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31.
32.
A new donor explosive, ROWANEX 3601 has been selected for use in the large scale gap test (LSGT). It was necessary to calibrate the peak pressure recorded on the central axis of the PMMA gap using calibrated piezo‐resistive pressure transducers as a function of the gap thickness. The stress history within the PMMA gap was measured and the peak pressure plotted against gap thickness as a calibration. Further effects were noted relating to the curvature of front exiting the donor charge and the validity of the measurement of the transmitted shock at small gap thicknesses.  相似文献   
33.
Predictive spatial modelling is becoming an integral part of landscape planning. One emerging modelling approach is risk assessment. This paper illustrates the application of risk assessment techniques within a regional context for landscape planning and design, as urban development expands into mountainous building environments. The investigation examines the susceptibility of building sites in a portion of the Front Range mountains of Colorado/Wyoming to catastrophic disturbance by four landscape hazards: flooding, rockfall, fire and avalanche. A hazard rating model is applied to a portion of the Front Range, the Pingree Park vicinity, by employing geographic information system technology. We discovered that, below the tree-line, approximately 75% of the landscape contained a high risk rating and the remaining portion a moderate risk rating. This study implies that there is no long-term, safe building site in the study area. Assuming that the Pingree Park vicinity is a representative sample of the Front Range, our results would indicate that the long-term prospects for structures in the mountainous region of Colorado are not particularly promising; however, much more extensive study would be required before a definitive answer could be derived. Nevertheless, this investigation illustrates the basic principles and presents essential literature for landscape risk assessment planning.  相似文献   
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35.
The salient features of a study of the dynamic wetting behaviour of several polyester tapes are given, together with the complementary fluid and air entrainment phenomena. Analysis of the data shows that there is no significant difference between data from different tape surfaces and that a correlation between Weber and Reynolds number adequately describes the results. A practical empirical formula (r > 0.99) is given which relates the air entrainment velocity to fluid properties. This has the form: This formula agrees with experimental data for fluids with viscosity in the range 0.004 < μ <0.5 Nsm?2 and surface tension in the range 0.025 < σ < 0.064 Jm?2 whilst predicting the air entrainment velocity to within 10% of experimentally determined value.  相似文献   
36.
This paper describes a straightforward procedure to immobilize oligonucleotides on glass substrates in well-defined micropatterns by microcontact printing with a dendrimer-modified stamp. The oligonucleotides are efficiently immobilized by "click" chemistry induced by microcontact printing. Acetylene-modified oligonucleotides were treated with an azide-terminated glass slide under the confinement of the dendrimer-modified stamp, without the use of a Cu(I) catalyst. The immobilization is an irreversible, covalent, and one-step reaction that results in stable attachment of the oligonucleotides. Oligonucleotides with the acetylene-modification at the 5' terminus hybridize selectively with full-length, complementary targets. Strands with more than one acetylene linker do not hybridize with complementary strands.  相似文献   
37.
Mycotoxins are common dietary contaminants in most regions of the world. The frequency of exposure to the various families of mycotoxins is often dependent on geographic location, national wealth and related agricultural and regulatory infrastructure, combined with diversity of diet and degree of food sufficiency. Deoxynivalenol (DON) is a Fusarium mycotoxin that frequently contaminates wheat, corn and barley in temperate regions. A number of acute poisoning incidences have been linked to DON-contaminated foods and chronic exposure to lower levels of DON has been predicted in many regions. DON is a potent animal toxin and exposure in humans may cause gastroenteritis, growth faltering and immune toxicity. An ability to conduct accurate exposure assessment at the individual level is required to fully understand the potential health consequences for humans. To date, such exposure biomarkers have been lacking for many important mycotoxins, including DON. To better assess exposure to DON at the individual level, we have developed a robust urinary assay, incorporating immunoaffinity column (IAC) enrichment and LC–MS detection. Further refinement of this urinary assay, by inclusion of 13C-DON as an internal standard, was then undertaken and tested within the UK. DON was frequently observed in urine and was significantly associated with cereal intake. A dietary intervention study demonstrated that avoiding wheat in the diet markedly reduced urinary levels of DON. This biomarker requires further validation but our initial data suggest it may provide a useful tool in epidemiological investigations of the potential health consequences of this common environmental toxin.  相似文献   
38.
Fretheim  K.  Sleigh  R. W.  Burley  R. W. 《Lipids》1986,21(2):127-131
In a study of lipid-protein interactions in egg yolk, it was found that L-α-dipalmitoyl lecithin gave two distinct noncovalent complexes (A and B) with apovitellenin I, an apoprotein in the major yolk lipoprotein. Interaction took place under widely varied conditions, and yolk lecithin gave similar complexes. Complex A, which was formed within minutes, consisted of round particles of about 9 nm diameter. Complex B, which was formed more slowly, consisted of larger, particles. Possibly resembling curved discs, with diameter of 30–40 nm. The preparation and some properties of these complexes are described. It is suggested that they may be suitable for an extensive study of phospholipid-protein interactions in yolk.  相似文献   
39.
以旅游为目的而研究历史景观的研究者们依赖于大量的档案、文献和私人收藏,从而收集到有关旅游地空间特征的众多信息,这些信息有助于旅游地游憩诠释及历史保护。在本研究中,我们的兴趣在于调查信息数量与完整性之间的关系,这些信息是密歇根州立档案馆为州属的机构(费耶特历史州立公园,由密歇根州立公园处所主管的机构)而收集的;同时,我们的兴趣还在于这些有关机构提供的信息资源的可利用程度。我们还对记录和报告等信息资源因何而被选为档案的过程感兴趣。我们发现当密歇根州有涉及州立机构的档案和收藏信息时,涉及场地的少量信息会被永久留存——主要是捐赠的照片和一些打印信件。相反,密歇根自然资源部州立公园处拥有广泛得多的业务资料,包括测绘的建筑图和旅游地平面图。此外,费耶特州立公园办公室还拥有由公园主管者每周完成的一份旅游地详细活动的报告。一些私人收藏因包含照片而很有价值,然而,密歇根自然资源部的资料以及私人收藏可能不会被永久存档。我们认为,涉及一个州的历史财产信息应该广泛传播,不应该被权力者独享。我们建议,州立档案馆只是以历史旅游地为目的的众多信息来源之一,研究者必须依靠个人的关系并持之以恒地去收集相应的信息。  相似文献   
40.
Meeting of the Midlands Region, held at the Carpet Trades Ltd Canteen, Kidderminster, on 13 February 1969, Mr D. O. Douglas in the chair The essential features of hank-dyeing machines are discussed in relation to the application of Fick's laws of diffusion to the mass-transfer processes occurring during dyeing. Dispersion equations and a mathematical model of the dyeing process are developed. The determination of dispersion coefficients on model hank systems is described. The results have been applied to the mathematical model using digital- and analogue-computer programs. The predictions of the computer-simulated dyeing process with respect to the distribution of dye within a hank are reasonably accurate in comparison with practical dyeings. The analogue-computer simulation of dyeing processes has general applicability beyond hank dyeing, provided that the appropriate system variables are known.  相似文献   
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