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排序方式: 共有842条查询结果,搜索用时 5 毫秒
1.
Aqueous extracts of the coralline red algaeBossiella orbigniana have been shown to catalyze the enzymatic oxidation of arachidonic acid to a previously unreported ω6 eicosapentaenoic acid
product. This unique fatty acid contains a conjugated tetraene with absorption maxima at 293, 306, and 321 nm, and was identified
by spectral methods as 5(Z),8(Z),10(E),12(E),14(Z)-eicosapentaenoic acid. The compound was given the trivial name bosseopentaenoic
acid. Under experimental conditions, production of bosseopentaenoic acid was linear up to 2 hr and dioxygen was consumed.
Bosseopentaenoic acid, along with several other conjugated tetraenes, was also present in the algae endogenously as revealed
by a comparison of the ultraviolet (UV) spectra and the high-performance liquid chromatographic (HPLC) pattern of the purified
product and the organic extract ofBossiella. 相似文献
2.
Vassilis Agouridas Alison McKay Henri Winand Alan de Pennington 《Requirements Engineering》2008,13(1):19-48
This paper reports results of research into the definition of requirements for new consumer products––specifically, electro-mechanical
products. The research dealt with the derivation of design requirements that are demonstrably aligned with stakeholder needs.
The paper describes a comprehensive process that can enable product development teams to deal with statements of product requirements,
as originally collected through market research activities, in a systematic and traceable manner from the early, fuzzy front
end, stages of the design process. The process described has been based on principles of systems engineering. A case study
from its application and evaluation drawn from the power sector is described in this paper. The case study demonstrates how
the process can significantly improve product quality planning practices through revision of captured product requirements,
analysis of stakeholder requirements and derivation of design requirements. The paper discusses benefits and issues from the
use of the process by product development teams, and identifies areas for further research. Finally, the conclusions drawn
from the reported research are presented.
相似文献
Vassilis AgouridasEmail: |
3.
A new approach is introduced for turbidite modeling, leveraging the potential of computational fluid dynamics methods to simulate the flow processes that led to turbidite formation. The practical use of numerical flow simulation for the purpose of turbidite modeling so far is hindered by the need to specify parameters and initial flow conditions that are a priori unknown. The present study proposes a method to determine optimal simulation parameters via an automated optimization process. An iterative procedure matches deposit predictions from successive flow simulations against available localized reference data, as in practice may be obtained from well logs, and aims at convergence towards the best-fit scenario. The final result is a prediction of the entire deposit thickness and local grain size distribution. The optimization strategy is based on a derivative-free, surrogate-based technique. Direct numerical simulations are performed to compute the flow dynamics. A proof of concept is successfully conducted for the simple test case of a two-dimensional lock-exchange turbidity current. The optimization approach is demonstrated to accurately retrieve the initial conditions used in a reference calculation. 相似文献
4.
Yimin Yao Alison Findlay Jessica Stolp Benjamin Rayner Kjetil Ask Wolfgang Jarolimek 《International journal of molecular sciences》2022,23(10)
Systemic sclerosis (SSc) is characterised by progressive multiple organ fibrosis leading to morbidity and mortality. Lysyl oxidases play a vital role in the cross-linking of collagens and subsequent build-up of fibrosis in the extracellular matrix. As such, their inhibition provides a novel treatment paradigm for SSc. A novel small molecule pan-lysyl oxidase inhibitor, PXS-5505, currently in clinical development for myelofibrosis treatment was evaluated using in vivo rodent models resembling the fibrotic conditions in SSc. Both lysyl oxidase and lysyl oxidase-like 2 (LOXL2) expression were elevated in the skin and lung of SSc patients. The oral application of PXS-5505 inhibited lysyl oxidase activity in the skin and LOXL2 activity in the lung. PXS-5505 exhibited anti-fibrotic effects in the SSc skin mouse model, reducing dermal thickness and α-smooth muscle actin. Similarly, in the bleomycin-induced mouse lung model, PXS-5505 reduced pulmonary fibrosis toward normal levels, mediated by its ability to normalise collagen/elastin crosslink formation. PXS-5505 also reduced fibrotic extent in models of the ischaemia-reperfusion heart, the unilateral ureteral obstruction kidney, and the CCl4-induced fibrotic liver. PXS-5505 consistently demonstrates potent anti-fibrotic efficacy in multiple models of organ fibrosis relevant to the pathogenesis of SSc, suggesting that it may be efficacious as a novel approach for treating SSc. 相似文献
5.
