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851.
This study focuses on the effect of long-term exposure to high-temperature atmosphere on mechanical properties of carbon fiber reinforced plastic (CFRP) laminate with polycyanate resin system. Transversely oriented unidirectional laminate of carbon fiber/polycyanate (T700SC/FSD-M-08178) CFRP was employed on isothermal aging at 180 °C in air up to 4000 h. Matrix crack extension during isothermal aging was observed by soft X-ray radiography. Tensile and compressive tests were conducted on both non-aged and aged (500, 1000, 2000, and 4000 h) specimens with an acoustic emission (AE) measurement in order to evaluate mechanical properties and damage behavior due to thermo-oxidative degradation. After tensile tests, the fracture surface observation with a scanning electron microscopic (SEM) apparatus was also carried out to characterize damage extension due to thermo-oxidative degradation. The results show that thermo-oxidation induced matrix cracks preferentially in perpendicular area along the fiber direction and the matrix crack propagated along the fiber direction. Due to the crack onset, tensile strength was sharply dropped, even though compression strength was slightly changed. From the AE measurement result, the failure mode change was detected for the tension test. Comparing the soft X-ray radiography result with the SEM observation result, the fracture for tension test did not occur at the maximum crack length location for the longer thermo-oxidative aged specimen. 相似文献
852.
Naomi Asahara Xue Bin Zhang Yoshiyuki Ohta 《Journal of the science of food and agriculture》1992,58(3):395-401
The microbiological flora of miso, a traditional fermented food in Japan, were investigated. Bacteria, a yeast and a mould were isolated and identified as Pediococcus acidilactici, Leuconostoc paramesenteroides, Micrococcus halobius, Zygosaccharomyces rouxii and Aspergillus sp. P acidilactici strains were dominant bacteria in miso. The binding and antimutagenic activities of all microbial strains towards mutagenic pyrolysates were investigated. The lyophilised cells of strains of the bacteria and yeast showed the largest antimutagenic effect on 3-amino-l-methyl-[5H]pyrido[4,3-b]indole (Trp-P-2), but the mould was less antimutagenic than the bacteria and yeast. Most strains tested had no effective antimutagenic activity against 2-amino-3-methyl imidazo[4,5-f] quinoline (IQ). Trp-P-2 was effectively bound by all non-mould strains but binding of IQ to cells was much less effective. Among the strains tested, Leuconostoc paramesenteroides No 28 indicated the highest binding activity, not only to Trp-P-2 but also to IQ (30% binding capacity). As the concentration of Trp-P-2 was increased, the limits of binding ability of P acidilactici No 23, Z rouxii No 6 and Aspergillus sp 1 were 650, 500 and 400μg per 5 mg respectively. The binding ability and antimutagenicity for Trp-P-2 of all strains was reduced by autoclaving at 100°C for 5 min or 121°C for 15 min, by 6–20% and 7–28%, respectively. Aspergillus sp 1 was unaffected by autoclaving. The binding ability and antimutagenicity of cell walls towards Trp-P-2 was very high, being more than 85 YO effective, but it was lower than that of cytoplasm. 相似文献
853.
Hiromi Yoshida Yuka Tomiyama Megumi Tanaka Yoshiyuki Mizushina 《Journal of the science of food and agriculture》2007,87(14):2709-2714
BACKGROUND: The fatty acid distribution of triacylglycerols (TAG) and major phospholipids (PL) obtained from four varieties of peas (Pisum sativum) was investigated. The total lipids extracted from the peas were separated by thin layer chromatography into seven fractions. RESULTS: The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while hydrocarbons, steryl esters, free fatty acids and diacylglycerols (sn‐1,3 and sn‐1,2) were also present in minor proportions (5.6–9.2%). The main PL components isolated from the four varieties were phosphatidylcholine (42.3–49.2%), phosphatidylinositol (23.3–25.2%) and phosphatidylethanolamine (17.7–20.5%). Significant differences (P < 0.05) in fatty acid distribution were found for different pea varieties. Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. However, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident among the four varieties: unsaturated fatty acids were predominantly located in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in the oils of the peas. CONCLUSION: These results should be useful to both producers and consumers for the manufacture of pea foods in Japan. Copyright © 2007 Society of Chemical Industry 相似文献
854.
