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11.
以B03作分散剂,对湖北省钟祥县杨榨累托石粘土矿物进行了机械搅拌擦洗,使累托石矿物微粒较充分地分散解离,然后通过离心力场的作用,使累托石与水云母、叶腊石、绿泥石、石英等脉石矿物分离,累托石精矿纯度达90%左右,B03的使用为工业生产高纯累托石产品奠定了基础。 相似文献
12.
William K. McGrane Ph.D. 《臭氧:科学与工程》1992,14(3):231-244
This paper builds on a prior paper by this author, McGrane (1991). In that paper, ozone is used as the sole means of cooling tower water treatment. The paper discusses water conservation by increased cycles of concentration, greatly increased efficiency through extremely low biological populations, and corrosion data which is compared to ozonated and chemically treated towers.
New in this paper are the results from the combination of a low pressure reverse osmosis system with ozone treatment for cooling tower water. Scale formation has continued to plague cooling towers with high concentrations of calcium in the make-up water. The use of a mineral removal system in cases of extremely hard water has made ozone an attractive alternative to traditional chemicals in many areas. 相似文献
13.
The prediction of the production rate of the hematite ore beneficiation process is important to plant-wide optimization. This paper presents a data-based multi-model approach to predict the production rate with multiple operating modes. The inputs of the predictive model are the performance indices of each unit process, and the output is the global production index (the production rate) of the hematite ore beneficiation process. The multiple models are developed by integrating the fuzzy clustering algorithm and machine learning algorithm. A global model, Takagi–Sugeno–Kang fuzzy model, and multiple neural network model were compared using the data obtained from a practical industrial process, and the effectiveness of the proposed algorithm was proven. 相似文献
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《Advanced Powder Technology》2023,34(7):104049
Constructing heterojunctions is an excellent way to enhance the photocatalytic property of semiconductors. Herein, a range of S-scheme BiOCl/g-C3N4 heterojunctions with varying mass ratios were designed using a facile hydrothermal route, and their photocatalytic ability was assessed by degrading the ethyl xanthate (EX) under visible light (λ > 400 nm). The results showed that the degradation efficiency of BiOCl/g-C3N4-0.1 heterojunction for EX was up to 91.2 % within 180 min, and its apparent rate constants (Kapp) were 4.3 and 11 times greater than those of BiOCl and g-C3N4, respectively. The experimental and characterization results revealed that the excellent photocatalytic property was ascribed to the construction of S-scheme heterojunctions. Such structure not only enhanced the visible light response but also facilitated the efficient separation of photoinduced carriers with the S-scheme transfer route, retaining strong redox-capable holes and electrons to participate in surface reactions. Furthermore, the cycling experiments indicated that the fabricated photocatalysts have great recyclability and stability. Based on the results of active substance capture, the S-scheme charge transfer model was proposed and the photodegradation mechanism of EX was reasonably elucidated. Overall, this work offers some theoretical direction for the design and construction of S-scheme heterojunctions with superior visible-light-driven photocatalytic performance. 相似文献
16.
Guy Serbin Craig S.T. Daughtry James B. Reeves III 《Remote sensing of environment》2009,113(1):224-1836
The management of crop residues (non-photosynthetic vegetation) in agricultural fields influences soil erosion and soil carbon sequestration. Remote sensing methods can efficiently assess crop residue cover and related tillage intensity over many fields in a region. Although the reflectance spectra of soils and crop residues are often similar in the visible, near infrared, and the lower part of the shortwave infrared (400-1900 nm) wavelength region, specific diagnostic chemical absorption features are evident in the upper shortwave infrared (1900-2500 nm) region. Two reflectance band height indices used for estimating residue cover are the Cellulose Absorption Index (CAI) and the Lignin-Cellulose Absorption (LCA) index, both of which use reflectances in the upper shortwave infrared (SWIR). Soil mineralogy and composition will affect soil spectral properties and may limit the usefulness of these spectral indices in certain areas. Our objectives were to (1) identify minerals and soil components with absorption features in the 2000 nm to 2400 nm wavelength region that would affect CAI and LCA and (2) assess their potential impact on remote sensing estimates of crop residue cover. Most common soil minerals had CAI values ≤ 0.5, whereas crop residues were always > 0.5, allowing for good contrast between soils and residues. However, a number of common soil minerals had LCA values > 0.5, and, in some cases, the mineral LCA values were greater than those of the crop residues, which could limit the effectiveness of LCA for residue cover estimation. The LCA of some dry residues and live corn canopies were similar in value, unlike CAI. Thus, the Normalized Difference Vegetation Index (NDVI) or similar method should be used to separate out green vegetation pixels. Mineral groups, such as garnets and chlorites, often have wide ranges of CAI and LCA values, and thus, mineralogical analyses often do not identify individual mineral species required for precise CAI estimation. However, these methods are still useful for identifying mineral soils requiring additional scrutiny. Future advanced multi- and hyperspectral remote sensing platforms should include CAI bands to allow for crop residue cover estimation. 相似文献
17.
