全文获取类型
收费全文 | 1185篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 101篇 |
化学工业 | 171篇 |
金属工艺 | 14篇 |
机械仪表 | 14篇 |
建筑科学 | 35篇 |
矿业工程 | 3篇 |
能源动力 | 26篇 |
轻工业 | 93篇 |
水利工程 | 24篇 |
石油天然气 | 4篇 |
无线电 | 152篇 |
一般工业技术 | 200篇 |
冶金工业 | 273篇 |
原子能技术 | 33篇 |
自动化技术 | 65篇 |
出版年
2022年 | 10篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 16篇 |
2015年 | 14篇 |
2014年 | 17篇 |
2013年 | 43篇 |
2012年 | 20篇 |
2011年 | 46篇 |
2010年 | 47篇 |
2009年 | 46篇 |
2008年 | 49篇 |
2007年 | 47篇 |
2006年 | 42篇 |
2005年 | 41篇 |
2004年 | 36篇 |
2003年 | 35篇 |
2002年 | 34篇 |
2001年 | 40篇 |
2000年 | 26篇 |
1999年 | 28篇 |
1998年 | 104篇 |
1997年 | 64篇 |
1996年 | 56篇 |
1995年 | 32篇 |
1994年 | 28篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 25篇 |
1990年 | 17篇 |
1989年 | 11篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1975年 | 11篇 |
1974年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有1208条查询结果,搜索用时 31 毫秒
111.
H Uchiyama S Komazaki M Oyama T Matsui Y Ozeki 《Canadian Metallurgical Quarterly》1997,7(8):1159-1165
Galectins are a family of lectins that recognize beta-D-galactosides independently of calcium ions, and are widely distributed in animals. To characterize a galectin previously purified from oocytes of Rana catesbeiana (American bullfrog), we studied its distribution and localization in several tissues from this frog. Hemagglutination assay and western blotting showed that this lectin is present in many tissues including the liver, skin, kidney, skeletal muscle, and sciatic nerve, but is particularly concentrated in the ovary. Light microscopic immunohistochemistry showed that this lectin is localized in such places as cell-cell junctions, basement membranes, extracellular matrix, or secretory substances in several organs, indicating that this galectin is mainly distributed extracellularly. However, in the ovary, light microscopy showed that this lectin is present in or associated with the yolk platelet. Electron microscopy further revealed that it is localized in the periphery of the yolk platelet (the yolk plasm), but not in the cortical granule. These results indicate that Rana oocytes contain abundant galectin in their yolk platelets in contrast to Xenopus laevis oocytes, which have been found not to contain galectins but other classes of lectins in their yolk platelets and cortical granules. 相似文献
112.
Akata M. Nagataki Y. Koyabu K. Mukai K. Yoshida S. Morisaki S. Eda M. Ueki I. Matsui T. 《Solid-State Circuits, IEEE Journal of》1990,25(2):458-465
A subscriber line interface circuit (SLIC) two-chip set that eliminates off-chip functional trimming and integrates coin telephone set facilities as well as BORSCHT functions is described. The LSI chip set consists of (a) a subscriber interface IC fabricated using a 320-V dielectrically isolated bipolar process with on-chip thin-film resistors and double-layer metal, and (b) a subscriber processor IC with oversampling A-D/D-A converters and a microprogrammable digital signal processor (DSP), using a 1.6-μm CMOS process. Chip sizes are 5.5 mm×6.06 mm and 6.0 mm×5.7 mm, respectively. Using the two-chip set, an SLIC for a coin telephone set can be designed without using high-precision filter components or hybrid ICs with functional trimming 相似文献
113.
This paper presents an investigation on the effects of fine mineral powders on the fluidity and rheological properties of concrete. It was observed that the fluidity of concrete increased noticeably, and the plastic viscosity decreased, when vitreous powders were substituted partially for cement. It was found that vitreous powders have a strong dispersion effect on the fluidity and rheological properties of concrete, and this effect can be correlated with the vitreous content of the powders incorporated. 相似文献
114.
H Tanigami N Yahagi K Kumon Y Watanabe M Haruna J Matsui H Hayashi 《Canadian Metallurgical Quarterly》1997,21(1):21-23
Eight new 0 (91-98) and H (46-49) antigens are described. Their reference strains come from Czech Republic, Cuba and USA. The majority of reference strains are of human origin. Some of the new antigens have been found in other strains coming mostly from water. 相似文献
115.
H Kaneko KO Orii E Matsui N Shimozawa T Fukao T Matsumoto A Shimamoto Y Furuichi S Hayakawa K Kasahara N Kondo 《Canadian Metallurgical Quarterly》1997,240(2):348-353
Bloom syndrome (BS) is a rare genetic disorder characterized by small body size, sun sensitivity, immunodeficiency and a high predisposition to various types of cancer. BLM was identified as the causative gene for BS, and BLM protein is homologous to DNA helicase. There are two putative nuclear localization signals (NLSs) within amino acid residues 1334-1349 in the C-terminus of the BLM protein, which has the distinctive structure of two basic residue arms separated by a spacer. The entire coding or deleted BLM sequences of various sizes were ligated into an enhanced green fluorescent protein (EGFP) vector and transfected into HeLa cells. The EGFP vector harboring the entire BLM coding sequence was transported to the nucleus. The BLM protein truncated at 1341 amino acid, containing an intact helicase domain and only one proximal arm, was not transported to the nucleus. The BLM protein truncated at 1357 amino acid, containing an intact helicase domain and two arms, was transported to the nucleus. The EGFP vector harboring DNA fragments encoding a protein having only the distal arms of basic amino acids in the C-terminus was also transported to the nucleus. The truncated BLM proteins corresponding to previously reported mutated BLM proteins were retained in the cytoplasm or both the cytoplasm and the nucleus as was the EGFP vector with no insert. These results show that the BLM protein translocates into the nucleus and that the distal arm of the bipartite basic residues in the C-terminus of the BLM protein is essential for targeting the nucleus. 相似文献
116.
