全文获取类型
收费全文 | 7513篇 |
免费 | 149篇 |
国内免费 | 15篇 |
学科分类
工业技术 | 7677篇 |
出版年
2023年 | 27篇 |
2022年 | 74篇 |
2021年 | 113篇 |
2020年 | 66篇 |
2019年 | 79篇 |
2018年 | 103篇 |
2017年 | 84篇 |
2016年 | 119篇 |
2015年 | 80篇 |
2014年 | 174篇 |
2013年 | 372篇 |
2012年 | 248篇 |
2011年 | 380篇 |
2010年 | 270篇 |
2009年 | 303篇 |
2008年 | 313篇 |
2007年 | 291篇 |
2006年 | 289篇 |
2005年 | 253篇 |
2004年 | 224篇 |
2003年 | 245篇 |
2002年 | 216篇 |
2001年 | 150篇 |
2000年 | 134篇 |
1999年 | 186篇 |
1998年 | 543篇 |
1997年 | 383篇 |
1996年 | 295篇 |
1995年 | 175篇 |
1994年 | 178篇 |
1993年 | 174篇 |
1992年 | 81篇 |
1991年 | 80篇 |
1990年 | 82篇 |
1989年 | 77篇 |
1988年 | 61篇 |
1987年 | 53篇 |
1986年 | 71篇 |
1985年 | 80篇 |
1984年 | 55篇 |
1983年 | 63篇 |
1982年 | 57篇 |
1981年 | 62篇 |
1980年 | 64篇 |
1979年 | 41篇 |
1978年 | 22篇 |
1977年 | 34篇 |
1976年 | 57篇 |
1975年 | 18篇 |
1973年 | 17篇 |
排序方式: 共有7677条查询结果,搜索用时 15 毫秒
61.
Applied Intelligence - A multi-agent system (MAS) is expected to be applied to various real-world problems where a single agent cannot accomplish given tasks. Due to the inherent complexity in the... 相似文献
62.
Akihiro Yamada Kuniko Kojima Koji Minami Hiroaki Sugiura Hiroshi Kida Kenji Samejima 《Journal of the Society for Information Display》2012,20(7):390-396
Stationary projectors mainly used in system applications have recently gained a wider application range, including general presentations in halls and large conference rooms and being used, for example, in digital signage and for monitoring purposes. Consequently, they are required to meet new market demands for durability, reliability, and flexibility in installation in addition to their conventional basic performance such as especially high brightness. To achieve especially high brightness, a new optical system with two lamps is proposed; the profile of the cover glass that prevents the glass from scattering is made aspherical, the profile of the beam‐combining mirror is improved with its position optimized, and the size of the incident plane of the integrator rod is made larger (1.1 times). These measures resulted in an optical system of an even higher efficiency with 7000 lm, which is the highest in its class (according to a June 2010 investigation). Also, the arrangement of two parallel lamps completely eliminated the effect of heat passing from one lamp to the other, which helped secure durability, reliability, and flexibility in installation. Furthermore, the combined use of the unique non‐telecentric optical system, adopted from the conventional single‐lamp model, helps maintain the class‐highest contrast ratio.1,2 相似文献
63.
Kenji Takizawa Tayfun E. Tezduyar 《Archives of Computational Methods in Engineering》2012,19(1):125-169
The computational challenges posed by fluid–structure interaction (FSI) modeling of parachutes include the lightness of the
parachute canopy compared to the air masses involved in the parachute dynamics, in the case of “ringsail” parachutes the geometric
complexities created by the construction of the canopy from “rings” and “sails” with hundreds of ring “gaps” and sail “slits”,
and in the case of parachute clusters the contact between the parachutes. The Team for Advanced Flow Simulation and Modeling
() has successfully addressed these computational challenges with the Stabilized Space–Time FSI (SSTFSI) technique, which was
developed and improved over the years by the and serves as the core numerical technology, and a number of special techniques developed in conjunction with the SSTFSI
technique. The quasi-direct and direct coupling techniques developed by the , which are applicable to cases with incompatible fluid and structure meshes at the interface, yield more robust algorithms
for FSI computations where the structure is light and therefore more sensitive to the variations in the fluid dynamics forces.
The special technique used in dealing with the geometric complexities of the rings and sails is the Homogenized Modeling of
Geometric Porosity, which was developed and improved in recent years by the . The Surface-Edge-Node Contact Tracking (SENCT) technique was introduced by the as a contact algorithm where the objective is to prevent the structural surfaces from coming closer than a minimum distance
in an FSI computation. The recently-introduced conservative version of the SENCT technique is more robust and is now an essential
technology in the parachute cluster computations carried out by the . We provide an overview of the core and special techniques developed by the , present single-parachute FSI computations carried out for design-parameter studies, and report FSI computation and dynamical
analysis of two-parachute clusters. 相似文献
64.
