全文获取类型
收费全文 | 477篇 |
免费 | 12篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 491篇 |
出版年
2023年 | 2篇 |
2022年 | 12篇 |
2021年 | 13篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 13篇 |
2015年 | 7篇 |
2014年 | 16篇 |
2013年 | 25篇 |
2012年 | 16篇 |
2011年 | 33篇 |
2010年 | 19篇 |
2009年 | 27篇 |
2008年 | 15篇 |
2007年 | 29篇 |
2006年 | 9篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 16篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 15篇 |
1995年 | 6篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有491条查询结果,搜索用时 15 毫秒
1.
Moritoshi Yasunaga Noriyuki Aibe Yoshiki Yamaguchi Yorihisa Yamamoto Takaaki Awano Ikuo Yoshihara 《Artificial Life and Robotics》2008,12(1-2):219-222
Watching and tracking an object while seeing a much wider view is one of advantages of the eye system. We proposed and developed
a tracking camera system that mimics the eyes by using double-lens modules. In the system, a wide view is captured through
the wide-lens module, while the target in it is tracked and magnified through the telescopic lens module. Electronic circuits
for tracking control are implemented onto the reconfigurable VLSI or FPGA in order to embed the parallelism in the tracking
algorithm into the hardware. A successfully developed FPGA-based prototype performs high-speed tracking at the video-rate.
This work was present in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27,
2007 相似文献
2.
Matano T. Takai Y. Takahashi T. Sakito Y. Fujii I. Takaishi Y. Fujisawa H. Kubouchi S. Narui S. Arai K. Morino M. Nakamura M. Miyatake S. Sekiguchi T. Koyama K. 《Solid-State Circuits, IEEE Journal of》2003,38(5):762-768
A 1-Gb/s/pin 512-Mb DDRII SDRAM has been developed using a digital delay-locked loop (DLL) and a slew-rate-controlled output buffer. The digital DLL has a frequency divider for DLL input, performs at an operating frequency of up to 500 MHz at 1.6 V, and provides internal clocking with 50% duty-cycle correction. The DLL has a current-mirror-type interpolator, which enables a resolution as high as 14 ps, needs no standby current, and can operate at voltages as low as 0.8 V. The slew-rate impedance-controlled output buffer circuit reduces the output skew from 107 to 10 ps. This SDRAM was tested using a 0.13-/spl mu/m 126.5-mm/sup 2/ 512-Mb chip. 相似文献
3.
Ryu Nakadate Yoshiki MatsunagaJorge Solis Atsuo Takanishi Eiichi MinagawaMotoaki Sugawara Kiyomi Niki 《Mechanism and Machine Theory》2011,46(8):1066-1083
The ultrasound diagnosis of the carotid artery is one of the most common non-invasive methods to detect early stage heart and cerebrovascular diseases. However, the precision and repetitiveness of the probe positioning depend exclusively on the operator's skills and dexterity. For this purpose, we propose the development of a robot assisted system to enhance the accuracy and repetitiveness of the probe positioning to measure the wave intensity (WI) index. In this paper, the Waseda-Tokyo Women's Medical-Aloka Blood Flow Measurement Robot System No. 2 Refined (WTA-2R) is presented. The WTA-2R consists of a conventional ultrasound diagnosis system, a 6-DOFs parallel link slave manipulator, a 6-DOFs serial link passive arm, and a master device. Experiments were carried out to verify its effectiveness in terms of accuracy and required time to perform the task. From the experimental results, the positioning accuracy and reduction of required time were confirmed. 相似文献
4.
Nobuyuki?KobayashiEmail author Tsubasa?Wago Yoshiki?Sugawara 《Multibody System Dynamics》2011,26(3):265-281
A method of reducing the system matrices of a planar flexible beam described by an absolute nodal coordinate formulation (ANCF)
is presented. In this method, we focus that the bending stiffness matrix expressed by adopting a continuum mechanics approach
to the ANCF beam element is constant when the axial strain is not very large. This feature allows to apply the Craig–Bampton
method to the equation of motion that is composed of the independent coordinates when the constraint forces are eliminated.
