全文获取类型
收费全文 | 117篇 |
免费 | 6篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 61篇 |
金属工艺 | 1篇 |
建筑科学 | 1篇 |
能源动力 | 5篇 |
轻工业 | 23篇 |
水利工程 | 1篇 |
无线电 | 3篇 |
一般工业技术 | 12篇 |
冶金工业 | 2篇 |
自动化技术 | 12篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 2篇 |
2019年 | 7篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 0 毫秒
61.
Dr. Kazuo Harada Shoko Aoyama Dr. Akimasa Matsugami Dr. Penmetcha K. R. Kumar Dr. Masato Katahira Dr. Nobuo Kato Dr. Junko Ohkanda 《Chembiochem : a European journal of chemical biology》2014,15(6):794-798
The stereochemical theory claims that primitive coded translation initially occurred in the RNA world by RNA‐directed amino acid coupling. In this study, we show that the HIV Tat aptamer RNA is capable of recognizing two consecutive arginine residues within the Tat peptide, thus demonstrating how RNA might be able to position two amino acids for sequence‐specific coupling. We also show that this RNA can act as a template to accelerate the coupling of a single arginine residue to the N‐terminal arginine residue of a peptide primer. The results might have implications for our understanding of the origin of translation. 相似文献
62.
Cover Picture: RNA‐Directed Amino Acid Coupling as a Model Reaction for Primitive Coded Translation (ChemBioChem 6/2014) 下载免费PDF全文
63.
Tai PT Nishijo M Kido T Nakagawa H Maruzeni S Naganuma R Anh NT Morikawa Y Luong HV Anh TH Hung NN Son le K Tawara K Nishijo H 《Environmental science & technology》2011,45(15):6625-6632
In an operation by United States Armed Forces during 1961 to 1971, large quantities of herbicides were sprayed in South Vietnam. These herbicides contained 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD), the most toxic congener of dioxins. Several decades after the herbicide spraying ceased, dioxin concentrations in the environment and human remained elevated in the sprayed areas. Breast milk samples from 520 nursing mothers residing in areas including the hot spots as well as the sprayed and unsprayed areas were collected to quantify the levels of dioxins. The total toxic equivalents of 2,3,7,8-substitued PCDDs/PCDFs in breast milk of mothers living in the hot spots, and the sprayed and unsprayed areas were 14.10 pg/g lipid, 10.89 pg/g lipid, and 4.09 pg/g lipid for primiparae and 11.48 pg/g lipid, 7.56 pg/g lipid, and 2.84 pg/g lipid for multiparae, respectively, with significant differences in the values among the three areas. In the hot spots, dioxin levels were highly correlated with the residency of mothers after adjustment for their age and parity. 相似文献
64.
Takeshi Hasegawa Yuhki Kasahara Shoko Yoshida Takayuki Kurashina Shotaro Aoki Kenji Yoza Kenji Nomiya 《Inorganic chemistry communications》2007,10(12):1416-1419
The title compound 1 with a formula of (Bu4N)4[α2-P2W17O61{Me3N+(CH2)3Si}2O] · CH3CN was obtained in 77.1% (4.21 g scale) yield by a 1:2 molar-ratio reaction of the mono-lacunary Dawson polyoxometalate (POM) [P2W17O61]10− with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride ([Me3N(CH2)3Si(OMe)3]Cl) in mixed water/acetonitrile solution under acidic conditions and unequivocally characterized with complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), FTIR, solution (31P, 1H, 13C and 29Si) NMR and X-ray crystallography. Compound 1 contained two types of the ammonium cations, i.e., the counterions Bu4N+ (free cations) and the terminal quaternary ammonium ions (bound cations) which are connected to the POM through the organosilyl groups. 相似文献
65.
Masato Yamamura Shoko NakamuraToshihisa Kajiwara Hiroyuki KageKitaro Adachi 《Polymer》2003,44(16):4699-4704
We demonstrated that the introduction of a temperature gradient along the free surface induces a particular stripe pattern in phase-separating fluids. The horizontal temperature gradient drove lateral-periodic spiral liquid motion flowing from warmer to cooler places due to thermocapillarity. Properly chosen polymer compositions and initial film thicknesses in ternary solutions allowed us to promote a phase separation in the presence of spiral flow, which assembled the demixed polymer droplets along the flow-stagnation lines. The resulting assembled phases aligned in the temperature gradient direction and eventually formed periodic polymer stripes involving the same spacing as that of the flow axis. The critical condition for the stripe pattern formation was given by the ratio of two relevant film thicknesses, i.e. the thickness for the onset of the phase separation and that for the cessation of liquid motion. 相似文献
66.
