全文获取类型
收费全文 | 1478篇 |
免费 | 80篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 20篇 |
综合类 | 1篇 |
化学工业 | 341篇 |
金属工艺 | 15篇 |
机械仪表 | 33篇 |
建筑科学 | 26篇 |
矿业工程 | 2篇 |
能源动力 | 28篇 |
轻工业 | 157篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 250篇 |
一般工业技术 | 280篇 |
冶金工业 | 232篇 |
原子能技术 | 24篇 |
自动化技术 | 154篇 |
出版年
2023年 | 10篇 |
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 16篇 |
2019年 | 29篇 |
2018年 | 38篇 |
2017年 | 35篇 |
2016年 | 38篇 |
2015年 | 23篇 |
2014年 | 48篇 |
2013年 | 72篇 |
2012年 | 65篇 |
2011年 | 104篇 |
2010年 | 71篇 |
2009年 | 58篇 |
2008年 | 75篇 |
2007年 | 65篇 |
2006年 | 59篇 |
2005年 | 41篇 |
2004年 | 38篇 |
2003年 | 44篇 |
2002年 | 48篇 |
2001年 | 37篇 |
2000年 | 43篇 |
1999年 | 37篇 |
1998年 | 84篇 |
1997年 | 63篇 |
1996年 | 46篇 |
1995年 | 22篇 |
1994年 | 20篇 |
1993年 | 28篇 |
1992年 | 16篇 |
1991年 | 5篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1978年 | 2篇 |
1977年 | 10篇 |
1976年 | 16篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有1566条查询结果,搜索用时 15 毫秒
1.
Tomohiro Toigawa Yasuhiro Tsubata Takeshi Kai Takuya Furuta Yuta Kumagai Tatsuro Matsumura 《溶剂提取与离子交换》2021,39(1):74-89
ABSTRACT Absorbed-dose estimation is essential for evaluation of the radiation tolerance of minor-actinide-separation processes. We propose a dose-evaluation method based on radiation permeability, with comparisons of heterogeneous structures seen in the solvent-extraction process, such as emulsions forming in the mixture of the organic and aqueous phases. A demonstration of radiation-energy-transfer simulation is performed with a focus on the minor-actinide-recovery process from high-level liquid waste with the aid of the Monte Carlo radiation-transport code PHITS. The simulation results indicate that the dose absorbed by the extraction solvent from alpha radiation depends upon the emulsion structure, and that from beta and gamma radiation depends upon the mixer-settler-apparatus size. Non-negligible contributions of well-permeable gamma rays were indicated in terms of the plant operation of the minor-actinide-separation process. 相似文献
2.
3.
Hiromichi Ichinose Masanori Taira Sachiko Furuta Hiroaki Katsuki 《Journal of the American Ceramic Society》2003,86(9):1605-1608
Niobium- or vanadium-doped anatase sols were prepared by hydrothermal treatment of 0.1 mol/dm3 peroxotitanium complex aqueous solutions dissolving 0–10 mol% niobium or vanadium at 100°C for 8 h. Niobium-doping caused the increase of lattice constants of anatase and the shape change of anatase crystal from spindle-like to cubic-like structure, but no change of the optical absorbance. Vanadium-doping caused the decrease of lattice constant of c -axis, the miniaturization of anatase crystal and the increase of optical absorbance at the wavelength from 350–700 nm. 相似文献
4.
M Furuta K Hayakawa S Katano Y Saito Y Nakayama T Takahashi R Imai T Ebara N Mitsuhashi H Niibe 《Canadian Metallurgical Quarterly》1996,26(2):95-98
Vaccination with peptides that induce a specific immune response is a potential prophylactic or therapeutic strategy against viral infections and tumors. Because of the extensive polymorphism of the HLA loci, synthetic peptide vaccines must consist of a cocktail of peptides that bind specifically to different HLA molecules. Such cocktails should be optimized for the target population as each population has its specific HLA gene frequencies. To achieve maximum population coverage with a minimum number of peptides, information is needed on the ranking of the most frequent HLA phenotypes. We introduce the minimal phenotype panel, which is the smallest combination of HLA antigens selected so that the proportion of individuals in a population that express at least one of the antigens in the panel exceeds a desired minimum value. We developed a method for assembling minimal phenotype panels based on known HLA class I gene frequencies. We give an example based on a set of 2446 well-defined HLA-typed, random, healthy, unrelated, Dutch Caucasoid individuals. In addition, we discuss the possibility of assembling minimal phenotype panels based on two-locus haplotypes, which enables the assembly of phenotype panels from the antigens of both loci. 相似文献
5.