The fenestrated endotheliocyte of peritubular and glomerular capillaries in rat and mouse kidneys were observed with SEM and TEM. In the glomerular capillary, so-called "pored-domes" were found not only at the fenestrated areolae but also at the nuclear region of the endotheliocyte. At the region between filtration surface and nuclear region, they accumulated to construct a sponge-like structure. The endotheliocyte of peritubular capillary also showed small "pored-domes". The size and morphology of the pores in the "pored-domes" of glomerular and peritubular capillaries were similar to those of areolae fenestratae of the respective capillary. Based on the findings, we assumed that pored-domes and the sponge-like structure are the reservoir for the fenestrated area of the endotheliocyte to accommodate the rapid expansion of capillary lumen. 相似文献
65.
Experimental vapor pressures andP--T data of an important alternative refrigerant, 1, 1-difluoroethane (HFC-152a), have been measured by means of a constant-volume method coupled with expansion procedures. SixtyP--T data were measured along eight isochores in a range of temperaturesT from 330 to 440 K, at pressuresP from 1.6 to 9.3 MPa, and at densities from 51 to 811 kg·m–3. Forty-six vapor pressures were also measured at temperatures from 320 K to the critical temperature. The uncertainties of the temperature and pressure measurements are within ±7mK and ±2kPa, respectively, while the uncertainty of the density values is within ±0.1%. The purity of the sample used is 99.9 wt%. On the basis of the measurements along each isochore, five saturation points were determined and the critical pressure was determined by correlating the vapor-pressure measurements. The second and third virial coefficients for temperatures from 360 to 440 K have also been determined. 相似文献
66.
Yoshiro Nakamura Akira Watanabe Kunio Mori Kosaku Tamura Michio Inagaki 《Journal of Materials Science》1986,21(12):4485-4488
A binary blend which consists of two incompatible polymers such as poly(vinyl chloride) and polyethylene has been performed through a partial co-crosslinking reaction with peroxide to give a co-crosslinked blend with a uniform dispersion of small polyethylene particles and with an improved mechanical property. The results are obtained through the formation of a co-crosslinked product which acts as a potential solid phase dispersant as well as a well-bonded reinforcing interlayer on polyethylene particles uniformly dispersed in poly(vinyl chloride) matrix. The resulting blends (PVC/PE=10/90 wt) give carbon spherules of 0.5 to 1m diameter through pressure-carbonization at 650° C for 1 h. 相似文献
67.
This paper introduces a new method of adapting the virtual world of an offline programming model to an actual robotic cell by attaching a CCD camera to the robot. This method requires no specific camera attachment location or optical camera calibration. Furthermore, there is no operational requirement for setting robotic camera location. Robot motion is autonomously generated to identify the camera view line. The view line is adjusted to pass through the designated target point, utilizing visual feedback motion control. This method calibrates reference points between the virtual world of an offline model to an actual robotic cell. 相似文献
68.
We examined the influence of polyaniline (PAn)'s unit sequence and doping with low molecular weight dopants or polymer dopants on permeation property. It was found that CO2 permeability was increased by the formation of a quinonediimine unit in PAn with the oxidation. CO2 sorption amount of PAn was decreased by oxidation. The increase of CO2 permeability with oxidation, therefore, resulted from the increase of diffusivity, which was attributable to morphological variation by the increase of a quinonediimine unit. The permselectivity of PAn films was found to be remarkably improved by doping. In particular, the selectivity value of the PAn film doped with polyvinyl sulphonic acid as a polymer dopant went up to over 2,000. This remarkable increase of selectivity was found to result in the increase of selectivity, depending on diffusivity. It was also found that the permselectivity of the PAn film doped by polymer dopants was surpassed, as compared with that doped by low molecular dopants. © 1995 John Wiley & Sons, Inc. 相似文献
69.
The wax esters of sperm whale head oil have been characterized by gas-liquid chromatography on an APOLAR 10C column according
to their carbon number and number of double bonds. The novel technique permits the direct quantitative analysis of saturated
and unsaturated wax esters. 相似文献
70.
高速气流冲击式粉体表面改性装置——HYBRIDIZATION系统及应用 总被引:4,自引:0,他引:4
利用高速气流冲击法进行粉体/粉体系表面改性技术,是迄今为止各种粉体材料开发中最为引人注目的技术之一。HYBRIDIZATION(下称HYB)系统是利用高速气流冲击法对微粉体进行干式/机械化处理,是使材料复合化的最实用的装置,可对各类有机物、无机物、金属等进行广泛组合,通用性很强,适用于许多行业领域。从本文所述的系统构成、型式,有关的典型球形化处理的运转特性,利用复合化高温粉体测定被处理粉体表面温度,利用颜料改变色调等的处理特点及该系统的适用性等(一部分是从已发表的学术论文及专利上摘录的),可以说明HYB系统的概况。 相似文献