全文获取类型
收费全文 | 281篇 |
免费 | 21篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 110篇 |
金属工艺 | 4篇 |
机械仪表 | 8篇 |
建筑科学 | 7篇 |
能源动力 | 7篇 |
轻工业 | 71篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 14篇 |
一般工业技术 | 46篇 |
冶金工业 | 8篇 |
原子能技术 | 5篇 |
自动化技术 | 14篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 16篇 |
2011年 | 22篇 |
2010年 | 21篇 |
2009年 | 11篇 |
2008年 | 13篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 10篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有302条查询结果,搜索用时 328 毫秒
111.
Nakamura M. Takahashi T. Akiba T. Kitsukawa G. Morino M. Sekiguchi T. Asano I. Komatsuzaki K. Tadaki Y. Songsu Cho Kajigaya K. Tachibana T. Sato K. 《Solid-State Circuits, IEEE Journal of》1996,31(9):1302-1307
A 29-ns (RAS access time), 64-Mb DRAM with hierarchical array architecture has been developed. For consistent high yields and high speed, a CMOS segment driver circuit is used as a hierarchical word line scheme. To achieve high speed, precharge signal (PC) drivers for equalizing the bit lines pairs, and shared sense amplifier signal (SHR) drivers are distributed in the array. To enhance sense amplifiers speed in low array voltage, an over driven sense amplifier is adopted. A hierarchical I/O scheme with semidirect sensing switch is introduced for high speed data transfer in the I/O paths. By combining these proposed circuit techniques and 0.25-μm CMOS process technologies with phase-shift optical lithography, an experimental 64-Mb DRAM has been designed and fabricated. The memory cell size is 0.71×1.20 μm 2, and the chip size is 15.91×9.06 mm2. A typical access time under 3.3 V power supply voltage is 29 ns 相似文献
112.
113.
Naoki Sugimoto Chikako Yomota Noriko Furusho Kyoko Sato Takeshi Yamazaki Kenichi Tanamoto 《Food Additives & Contaminants》2006,23(12):1253-1259
The application of liquid chromatography-nuclear magnetic resonance spectroscopy (LC-NMR) for the direct identification of ethyldimethylpyrazine, a food flavouring agent, has been studied. The commercial product is a mixture of two regio-isomers, 2-ethyl-3,5-dimethylpyrazine (1) and 2-ethyl-3,6-dimethylpyrazine (2); however, the exact composition of the mixture is unknown. Structural characterization by LC-MS and GC-MS was not possible because both regio-isomers yield the same molecular related ion and ion fragmentation. To rapidly identify the two regio-isomers, the product was analyzed by LC-NMR with on-flow and fraction loop modes. From the results, the structure elucidations of the two regio-isomers could be carried out without the need to isolate the isomers by the usual procedures. 相似文献
114.
Tomoaki Sakamoto Tetsuo Sasaki Noriko Katori Yukihiro Goda 《Journal of Infrared, Millimeter and Terahertz Waves》2016,37(10):1007-1020
We conducted a time-course analysis of the pseudo-polymorphism conversion (i.e., the hydration and dehydration) of the xanthine-related compound theophylline during wet granulation and drying processes, using terahertz spectroscopy. We also investigated the amorphization mechanism of theophylline hydrate during a drying process in a vacuum using terahertz, mid-infrared (mid-IR), and near-infrared (near-IR) spectroscopy. After a high-shear granulation process using a mixture of theophylline, hydroxypropyl cellulose (HPC), and water, the terahertz spectrum (which was similar to that of an anhydride) was changed to a spectrum that was quite similar to that of a monohydrate. This result suggests that (1) an anhydride was converted to a monohydrate during the wet granulation process and (2) the spectrum was changed to the original waveform after the drying process with heat. This phenomenon indicates that the theophylline monohydrate was reconverted to an anhydride during the drying process. When wet granules were dried in a vacuum, the terahertz absorption lessened and finally disappeared with the passage of time, suggesting that the theophylline monohydrate in the granules was converted to an amorphous state. During the drying process with heat, the dehydration progressed temperature dependently regardless of the presence/absence of HPC. In addition, the reconversion from a monohydrate to an anhydride was completed concurrently with the completion of dehydration. The conversion rate of theophylline from a monohydrate to an amorphous form in granules (with HPC) was faster than that without HPC. This observation suggests that HPC promotes the amorphization of theophylline. 相似文献
115.
