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81.
用 CaF_2单晶和 ZrO_2(+MgO)为固体电解质分别构成原电池:■和 Pt,B_((s)),NdBO_(3(s)),Nd(BO_2)_(3(s))|ZrO_2|Cr_2O_(3(s)),Cr_((s)),Pt联合测了 NdBO_3和 Nd(BO_2)_3的标准生成自由能:ΔG~0_(NdBO_3)=-1757+3.8×10~(-1)TΔG~0_(Nd)(BO_2)_3=-3435+8.8×10~(-1)T由此求出由氧化物生成 NdBO_3及 Nd((BO_2)_3)的反应的标准生成自由能变化:1/2Nd_2O_(3(s))+1/2B_2O_(3■)=NdBO_(3(s))ΔG~0_(NdBO_3)=-242+1.4×10~(-1)T和 1/2Nd_2O_(3(s))+3/2B_2O_(3(s))=Nd(BO_2)_(3■)ΔG~0′_(NdBO_2)3=-693+4.6×10~(-1)T 相似文献
82.
The erucic acid content of broccoli florets, sprouts, and seeds was found to be about 0.8, 320, and 12100 mg/100 g, respectively. Using the erucic acid limit established for canola oil in the U.S.A. and Canada as a guideline, the estimated dietary intake of erucic acid from florets and sprouts was considered of little consequence, whereas in seeds a relatively small amount (about 35 g/wk) equaled our calculated exposure limit for erucic acid. Additionally, the most complete fatty acid distribution yet published for the various forms of broccoli are presented. 相似文献
83.
ALEJANDRO G. MARANGONI 《Journal of food science》1994,59(5):1096-1099
Candida rugosa lipase (CRL) and Pseudomonas fluorescein lipase (PFL) were used to hydrolyze a low-melting point butteroil fraction in the absence of orgaic solvents. CRL and PFL displayed pH activity optima of 6.7 and 7.8, and temperature-activity optima of 40–50°C and 35°C, respectively. Maximum activity for PFL was observed at 5% (v/v) water content. CRL showed higher specificity towards butyric acid relative to PFL after 3 hours of hydrolysis at 40°C (22.3 mol% vs 7.8 mol%, respectively). Both enzymes displayed, however, high specificities towards palmitic and oleic acids. CRL's inherent specificity towards butyric acid makes it an ideal choice for a biological catalyst to generate useful dairy flavor profiles. 相似文献
84.
M. Kobayashi M. Mukai H. Takahashi N. Ohno T. Kawakami T. Ishikawa 《International journal for numerical methods in engineering》2003,58(10):1523-1543
This paper describes the implicit integration and consistent tangent modulus of an inelastic constitutive model with transient and steady strain rates, both of which are time‐ and temperature‐dependent; the transient rate is influenced by the evolution of back stress decomposed into parts, while the steady rate depends only on applied stress and temperature. Such a non‐unified model is useful for high‐temperature structural analysis and is practical owing to the ease in determining material constants. The implicit integration is shown to result in two scalar‐valued coupled equations, and the consistent tangent modulus is derived in a quite versatile form by introducing a set of fourth‐rank constitutive parameters into the discretized evolution rule of back stress. The constitutive model is, then, implemented in a finite element program and applied to a lead‐free solder joint analysis. It is demonstrated that the implicit integration is very accurate if the multilinear kinematic hardening model of Ohno and Wang is employed, and that the consistent tangent modulus certainly affords quadratic convergence to the Newton–Raphson iteration in solving nodal force equilibrium equations. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
85.