On an earthspace propagation path with the low elevation angle of 10 deg, the phase between co- and crosspolar signals occasionally showed rapid and irregular fluctuations during fine weather. These fluctuations were generally significant during the daytime, and were strongly in phase with the occurrence of the copolar amplitude scintillations. This could be attributed to the combined effects of the crosspolar phase pattern of the receiving antenna and small fluctuations of the angle of arrival of the radiowaves. 相似文献
6.
7.
Hitoshi Furuta Jianhong He Eiichi Watanabe 《Computer-Aided Civil and Infrastructure Engineering》1996,11(1):37-45
Abstract: An efficient knowledge-acquisition support method is required for improvement and maintenance of the knowledge base in durability evaluation of an RC bridge deck. Such a method is proposed in this paper to automatically acquire fuzzy production rules. This method makes joint use of genetic algorithms and a neural network. Using a neural network as a subsystem, the evaluation function of genetic algorithms can be provided with the weights of the neural network. Introducing a neural network into genetic algorithms, it is possible to acquire new knowledge so that the method is useful when it is difficult to acquire knowledge in the field. 相似文献
8.
Takuma Suzuki Hang-Ju Ko Agus Setiawan Jung-Jin Kim Koh Saitoh Masami Terauchi Takafumi Yao 《Materials Science in Semiconductor Processing》2003,6(5-6):519-521
We report the successful growth of Ga-polar GaN epilayers on O-polar ZnO templates pre-deposited on c-sapphire. Prior to GaN growth, NH3 is exposed onto the ZnO template. The polarity of the GaN layers is confirmed by etching of the surface and by conversion beam electron diffraction (CBED), while the O-polar ZnO is confirmed by CBED. It is suggested that the NH3 pre-exposure helps form a Zn3N2 layer, which possesses inversion symmetry and inverts the crystal from anion polar to cation polar. 相似文献
9.
Plastic deformation in a multifunctional Ti-Nb-Ta-Zr-O alloy 总被引:7,自引:0,他引:7
S. Kuramoto T. Furuta J. H. Hwang K. Nishino T. Saito 《Metallurgical and Materials Transactions A》2006,37(3):657-662
Mechanisms for plastic deformation in the newly developed Ti-24 at. pct (Ta + Nb + V)-(Zr,Hf)-O alloys (Gum Metal) were investigated
in relation to their unique properties. Transmission electron microscopy revealed that the microstructure after deformation
was characterized by highly distorted crystal images, which are accompanied by numerous “giant faults.” Such plastic behavior
implies that a large amount of elastic stain energy was stored discretely and hierarchically during cold working. Calculated
elastic constants of the Ti-X (Nb,Ta,Mo,V) binary systems predicted that Young’s modulus in 〈001〉 and shear moduli along some
directions including slip systems in a bcc crystal were extraordinary small. The low modulus not only well explains the highly
distorted microstructure observed in the cold-worked specimens, but also signifies that ideal shear strength of the developed
alloys is a very small value, which is close to the practical strength required for plastic deformation in the alloy. This
implies that the giant faults observed in the deformed specimen were formed without the aid of dislocation glide. 相似文献
10.
A mica-based machinable glass-ceramic has been converted to a glass-ceramic containing cordiertie and body-centered cubic chondrodite through heat treatment at temperatures higher than that used for the crystallization of mica. The machinability is lost, microhardness increases, and the thermal expansion coefficient decreases with the change of the crystalline phase from mica to cordierite and chondrodite. 相似文献