116.
117.
Kotaro Hama Toru Nagai Chiho Nishizawa Kazutaka Ikeda Masashi Morita Noriko Satoh Hiroki Nakanishi Tsuneo Imanaka Nobuyuki Shimozawa Ryo Taguchi Keizo Inoue Kazuaki Yokoyama 《Lipids》2013,48(12):1253-1267
The ratio of C26:0/C22:0 fatty acids in patient lipids is widely accepted as a critical clinical criterion of peroxisomal diseases, such as Zellweger syndrome and X-linked adrenoleukodystrophy (X-ALD). However, phospholipid molecular species with very long chain fatty acids (VLCFA) have not been precisely characterized. In the present study, the structures of such molecules in fibroblasts of Zellweger syndrome and X-ALD were examined using LC–ESI–MS/MS analysis. In fibroblasts from Zellweger patients, a large number of VLCFA-containing molecular species were detected in several phospholipid classes as well as neutral lipids, including triacylglycerol and cholesteryl esters. Among these lipids, phosphatidylcholine showed the most diversity in the structures of VLCFA-containing molecular species. Some VLCFA possessed longer carbon chains and/or larger number of double bonds than C26:0-fatty acid (FA). Similar VLCFA were also found in other phospholipid classes, such as phosphatidylethanolamine and phosphatidylserine. In addition, VLCFA-containing phospholipid species showed some differences among fibroblasts from Zellweger patients. It appears that phospholipids with VLCFA, with or without double bonds, as well as C26:0-FA might affect cellular functions, thus leading to the pathogenesis of peroxisomal diseases, such as Zellweger syndrome and X-ALD. 相似文献
118.
119.
120.
PER1, GUP1 and CWH43 of methylotrophic yeast Ogataea minuta are involved in cell wall integrity
下载免费PDF全文
![点击此处可从《Yeast (Chichester, England)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xin‐Xin Xu Akiko Komatsuzaki Yasunori Chiba Xiao‐Dong Gao Takehiko Yoko‐o 《Yeast (Chichester, England)》2018,35(2):225-236
In eukaryotes, the glycosylphosphatidylinositol (GPI) modification of many glycoproteins on the cell surface is highly conserved. The lipid moieties of GPI‐anchored proteins undergo remodelling processes during their maturation. To date, the products of the PER1, GUP1 and CWH43 genes of the yeast Saccharomyces cerevisiae have been shown to be involved in the lipid remodelling. Here, we focus on the putative GPI remodelling pathway in the methylotrophic yeast Ogataea minuta. We found that the O. minuta homologues of PER1, GUP1 and CWH43 are functionally compatible with those of S. cerevisiae. Disruption of GUP1 or CWH43 in O. minuta caused a growth defect under non‐permissive conditions. The O. minuta per1Δ mutant exhibited a more fragile phenotype than the gup1Δ or cwh43Δ mutants. To address the role of GPI modification in O. minuta, we assessed the effect of these mutations on the processing and localization of the O. minuta homologues of the Gas1 protein; in S. cerevisiae, Gas1p is an abundant and well‐characterized GPI‐anchored protein. We found that O. minuta possesses two copies of the GAS1 gene, which we designate GAS1A and GAS1B. Microscopy and western blotting analysis showed mislocalization and/or lower retention of Gas1Ap and Gas1Bp within the membrane fraction in per1Δ or gup1Δ mutant cells, suggesting the significance of lipid remodelling for GPI‐anchored proteins in O. minuta. Localization behaviour of Gas1Bp differed from that of Gas1Ap. Our data reveals, for the first time (to our knowledge), the existence of genes related to GPI anchor remodelling in O. minuta cells. 相似文献