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121.
122.
Reliability analysis of a multidisciplinary system is computationally intensive due to the involvement of multiple disciplinary models and coupling between the individual models. When the system inputs and outputs are varying over time and space, the reliability analysis is even more challenging. This paper proposes a surrogate model-based method for the reliability analysis of a multidisciplinary system with spatio-temporal output. The transient characteristics of the multidisciplinary system output under time-dependent variability are analyzed first. Based on the transient analysis, surrogate models are built for individual disciplinary analyses instead of a single surrogate model for the fully coupled analysis. To address the challenge introduced by the high-dimensionality of spatially varying inter-disciplinary coupling variables, a data compression method is first employed to convert the high-dimensional coupling variables into low-dimensional latent space. Kriging surrogate modeling is then used to build surrogates for the individual disciplinary models in the latent space. Based on the individual disciplinary surrogate models, reliability analysis of the coupled multidisciplinary system under time-dependent uncertainty is investigated. Further, epistemic uncertainty sources, such as data uncertainty and model uncertainty, lead to uncertainty in the reliability estimate. Therefore, an auxiliary variable approach is used to efficiently include the epistemic uncertainty sources within the reliability analysis. An aircraft panel subjected to hypersonic flow conditions is used to demonstrate the proposed method. The analysis involves four interacting disciplinary models, namely, aerodynamics, aerothermal analysis, heat transfer, and structural analysis. The results show that the proposed method is able to effectively perform reliability analysis of a multidisciplinary system with spatio-temporal output. 相似文献
123.
Ganesh?C.?Sankaran Krishna?M.?SivalingamEmail author 《Photonic Network Communications》2017,33(2):87-101
This paper presents a survey of data center network architectures that use both optical and packet switching components. Various proposed architectures and their corresponding network operation details are discussed. Electronic processing-based packet switch architectures and hybrid optical–electronic-based switch architectures are presented. These hybrid optical switch architectures use optical switching elements in addition to traditional electronic processing entities. The choice of components used for realizing functionality including the network interfaces, buffers, lookup elements and the switching fabrics have been analyzed. These component choices are summarized for different architectures. A qualitative comparison of the various architectures is also presented. 相似文献
124.
Glucoamylase immobilized on montmorillonite: influence of nature of binding on surface properties of clay-support and activity of enzyme 总被引:1,自引:0,他引:1
Glucoamylase was immobilized on acid activated montmorillonite clay via two different procedures namely adsorption and covalent
binding. The immobilized enzymes were characterized by XRD, NMR and N2 adsorption measurements and the activity of immobilized glucoamylase for starch hydrolysis was determined in a batch reactor.
XRD shows intercalation of enzyme into the clay matrix during both immobilization procedures. Intercalation occurs via the
side chains of the amino acid residues, the entire polypeptide backbone being situated at the periphery of the clay matrix.
27Al NMR studies revealed the different nature of interaction of enzyme with the support for both immobilization techniques.
N2 adsorption measurements indicated a sharp drop in surface area and pore volume for the covalently bound glucoamylase that
suggested severe pore blockage. Activity studies were performed in a batch reactor. The adsorbed and covalently bound glucoamylase
retained 49% and 66% activity of the free enzyme respectively. They showed enhanced pH and thermal stabilities. The immobilized
enzymes also followed Michaelis–Menten kinetics. K
m was greater than the free enzyme that was attributed to an effect of immobilization. The immobilized preparations demonstrated
increased reusability as well as storage stability. 相似文献
125.
