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131.
吕林女 《武汉理工大学学报(材料科学英文版)》2009,24(1):140-144
Fly ash (FA) and ground granulated blast-furnace slag (GGBFS) were added to improve the performances of regenerated binding
materials (RBM) which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests,
compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of
the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve
the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM,
FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at
earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new
combined binding materials can be prepared by blending them together.
Funded by the National Science Foundation of China(No. 50508034) 相似文献
132.
The effect of grinding on the chemical and physical properties of rice husk ash was studied. Four rice husk ashes with different finenesses,i.e. coarse original rice husk ash (RHA0),RHA1,RHA2,and RHA3 were used for the study. Ordinary Portland cement (OPC) was partially replaced with rice husk ash at 20% by weight of binder. The water to binder ratio (W/B) of the mortar was maintained at 110%±5% with flow table test. Specific gravity,fineness,chemical properties,compressive strength,and porosity test of mor... 相似文献
133.
This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC), ground palm oil fuel ash (POA), and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces ... 相似文献
134.
The effects of quality and content of fly ash on the early-age cracking behavior of high-flowing concrete (HFC) were investigated.
The early-age cracking behavior of the HFC was analyzed by combining the tests of evaporation capacity and electrical resistivity
of the HFC. In these tests, a modified flat-type specimen was adopted. The results show that the HFC will have a lower evaporation
capacity when it is mixed with fine fly ash, while it will have a higher evaporation capacity when grade III fly ash is used
as mineral admixture. And the electrical resistivity rate of HFC reduces with the increase of the content of fly ash. A nonlinear
relationship exists between the cracking time of HFC and the minimum electrical resistivity. The early-age cracking behavior
of HFC with fly ash can be enhanced by appropriately increasing the fine particle content and MgO, K2O, and SO3 contents of fly ash. The optimal content of fly ash, which makes a satisfied early-age cracking behavior of HFC, is obtained.
And when the content of fly ash exceeds a critical value, the early-age cracking behavior of HFC will rapidly decrease.
Foundation item: Project(50478003) supported by the National Natural Science Foundation of China; Project(2002F007) supported by the Natural
Science Foundation of Fujian Province, China 相似文献
135.
To improve the environmental benefits and solve the problems of large shrinkage and high brittleness, the partial replacement
of calcined kaolin by fly ash as a raw material for geopolymer synthesis and the influences of polypropylene (PP) fiber on
the mechanical properties and volume stability were investigated. The results show that compressive strength of the geopolymer
containing 33.3%(mass fraction) fly ash by steam curing at 80 °C for 6 d is improved by 35.5%. The 3-day compressive strength,
flexural strength and impacting energy of geopolymers containing 0.05%PP fiber increase by 67.8%, 36.1% and 6.25%, while the
shrinkage and modulus of compressibility decrease by 38.6% and 31.3%, respectively. The results of scanning electron microscopy
(SEM) and the appearances of crack growths confirm that PP fiber can offer a bridging effect over the harmful pores and defects
and change the expanding ways of cracks, resulting in a great improvement of strength and toughness.
Foundation item: Project(2006AA06Z225) supported by the National High-Tech Research and Development Program of China 相似文献
136.
137.
蒙脱石/粉煤灰复合材料吸附含锌废水的研究 总被引:2,自引:1,他引:1
以蒙脱石、粉煤灰为原料,添加一定量的粘结剂混合造粒制成复合颗粒吸附剂,用于处理含Zn2+废水,实验研究了吸附反应时间、吸附剂投加量、废水初始浓度及介质pH值对吸附性能的影响。研究结果表明:蒙脱石/粉煤灰复合颗粒吸附剂的最佳吸附工艺条件为:在室温下,吸附反应时间50 min,吸附剂投加量5.0 g/L,初始浓度40 mg/L,溶液pH值为5。在此条件下处理含Zn2+废水,吸附去除率为95.77%,处理后残余浓度为1.69 mg/L,达到国家一级排放标准(2.0 mg/L)。 相似文献
138.
任永中 《河北建筑工程学院学报》2010,28(1):49-52
通过实验,对活性炭和粉煤灰对染料废水的处理效果进行了比较讨论.结果表明,废水经活性炭吸附处理后,COD及色度去除率均较高.粉煤灰对色度的去除率较高,且价廉且属于废物再利用,符合国家节能减排政策,有较大的发展潜力. 相似文献
139.
农村简易垃圾焚烧炉周边土壤二恶英分布研究 总被引:1,自引:0,他引:1
为了解农村简易生活垃圾焚烧炉排放废气中二恶英对周边地区的环境影响,对焚烧炉周边6个环境土壤及焚烧炉排放的飞灰和灰渣中二恶英的分布规律进行了研究.检测结果显示,焚烧炉周边环境土壤样品中二恶英国际毒性当量在2.29~9.45 ng/kg(干基)之间,高于背景值(0.537 I TEQ ng/kg).而焚烧炉排放的飞灰及灰渣中二恶英国际毒性当量分别为3 454和32.2 ng/kg.利用主成分分析方法,发现环境土壤中的二恶英来源较为复杂,焚烧炉污染物排放不是土壤中二恶英的唯一来源. 相似文献
140.
脱硫石膏-粉煤灰活性掺合料设计及水化特性 总被引:3,自引:0,他引:3
针对电厂两大工业废渣--烟气脱硫石膏及粉煤灰,通过试验研发用于混凝土的活性复合矿物掺合料.以适当比例复合后的脱硫石膏及粉煤灰等量取代水泥掺入到水泥砂浆中,通过活性激发措施,以胶砂流动度、早期强度以及强度发展规律等作为控制指标探索脱硫石膏及粉煤灰的最优配比,同时通过微细观结构的SEM观测评价脱硫石膏-粉煤灰活性矿物掺合料在水泥基材料中的作用效应.结果表明,脱硫石膏及粉煤灰以1:2的比例复合等量取代水泥30%掺入水泥砂浆中,可获得较为优异的胶砂流动度、早期强度,而后期强度能赶上甚至超过基准水泥胶砂;SEM表明由于脱硫石膏及其它外加组分的活性激发效应,粉煤灰的活性得到有效激发,早期有明显的钙矾石生成.脱硫石膏-粉煤灰复合矿物掺合料的研发可大量消纳燃煤电厂的工业废渣,且在水泥基材料体系中具有优异的水化及低成本特性,具有显著的"绿色"效应,符合中国"可持续发展"的战略要求. 相似文献