Four numerical examples that compare the proposed method and the conventional ANCF are demonstrated to verify the performance
and accuracy of the proposed method. From these examples, it is verified that the proposed method can describe the large deformation
effects such as dynamic stiffening due to the centrifugal force, as well as the conventional ANCF does. The use of this method
also reduces the computing time, while maintaining an acceptable degree of accuracy for the expression characteristics of
the conventional ANCF when the modal truncation number is adequately employed. This reduction in CPU time particularly pronounced
in the case of a large element number and small modal truncation number; the reduction can be verified not only in the case
of small deformation but also in the case of a fair bit large deformation. 相似文献
5.
Summary Hydroboration polymerization of various ,-dicyanoalkanes with thexylborane produced the corresponding poly(cyclodiborazane)s, that consist of boron-nitrogen four-membered rings. The structures of the obtained polymers were confirmed by spectroscopic analyses such as 1H-, 11B-NMR and IR spectra. From the result of thermogravimetric analysis of the polymer prepared from adiponitrile and thexylborane, 12% of the inorganic materials remained after heating at 900°C. *** DIRECT SUPPORT *** AEB03051 00003 相似文献
6.
SiO2 thin film deposition on the inner surface of a poly(tetra-fluoroethylene) narrow tube by atmospheric-pressure glow microplasma 总被引:1,自引:0,他引:1
SiO2 thin films were deposited on the inner surfaces of a commercial poly(tetrafluoroethylene) narrow tube with an inner diameter of 0.5 mm using tetraethoxysilane/O2 feedstock gases and He carrier gas by atmospheric-pressure microplasma-enhanced chemical vapor deposition. A glow microplasma was generated inside the tube by radio frequency (RF) capacitively coupled discharge. X-ray photoelectron spectroscopy spectra showed that the tube inner surface was covered by a SiO2 thin film. Transparent SiO2 thin films were obtained with a deposition rate of 230 nm/min at an RF power of 6 W and substrate temperature of 100 °C. The wettability of the SiO2-coated tube was about 3 times as large as that of an untreated sample tube. 相似文献
7.
Hydrogenases catalyze uptake and production of H2. Heterolytic cleavage of H2 bound on [NiFe]-hydrogenase (E) produces two unequal H species to form E:HaHb, where Ha and Hb behave differently. The structures of various states of the enzyme established by crystallography and spectroscopy were used to construct a catalytic cycle of the enzyme. The Ni–Fe center of the active enzyme has the Ni–Fe bridging site vacant. The enzyme is suggested to bind H2 either at Ni or Fe atom. In E:HaHb, Ha is considered to be a protein-bound hydron (proton or deuteron) at the entrance to the hydrophobic gas tunnel. The structure of a synthetic hydrogenase-mimic suggests Hb to be the 6th ligand to Fe. Two successive one-electron processes from E:HaHb complete the catalytic cycle of H2 uptake. The reverse of the cycle operates in the H2 production. The proposed catalytic cycle is consistent with the kinetic, crystallographic and spectroscopic studies. 相似文献
8.
Y. Kawabata M. Utsuro S. Hayashi H. Yoshiki 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1988,30(4):557-566
Concentrations and depth distributions of the surface hydrogen and the surface deuterium in vacuum evaporated nickel layers and beryllium plates have been investigated by the ERDA method. It is shown that if the evaporation vacuum pressure is kept better than 10−6 Torr, the hydrogen adsorption from the residual gas during the evaporation is negligible and the hydrogen from residual or atmospheric gases after the evaporation is the main source of the surface hydrogen. Commercial beryllium plates are found to have surface hydrogen of about 1016 atoms cm2. Deuterium treated samples, either in D2 gas or heavy water, do not show more than possibly a partial replacement of hydrogen. The influence of substrates is small if the thickness of the evaporated nickel layer is more than 2000 Å. The measurements are in good agreement with previously published results. 相似文献
9.
10.
Summary
Novel through-spaceπ-conjugated polymer based on poly(p-henyleneethynylene)/poly(p-phenylenebutadiynylene) hybrids containing a [2.2]paracyclophane unit in the main chain was synthesized by copper-catalyzed
alkyne coupling reaction. The structure of the polymer was supported by 1H NMR and IR spectra. The obtained polymer was soluble in common organic solvents such as THF, CH2C12, CHC13 and toluene. The number-average of molecular weight of the polymer was estimated to be 63000 by GPC. The polymer emitted
a bluish green light in solution and in the solid state.
Received:24 September 2002/Revised version: 19 November 2002/Accepted: 19 November 2002
Correspondence to Yoshiki Chujo 相似文献