Yoshirou Kuromitsu Sea Fue Wang Shoko Yoshikawa Robert E. Newnham 《Journal of the American Ceramic Society》1994,77(3):852-856
Evolution of interfacial microstructure between BaTiO3 and the binary glasses used as frits in thick-film technology has been studied. Possible reaction mechanisms for the interfacial compounds have been determined by comparing the results of the sintering study with the reaction of BaTiO3 , powder with glass powders. The interfacial microstructure can be divided into two types. The first type of interfacial microstructure is observed for glasses rich in PbO or Bi2 O3 network modifiers and is characterized by the penetration of glass into the BaTiO3 grain boundaries, accompanied by incorporation of Pb into the perovskite lattice. The second type of interfacial microstructure is observed for glasses rich in B2 O3 or SiO2 network formers and is characterized by the formation of interfacial compounds. 相似文献
67.
We present a new design of a lithium gel-polymer battery, fabricated with a (LILP) composite consisting of a lithium salt dissolved in an ionic liquid (binary Li-IL) and an ultra high molecular weight ionic liquid polymer (ILP). This polymer, with a Mw of over a million, was prepared by the bulk radical polymerization of a novel ionic liquid monomer, N,N-diethyl-N-(2-methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide (DEMM-TFSI). The polymer could form a binary Li-IL solid at a concentration of only 5 wt%. We selected high power-active electrode materials, and combined them with the LILP system. The demonstration vapor-free cell had a higher discharge performance than a conventional lithium polymer battery: at 40 °C, it retained 83% of its discharge capacity at a 3 C current, and relatively good cycle performance. This is the first report of to knowledge that a lithium ion cell with a LILP system performed, in terms of cell performance and cycle durability, at a level of practical utility. 相似文献
68.
69.
Enos Tangke Arung Shoko Furuta Hiroya Ishikawa Irawan Wijaya Kusuma Kuniyoshi Shimizu Ryuichiro Kondo 《Food chemistry》2011
In an effort to find a new whitening agent, we have found that the methanol extract of the dried skin of Allium cepa showed inhibition of melanin formation. Bioassay-guided fractionation led to the isolation of quercetin (1) and quercetin 4’-O-β-glucoside (3) from A. cepa as the inhibitors of melanin formation in B16 melanoma cells with IC50 values of 26.5 and 131 μM, respectively. In addition, we evaluated the effect of some quercetin derivatives, such as isoquercitrin (2), quercetin 3,4’-O-diglucoside (4), rutin (5) and hyperin (6) on B16 melanoma cells. These quercetin derivatives did not show any inhibition of melanin formation. Furthermore, the ORAC values of compounds 1–6 were 7.64, 8.65, 4.82, 4.32, 8.17 and 9.34 μmol trolox equivalents/μmol, respectively. Dried skin of red onion showed inhibitory activity against melanin formation in B16 melanoma cells, as well as antioxidant properties. 相似文献
70.
Weanling rats were fed a riboflavin-deficient diet. The mitochondrial fatty acid oxidation in liver was depressed in riboflavin
deficiency but restored after supplementation of riboflavin. Among the enzymes involved in this system, only the acyl-CoA
dehydrogenase (EC 1.3.99.2 and 1.3.99.3) activities varied with the change in fatty acid oxidation. An accumulation of the
apoforms of acyl-CoA dehydrogenases was found in riboflavin deficiency. The levels of electron transfer flavoprotein and other
enzymes involved in the β-oxidation system remained unchanged. The peroxisomal fatty acid oxidation and levels of individual
enzymes of this system remained constant. No accumulation of the apoform of acyl-CoA oxidase was observed under simple, riboflavin-deficient
conditions. However, accumulation of a large amount of apo-acyl-CoA oxidase was observed when the peroxisomal system was induced
by administration of a peroxisome proliferator, di(2-ethylhexyl)phthalate, under riboflavin-deficient conditions. 相似文献