全文获取类型
收费全文 | 355篇 |
免费 | 5篇 |
专业分类
电工技术 | 15篇 |
化学工业 | 95篇 |
金属工艺 | 5篇 |
机械仪表 | 3篇 |
建筑科学 | 4篇 |
能源动力 | 7篇 |
轻工业 | 15篇 |
水利工程 | 1篇 |
无线电 | 53篇 |
一般工业技术 | 27篇 |
冶金工业 | 113篇 |
原子能技术 | 17篇 |
自动化技术 | 5篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2018年 | 7篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1998年 | 41篇 |
1997年 | 27篇 |
1996年 | 17篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有360条查询结果,搜索用时 15 毫秒
1.
This letter extends a low-density parity-check code construction using maximum-length linear congruential sequences by Prabhakar and Narayanan. The corresponding bipartite graphs of their construction were guaranteed to have a girth larger than four by a sufficient condition. However, their sufficient condition was limited to regular codes and data-node degree equal to three. The extension in this letter allows arbitrary data-node degrees and is applicable to irregular codes. Further, simpler sufficient conditions are derived and larger girths are addressed. 相似文献
2.
T Takeshita T Arita H Asao N Tanaka M Higuchi H Kuroda K Kaneko H Munakata Y Endo T Fujita K Sugamura 《Canadian Metallurgical Quarterly》1996,225(3):1035-1039
We molecularly cloned a cDNA coding for a novel phosphotyrosine molecule with a 70 kDa molecular mass, named STAM (signal transducing adaptor molecule), which is tyrosine-phosphorylated rapidly after stimulation with various cytokines such as IL-2, IL-3, IL-4, IL-7, GM-CSF, EGF and PDGF. STAM contains an SH3 (Src-homology 3) domain and the ITAM (immunoreceptor tyrosine-based activation motif), suggesting that STAM acts as an adaptor molecule involved in signal transducing pathways from the cytokine receptors. 相似文献
3.
Osteoclastic features of multinucleated giant cells responding to synthetic hydroxyapatite implanted in rat jaw bone. 总被引:2,自引:0,他引:2
N Takeshita T Akagi M Yamasaki T Ozeki T Nojima Y Hiramatsu N Nagai 《Journal of electron microscopy》1992,41(3):141-146
Multinucleated giant cells (MGCs) that responded to synthetic hydroxyapatite (HAP) implanted in rat mandibles were studied with electron microscopy. HAP used in this study sintered at 200 degrees C (HAP200) and at 125 degrees C (HAP1250) after the synthesis by a wet method. One to three weeks after the intraosseous implantation of HAP, MGCs responding to HAP200 had not only well-developed ruffled border and the clear zone but well-developed perinuclear Golgi complex, many mitochondria and vesicles in their cytoplasms. MGCs responding to HAP1250 had the clear zone, but not the ruffled border although they showed similar cytoplasmic features to those of MGCs responding to HAP200. They merely extended short slender cytoplasmic processes to HAP1250. These results suggest that although osteoclast-like MGCs respond to HAP implanted in the bone, the development of the ruffled border-clear zone system depends on physicochemical properties of HAP. 相似文献
4.
Y Kato S Yamaguchi H Sano Y Ogura K Katada G Takeshita F Imai T Kanno M Abe 《Canadian Metallurgical Quarterly》1996,39(4):113-115
A patient with subacute bacterial endocarditis and a peripheral mycotic aneurysm is presented. We used a combined multi-slice surface anatomy scanning (SAS) and contrast-enhanced MR angiography image to determine the exact location of the small lesion by applying a skin marker on the scalp and visualizing the relationship of the marker to the brain surface structures and to the lesion. This technique was useful for the removal of a small peripheral aneurysm using only a limited craniotomy. 相似文献
5.
Isao Mochida Hideichi Matsuoka Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):587-594
Using low-rank coals, the modifying activities of some petroleum, coal tar and aromatic hydrocarbon additives have been examined to find procedures for their utilization in the preparation of blast furnace coke. Petroleum pitch, especially after hydrogenation, exhibited excellent modifying activity even with non-fusible coals. In contrast, the activity of coal tar was very limited with such coals. The napththenic component, revealed by n.m.r. of the additives, appears to be important in the co-carbonization by inducing fusibility and anisotropic development in such coals. Co-carbonization to recover the dehydrogenated additives was attempted. However, there was no development of the anisotropy in the resultant coke by dissolution of the coal particles although the coal particles were firmly fixed in the matrix. Acid-refluxing treatment of non-fusible coals was found to enhance their modification susceptibility, indicating that some of the acid-soluble mineral matter is important in the thermal depolymerization or fusion process of the coal. 相似文献
6.