Robert L. Wolff 《Journal of the American Oil Chemists' Society》1994,71(3):277-283
Twelve commercial samples of French butter, purchased in October–November, and 12 other samples, purchased in May–June, were
analyzed with particular attention to theirtrans-octadecenoic acid contents. The isomeric fatty acids were quantitated by a combination of gas-liquid chromatography (GLC)
of total fatty acids as isopropyl esters on a polar capillary column (CPSil 88) and of silver nitrate-impregnated thin-layer
chromatography followed by GLC of the pooled saturated (used as internal standards) andtrans-octadecenoic acid fractions. Autumn butters contained 3.22±0.44%trans-octadecenoic acids (relative to total fatty acids), whereas those collected during the spring contained 4.28±0.47% (P<0.01). Minimum and maximum values for the two sets of butters were 2.46 (autumn) and 5.10% (spring), respectively. The annual
mean value for thetrans-octadecenoic acid content in all butter samples was 3.8% of total fatty acids (ca. 2% for thetrans-11 18∶1 acid). This value allows calculation of the daily individual intake oftrans-octadecenoic acids from dairy products by populations of member states of the European Economic Community (EEC). It varies
from 0.57 g (Portugal) to 1.66 g (Denmark). The mean value for the twelve countries of the EEC is 1.16 g/person/d, which is
close to data published for the United States. In France, the consumption oftrans octadecenoic acids from dairy fat is higher than that from margarines (ca. 1.5 vs. 1.1 g/person/d). 相似文献
86.
87.
M. Safar D. Bertrand P. Robert M. F. Devaux C. Genot 《Journal of the American Oil Chemists' Society》1994,71(4):371-377
The combination of attenuated total reflectance (ATR) and mid-infrared spectroscopy (MIRS) with statistical multidimensional
techniques made it possible to extract relevant information from MIR spectra of lipid-rich food products. Wavenumber assignments
for typical functional groups in fatty acids were made for standard fatty acids: Absorption bands around 1745 cm−1, 2853 cm−1, 2954 cm−1, 3005 cm−1, 966 cm−1, 3450 cm−1 and 1640 cm−1 are due to absorption of the carbonyl group, C−H stretch, =CH double bonds of lipids and O−H of lipids, respectively. In
lipid-rich food products, some bands are modified. Water strongly absorbs in the region of 3600–3000 cm−1 and at 1650 cm−1 in butters and margarines, allowing one to rapidly differentiate the foods as function of their water content. Principal
component analysis was used to emphasize the differences between spectra and to rapidly classify 27 commercial samples of
oils, butters and margarines. As the MIR spectra contain information about carbonyl groups and double bonds, the foods were
classified with ATR-MIR, in agreement with their degree of esterification and their degree of unsaturation as determined from
gas-liquid chromatography analysis. However, it was difficult to differentiate the studied food products in terms of their
average chainlength. 相似文献
88.
89.
Anacardic acids, 6-pentadec(en)ylsalicylic acids isolated from the cashew Anacardium occidentale L. (Anacardiaceae) nut and apple, were found to possess preventive antioxidant activity while salicylic acid did not show this activity. These anacardic acids prevent generation of superoxide radicals by inhibiting xanthine oxidase (EC 1.1.3.22, Grade IV) without radical-scavenging activity. Notably, the inhibition kinetics of anacardic acids do not follow hyperbolic dependence of enzyme inhibition on inhibitor contents (Michaelis–Menten equation) but follow the Hill equation instead. Anacardic acid (C15:1) inhibited the soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) catalyzed oxidation of linoleic acid with an IC50 of 6.8 μM. The inhibition is a slow and reversible reaction without residual enzyme activity. The inhibition kinetics indicate that anacardic acid (C15:1) is a competitive inhibitor and the inhibition constant, KI, was 2.8 μM. Anacardic acids act as antioxidants in a variety ways, including inhibition of various prooxidant enzymes involved in the production of the reactive oxygen species and chelate divalent metal ions such as Fe2+ or Cu2+, but do not quench reactive oxygen species. The C15-alkenyl side chain is largely associated with the activity. 相似文献
90.
William E Acree Jr Michael H Abraham 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(8):1441-1446
The contentions made in an earlier paper [J Chem Technol Biotechnol 80 : 133–137 (2005)] that the coefficients of the Abraham solvation equation do not provide meaningful information on the molecular properties of ionic liquid solvents is refuted. The objections noted in the earlier paper disappear when the solvation equation model is correctly applied to the experimental data. It is further shown that the coefficients of the Abraham solvation equations can be used to characterize ionic liquids and can be used to select solvents for the solubility of gaseous solutes. Copyright © 2006 Society of Chemical Industry 相似文献