全文获取类型
收费全文 | 1473篇 |
免费 | 29篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 103篇 |
综合类 | 1篇 |
化学工业 | 416篇 |
金属工艺 | 36篇 |
机械仪表 | 33篇 |
建筑科学 | 29篇 |
矿业工程 | 1篇 |
能源动力 | 59篇 |
轻工业 | 98篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 97篇 |
一般工业技术 | 319篇 |
冶金工业 | 96篇 |
原子能技术 | 42篇 |
自动化技术 | 172篇 |
出版年
2022年 | 27篇 |
2021年 | 23篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 18篇 |
2016年 | 27篇 |
2015年 | 17篇 |
2014年 | 40篇 |
2013年 | 71篇 |
2012年 | 54篇 |
2011年 | 93篇 |
2010年 | 52篇 |
2009年 | 54篇 |
2008年 | 78篇 |
2007年 | 74篇 |
2006年 | 58篇 |
2005年 | 58篇 |
2004年 | 48篇 |
2003年 | 53篇 |
2002年 | 53篇 |
2001年 | 36篇 |
2000年 | 27篇 |
1999年 | 30篇 |
1998年 | 61篇 |
1997年 | 50篇 |
1996年 | 33篇 |
1995年 | 24篇 |
1994年 | 21篇 |
1993年 | 31篇 |
1992年 | 18篇 |
1991年 | 23篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 19篇 |
1987年 | 13篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 22篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 16篇 |
1978年 | 12篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1973年 | 4篇 |
排序方式: 共有1506条查询结果,搜索用时 15 毫秒
11.
Yuta Uenoyama Atsushi Matsuda Kazune Ohashi Koji Ueda Misaki Yokoyama Takuya Kyoutou Kouji Kishi Youichi Takahama Masaaki Nagai Takaaki Ohbayashi Osamu Hotta Hideki Matsuzaki 《International journal of molecular sciences》2022,23(9)
Aberrant glycosylation of IgA1 is involved in the development of IgA nephropathy (IgAN). There are many reports of IgAN markers focusing on the glycoform of IgA1. None have been clinically applied as a routine test. In this study, we established an automated sandwich immunoassay system for detecting aberrant glycosylated IgA1, using Wisteria floribunda agglutinin (WFA) and anti-IgA1 monoclonal antibody. The diagnostic performance as an IgAN marker was evaluated. The usefulness of WFA for immunoassays was investigated by lectin microarray. A reliable standard for quantitative immunoassay measurements was designed by modifying a purified IgA1 substrate. A validation study using multiple serum specimens was performed using the established WFA-antibody sandwich automated immunoassay. Lectin microarray results showed that WFA specifically recognized N-glycans of agglutinated IgA1 in IgAN patients. The constructed IgA1 standard exhibited a wide dynamic range and high reactivity. In the validation study, serum WFA-reactive IgA1 (WFA+-IgA1) differed significantly between healthy control subjects and IgAN patients. The findings indicate that WFA is a suitable lectin that specifically targets abnormal agglutinated IgA1 in serum. We also describe an automated immunoassay system for detecting WFA+-IgA1, focusing on N-glycans. 相似文献
12.
理论上研究了吸收层材料的光学常数,该常数满足从紫外线到近红外波长范围的四层结构的光子-热转换的高效率。通过使用有效介质近似(EMA)模型,复合材料(金属陶瓷)的光学性能与模拟材料的光学性能非常吻合。此外,提出了使用Ti-MgF2金属陶瓷作为吸收层的具有高光子-热转换效率的四层膜结构,其在300~1 600 nm的波长范围内具有约95.1%的高吸收率。研究结果为实现高效率的光热转换器件提供了新途径,显示了优良的应用前景。 相似文献
13.
Satoshi Nakata Kenichi Yoshikawa Osamu Shima Hiroshi Terada 《Advanced functional materials》1992,1(6):281-286
A new chemical sensing system using an electrical oscillator has been developed. This sensing system measures the electrical ‘non-linearity’ at the surface of an electrode immersed in a test solution: a sinusoidal voltage is applied to the electrode and the higher harmonics of the output current are obtained by Fourier transformation. This sensing system has been used to detect and quantify surfactant molecules in solutions. The relative intensity P2/P1 of the peaks of the second (P2) and first (P1) harmonics in the output current was found to be linearly correlated with the logarithms of the concentrations of cationic surfactants such as cetylpyridium bromide (CPB) and cetyl-N,N,N-trimethylammonium bromide (CTAB), but not with those of the anionic surfactant sodium dodecyl sulfate (SDS) or the neutral surfactant Triton X-100. The reproducibility of this sensing system was shown to be excellent. 相似文献
14.
Kushta T. Narita K. Kaneko T. Saeki T. Tohya H. 《Microwave and Wireless Components Letters, IEEE》2003,13(5):169-171
We present results of study of the resonance stub effect occurring in a transition from a through via hole to a stripline in a multilayer printed circuit board (PCB). This effect for via structures including ground vias is estimated by numerical simulations and measurements in the frequency band up to 20 GHz. Ways to alleviate problems in the design of interconnections embedded in multilayer PCBs due to the resonance stub effect and possible applications of the effect in microwave filtering are traced. 相似文献
15.
