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1.
Emissions of ultrasonic vocalizations (USVs) by rat pups (Rattus norvegicus) during hypothermia have consequences for recovery and warming. The effects on dam behavior of USVs emitted by 3- to 11-day-old pups during hypothermia at rectal temperatures between 18 and 22°C was investigated Rat dams were tested in a Y maze with the home cage as a start box. Dams were given, in one condition, a choice between a hypothermic pup emitting USVs or a hypothermic, silent (anesthetized) pup and, in the other, a choice between 2 hypothermic, silent pups. Although differing in some acoustic properties from normal isolation calls, USVs emitted by hypothermic pups both elicited maternal search behavior and acted as directional cues for dams, in comparisons with control dams exposed only to silent pups. Thus USVs of pups recovering from extreme hypothermia have communicative as well as physiological significance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Dennis D. Pietronigro Myron L. Seligman W. Barrie G. Jones Harry B. Demopoulos 《Lipids》1976,11(11):808-813
Deoxyribonucleic acid (DNA) is associated with the cell membrane of prokaryotes and the inner nuclear membrane of eukaryotes.
The unsaturated fatty acids of phospholipids, which constitute the bilaminar structure of membranes, undergo autoxidation
in the presence of O2. Calf thymus DNA was incubated with methyl archidonate-enriched phosphatidyl choline liposomes in order to study the effect
of DNA upon the oxidation of phospholipids while present in their natural in vivo bilayer configuration. DNA retarded the
rate of lipid oxidation and the TBA test, but it did not alter the induction period. These results suggest that DNA is scavenging
free radicals produced within the phospholipid bilayer. 相似文献
4.
Nikos Papadakis Dimitris Plexousakis Myron Papadakis Harris Manifavas 《Journal of Intelligent Information Systems》2012,38(1):41-94
In this paper we study the ramification problem in the setting of temporal databases. Standard solutions from the literature
on reasoning about action are inadequate because they rely on the assumption that fluents persist, and because actions have
effects on the next situation only. In this paper we provide a solution to the ramification problem based on an extension
of the situation calculus and the work of McCain and Turner. More specifically, we study the case where there are conflicting
effects of an action, a particularly complex problem. Also we present a tool which implements the proposed solution. 相似文献
5.
Erol Hakanoglu Myron B Fiering E. A. C. Croucht Richard Wilsont Lauren Zeise 《Civil Engineering and Environmental Systems》2013,30(2):84-96
Based on previous work, this paper aims to show how approximate methods of estimating exposure can lead to a preliminary ranked list of chemicals for regulation of carcinogens. This list is likely to be more reliable, than those so far generated. The paper argues four main points. Firstly that an indication of the route by which the total production of a hazardous material is distributed and enters the human body should be explicitly included in calculations. Second, simple calculations based on conservative bounds should be made to establish a ranking or set of priorities for regulation. Third, an improved system for establishing regulatory priorities can be based on formal analysis using regret functions. Finally some simple, bounded, calculations based on commonly used herbicides and pesticides are made and it is shown how some regulatory processes could be modified. 相似文献
6.
Roger D. Masters Myron J. Coplan 《The International journal of environmental studies》2013,70(4):435-449
Toxic metals like lead, manganese, copper and cadmium damage neurons and deregulate neurotransmitters like serotonin and dopamine (which are essential to normal impulse control and learning). Earlier studies show that — controlling for socio‐economic and demographic factors — environmental pollution with lead is a highly significant risk factor in predicting higher rates of crime, attention deficit disorder or hyperactivity, and learning disabilities. Exposure and uptake of lead has been associated with industrial pollution, leaded paint and plumbing systems in old housing, lead residues in soil, dietary habits (such as shortages of calcium and iron), and demographic factors (such as poverty, stress, and minority ethnicity). We report here on an additional “risk co‐factor” making lead and other toxic metals in the environment more dangerous to local residents: the use of silicofluorides as agents in water treatment. The two chemicals in question — fluosilicic acid and sodium silicofluoride — are toxins that, despite claims to the contrary, do not dissociate completely and change water chemistry when used under normal water treatment practices. As a result, water treatment with siliconfluorides apparently functions to increase the cellular uptake of lead. Data from lead screening of over 280,000 children in Massachusetts indicates that silicofluoride usage is associated with significant increases in average lead in children's blood as well as percentage of children with blood lead in excess of 10μg/dL. Consistent with the hypothesized role of silicofluorides as enhancing uptake of lead whatever the source of exposure, children are especially at risk for higher blood lead in those communities with more old housing or lead in excess of 15 ppb in first draw water samples where silicofluorides are also in use. Preliminary findings from county‐level data in Georgia confirm that silicofluoride usage is associated with higher levels of lead in children's blood. In both Massachusetts and Georgia, moreover, behaviors associated with lead nurotoxicity are more frequent in communities using silicofluorides than in comparable localities that do not use these chemicals. Because there has been insufficient animal or human testing of silicofluoride treated water, further study of the effect of silicofluorides is needed to clarify the extent to which these chemicals are risk co‐factors for lead uptake and the hazardous effects it produces. 相似文献
7.
