全文获取类型
收费全文 | 1094篇 |
免费 | 20篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 1116篇 |
出版年
2023年 | 3篇 |
2021年 | 18篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 45篇 |
2012年 | 34篇 |
2011年 | 50篇 |
2010年 | 29篇 |
2009年 | 44篇 |
2008年 | 34篇 |
2007年 | 40篇 |
2006年 | 42篇 |
2005年 | 30篇 |
2004年 | 39篇 |
2003年 | 32篇 |
2002年 | 22篇 |
2001年 | 27篇 |
2000年 | 30篇 |
1999年 | 28篇 |
1998年 | 125篇 |
1997年 | 68篇 |
1996年 | 40篇 |
1995年 | 37篇 |
1994年 | 20篇 |
1993年 | 28篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 16篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1932年 | 2篇 |
排序方式: 共有1116条查询结果,搜索用时 15 毫秒
11.
Kiyoaki Imoto Kohshin Takahashi Takahiro Yamaguchi Teruhisa Komura Jun-ichi Nakamura Kazuhiko Murata 《Solar Energy Materials & Solar Cells》2003,79(4):459-469
Here, we reported that a new carbon electrode prepared with an activated carbon was superior to a Pt sputtered electrode as the counter electrode of dye-sensitized solar cells. The photovoltaic performance was largely influenced by the roughness factor of carbon electrode. The open-circuit voltage increased by about 60 mV using the carbon counter electrode compared to the Pt counter electrode because of positive shift of the formal potential for I3−/I− couple. 相似文献
12.
Keita Yagi Junji Murata Yasuhisa Sano Hidekazu Goto 《Science and Technology of Advanced Materials》2007,8(3):166-169
The copper damascene process is one of the most promising technologies for fabricating Cu wirings for electronic devices such as LSIs. In this research, the fabrication of damascene Cu wirings was conducted using solid acidic catalyst. When a Cu-plated wafer, whose oxide is a basic oxide is dipped into a mixture of oxidizing solution and acidic solution, surface atoms are ionized and etched off into the solution. However, because conventional nonelectrolytic etching does not have a reference surface, it is difficult to utilize for planarization. Therefore, a new nonelectrolytic machining method using a cation-exchange fabric instead of an acidic solution was developed. To be more precise, the planarization of a Cu-plated wafer was carried out by rubbing with the cation-exchange fabric in ozone water. Basically, this method exploits chemical reactions so that the physical properties of the workpiece surface are not deteriorated. Furthermore, this method uses no chemicals except for ozone water, which easily dissociates into water and oxygen molecules; thus, this method is a low-cost, environmentally friendly process. In this paper, as a preliminary experiment, the nonelectrolytic etching of a Cu sample using solutions of O3 and CO2 was carried out to inspect the dependence of the etching rate on [O3] and [H+]. The results indicate that the etching rate increased as [O3] and [H+] increased. When [H+] was high relative to [O3], a smooth etch-pit-free surface was achieved. Next, nonelectrolytic etching using a cation-exchange fabric was carried out, and properties similar to those in the case of etching using solutions were obtained. Finally, damascene Cu wirings were fabricated using ozone water and a cation-exchange catalyst. 相似文献
13.
Recently, progress has been made in the Generalized Multi-Protocol Label Switching (GMPLS) and Automatic Switched Optical
Networks (ASON) standardizations. These technologies realize construction of large-scaled optical networks, interconnections
among single-domain Wavelength Division Multiplexing (WDM) networks, and direct communication over multi-domain WDM networks.
Meanwhile, it is known that the topology of the Internet exhibits the power-law attribute. Since the topology of the Internet,
which is constructed by interconnecting ASs, exhibits the power-law, there is a possibility that large-scale WDM networks,
which are constructed by interconnecting WDM networks, will also exhibit the power-law attribute. One of the structural properties
of a topology that adheres to the power-law is that most nodes have just a few links, although some have a tremendous number
of them. Another property is that the average distance between nodes is smaller than in a mesh-like network. A natural question
is how such a structural property performs in WDM networks. In this paper, we first investigate the property of the power-law
attribute of physical topologies for WDM networks. We compare the performance of WDM networks with mesh-like and power-law
topologies, and show that links connected to high-degree nodes are bottlenecks in power-law topologies. To relax this, we
introduce a concept of virtual fiber, which consists of two or more fibers, and propose its configuration method to utilize
wavelength resources more effectively. We compare performances of power-law networks with and without our method by computer
simulations. The results show that our method reduces the blocking probabilities by more than one order of magnitude. 相似文献
14.
M Murata 《Canadian Metallurgical Quarterly》1993,65(11):1434-1438
15.
A two-step procedure for restoring scintigraphic images is described. The first step uses a local-statistics algorithm for improvement in signal-to-noise ratio by smoothing the Poisson noise. The second step aims at improvement in spatial resolution by removing the linear blur using the iterative restoration algorithm. We present some results of computer simulations and restoration of scintigraphic images that demonstrate the effectiveness of the proposed procedure. 相似文献
16.
The pre-treatment of a silica-supported gallium oxide catalyst with H2 at 823 K increased the yield of aromatics and the selectivity to aromatics in the dehydrogenation of propane over the catalyst at 823 K. Gallium oxide in the catalyst was partially reduced with H2 at 823 K. NH3 desorption and DRIFTS studies on the gallium oxide catalyst suggest that the dehydrogenation of propane over a silica-supported gallium oxide catalyst would proceed in the following way: (1) the dehydrogenation of propane to produce propene would occur on Ga sites including Gaδ+–H sites and (2) the aromatization of propene to aromatics on Ga–O–H acid sites. 相似文献
17.
K. Wakui K. Satoh G. Sawada K. Shiozawa K. Matano K. Suzuki T. Hayakawa Y. Yoshimura K. Murata F. Mizukami 《Catalysis Letters》2002,81(1-2):83-88
Dehydrogenative cracking reaction of n-butane was studied using HZSM-5 catalyst modified with various metal oxides. Alkaline earth (magnesium), transition metal (cobalt) and rare earth (lanthanum) elements are used for the modification. The selectivity of the products was studied at low conversion (20%). Methane, ethane, ethylene, propylene, butenes and butadiene were the main products. With the use of the cobalt- or magnesium-containing HZSM-5, dehydrogenative cracking was observed and the selectivity of ethylene was much larger than that of ethane. On the other hand, the selectivity of ethylene and ethane were almost the same in the reaction using the lanthanum-containing HZSM-5. It is considered that the cobalt- and magnesium-loaded sites on HZSM-5 played an important role in the dehydrogenative cracking. 相似文献
18.
19.
20.
Question-Answering Bulletin Boards (QABB), such as Yahoo! Answers and Windows Live QnA, are gaining popularity recently. Questions
are submitted on QABB and let somebody in the internet answer them. Communications on QABB connect users, and the overall
connections can be regarded as a social network. If the evolution of social networks can be predicted, it is quite useful
for encouraging communications among users. Link prediction on QABB can be used for recommendation to potential answerers.
Previous approaches for link prediction based on structural properties do not take weights of links into account. This paper
describes an improved method for predicting links based on weighted proximity measures of social networks. The method is based
on an assumption that proximities between nodes can be estimated better by using both graph proximity measures and the weights
of existing links in a social network. In order to show the effectiveness of our method, the data of Yahoo! Chiebukuro (Japanese
Yahoo! Answers) are used for our experiments. The results show that our method outperforms previous approaches, especially
when target social networks are sufficiently dense.
相似文献
Tsuyoshi MurataEmail: |