Nagata Y Matsuda M Komatsu H Imura Y Sawada H Ohtsubo Y Tsuda M 《Journal of Bioscience and Bioengineering》2005,99(6):603-610
The Burkholderia multivorans strain ATCC 17616 carries three circular chromosomes with sizes of 3.4, 2.5, and 0.9 Mb. To reveal the distribution and organization of the genes for fundamental cell functions on the genome of this bacterium, the dnaA and dnaK gene regions of ATCC 17616 were cloned and characterized. The gene organization of the dnaA region was rnpA-rmpH-dnaA-dnaN-gyrB with a single consensus DnaA-binding box (TTATCCACA) between the rmpH and dnaA genes. This intergenic region, however, did not work as an autonomously replicating sequence in ATCC 17616. On the other hand, the gene organization of the dnaK region was grpE-orf1 (gene for thioredoxin homologue)-dnaK-dnaJ-pabB (gene for p-aminobenzoate synthetase component homologue). A putative heat-shock promoter that showed good homology to the sigma32-dependent promoter consensus sequence in Escherichia coli was found upstream of the grpE gene, suggesting that these five genes constitute an operon. In M9 succinate minimal medium the dnaJ mutant grew more slowly than the wild-type strain, indicating that this operon is functional. Pulsed-field gel electrophoresis and Southern blot analyses indicated that both the dnaA and dnaK gene regions exist as single copies on the 3.4 Mb chromosome. 相似文献
855.
Extracted lipids obtained from black and red rices were analysed by high-performance liquid chromatography (HPLC), for endogenous tocochromanols. The molecular species and fatty acid (FA) distribution of triacylglycerols (TAG) isolated from these total lipids were analysed by a combination of AgNO3 thin-layer chromatography (TLC) and gas chromatography (GC), and were investigated in relation to the content of endogenous tocochromanols. With a few exceptions, the predominant tocols were γ-tocotrienol and α-tocopherol, followed by α-tocotrienol (red) and γ-tocopherol (black) with much smaller amounts of β-, δ-tocopherols and δ-tocotrienol. The lipids of these rices were comprised mainly of TAG (76.4–80.5%), free FA (7.2–9.8%), and phospholipids (3.5–3.6%), whilst other components were present in minor proportions (0.1–4.1%). The principal FA components were palmitic (16:0), oleic (18:1n − 9) and linoleic (18:2n − 6) acids. Fifteen different TAG molecular species were detected and quantified by successive applications of AgNO3-TLC and GC. The major TAG components were S2M (7.0–7.8%), SM2 (12.6–12.9%), M3 (15.7–16.5%), SMD (23.5–23.7%), SD2 (5.7–5.8%), M2D (9.3–9.8%), MD2 (8.1–8.6%) and D3 (5.8–7.4%) (where S, M, D, and T denote a saturated FA, a monene, a diene, and a triene, respectively). The results suggested that these rice lipids contain large amounts of nutraceuticals with proven positive health effects. 相似文献
856.
Kohei Kamiya Wakako Hamabe Shogo Tokuyama Ken Hirano Toshiko Satake Yuko Kumamoto-Yonezawa Hiromi Yoshida Yoshiyuki Mizushina 《Food chemistry》2010
During the course of our studies to develop new uses for the Noni (Morinda citrifolia) root, 10 anthraquinones, rubiadin (1), rubiadin 1-methyl ether (2), lucidin (3), damnacanthol (4), 1,3-dihydroxy-2-methoxymethylanthraquinone (5), 3-hydroxy-1-methoxy-2-methoxymethylanthraquinone (6), nordamnacanthal (7), damnacanthal (8), sorandidiol (9) and morindone (10), were isolated. Compounds 5, 6, 7, 8 and 10 exhibited remarkable inhibition against the activities of animal pols, and compound 10 was the strongest inhibitor in the anthraquinones investigated. Among mammalian pols, compound 10 inhibited the pol activities of A- (pol γ), B- (pols α, δ and ε) and Y- (pols η, ι and κ) families, but did not influence the activities of X-family pols (pols β, λ and terminal deoxynucleotidyl transferase). The tendency of pol inhibition showed a positive correlation with the suppression of human colon cancer cell HCT116 growth. These results suggested that the Noni root containing anthraquinones may be used as an anticancer functional food. 相似文献
857.
