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排序方式: 共有824条查询结果,搜索用时 15 毫秒
81.
Multisweep cyclic voltammetric (CV) responses of nickel, copper, Monel and nickel–copper alloy had been extensively studied and compared in a variety of non-aqueous solvents such as acetonitrile (AN), propylene carbonate (PC) and sulfolane containing triethylamine trishydrogen fluoride (TEA·3HF) ionic liquid. The quantity of dissolution as well as surface morphological transformation on the electrode surfaces as a result of anodic polarization were investigated using atomic absorption spectroscopy (AAS) and scanning electron microscopy (SEM) respectively. The nature of crystallites formed on the polarized electrode was characterized using X-ray diffraction (XRD). The voltammetric study clearly indicates that Ni, Monel and Ni–Cu alloy are passive and stable in neat TEA·3HF medium in the recorded potential region of CV. Surface morphology of Ni after polarization, reveals the generation of pits, whereas the evolution of small crystallites of CuF2 are noted on the polarized alloy material, as evidenced by SEM pictures. Copper electrode shows reversible voltammetric characteristics with high charge recovery ratio (qc/qa) suggesting that in this medium, Cu can certainly serve as reference electrode. Addition of water in TEA·3HF medium increases the solubility and stability of these metal fluoride film. In solvents such as PC, AN and sulfolane containing TEA·3HF, Ni and their alloys exhibit remarkable passivity and the charge recovery ratio decreases to some extent for Cu. In TEA·3HF/AN medium, the dissolution of Cu is very high. The present investigation suggests that the relative stability of all the four electrodes in neat TEA·3HF and solvents containing 0.1 M TEA·3HF decreases in the order: Ni > Monel > Ni–Cu alloy > Cu and relative solubility of metal fluoride films in the three solvents increases in the order: PC < sulfolane < AN. 相似文献
82.
A R Noel 《Laboratory practice》1972,21(11):815-816
83.
B. Piro A. Kapella V.H. Le G. Anquetin Q.D. Zhang S. Reisberg V. Noel L.D. Tran H.T. Duc M.C. Pham 《Electrochimica acta》2011,56(28):10688
In the present work, we report first results about a technology using a conjugated copolymer poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-2-carboxyethyl-1,4-naphthoquinone) acting both as immobilizing and transducing element for reagentless immunosensor, and its application for the detection of HPV infection. It was shown that the reagentless immunosensor was able to detect the interaction between antigenic peptide L1 from HPV-16 major capsid protein, a dominant epitope involved in viral infection as well as in prophylactic vaccine, and the relevant antibody. 相似文献
84.
This work is focused on determining the rate controlling mechanisms of decarburisation of iron-carbon droplets with gas mixtures containing up to 10% oxygen at 1723 K. The results indicate that the decarburisation rate is limited by the transport of oxygen in the bulk gas to the melt surface. The work also shows the absence of any significant resistance to decarburisation from interfacial chemical kinetics or gas phase reactions. Phosphorus in the melt shows no influence on the rate of decarburisation. Chromium has no significant effect on the decarburisation rate. 相似文献
85.
Two different samples of ceria have been characterized by temperature programmed reduction in carbon monoxide (CO-TPR), surface area determination and transmission electron microscopy (TEM). The much higher reducibility at temperatures below 550 °C of a sample prepared by decomposition of cerium carbonate, compared to a commercial ceria, was attributed to the much lower crystallinity. When this ceria, in the partly reduced state, was brought in contact with water vapour, it was readily reoxidised with evolution of hydrogen. The oxygen storage capacity of this sample, determined in cycling experiments, was considerably lowered by the presence of water. 相似文献
86.
