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101.
Several triacyl glycerides (2), having terminal epoxy functionalities on aliphatic residues of varying chain length, were allowed to react with either 4,4′-methylenedianiline or phthalic anhydride to give a new group of glassy network polymers with glass transition temperatures (Tgs) of 48-133 °C. Although cured 2 have substantially lower moduli than do conventional epoxy thermosets based on bisphenol A-diglycidyl ether (BADGE), the crosslinked triglycerides adhere strongly to steel and aluminum and are much more ductile and considerably tougher than commercial epoxy systems. In addition to a comparison of thermal and mechanical properties of thermosets based on 2, BADGE and common epoxidized linseed oil, reactivity differences among these epoxy resins are briefly discussed.  相似文献   
102.
Evaluated the ability of 2 screening instruments for geriatric psychiatric patients: one by A. Simon et al and the other by R. D. Savage and P. G. Britton. The overall correctness in discriminating was 66% for the Simon et al scale and 74% for the Savage and Britton scale, although the former misidentified normals as impaired, and the latter misidentified impaired Ss as normal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
103.
An increasing fraction of volatile organic compounds (VOC) emissions come from the domestic use of solvents, contained within myriad commonplace consumer products. Emission rates are often poorly characterized and depend significantly on individual behavior and specific product formulation and usage. Time-concentration profiles of volatile organic compounds (VOCs) arising from the use of a representative selection of personal care products (PCPs) during showering are generated, and person-to-person variability in emissions calculated. A panel of 18 participants used a standardized set of products, dosages, and application times during showering in a controlled indoor bathroom setting. Proton transfer mass spectrometry was used to measure the in-room VOC evolution of limonene (representing the sum of monoterpenes), benzyl alcohol, and ethanol. The release of VOCs had reproducible patterns between users, but noticeable variations in absolute peak concentrations, despite identical amounts of material being used. The amounts of VOC emitted to air for one showering activity were as follows: limonene (1.77 mg ± 42%), benzyl alcohol (1.07 mg ± 41%), and ethanol (0.33 mg ± 78%). Real-world emissions to air were between 1.3 and 11 times lower than bottom-up estimates based on dynamic headspace measurements of product emissions rates, likely a result of PCPs being washed away before VOC evaporation could occur.  相似文献   
104.
The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier.  相似文献   
105.
106.
Evaluated the relation between self-reported frequency of nightmares, a number of saliency measures of the nightmare experience, and a self-report measure of annihilation anxiety (appended) for 1,357 undergraduates from 2 independent populations. A significant positive relation was found between nightmare frequency and salience and annihilation anxiety. Findings were cross-validated across both samples. Results are discussed within the context of object relations and ego psychology theory utilizing an ego boundary model and are consistent with previous research (e.g., E. Hartmann, 1991) demonstrating boundary impairment in Ss with self-reported frequent nightmares. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
107.
Mice were infected intranasally with a serotype 2 pneumococcus, a pneumolysin-negative derivative (PLN-A), or an autolysin-negative derivative (AL-2). Numbers of wild type pneumococci were seen in the lung from approximately 12 h after infection and were first detected in the blood around this time. Immunofluorescent staining of lung sections showed that pneumolysin was produced in vivo. Pneumococcal infection resulted in alteration of the composition of the blood but not the bone marrow. Some of the hematologic changes did not occur after PLN-A. PLN-A had a slower growth rate in the lung and bacteremia was delayed. AL-2 was rapidly cleared from the lungs and was not detected in the blood. These events paralleled the pattern of histology in the lung, with the severity of inflammation reduced with PLN-A and no inflammation or hematologic changes with AL-2.  相似文献   
108.
109.
Methylphosphonate (MP) oligodeoxynucleotides (MPOs) are metabolically stable analogs of conventional DNA containing a methyl group in place of one of the non-bonding phosphoryl oxygens. All 16 possible chiral R(P) MP dinucleotides were synthesized and derivatized for automated oligonucleotide synthesis. These dimer synthons can be used to prepare (i) all-MP linked oligonucleotides having defined R(P) chirality at every other position (R(P) chirally enriched MPOs) or (ii) alternating R(P) MP/phosphodiester backbone oligonucleotides, depending on the composition of the 3'-coupling group. Chirally pure dimer synthons were also prepared with 2'-O-methyl sugar modifications. Oligonucleotides prepared with these R(P) chiral methylphosphonate linkage synthons bind RNA with significantly higher affinity than racemic MPOs.  相似文献   
110.
This article traces the connection between expert systems used as consultants in medicine and their design for instructional purposes in education. It is suggested that there are important differences between these applications. Recognizing these differences leads to the view that the development of intelligent computer-assisted instructions (ICAI) should be guided by empirical research into social/psychological consequences and by ethical inquiries into the acceptability of those consequences. Three proposals are put forward: (1) that the pedagogical role of intelligent CAI be clarified, (2) that forms of intelligent CAI be developed that aim primarily at refining rather than replacing human judgements, and (3) that ICAI research and development projects contain components which address ethical and social/psychological components and which are equitably-funded, integral parts of the overall development effort.This work was supported in part by funds from the Foundation of the University of North Carolina at Charlotte and from the State of North Carolina. An earlier version of this paper was read at the Human Dimension in Artificial Intelligence Symposium held at the University of Kentucky (April 1988).  相似文献   
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