Wei Zhang Kenji Ochi Michiya Fujiki Masanobu Naito Masaaki Ishikawa Kei‐ichi Kaneto Wataru Takashima Akinori Saeki Shu Seki 《Advanced functional materials》2010,20(22):3941-3947
In this paper a simple, casting solution technique for the preparation of two‐dimensional (2D) arrays of very‐high molecular weight (MW) 1D‐Pc supramolecular inorganic polymers is described. The soluble fluoroaluminium tetra‐tert‐butylphthalocyanine (ttbPcAlF) is synthesized and characterized, which can be self‐assembled to form 2D arrays of very‐high‐MW 1D‐Pc supramolecular inorganic polymers. High‐resolution transmission electron microscopy (HRTEM) demonstrates that the 1D‐ttbPcAlF, having a cofacial ring spacing of ~0.36 nm and an interchain distance of ~1.7 nm, self‐assembles into 2D‐nanosheets (~140 nm in length, ~20 nm in width, and equivalent to MW of 3.2 × 105 g mol?1). The film cast from a 1,2‐dichloroethane (DCE) solution shows a minimum hole‐mobility of ~0.3 cm2 V?1 s?1 at room temperature by flash‐photolysis time‐resolved microwave conductivity (TRMC) measurements and a fairly high dark dc‐conductivity of ~1 × 10?3 S cm?1. 相似文献
16.
Fujiwara Osamu 《电子科学学刊(英文版)》2008,25(3):384-388
Characteristic measurement of contact discharge currents are made through a hand-held metal rod from charged human body. Correlation coefficients are obtained, through Statistic Package for Social Science (SPSS), for various charge voltages, which is based on the effect test of electrode contact approach speeds on discharge current parameters of current peaks, maximum rising slope and spark lengths. Discharge parameters at charge voltage 300V are independent on approach speed. For charge voltages equal to and higher than 500V, the contact approach speed has strong positive correlation with discharge parameters of the peak current and the maximum rising slope, whereas has strong negative correlation with the spark length. 相似文献
17.
Osamu Hanaizumi Yong-Gi Lee Isao Takahashi Tomohiko Nakajo Jun-Ichi Murota Shojiro Kawakami 《Optical Fiber Technology》1995,1(4)
A laminated polarization splitter for the wavelength region longer than 1.3 μm is fabricated for the first time. It is composed of a-SiC:H/SiO2 alternative multilayers prepared by plasma-enhanced chemical vapor deposition. Splitting behavior is also verified experimentally. It has low absorption loss even for the wavelength region around λ = 1.3 μm because the band-gap energy of a-Sic is larger than that of a-Si. The measured splitting angle is 13.8°, which is 2.4 times larger than the 5.7° splitting angle of rutile. The absorption loss of the multilayer is reduced to 1 × 10-3 dB/μm at λ = 1.3 μm. The magnitude of the residual stress is 9.45 × 108 dyn/cm2, which is about one-third of that prepared by the rf bias sputtering equipment which is used for another project of our group. The deposition rate of SiO2, is increased to 135 nm/min, which is 27 times larger than that prepared by the sputtering equipment. 相似文献
18.
Chil-Woo Lee Osamu Hasegawa Wiwat Wongwarawipat Hiroshi Dohi Mitsuru Ishizuka 《Journal of Visual Communication and Image Representation》1991,2(4)
This paper describes a system that can synthesize realistic sequential images of moving goldfish based on the image understanding result of real goldfish. To analyze and synthesize images in real-time, we have constructed a hardware system that consists of 32 paralell transputers with a high-speed visual-data interface called VIT (Visual Interface for Transpputer Network). The system is very flexible and powerful for various types of image processing because it can be extended according to the required computational cost. In the understanding process, we assume that the target object, a goldfish in this case, deforms its shape pliably in 3-D space and moves only in a two-dimensional direction. A modeling, called the Bone-Structured Solid Modeler, which is suitable for representing deformable objects such as living things, plays an important role in the understanding and synthesis processes of the deformable object. Three types of constraints for motion, namely, static, dynamic, and object, are utilized to verify the estimated pose and orientation of the object. In the motion synthesis process, realistic moving images are synthesized by controlling the model employing the motion understanding result. Simulation results are presented to show the effectiveness of the system. The technology discussed in this paper is expected to play a key role in the realization of future visual human interfaces. 相似文献
19.
The paper summarises Japanese activities concerning photovoltaic systems including those for residential use, which is one of the major targets for a domestic alternative energy supply. Fiscal year 1999 marked the 25th anniversary of the Sunshine Project that was initiated in July 1974. The Sunshine Project was subsequently reorganised into the New Sunshine Program to include renewable energy, energy conservation and environmental technology. The major target of the Photovoltaic Technology Development Project in the Programme, from an early stage of R&D, has been focused on utility-connected, residential applications mounted on roofs. Recently, it can be considered that technologies for the target have been fundamentally established and a series of new activities have been introduced to promote the commercialisation and diffusion of PV systems. To review those activities, several condensed tables are presented, i.e., R&D history of residential applications, recent trends in regulation and code improvements, and new institutional activities to disseminate PV systems. The authors also present performance results collected from a large number of PV systems by using a very effective evaluation method called the ‘SV method’. The paper finishes by introducing a good example of simple system monitoring with good verification that can establish a knowledge circle from a variety of PV fields, including to factories, engineers, owners and investors, and it seems to be quite cost-effective. 相似文献
20.
Hydrogen is a clean alternative to conventional hydrocarbon fuels, but it is very important to reduce the nitrogen oxides (NOx) emissions generated by hydrogen combustion. The rich-lean combustion or staged combustion is known to reduce NOx emissions from continuous combustion burners such as gas turbines and boilers, and NOx reduction effects have been demonstrated for hydrocarbon fuels. The authors applied rich-lean combustion to a hydrogen gas turbine and showed its NOx reduction effect in previous research. The present study focused on experimental measurements of NO and NO2 emissions from a coaxial rich-lean burner fueled with hydrogen. The results were compared with diffusion combustion and methane rich-lean combustion. Significant reductions in NO and NO2 were achieved with rich-lean combustion. The NO and NO2 reduction effects by rich-lean combustion relative to conventional diffusion combustion were higher with hydrogen than with methane. 相似文献