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111.
Granitic pegmatite is used as raw material for industrial minerals in the production of feldspar and quartz for glass, ceramic and porcelain. One of the most important quality parameters in the feldspar is the content of iron (Fe). At the Lillesand plant, Norway, pegmatite is floated to produce quartz, albite and microcline products. Fe is mostly removed through flotation and magnetic separation, but some Fe is still present in the final products, the amount depending on the raw material source. Rietveld X-ray Diffraction (XRD), Point counting by optical microscopy, and Electron Microprobe Analysis (EPMA) combined with image analysis of Back-Scatter Electron (BSE) images was used to quantify the mineralogy and to map the distribution Fe in the pegmatites. The study showed that Fe is present as mineral inclusions in feldspar, in addition to its occurrence in minor mineral components such as mica and chlorite. The frequency of Fe-mineral inclusions was higher in albite than in microcline, and they were often associated with micro-fractures and areas of alteration. These findings reveal a potential for reducing total Fe2O3 in the microcline products. 相似文献
112.
With the installation of ultrafine grinding on many platinum operations in southern Africa, there were concerns as to whether this would cause rheologically complex behaviour during the subsequent flotation of the ore. Rheologically complex behaviour refers to the non-Newtonian behaviour experienced by some suspensions, associated with exponential increases in yield stress and viscosity with increasing solids content. This is attributed to particle size and solids concentration effects, surface chemistry, and mineralogy. In this study, the rheological behaviour of two different platinum ores; a western limb UG2 ore and a Great Dyke platinum ore were investigated and compared with that of single mineral studies of the major gangue minerals of platinum ores (chromite, orthopyroxene, plagioclase and talc). The results show that Great Dyke ore is considerably more rheologically complex than UG2 ore. Great Dyke flotation concentrate shows high yield stress and viscosity at low solids concentrations (>20 vol.% solids). Should the ROM ore in a Great Dyke flotation operation suddenly show significant changes in ore mineralogy, the rheological properties of the slurry should be considered since they may be detrimental to the overall performance of the operation (e.g. loss of recovery through poor gas dispersion). In contrast, the rheological behaviour of UG2 flotation samples shows little cause for concern for the plant operator. Comparison of the pure mineral samples shows that the complex rheological behaviour of the Great Dyke ore may be attributed to the high degree of low temperature alteration and the formation of phyllosilicate minerals such as talc, more than particle size effects. 相似文献
113.
Santiago P. Aubourg Vanesa Losada & Ricardo Prego 《International Journal of Food Science & Technology》2007,42(12):1456-1464
Lipid and trace mineral composition were studied in different sites of the edible flesh of farmed and wild turbot (Psetta maxima). Lipid matter (total content, sterols, tocopherols) showed to accumulate in the edge zone (EZ), except for phospholipid (PL), which provided a distribution that was found to be independent from the kind of turbot and the zone considered. Fatty acid composition of total lipids showed a non‐homogeneous distribution, as the EZ exhibited a different fatty acid group composition (higher monounsaturated and lower polyunsaturated and ω3/ω6 ratio values) than the other zones considered; fewer differences were observed by considering the PL fatty acid composition. Most minerals (Ca, Cu, Fe, Mn and Se) studied showed to be homogeneously distributed along the muscle sites of the wild fish, while more differences were obtained when considering the farmed one. For both kinds of turbots, the most important difference was obtained in the case of Zn, as a largely higher content in the EZ than in the other zones was detected. A close relationship between Zn and total lipid contents (r2 = 0.90 and 0.76 for farmed and wild turbots, respectively) was observed. 相似文献
114.
The period of the minerals resource construction items is very long, which affected largely by the changeable market. The
discontinuance evalution theory and content of construction item about the resource used up and economic evalution theories
of the invest were brought forward from the two aspects of the resource using value and the income rate. 相似文献
115.
Madhev B. Subramaniam Norman Blakebrough Mohd A. Hashim 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1990,48(1):41-60
Colloidal gas aphrons (CGAs), generated from dilute solutions of four surfactants, were used to clarify palm oil mill effluent (POME), suspensions of microalgae and suspensions of three inorganic minerals. In POME and the algal suspensions, each CGA was most effective at a pH value close to the pK value of the surfactant concerned. This effect was not tested in the inorganic suspensions. The efficiency of air utilization was directly related to the concentration of solids in the suspensions, the size, density and nature of the solids having secondary effects. Comparison with data in the literature led to a general correlation embracing a variety of suspensions and flotation systems. Shedding of collected material from the foam layer was also a direct function of solids concentration. CGAs offer advantages over other systems of air-assisted flotation in relation to the requirements for equipment and to the management of process operations. 相似文献
116.
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118.
根据铌矿浮选药剂的现状,本文综述了脂肪酸类捕收剂、羟肟酸类捕收剂、膦酸类捕收剂及胂酸类捕收剂与铌矿物作用机理。针对铌矿物捕收剂在捕收能力及选择性等方面存在的问题,提出了对开发新型铌矿物捕收剂的要求。总结了铌矿浮选调整剂的研究现状,指出了脉石矿物有效抑制剂研究是铌矿浮选调整剂研究的重点。对于铌矿的浮选,目前大多数研究是采用传统的化学药剂来改变铌矿物与其它矿物间的可浮性差异,效果仍不理想。本文通过分析含铌矿物的特点,提出了铌矿生物预处理新思路。应用生物预处理对目的矿物和脉石矿物表面进行改性,达到扩大目的矿物与脉石矿物可浮性差异的目的,以实现铌矿物的高效回收。 相似文献
119.
以晋城矿区寺河井田为研究对象,借助扫描电镜和X射线衍射仪得出煤中矿物成分和充填方式;基于煤储层几何模型结合渗流理论,构建了煤体原始渗透率和矿物溶解后渗透率变化的数学模型;在对寺河矿孔径分布、不同矿物溶解度测试基础上,探讨了注CO2后与煤中不同矿物反应渗透率的变化规律。研究结果表明:煤中矿物主要为黏土和碳酸盐矿物;煤中矿物主要以薄膜状附着和完全或半充填于煤层裂隙2种充填方式存在;不同矿物溶解、沉淀时间差异性导致注CO2后煤储层渗透率呈现先增加后减小趋势;在矿物含量相同条件下,在大孔径孔裂隙中附着或充填的矿物含量越高,矿物溶解后煤储层渗透率增加越多。煤层注CO2后煤层渗透率变化实验测试一定程度上验证了数学模型的可靠性。 相似文献
120.
Norma Retamal Jos M. Durn Jesús Fernndez 《Journal of the science of food and agriculture》1987,38(4):303-311
The moisture, ash, free reducing sugar, starch, ether extractive, crude protein, amino acid and the heat energy contents of young and mature cladodes of Opuntia ficus-indica, with or without fruits, are described. The measurements were made in each of the following stages of development: vegetative growth (March), full vegetative development, and at the beginning of fructification (October). Independently of developmental stage (different cladode types) the highest values were reached always in young cladodes in the following months: moisture content in March and October; ash and free reducing sugars in March; starch and ether extractive in September and October; crude protein in March and July. Crude fibre was maximal in September and global heat energy in October. The nutritive and caloric value of cladodes are compared to other products used for livestock nutrition. 相似文献