Sai Madhukar Reddy Jung Jin Park Suok‐Min Na Mazin M. Maqableh Alison B. Flatau Bethanie J. H. Stadler 《Advanced functional materials》2011,21(24):4677-4683
Arrays of nanowires are fabricated with alternating segments of the magnetostrictive alloy Fe1–xGax and Cu using electrochemical deposition in nanoporous anodic aluminium oxide (AAO) templates. The difficult nature of Ga‐alloy electrochemistry is overcome by controlling mass‐transfer and hydrodynamic conditions using novel rotating disk electrode templates to obtain highly uniform segment lengths throughout the arrays. Extensive structural characterization by XRD, EBSD and TEM reveals a strong <110> textured Fe1–xGax growth. Furthermore, using vibrating sample magnetometry (VSM), we demonstrate that control of magnetization reversal processes is possible once uniform aspect ratios are obtained for both the Fe–Ga and Cu segments. 相似文献
6.
Whole grains — impact of consuming whole grains on physiological effects of dietary fiber and starch
Alison M. Stephen 《Critical reviews in food science and nutrition》1994,34(5-6):499-511
Much of the present research on the physiological effects of dietary fiber and starch has been done on sources isolated from the parent material, and it is not clear whether they have the same effects if fed in the intact or whole grain. For dietary fiber, physiological effect depends on extent of fermentation in the large intestine, and this is influenced by chemical composition, solubility, physical form, and presence of lignin or other compounds. All of these factors are altered by isolation of a fiber source from the whole grain, and hence effects of eating fiber vary. Similarly, physical form and presence in the whole grain will affect digestibility of starch in the small intestine, which in turn influences the glycemic response and colonic effects determined by the extent of malabsorption and entry into the colon. Starch that enters the colon is fermented and produces short‐chain fatty acids, particularly butyrate, which is necessary to maintain a healthy mucosa. Hence, their presence within the whole grain may have important implications for health for both dietary fiber and starch. Evidence indicates that such effects are beneficial and that whole‐grain consumption should be encouraged. 相似文献
7.
Plasmonic Nanoparticles as a Physically Unclonable Function for Responsive Anti‐Counterfeit Nanofingerprints 下载免费PDF全文
Far‐field scattering of randomly deposited Au nanoparticles (NPs) is demonstrated as a physically unclonable optical function for anti‐counterfeit applications in which the scattering patterns are easily produced yet impractical to replicate. Colloidal metal NPs are superb components for nanoscale labels owing to their small dimensions and intense far‐field scattering visible at wavelengths that depend on colloidal size, shape, composition, and their local environment. The feasibility of Au NP depositions as nanofingerprints is presented using a simple pattern matching algorithm. These NPs offer extended functionality as environmental sensors. Taking advantage of the local refractive index dependent scattering wavelengths of metal NPs, a detectable color change is also demonstrated from a nanofingerprint comprised of Au and Ag NPs when placed in media with different refractive index. The facile deposition method coupled with the intense scattering and optical response of metal NPs provides physically unclonable tags (nanofingerprints) with the ability to serve as tamper‐evident and aging labels. 相似文献
8.
Evangelia Komitopoulou Ioannis S. Boziaris E. Alison Davies Joss Delves-Broughton &Martin R. Adams 《International Journal of Food Science & Technology》1999,34(1):81-85
Summary The acid-tolerant and heat-resistant bacterium Alicyclobacillus acidoterrestris is a spoilage problem in pasteurized and heat-treated fruit juices. In this study it was shown to grow in orange juice, grapefruit juice and apple juice to produce detectable taint at levels of about 104 –105 c.f.u. ml−1 . Decimal reduction times were determined at 80 °, 90 ° and 95 °C in each juice and confirmed the heat-resistant nature of the spores under normal juice pasteurization conditions. They also confirmed that heat sensitivity increased with decreasing pH but that this effect was less pronounced at higher temperatures. The organism was, however, sensitive to the bacteriocin food preservative nisin. The presence of nisin during heating decreased the D value by up to 40% and the MIC for nisin against spores at 25 °C was only 5 International Units (IU) ml−1 . The results indicate that use of nisin is a potentially useful way of controlling this organism in fruit juices and fruit juice-containing products. 相似文献
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