Y. Kubota R. Toda M. Kamada S. Nakamura T. Matsui Hiroshi Fukuyama 《Journal of Low Temperature Physics》2014,175(1-2):160-166
We describe some details of a new experimental setup for torsional oscillator (TO) measurement of $^4$ He monolayers adsorbed on a graphite surface. This setup is designed to seek for the possible supersolid phase, in which crystalline order coexists with superfluidity, in two dimensional (2D) solid $^4$ He below 300 mK. Among such 2D solids, the commensurate phase in the second layer on graphite is the most hopeful candidate for the novel supersolid phase since it is the lowest-density quantum solid ever found. An exfoliated graphite substrate we used is ZYX which has at least ten times longer surface coherence length compared to Grafoil, an exfoliated graphite most commonly used in previous experiments. The first version of TO we made has the resonant frequency of 786.8 Hz and the Q value of $1.1\times 10^5$ at $T \le 10$ mK. The resonant frequency of this particular TO without any He samples ( $f_{\mathrm {cell}}$ ) showed unexpectedly large temperature variation and non-reproducibility below 1 K as well as sudden jumps when mechanical shocks are applied to the experimental apparatus. We found the stability of $f_{\mathrm {cell}}$ is highly correlated with the temperature stability of 1 K pot in dilution refrigerator. 相似文献
117.
Highly Oriented Polymer Semiconductor Films Compressed at the Surface of Ionic Liquids for High‐Performance Polymeric Organic Field‐Effect Transistors
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
118.
Hosokai S Kasiwaya Y Matsui K Okinaka N Akiyama T 《Environmental science & technology》2011,45(2):821-826
This paper describes the reduction of hematite with ammonia for ironmaking, in which the effect of temperature on the products was examined. The results showed that the reduction process began at 430 °C during heating, and with an increase in temperature, the reduction mechanism changed apparently from a direct reduction of ammonia (Fe(2)O(3) + 2NH(3) → 2Fe + N(2) + 3H(2)O) to an indirect reduction via the thermal decomposition of ammonia (2NH(3) → N(2) + 3H(2), Fe(2)O(3) + 3H(2) → 2Fe + 3H(2)O) at temperatures over 530 °C. The final product obtained at 600 and 700 °C was pure metallic iron, in contrast with that formed at 450 °C, that is, a mixture of metallic iron and iron nitride. The results suggest the possibility of using ammonia as a reducing agent for carbonless ironmaking, which is operated at a much lower temperature than 900 °C in conventional coal-based ironmaking. 相似文献
119.
Roberto de la Rica Christophe Pejoux Hiroshi Matsui 《Advanced functional materials》2011,21(6):1018-1026
This feature article highlights our recent applications of functional peptide nanotubes, self‐assembled from short peptides with recognition elements, as building blocks to develop sensors. Peptide nanotubes with high aspect ratios are excellent building blocks for a directed assembly into device configurations, and their combined structures with nanometric diameters and micrometric lengths enables to bridge the “nanoworld” and the “microworld”. When the peptide‐nanotube‐based biosensors, which incorporate molecular recognition units, apply alternating current probes to detect impedance signals, the peptide nanotubes behave as excellent building blocks of the transducer for the detection of target analyes such as pathogens, cells, and heavey metal ions with high specificity. In some sensor configurations, the electric signal can be amplified by coupling them with ion‐specific mineralization via molecular recognition of peptides. In general the detection limit of peptide nanotube chips sensors is very low and the dynamic range of detection can be widened by improved device designs. 相似文献
120.
Shinsuke Kajioka Naoki Wakamiya Hiroki Satoh Kazuya Monden Masato Hayashi Susumu Matsui Masayuki Murata 《Ad hoc Networks》2011,9(5):911-927
To accommodate real-time multimedia application while satisfying application QoS requirements in a wireless ad-hoc network, we need QoS control mechanisms. In this paper, we propose a new routing mechanism to support real-time multimedia communication by efficiently utilize the limited wireless network capacity. Our mechanism considers a wireless ad-hoc network composed of nodes equipped with multiple network interfaces to each of which a different wireless channel can be assigned. By embedding information about channel usage in control messages of OLSRv2, each node obtains a view of topology and bandwidth information of the whole network. Based on the obtained information, a source node determines a logical path with the maximum available bandwidth to satisfy application QoS requirements. Through simulation experiments, we confirmed that our proposal effectively routed multimedia packets over a logical path avoiding congested links. As a result, the load on a network is well distributed and the network can accommodate more sessions than QOLSR. We also conducted practical experiments using wireless ad-hoc relay nodes with four network interfaces and verified the practicality of our proposal. 相似文献