Binding Mode and Structure–Activity Relationships around Direct Inhibitors of the Nrf2–Keap1 Complex 下载免费PDF全文
Dr. Eric Jnoff Dr. Claudia Albrecht Dr. John J. Barker Dr. Oliver Barker Dr. Edward Beaumont Dr. Steven Bromidge Dr. Frederick Brookfield Dr. Mark Brooks Dr. Christian Bubert Dr. Tom Ceska Vincent Corden Dr. Graham Dawson Dr. Stephanie Duclos Dr. Tara Fryatt Dr. Christophe Genicot Dr. Emilie Jigorel Dr. Jason Kwong Rosemary Maghames Innocent Mushi Dr. Richard Pike Dr. Zara A. Sands Dr. Myron A. Smith Dr. Christopher C. Stimson Dr. Jean‐Philippe Courade 《ChemMedChem》2014,9(4):699-705
An X‐ray crystal structure of Kelch‐like ECH‐associated protein (Keap1) co‐crystallised with (1S,2R)‐2‐[(1S)‐1‐[(1,3‐dioxo‐2,3‐dihydro‐1H‐isoindol‐2‐yl)methyl]‐1,2,3,4‐tetrahydroisoquinolin‐2‐carbonyl]cyclohexane‐1‐carboxylic acid (compound (S,R,S)‐ 1 a ) was obtained. This X‐ray crystal structure provides breakthrough experimental evidence for the true binding mode of the hit compound (S,R,S)‐ 1 a , as the ligand orientation was found to differ from that of the initial docking model, which was available at the start of the project. Crystallographic elucidation of this binding mode helped to focus and drive the drug design process more effectively and efficiently. 相似文献
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Role of soil freezing events in interannual patterns of stream chemistry at the Hubbard Brook Experimental Forest,New Hampshire 总被引:1,自引:0,他引:1
Fitzhugh RD Likens GE Driscoll CT Mitchell MJ Groffman PM Fahey TJ Hardy JP 《Environmental science & technology》2003,37(8):1575-1580
Soil freezing is a disturbance of the below ground environment, potentially resulting in increased losses of NO3- and surface water acidification. Here, we report the effects of soil freezing on interannual variation in stream chemistry at the Hubbard Brook Experimental Forest, New Hampshire. Data from 1970 to 1997 of soil frost depth, snow cover, precipitation, air temperature, and stream discharge and chemistry were used in a stepwise linear regression model to select the variables that best predicted deviations of annual stream concentrations from 4-year running averages. Variables quantifying soil freezing severity were selected as significant predictors of short-term fluctuations in stream K+, NO3-, Ca2+, and Mg2+ concentrations from 1970 to 1989, explaining 59 and 47% of the short-term variability in K+ and NO3-, respectively. Fine-root mortality and disturbance of root-soil-microbe interactions, with subsequent effects on decomposition and nutrient uptake, likely contributed to the mobilization of K+ and NO3- to streamwater following severe soil freezing events. The relationship between soil freezing and stream chemistry, however, weakened during the period 1990-1997. Because soil freezing has had inconsistent effects on stream chemistry during the period 1970-1997, it is unclear whether future changes in the frequency, duration, and depth of soil freezing events as the result of changes in the snow cover regime under a warmer climate will have significant impacts on the losses of NO3- and nutrient-base cations from temperate northern ecosystems. 相似文献