Dust source identification using MODIS: A comparison of techniques applied to the Lake Eyre Basin, Australia 总被引:1,自引:0,他引:1
The impact of mineral aerosol (dust) in the Earth's system depends on particle characteristics which are initially determined by the terrestrial sources from which the sediments are entrained. Remote sensing is an established method for the detection and mapping of dust events, and has recently been used to identify dust source locations with varying degrees of success. This paper compares and evaluates five principal methods, using MODIS Level 1B and MODIS Level 2 aerosol data, to: (a) differentiate dust (mineral aerosol) from non-dust, and (2) determine the extent to which they enable the source of the dust to be discerned. The five MODIS L1B methods used here are: (1) un-processed false colour composite (FCC), (2) brightness temperature difference, (3) Ackerman's (1997: J.Geophys. Res., 102, 17069-17080) procedure, (4) Miller's (2003:Geophys. Res. Lett. 30, 20, art.no.2071) dust enhancement algorithm and (5) Roskovensky and Liou's (2005: Geophys. Res. Lett. 32, L12809) dust differentiation algorithm; the aerosol product is MODIS Deep Blue (Hsu et al., 2004: IEEE Trans. Geosci. Rem. Sensing, 42, 557-569), which is optimised for use over bright surfaces (i.e. deserts). These are applied to four significant dust events from the Lake Eyre Basin, Australia. OMI AI was also examined for each event to provide an independent assessment of dust presence and plume location. All of the techniques were successful in detecting dust when compared to FCCs, but the most effective technique for source determination varied from event to event depending on factors such as cloud cover, dust plume mineralogy and surface reflectance. Significantly, to optimise dust detection using the MODIS L1B approaches, the recommended dust/non-dust thresholds had to be considerably adjusted on an event by event basis. MODIS L2 aerosol data retrievals were also found to vary in quality significantly between events; being affected in particular by cloud masking difficulties. In general, we find that OMI AI and MODIS AQUA L1B and L2 data are complementary; the former are ideal for initial dust detection, the latter can be used to both identify plumes and sources at high spatial resolution. Overall, approaches using brightness temperature difference (BT10-11) are the most consistently reliable technique for dust source identification in the Lake Eyre Basin. One reason for this is that this enclosed basin contains multiple dust sources with contrasting geochemical signatures. In this instance, BTD data are not affected significantly by perturbations in dust mineralogy. However, the other algorithms tested (including MODIS Deep Blue) were all influenced by ground surface reflectance or dust mineralogy; making it impossible to use one single MODIS L1B or L2 data type for all events (or even for a single multiple-plume event). There is, however, considerable potential to exploit this anomaly, and to use dust detection algorithms to obtain information about dust mineralogy. 相似文献
18.
A new program capable of rapidly and accurately reducing a two-dimensional X-ray diffraction pattern obtained from a Debye-Scherrer or Gandolfi camera to a quantitative digital diffractogram is described. By implementing geometric optimization routines based on the symmetry and sharpness of diffraction lines, the optimal configuration of the camera, X-ray path, and sample can be determined, thus providing the best possible set of integration parameters. Results for NIST standard reference materials 640c (Si) and 676 (Al2O3) are included to illustrate program functionality. 相似文献
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各种工程项目的数量和规模的不断增加,进一步加大了社会对矿产的需求量。基于此种情况,本文对深部地质勘查和钻探找矿技术进行研究。通过实际的工程案例对该技术进行分析,希望可以对深部找矿工作提供一定的帮助。 相似文献