全文获取类型
收费全文 | 140篇 |
免费 | 4篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 46篇 |
金属工艺 | 5篇 |
机械仪表 | 3篇 |
建筑科学 | 1篇 |
能源动力 | 9篇 |
轻工业 | 12篇 |
水利工程 | 2篇 |
无线电 | 6篇 |
一般工业技术 | 22篇 |
冶金工业 | 8篇 |
原子能技术 | 4篇 |
自动化技术 | 19篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1987年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有144条查询结果,搜索用时 15 毫秒
91.
We introduce a BDD with redundant variables as an Indexed BDD (IBDD) and define PolyIBDD as the class of Boolean functions represented by polynomial-sized IBDDs for the number of input variables. Assuming that the class of languages on {0, 1}* that are accepted by logarithmic space bounded DTMs is DLOG, the following relation holds. PolyIBDD = DLOG. That is to say that languages which belong to DLOG also belong to PolyIBDD. We also show examples of polynomial-sized IBDD's construction from logarithmic space bounded DTMs. 相似文献
92.
Tracking the presence, distribution and disappearance of biological soil crusts is important for ecosystem management of desert regions and provides highly valuable information on desertification and climate change studies in arid environments. Based on the analysis of the spectral features of biological soil crusts, we propose a new biological soil crust index (BSCI) for biological soil crusts mapping. Using both a radiative transfer simulation and an analysis of a Landsat Enhanced Thematic Mapper Plus (ETM+) image, we examined the ability of satellite remote sensing to detect and map biological soil crusts. Our simulation indicated that Landsat ETM+ data could be used, after atmospheric correction, to detect biological soil crusts if 33% or more of any pixel was accounted for by biological soil crusts. When the proposed BSCI was applied to the detection of biological soil crusts in the Gurbantonggut Desert, Xingjiang, China, a Kappa coefficient of 0.82 and an overall accuracy of 94.7% were achieved. These experimental results indicate that the new index is applicable to identification of lichen-dominated biological soil crusts, and therefore has good potential for biological soil crust detection and mapping in cool and cold deserts. 相似文献
93.
Smith Marilyn Chapnik; Besner Derek; Miyoshi Hiroto 《Canadian Metallurgical Quarterly》1994,20(1):104
It is widely assumed that semantic priming in visual word recognition is automatic when the task requires word-level analysis. The present experiments show that this conclusion is too strong. Whether brief-duration primes facilitated the processing of related targets in lexical decision depended on the context in which the primes were seen. Semantic priming occurred if Ss saw only brief primes (blocked condition) but was minimal if longer primes were presented as well (mixed condition). Converging operations indicate that this modulation of semantic priming reflects operations beyond the lexical level rather than early encoding deficits. Rather than being automatic, semantic priming depends on the context in which a word is read. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
The reaction of an equimolar mixture of SrCO3 and GeO2 proceeds in five stages, [1]–[5]. The overall reaction of [1], [2], and [3] is best described by the Jander equation, the apparent activation energy being 47.6 kcal mol?1 irrespective of the ball-milling time. β-Strontium metagermanate is formed directly at lower temperatures from amorphous material prepared by the simultaneous hydrolysis of strontium and germanium alkoxides. Kinetic studies of β-SrGeO3 formation and β- → α-SrGeO3 transformation are carried out by means of X-ray diffraction. 相似文献
95.
We consider the problem of providing a fixed width confidence interval for the difference of two normal means when the variances are unknown and unequal. We propose a two-stage procedure that differs from those of Chapman (1950) and Ghosll (1975). The procedure provides the desired confidence, subject to the restriction on the width, for certain values of the design parameter h. Values of h are given by the Monte Carlo rnethod for various combinations of first stage sample size and confidence level. Finally, it is shown that the procedure is asymptotically more efficient than those of Chapmail and Ghosh with respect to total sample size, as the width of the interval approaches zero. 相似文献
96.
