in addition to the pulse of radial artery. Finally, by using the FGF, PDMS, and μ‐LEDs, a stretchable touch sensor array is fabricated, thus demonstrating its potential application as an artificial skin. 相似文献
84.
High‐Performance Transition Metal Dichalcogenide Photodetectors Enhanced by Self‐Assembled Monolayer Doping 下载免费PDF全文
Dong‐Ho Kang Myung‐Soo Kim Jaewoo Shim Jeaho Jeon Hyung‐Youl Park Woo‐Shik Jung Hyun‐Yong Yu Chang‐Hyun Pang Sungjoo Lee Jin‐Hong Park 《Advanced functional materials》2015,25(27):4219-4227
Most doping research into transition metal dichalcogenides (TMDs) has been mainly focused on the improvement of electronic device performance. Here, the effect of self‐assembled monolayer (SAM)‐based doping on the performance of WSe2‐ and MoS2‐based transistors and photodetectors is investigated. The achieved doping concentrations are ≈1.4 × 1011 for octadecyltrichlorosilane (OTS) p‐doping and ≈1011 for aminopropyltriethoxysilane (APTES) n‐doping (nondegenerate). Using this SAM doping technique, the field‐effect mobility is increased from 32.58 to 168.9 cm2 V?1 s in OTS/WSe2 transistors and from 28.75 to 142.2 cm2 V?1 s in APTES/MoS2 transistors. For the photodetectors, the responsivity is improved by a factor of ≈28.2 (from 517.2 to 1.45 × 104 A W?1) in the OTS/WSe2 devices and by a factor of ≈26.4 (from 219 to 5.75 × 103 A W?1) in the APTES/MoS2 devices. The enhanced photoresponsivity values are much higher than that of the previously reported TMD photodetectors. The detectivity enhancement is ≈26.6‐fold in the OTS/WSe2 devices and ≈24.5‐fold in the APTES/MoS2 devices and is caused by the increased photocurrent and maintained dark current after doping. The optoelectronic performance is also investigated with different optical powers and the air‐exposure times. This doping study performed on TMD devices will play a significant role for optimizing the performance of future TMD‐based electronic/optoelectronic applications. 相似文献
85.
Yong‐Joon Kim Jong‐Hwa Woo Myung‐Soo Kim Gershon Elber 《Computer Animation and Virtual Worlds》2015,26(3-4):423-432
We present an interactive tree modeling and deformation system that supports an efficient collision detection and avoidance using a bounding volume hierarchy of sweep surfaces. Starting with conventional tree models (given as meshes), we convert them into sweep surfaces and deform their branches interactively while detecting and avoiding collisions with many other branches. Multiple tree models (sharing the same topology) can be generated with great ease using this sweep‐based approach, and they can serve as a basis for the generation of a multiparameter family of trees. We demonstrate the effectiveness of our approach in an automatic generation of similar trees, the colonization of trees to form a forest, and the tree growth, aging, and withering simulations. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
86.
介绍了真空缓冷炉渣的工艺矿物学特性。试验研究结果表明,该炉渣属于中等可碎性偏难,硬度系数在8 ̄16之间,在磨矿细度为-0.016mm占89%时,粗、扫选抛尾粗精矿再磨再选,以Z-200、SN-9和丁胺为混合捕收剂,最终得到铜精矿产率为4.59%,精矿含铜23.48%,含金5.8g/t,铜回收率为83.70%;尾矿含铜0.22%,含金0.18g/t。 相似文献
87.
A comprehensive kinetic model for a semibatch direct esterification reactor has been developed. The solid-liquid equilibirium of terephthalic acid was considered in the modeling. Effects of the monomer feed ratio, reaction temperatures, and oligomer addition on the conversion, degree of polymerization, and the formation of diethylene glycol were studied. © 1996 John Wiley & Sons, Inc. 相似文献
88.
In this article the leader election algorithm based on the performance and operation rate of nodes and links is proposed. 相似文献
89.
Kim NK Cho S Lee SH Park HR Lee CS Cho YM Choy YH Yoon D Im SK Park EW 《Meat science》2008,80(4):1068-1073
Proteomic profiling by two-dimensional gel electrophoresis and mass spectrometry of longissimus dorsi muscle tissue from Korean native cattle identified seven proteins that are differentially expressed in animals producing low and high quality grade beef. The expression level of alpha actin is increased in high quality grade beef and the expression levels of T-complex protein 1 (TCP-1), heat shock protein beta-1 (HSP27), and inositol 1,4,5-triphosphate receptor type1 (IP3R1), a new protein to be associated with meat quality, are increased in low quality grade beef. In particular, the quantitation of HSP27 and IP3R1 by both silver staining and immunoblotting correlated well with intramuscular fat content, meat tenderness, and free calcium levels. The data suggest that HSP27 and IP3R1 are potential meat quality biomarkers and their identification provides new insight into the molecular mechanisms and pathways associated with overall beef quality. 相似文献
90.
Maniyazagan Munisamy Hyeon-Woo Yang Naveenkumar Perumal Nayoung Kang Woo Seung Kang Sun-Jae Kim 《International journal of molecular sciences》2022,23(8)
The most pressing concerns in environmental remediation are the design and development of catalysts with benign, low-cost, and efficient photocatalytic activity. The present study effectively generated a flower-like indium oxide (In2O3-MF) catalyst employing a convenient MOF-based solvothermal self-assembly technique. The In2O3-MF photocatalyst exhibits a flower-like structure, according to morphology and structural analysis. The enhanced photocatalytic activity of the In2O3-MF catalyst for 4-nitrophenol (4-NP) and methylene blue (MB) is likely due to its unique 3D structure, which includes a large surface area (486.95 m2 g−1), a wide spectrum response, and the prevention of electron–hole recombination compared to In2O3-MR (indium oxide-micro rod) and In2O3-MD (indium oxide-micro disc). In the presence of NaBH4 and visible light, the catalytic performances of the In2O3-MF, In2O3-MR, and In2O3-MD catalysts for the reduction of 4-NP and MB degradation were investigated. Using In2O3-MF as a catalyst, we were able to achieve a 99.32 percent reduction of 4-NP in 20 min and 99.2 percent degradation of MB in 3 min. Interestingly, the conversion rates of catalytic 4-NP and MB were still larger than 95 and 96 percent after five consecutive cycles of catalytic tests, suggesting that the In2O3-MF catalyst has outstanding catalytic performance and a high reutilization rate. 相似文献