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991.
The phosphate removal abilities and crystallization performance of quartz sand, ceramsite, blast furnace slag and steel slag were investigated. The residual phosphate concentrations in the reaction solutions were not changed by addition of the ceramsite, quartz sand and blast furnace slag. The steel slag could provide alkalinity and Ca(2+) to the reaction solution due to its hydration activity, and performed a better phosphate removal performance than the other three. Under the conditions of Ca/P 2.0, pH 8.5 and 10 mg P/L, the phosphate crystallization occurred during 12 h. The quartz sand and ceramsite did not improve the phosphate crystallization, but steel slag was an effective seed crystal. The phosphate concentration decreased drastically after 12 h after addition of steel slag, and near complete removal was achieved after 48 h. The XRD analysis showed that the main crystallization products were hydroxyapatite (HAP) and the crystallinity increased with the reaction time. Phosphate was successfully recovered from low phosphate concentration wastewater using steel slag as seed material. 相似文献
992.
采用HPLC法,以水为溶剂,0.02mol/L醋酸铵溶液—甲醇(7525)为流动相,在254nm波长下,测定饮料中咖啡因含量。回收率>97%,与按国家标准GB/T16344—1996测定值比较,两种方法的相对偏差<2%。方法简便,有实用价值。 相似文献
993.
本文介绍了SRMC-I型纸浆打浆度自动在线检测仪的组成、原理、性能指标、功能和使用。实际应用表明,该检测仪工作稳定可靠,使用方便,提高了打浆度检测的实时性,可在造纸厂推广使用。 相似文献
994.
995.
Determination of sphinganine, sphingosine and Sa/So ratio in urine of humans exposed to dietary fumonisin B1 总被引:3,自引:0,他引:3
Fumonisin B1 (FB1) is an inhibitor of sphinganine N-acyltransferase and the increase in the sphinganine/sphingosine (Sa/So) ratio in urine or serum has been proposed as a biomarker to evaluate exposure to fumonisins. The objectives of this study were to (1) develop a liquid chromatographic method sufficiently sensitive to determine the low concentration of free Sa in male human urine, and (2) analyse So and Sa in human urine and monitor the Sa/So ratio in urine of humans exposed to FB1 in corn diets over 1 month. The liquid chromatographic method involved isolation from human urine of exfoliated cells followed by an extraction of free sphingoid bases and their separation and quantification by high performance liquid chromatography. The detection limits for So and Sa were 0.15ng/ml in female urine (2ml used) and 0.005ng/ml in male urine (60ml used). Twenty-eight healthy adult volunteers consumed for 1 month a normal diet containing their homegrown corn potentially contaminated with FB1. Immediately preceding the start of the test, morning urine samples for the determination of So and Sa were collected from each person, and the corn samples used in cooking were obtained from each family for the determination of FB1. At the end of the test period, morning-urine samples were collected from each person and analysed again. The daily FB1 intakes were estimated and used to assess the relationship between them and the urinary Sa/So ratios in humans exposed to dietary FB1 over 1 month. All the home grown corn samples contained FB1 ranging from 0.08 to 41.1mg/kg, and the estimated daily FB1 相似文献
996.
介绍用偶氮氯膦—mA分光光度法测定锌 -铝 -稀土合金镀层中的稀土量。该测定法稀土量在 0~ 1mg L范围内符合比尔定律 ,相对误差小于 2 .4 % ,加标回收率可达 97.6 %~ 99.4 % ,用于锌 -铝 -稀土合金镀层中稀土的测定 ,有良好的准确性和重现性。 相似文献
997.
998.
声场对糖浆气浮分离作用的研究 总被引:2,自引:0,他引:2
本文分别研究了声场及声场与PAM协同对糖浆气浮分离作用的影响。结果表明:在不加PAM的情况下,声场空化作用对气-固结合有负面影响;在PAM存在下,声场空化表现了声场凝聚效应,显著提高糖浆气浮清净效率,同时减少絮凝剂用量。 相似文献
999.
Downhole working conditions of sucker rod pumping wells are automatically identified on a computer from the analysis of dynamometer cards. In this process, extraction of feature parameters and pattern classification are two key steps. The dynamometer card is firstly divided into four parts which include different production information according to the "four point method" used in actual oilfield production, and then the moment invariants for pattern recognition are extracted. An improved support vector machine (SVM) method is used for pattern classification whose error penalty parameter C and kernel function parameter g are optimally chosen by the particle swarm optimization (PSO) algorithm. The simulation results show the method proposed in this paper has good classification results. 相似文献
1000.
岩性识别是天然气水合物储层测井评价的基础,准确的岩性识别结果可以为天然气水合物的勘探提供可靠的依据,在寻找天然气水合物和评估天然气水合物储量方面发挥着巨大的作用。针对漠河冻土区天然气水合物科学钻探 2孔(MK 2孔)的钻探情况,利用已钻井段地层的岩心资料和常规测井资料,分别采用交会图法和支持向量机法对研究区的地层开展了岩性识别研究。结果表明:研究区内有砂岩、泥岩、石灰岩、糜棱岩和泥质板岩5种岩石,其不同岩性的测井响应差异能够定性识别岩性;自然电位与电阻率测井参数的交会,能够有效的、定量识别研究区地层的岩性;支持向量机法所建立的岩性识别模型,对研究区地层的岩性识别率可达96.67%。所建立的测井识别方法较好地解决了该区地层岩性识别问题,也为类似地区的天然气水合物地层测井评价提供了一种重要的手段。 相似文献