Haut Marc W.; Leach Sharon; Kuwabara Hiroto; Whyte Shannon; Callahan Ty; Ducatman Alan; Lombardo Lynda J.; Gupta Naresh 《Canadian Metallurgical Quarterly》2000,14(4):551
Neuropsychological studies have documented frontal dysfunction in patients with a history of exposure to organic solvents. The deficits typically observed in these patients appear to be related to working memory (WM). This study used [1?O] water positron emission tomography (PET) to examine the pattern of neural activation during verbal working memory in patients with a history of exposure to solvents. Six individuals with solvent exposure were compared with 6 age- and education-matched controls. On the 2 WM tasks examined with PET, with equivalent task performance, participants with solvent exposure demonstrated frontal peaks that were atypical for the tasks, whereas the posterior peaks were typical for the tasks. The results support frontal dysfunction and compensatory use within anterior regions of the WM system in patients with solvent exposure. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
Hiroto Kikuchi Hiroaki Sakurai Taizo Nagura Tsutomu Aritsuka Fusao Tomita Atsushi Yokota 《Journal of Bioscience and Bioengineering》2010,109(3):240-243
The newly established difructose anhydride IV (DFA IV) production system is comprised of the effective production of levan from sucrose by Serratia levanicum NN, the conversion of the levan into DFA IV by levan fructotransferase from Arthrobacter nicotinovorans GS-9, which is highly expressed in an Escherichiacoli transformant, and a practical purification step. The chemical properties of DFA IV were also investigated. 相似文献
98.
The reaction of poly(methyl methacrylate) (PMMA), poly(i-butyl methacrylate), poly(2-hydroxyethyl methacrylate), and polymethacrylonitrile bearing organotellurium, organostibine, and organobismuthine ω-living polymer end groups with 2,2,6,6-tetramethylpiperidine 1-oxy (TEMPO) under thermal or photochemical conditions gave the corresponding ω-vinylidene functionalized polymethacrylates and polymethacrylonitrile with high end group fidelity. Treatment of the PMMA with ethyl 2-[(tributylstannyl)methyl]acrylate also gave a PMMA bearing the same ω-vinylidene end functionality. 1H NMR, GPC, MALDI TOF MS, and thermogravimetric analyses revealed the highly controlled and defined structure of poly(alkyl methacrylate)s and polymethacrylonitrile in terms of molecular weight, molecular weight distribution, and the ω-polymer end structure. 相似文献
99.
Hamazaki K Itomura M Huan M Nishizawa H Watanabe S Hamazaki T Sawazaki S Terasawa K Nakajima S Terano T Hata Y Fujishiro S 《Lipids》2003,38(4):353-358
A large number of papers have reported that administration of n−3 FA reduced serum TG concentrations in hypertriglyceridemic
patients. However, few studies have examined the effect of n−3 FA on serum concentrations of remnant-like particle (RLP) cholesterol.
Volunteers (n=41) whose serum TG concentrations were 100–300 mg/dL were recruited and randomly assigned to either an n−3 FA group or a
control group with stratification by sex, age, and serum TG level in a double-blind manner. The subjects in the n−3 FA group
were administered 125 ml of fermented soybean milk with fish oil containing 600 mg of EPA and 260 mg of DHA/d for 12 wk. The
controls consumed control soybean milk with olive oil. Fasting blood samples were obtained before the start of administration
and at 4, 8 and 12 wk. EPA concentrations in red blood cells increased significantly in all but one subject in the n−3 FA
group, with no significant changes in the control group. TG levels decreased more in the n−3 FA group than in the control
group at weeks 4 (P<0.05), 8 (P<0.01), and 12 (P<0.05) with their baseline as covariate. RLP cholesterol levels decreased more in the n−3 FA group than in the control at
weeks 8 (P<0.01) and 12 (P<0.05) with their baseline as covariate. The groups did not differ in the other lipid levels. It is likely that n−3 long-chain
FA may exert anti-atherosclerotic effects by lowering serum TG and RLP-cholesterol levels even at the dose of 860 mg/d. 相似文献
100.
Hiroto Sakashita 《Journal of Nuclear Science and Technology》2016,53(6):797-802
This paper investigates critical heat flux (CHF) in saturated pool boiling for water and TiO2 nanofluid on a 7-mm-diameter vertical copper surface at pressures of 0.1–0.8 MPa. The nanofluid was prepared by dispersing 0.002 wt% TiO2 nanoparticles in deionized water. The CHF of the nanofluid was enhanced about two times over that of water boiling at atmospheric pressure. With the increasing pressure, however, the CHF enhancement with the nanofluid decreases, and almost disappears at 0.8 MPa. 相似文献