The paper investigates the impact of the imposition of a broadly based energy tax on the US economy in general and the agricultural sectors in particular. The analytical approach used in the analysis consisted of a general equilibrium model composed of 12 producing sectors, 13 consuming sectors, six household categories, classified by income, and the government. The effects of a 10 cents per million Btu tax on energy on prices and quantities are examined. The results are revealing. For example, a 10 cents per million Btu tax on energy imposed at the point of production would result in lower output by the producing sectors (by about $9.154 billion), an increase in the consumption of goods and services (by about $20.292 billion), and a reduction in welfare (by about $4.30 billion). The government would realize an increase in revenue of about $6.356 billion. If the Btu tax were imposed at the point of consumption, there would be lower output by the producing sectors (by about $5.88 billion), an expansion in the consumption of goods and services (by about $19.830 billion), and a reduction in welfare (by about $7.066 billion). The government would realize an increase in revenue of $6.688 billion. The agricultural sectors would be minimally impacted. For example, if a 10 cents per million Btu tax were imposed at the point of production, output in the program crops sector would rise (by $8.3 million), output in the livestock sector would decline (by $83 million), output in the all-other-agriculture-commodities sector would be reduced (by $118 million), and output in the forestry sector would rise (by $34.7 million). If the Btu tax were imposed at the point of consumption, output in the program crops sector would fall (by $38 million), output in the livestock sector would decline (by $42 million), output in the all other agriculture commodities sector would be reduced (by $94 million), and output in the forestry sector would rise (by $221 million). 相似文献
87.
J. C. Leon F. Noel A. Fischer S. Azernikov F. Ollier 《The International Journal of Advanced Manufacturing Technology》2002,19(1):1-7
Stereolithography (STL) is the prevailing technology in rapid prototyping (RP) applications. The STL process involves mesh
triangulation of a sculptured object from a CAD model and then the extraction of cross-sections from the mesh model. In most
current systems, the resulting model suffers from topological problems, such as degenerate facets, undesired holes, or flipped
normals, which lead to invalid cross-sections that cannot be manufactured as layers. This paper proposes a hybrid system that
takes advantage of structured and unstructured mesh geometry in order to optimise the RP process and make it more robust and
accurate. The system has been developed as part of a joint project between the 3S Laboratory at Grenoble University, France
and the Laboratory for Computer Graphics and CAD at the Technion, Israel. Within the system, a constrained mesh simplification
model (3S Lab) is integrated with a multilevel model (CAD Lab). 相似文献
88.
Huang Wen-Yuan Heifner Richard G. Taylor Harold Uri Noel D. 《Water Resources Management》2000,14(1):35-58
The advantage of using insurance to help a farmeradopt a best nitrogen management plan (BNMP) thatreduces the impact of agricultural production on theenvironment is analytically and empiricallydemonstrated. Using an expected value analysis, it isshown that an insurance program can be structured soas to reduce a farmer's cost of bearing the adoptionrisk associated with changing production practicesand, thus, to improve the farmer's certaintyequivalent net return thereby promoting the adoptionof a BNMP. Using the adoption of growing-season onlyN fertilizer application in Iowa as a case study, itis illustrated how insurance may be used to promotethe adoption of this practice to reduce N fertilizeruse. It is shown that it is possible for a farmer andan insurance company both to have an incentive todevelop an insurance adoption program that willbenefit both the farmer and the insurance company,increasing net social welfare and improvingenvironmental quality in Iowa. 相似文献
89.
90.
Ü. Özgür X. Gu S. Chevtchenko J. Spradlin S. -J. Cho H. Morkoç F. H. Pollak H. O. Everitt B. Nemeth J. E. Nause 《Journal of Electronic Materials》2006,35(4):550-555
Thermal conductivities (κ) of melt-grown bulk ZnO samples thermally treated under different conditions were measured using
scanning thermal microscopy. Samples annealed in air at 1050°C for 3 h and treated with N-plasma at 750°C for 1 min. exhibited
κ=1.35±0.08 W/cm-K and κ=1.47±0.08 W/cm-K, respectively. These are the highest values reported for ZnO. Atomic force microscopy
(AFM) and conductive-AFM measurements revealed that surface carrier concentration as well as surface morphology affected the
thermal conductivity. 相似文献