An analytical method of stochastic seismic response and reliability analysis of hysteretic structures based on the theory of Markov vector process is presented, especially from the methodological aspect. To formulate the above analysis in the form of stochastic differential equations, the differential formulations of general constitutive laws for a class of hysteretic characteristics are derived. The differential forms of the seismic safety measures such as the maximum ductility ratio, cumulative plastic deformation, low-cycle fatigue damage are also derived. The state equation governing the whole nonlinear dynamical system which is composed of the shaping filter generating seismic excitations, hysteretic structural system and safety measures is determined as the Itô stochastic differential equations. By introducing an appropriate non-Gaussian joint probability density function, the statistics and joint probability density function of the state variables can be evaluated numerically under nonstationary state. The merit of the proposed method is in systematically unifying the conventional response and reliability analyses into an analysis which requires knowledge of only first order (single-time) statistics or probability distributions. 相似文献
858.
Ryotaro Shimada Tsutomu Kono Koji Masuda Yoshiyuki Komoda 《Advanced Powder Technology》2019,30(4):774-785
Aimed at optimizing the resin-molding process, a method for numerically analyzing aggregation and dispersion behavior of the filler in resin composite was proposed. The flow of a resin composite during molding was calculated by using computational fluid dynamics (CFD), and particle-size distribution (PSD) of the cluster in each computational domain of the CFD model was estimated by solving the population balance equation (PBE). The proposed numerical-analysis method is based on the thixotropy model of Usui et al. In the thixotropy model, PSD is calculated by taking into account the aggregation and dispersion rate of the cluster by Brownian coagulation, shear coagulation, and shear breakage. Shear-breakage rate of the cluster is evaluated by solving the energy balance of bonding energy of the primary particles cut at the breakage and the drag applied to the cluster by the flow of the fluid. The composite viscosity was calculated using Krieger and Dougherty’s model based on apparent-solid-volume fraction estimated from the calculated PSD. To solve the PBE at low calculation cost, it was discretized using the fixed-pivot technique of Kumar and Ramkrishna. The proposed method was incorporated into the general-purpose CFD software FLOW-3D®, and its accuracy was proved. 相似文献
859.
Raw sago starch digesting amylase was obtained from Penicillium brunneum No. 24. with strong ability to digest sago starch granules. The crude enzyme from this strain contains CMC-ase and avicelase. The specific activity of the enzyme did not increase proportionally with purification. We tried combination of our purified enzyme with other hydrolytic enzymes as a means of improving the hydrolysis of sago starch granules. Addition of cellulase at the initial stage of the hydrolyzation process resulted in an increase in the ability of raw starch digesting amylase to digest sago starch granules. Adding 10 unit/g starch of cellulase. followed of our purified raw starch digesting amylase in small portion at various time intervals was found effective in the hydrolysis of untreated sago starch granules. The treatment resulted in a convertion rate of untreated sago starch granules to glucose near to complete after 120h enzymes reaction, and was also effective in reducing the reaction time of hydrolysis of treated sago starch granules. This process showed that mainly glucose was produced. 相似文献
860.
Polymer-derived ceramics (PDCs) are being actively explored in various fields today because of their unique physiochemical properties. Very recent advances in the use of PDCs in energy storage technologies (e.g., batteries, supercapacitors) have motivated researchers to explore the possibilities of PDCs as electrocatalysts for use in energy conversion reactions. Impressively, the tunable functional properties, especially the electrical properties, of PDCs have helped to break through this “bottleneck” and enabled them to become promising materials for use in electrocatalytic conversion. This review presents an in-time summary of the progress in the development of PDCs for electrochemical energy conversion. First, a general introduction to the preparation of PDCs is provided. Later, the factors (e.g., chemical stability, electron conductivity) most closely related to electrocatalytic performance are discussed. Specifically, the parameters that affect the electron conductivity of PDCs are enumerated to delve into advanced strategies for achieving effective electrocatalysts. The relevant electrocatalytic conversion reactions (e.g., hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction) and utilization of PDCs in these reactions are also comprehensively introduced. Finally, the current challenges and future opportunities for PDC materials in the field of electrochemical energy conversion are summarized. 相似文献