Isao Mochida Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita Yoshinobu Komatsubara Kei-Ichiro Koba Harry Marsh 《Fuel》1984,63(1):136-139
Cokes were prepared from nine coals of different rank and characterized by surface area measurement, reactivity to carbon dioxide at 1473K and Raman-laser spectroscopy. Rates of gasification of cokes on a unit surlface area basis (K1 = g m?2 min?1) decreased with increasing rank of parent coal based on maximum oil reflectances. However rates of gasification could not be related to coke structure as measured by Raman-laser spectroscopy. 相似文献
7.
N‐Isopropylacrylamide/acrylic acid copolymer hydrogels were synthesized with ultrasound. The thermoresponsive phase behaviors of gels synthesized with ultrasound (US gels) were investigated and compared with those of gels synthesized in the absence of ultrasound (FR gels). The US gels showed thermoresponsive swelling behavior with a large hysteresis over a wide range of temperatures around its phase‐transition temperature. The hysteresis became larger with an increasing copolymerized acrylic acid content. The US gels were also characterized from the viewpoint of chemical, hydration, and macroscopic physical structures. Little difference was observed in the chemical and hydration structures of the FR gels and US gels. The macroscopic physical structure of the US gels was, however, distinct from that of the FR gels. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2449–2452, 2003 相似文献
8.
Isao Mochida Kenjiro Iwamoto Tsutomu Tahara Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):603-609
Reactivities of several coals of different ranks have been examined in degrading extractions with aromatic solvents under apparently non-hydrogenative reaction conditions. Pyrene and A240 pitch liquefied the fusible coals in high yields and the slightly-fusible coals in moderate yields, indicating the importance of fusibility in such liquefaction processes. A240-LS pitch is a powerful solvent for slightly-fusible coals. Considerable amounts of pyridine- or THF-soluble fractions were produced especially with A240-LS pitch. A240 pitch is a better solvent than pyrene for some slightly-fusible coals. However, the extent of depolymerization of liquefied coal, pyridine- or THF-solubility, was definitely inferior. Yields of such fractions are higher for lower-rank coals. The mechanism of coal liquefaction under apparently non-hydrogenative conditions is discussed with emphasis on the stabilization of thermal fragments derived from the coal. 相似文献
9.
Yuji Tatemoto Masaya Tsunekawa Shuji Yano Takenari Takeshita Katsuji Noda 《Chemical engineering science》2007,62(8):2187-2197
A relatively large wet material was immersed in a fluidized bed of hygroscopic porous particle (silica gel beads) under reduced pressure. And then the drying characteristics were compared with those in the case of inert particle (glass beads). The comparison of drying characteristics is performed experimentally and theoretically. In calculation, the water transfer from the sample to the fluidized bed was considered. The calculation results are in good agreement with the experimental data. The effects of the operational conditions (the pressure in the drying chamber and the temperature of the drying gas) on the drying characteristics were also examined in both fluidizing particles.The drying finishes earlier in the case of hygroscopic porous particle than in the case of inert particle regardless of pressure in the drying chamber, since the water transfer from the sample facilitates the drying in the case of hygroscopic porous particles. The temperature decrement in drying appears in the case of inert particle. This phenomenon is also observed in the case of hygroscopic porous particle, but the decrement degree of the temperature is much smaller than that in the case of inert particle. The difference of the minimum temperature in the sample in drying between the cases of hygroscopic porous particle and inert particle is very slight for different pressures in the drying chamber. 相似文献
10.
Hiroki Takeshita Yuan-Ji Gao Tomoyuki Natsui Erick Rodriguez Masamitsu Miya Katsuhiko Takenaka Tomoo Shiomi 《Polymer》2007,48(26):7660-7671
The microphase separation structure in the molten state and the structure formation in crystallization from such ordered melt were investigated for the blends of polystyrene–polyethylene block copolymers (SE) with polystyrene homopolymer (PS) and polyethylene homopolymer (PE) and for the blends consisting of two kinds of SE with different copolymer compositions from each other, using synchrotron small-angle X-ray scattering techniques (SAXS). The copolymer compositions of SE block copolymers employed were 0.34, 0.58 and 0.73 wt. fraction of PE, and their melt morphologies were cylindrical, lamellar and lamellar, respectively. Macrophase separation or the morphology change in the melt occurred depending on the molecular weight and the blend composition, as reported so far. In crystallization from such macrophase-separated and microphase-separated melts, the melt morphology was completely kept for all the blends. Crystallization behavior was also investigated for the blends. The crystallization within the spherical and cylindrical domains surrounded by glassy PS was not observed for SE/PS blends. In the crystallization from the macrophase-separated melt, two exothermal peaks were observed in the DSC measurements, while a single peak was observed for other blends. For the blends with PS, the degree of crystallinity was depressed and the apparent activation energy of crystallization was high, compared to those for the corresponding neat SE. For SE/PE and SE/SE blends, those were changed depending on the blend composition. 相似文献