Low-fat diets and diets containing n−3 fatty acids (FA) slow the progression of renal injury in the male Han:Sprague-Dawley
(SPRD)-cy rat model of polycystic kidney disease. To determine whether these dietary fat effects are similar in females and in another
model of renal cystic disease, in this study we used both male and female pcy mice to examine the effects of fat level and type on disease progression. Adult pcy mice were fed 4, 10, or 20 g soybean oil/100 g diet for 130 d in study 1. In study 2, weanling pcy mice were fed high or low levels of fat rich in 18∶2n−6 (corn oil, CO) 18∶3n−3 (flaxseed oil/CO 4∶1 g/g, FO), or 22∶6n−3
(algal oil/CO 4∶1 g/g, DO) for 8 wk. In adult pcy mice, low-compared with high-fat diets lowered kidney weights (2.4±0.2 vs. 3.1±0.2 g/100 g body weight, P=0.006) and serum urea nitrogen (SUN) (9.6±0.6 vs. 11.9±0.6 mmol/L, P=0.009), whereas in young pcy mice it reduced renal fibrosis volumes (0.44±0.04 vs. 0.62±0.04 mL/kg body weight, P<0.0001). FO feeding in young pcy mice mitigated the detrimental effects of high fat on fibrosis while not altering kidney size, function, and oxidative damage
when compared with the CO-fed mice. In contrast, DO-compared with CO-fed mice had higher kidney weights (2.64±0.07 vs. 2.24±0.08
g/100 g body weight, P=0.005), SUN (9.4±0.57 vs. 7.0±0.62 nmol/L, P<0.0001), and cyst volumes (7.9±0.28 vs. 6.2±0.30 mL/kg body weight, P<0.0001) and similar levels of oxidative damage and fibrosis. The FA compositions of the diets were reflected in the kidneys:
18∶2n−6, 18∶3n−3, and 22∶6n−3 were the highest in the CO, FO, and DO diets, respectively. Dietary effects on kidney disease
progression were similar in males and females. A low-fat diet slows progression of renal injury in male and female pcy mice, consistent with findings in the male Han:SPRD-cy rat. Dietary fat type also influenced renal injury, with flaxseed oil diets rich in 18∶3n−3 slowing early fibrosis progression
compared with diets rich in 18∶2n−6 or in 22∶6n−3. 相似文献
126.
H. S. Murali M. S. Mohan K. S. Manja R. Sankaran 《Journal of the American Oil Chemists' Society》1993,70(10):1039-1041
A few species ofFusarium have been evaluated for their potential to produce lipids. The isolates under investigation exhibited wide variation with
respect to the mycelial weight, total lipid content and percentage composition of polar and nonpolar lipids in which triglycerides
were the major components (81–90%). Palmitic, stearic, oleic and linoleic acids were the major fatty acids in both the fractions.
The polar lipids contained higher levels of linoleic acid, whereas nonpolar lipids contained oleic acid as the predominant
acid. Nonpolar lipids were more saturated than polar lipids. 相似文献
127.
The Pore Mouth Tailoring of Coal and Coconut Char Through Acid Treatment Followed by Coke Deposition
Kim Tae-Hwan S. Vijayalakshmi Son Seok-Jin Kim Jee Dong 《Journal of Porous Materials》2002,9(4):279-286
Carbon Molecular Sieves (CMS) obtained by coke deposition through deep cracking of hydrocarbons on the wide pore mouths of coal and coconut char are important adsorbents for separation of, difficult to separate, gaseous as well as liquid mixtures. The adsorption studies on these CMS show a high selectivity towards the adsorption of one or the other component from its mixture. In this work, CMS is prepared from pre treated raw materials like bituminous coal and coconut shell. The product samples are characterized in terms of kinetic adsorption and equilibrium adsorption of various gas adsorbents. It is observed that, all these samples are very good for CO2 removal from mixtures containing CH4 or H2 in it. The CMS prepared from coconut shell showed an uptake ratio 4, for adsorption of O2 and N2, indicating that separation of nitrogen from air is viable by choosing suitable conditions in Pressure Swing Adsorption (PSA) Technique. 相似文献
128.
The problem of the optimal distribution of two multifunctional catalysts is analyzed. Two methods for obtaining optimal catalyst profiles, an analytic-numeric method and the method of steepest ascent, are compared. Though the analytic-numeric method yields a more accurate solution, the method of steepest ascent is usually easier to apply. Optimal catalyst loading profiles are determined for two cases of commercial interest: selective oxidation of butene and naphtha reforming with bimetallic catalysts- A sequential loading of the bismuth molybdate and the vanadium phosphate catalysis is recommended for low butene concentration levels, while at higher butene levels a mixed loading of the two catalysts may be desirable. For commonly encountered naphtha feedstocks a sequential loading of the Pt-Re and the Pt-Ir catalysts tends to be optimal. These compare well with experimental evidence in the literature. 相似文献
129.
It has been repeatedly stressed in the literature that the commonly invoked assumption of a random distribution of adsorbates on the catalyst surface is suspect under certain operating conditions. Nonrandom distribution of the adsorbates can occur as a result of interaction between adsorbates and/or their inadequate mobility. We have studied the effect of adsorbate interactions on the rates and stability of catalytic reactions, and the salient features are outlined with several examples. An analysis of the thermodynamic data concerning the oxidation of SO2 on platinum is presented within the framework of the proposed model. 相似文献
130.