全文获取类型
收费全文 | 4740篇 |
免费 | 554篇 |
国内免费 | 103篇 |
专业分类
电工技术 | 227篇 |
综合类 | 573篇 |
化学工业 | 1734篇 |
金属工艺 | 75篇 |
机械仪表 | 56篇 |
建筑科学 | 1221篇 |
矿业工程 | 328篇 |
能源动力 | 189篇 |
轻工业 | 202篇 |
水利工程 | 177篇 |
石油天然气 | 27篇 |
武器工业 | 4篇 |
无线电 | 43篇 |
一般工业技术 | 287篇 |
冶金工业 | 125篇 |
原子能技术 | 7篇 |
自动化技术 | 122篇 |
出版年
2024年 | 10篇 |
2023年 | 49篇 |
2022年 | 123篇 |
2021年 | 165篇 |
2020年 | 148篇 |
2019年 | 113篇 |
2018年 | 125篇 |
2017年 | 175篇 |
2016年 | 182篇 |
2015年 | 200篇 |
2014年 | 313篇 |
2013年 | 245篇 |
2012年 | 352篇 |
2011年 | 354篇 |
2010年 | 249篇 |
2009年 | 323篇 |
2008年 | 239篇 |
2007年 | 358篇 |
2006年 | 284篇 |
2005年 | 257篇 |
2004年 | 210篇 |
2003年 | 185篇 |
2002年 | 162篇 |
2001年 | 106篇 |
2000年 | 93篇 |
1999年 | 92篇 |
1998年 | 54篇 |
1997年 | 43篇 |
1996年 | 25篇 |
1995年 | 22篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 1篇 |
排序方式: 共有5397条查询结果,搜索用时 15 毫秒
101.
采用混凝电解气浮-吸附过滤法处理洗染废水.试验结果表明:混凝电解气浮过程中,采用石墨作阴极,铁作阳极,电解电压一般控制在8~11 V,电能消耗约0.08 kW h/m3,CODC r可去除30%以上;吸附过滤过程选用新鲜粉煤灰作为吸附材料,粒度为0.3 mm,废水在吸附柱中的停留时间为2 h,CODC r可以去除50%以上. 相似文献
102.
103.
ZHAO Yi SUN Xiaojun XU Peiyao MA Shuangchen WANG Lidong & LIU Feng School of Environmental Science & Engineering North China Electric Power University Baoding China 《中国科学E辑(英文版)》2005,48(6):692-705
Using slurry mixed by fly ash and alkaline material, removal of SO2 in industrial waste gas had been reported in the 1970s, which was named the wet scrubbing[1]. Sincethen, there have been many reports about flue gas desulfurization using the reactive ab- sorbent prepared with flying ash. There are four kinds as follows: (1) Using slurry of fly ash as absorbent[2―4], which mainly utilize the property of fly ash for desulphurization, but the removal efficiency is not high. (2) Using fly ash a… 相似文献
104.
1INTRODUCTION Hydrationshrinkageisalsoknownaschemicalshrinkage[1].Thesolidvolumeincreasesafterce menthydrating,buttheabsolutevolumeofcementwatersystemreduces.Usuallythetotalamountofvolumeshrinkageofcementwatersystemis7%9%[1,2].Withthedevelopmentofthetechno logyofcementandconcrete,concretewithhighstrengthandhighperformanceisthedevelopingtendencynow.However,nowadays,comparedwithordinaryconcrete,thehydrationshrinkageofhighperformancecementconcreteincreasesobvi ouslybecauseoftheaccelerationof… 相似文献
105.
106.
D. M. Shaffer and M. K. McBeath (see record 2002-02027-006) plotted the optical trajectories of uncatchable fly balls and concluded that linear optical trajectory is the informational basis of the actions taken to catch these balls. P. McLeod, N. Reed, and Z. Dienes (see record 2002-11140-016) replotted these trajectories in terms of changes in the tangent of optical angle over time and concluded that optical acceleration is the informational basis of fielder actions. Neither of these conclusions is warranted, however, because the optical trajectories of even uncatchable balls confound the information that is the basis of fielder action with the effects of those same actions on these trajectories. To determine the informational basis of fielder action, it is necessary to do the control-theory-based Test for the Controlled Variable, in which the informational basis of catching is found by looking for features of optical trajectories that are protected from experimentally or naturally applied disturbances. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
用水泥对火电厂废渣-粉煤灰进行改性,利用改性粉煤灰吸附去除水中的Cr(VI)离子,试验研究了Cr(VI)初始浓度、吸附剂用量、吸附时间、溶液的酸度和吸附剂颗粒大小对吸附效果的影响,找出了吸附的最优条件。在最佳条件下,改性粉煤灰对Cr(VI)的去除率达95%以上。 相似文献
108.
Solidification of Municipal Solid Waste Incineration Fly Ash with Cement and Its Leaching Behaviors of Heavy Metals 总被引:3,自引:0,他引:3
YUQi-jun ShigeyoshiNagataki LINJin-mei 《武汉理工大学学报(材料科学英文版)》2003,18(1):55-60
The solidifying qffect of cement addition on municipal solid waste incineration fly ash ( MSWFA for short, collected from the gas exhaust system of MSW incinerator), the interaction of MSWFA with cement and water and the leaching of heavy metals from cement-solidified MSWFA are investigated. The main results show that : ( 1 ) when MSWFA is mixed with cement and water, 112 evolution, the formation and volume expansion of AFt will take place, the volume expansion can be reduced by ground rice husk ash addition ; (2) heavy metals do leach from cement-solidified MSWFA and at lower pH more leaching will occur; (3) compared with cement - so-lidified fly ash, the leachate of solidified MSWFA is with higher heavy metal contents ; (4) with the increment of cement addition leached heavy metals are decreased ; and (5) concentrations of Zn , Mn , Cu and Cd in all the leachates can meet the relevant Standards of Japan, but as the regulations for soil and groundwater protection of Japan are concerned, precautions against the leaching of Pb , Cl^- and Cr^6 and so on are needed. 相似文献
109.
陈美祝 《武汉理工大学学报(材料科学英文版)》2003,18(3)
1 IntroductionGenerally,gypsumisaddedinPortlandcementtocontrolthehydrationvelocityofcementandconsequentlyregulatethesettingtime ,whichmayalsoimproveaseriesofperformancesofcementsuchasincreasingitsearlystrength ,minishingdesiccationanddeformation ,improvingitsrheology ,durability ,frostresistanceandpermeabilityresistanceetc[1,2 ] .However ,inblendedcementitiousmate rialsmixedwithalargeramountofindustrialwastes (suchasslag ,flyash) ,besidesabovefunctions ,gypsumisstillaneffectivesulfateexcitant… 相似文献
110.
分析了 60 0 MW大型火力发电厂“飞灰 /底渣岛”的生产现场物位检测的难点 :应用场合很难捕捉温度、压力、输料速率、介电常数等工质变化规律 ,且没有现成的控制模式可参照。从物位测量传感器的测量原理、选型设计、新技术应用、PLC/DCS接口等多角度 ,提出了判断、分析、解决实际问题的新思路与建议 相似文献