全文获取类型
收费全文 | 93篇 |
免费 | 8篇 |
国内免费 | 19篇 |
专业分类
电工技术 | 1篇 |
综合类 | 6篇 |
化学工业 | 25篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 6篇 |
矿业工程 | 4篇 |
轻工业 | 21篇 |
石油天然气 | 7篇 |
无线电 | 1篇 |
一般工业技术 | 3篇 |
原子能技术 | 38篇 |
自动化技术 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 19篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有120条查询结果,搜索用时 250 毫秒
1.
灭多威在棉花及土壤中降解动态及残留量研究 总被引:6,自引:0,他引:6
按生产上常规用量,每亩喷施20%灭多威乳油60毫升防治二代棉铃虫,施药后7天在棉叶上及14天在土壤中其降解率分别为98.81%及88.09%;半衰期分别的1.56天及4.98天。防治二、三、四代棉铃虫,按有效剂量施药6次,有效成分72克/亩,棉籽和土壤中的最大残留量分别为0.023及0.084微克/克;再加大50%用量,有效成分108克/亩,最大残留量仅为0.034及0.214微克/克。结果表明,灭多威在棉叶上及土壤中降解较迅速,常规用量下,对棉籽及土壤污染较轻。 相似文献
2.
为解决露天矿潜孔钻机作业粉尘污染严重的问题,从传统除尘技术应用效果差、耗风量大、取水困难等事实出发,根据泡沫除尘机理及两相泡沫发泡原理,设计了一种适用于露天矿潜孔钻机的泡沫发生器,并对其发泡性能进行研究.通过开展泡沫发生器的泡沫流量、发泡倍数及半衰期等性能实验,确定出影响泡沫发生器发泡性能的主要因素,得出泡沫发生器的最佳工况点.实验结果表明:气体流量、液体流量(气液比)、发泡网及发泡剂质量分数是影响泡沫发生器发泡性能的4个主要因素,在工况为发泡网1、质量分数1.5%的配方2、气体压力0.7 MPa、液体流量18 L/min及气体流量30 m~3/h条件下,泡沫发生器发泡性能达到最佳,其流量为515 L/min,发泡倍数为22,半衰期为65 min.经现场试验,泡沫除尘后采场平均降尘率高达90%以上,应用效果良好. 相似文献
3.
4.
5.
L. Antonio González-Grajales Laura Pieper Stefan Görner Philipp Görner Rudolf Staufenbiel 《Journal of dairy science》2019,102(4):3609-3614
Few studies have compared individual variability of an intravenous glucose tolerance test (ivGTT) obtained daily in young cattle. The objective of this study was to evaluate the repeatability of glucose traits and insulin responses derived from ivGTT during 3 consecutive days in Holstein-Friesian cattle (bulls: n = 4, steers: n = 3, heifers: n = 3). Blood collections were performed from min 0 (basal concentrations) to min 63 (last measurement). Additional estimates included maximal concentration for glucose and insulin, glucose half-life time (GHLT), and glucose and insulin area under the curve. Glucose traits showed higher repeatability when compared with insulin responses. On average, the glucose trait and insulin response with the lowest coefficient of variation was GHLT (0.7%) and insulin area under the curve (21.3%), respectively. In addition, a general linear model with repeated measures was used to test for significant differences in glucose and insulin concentrations over time at different trial days. Both glucose and insulin concentrations were influenced by time point but not by trial day or time point × trial day. The results from this study showed that individual insulin responses were more variable than glucose traits. The high repeatability of GHLT evidenced the strict regulatory glucose disposal mechanisms occurring in young Holstein-Friesian cattle, whereas insulin responses showed high variability despite controlled management and nutritional practices. 相似文献
6.
《核技术(英文版)》2016,(6):271-275
In this paper,by considering the electrons in different external environments,including neutral atoms,a metal,and an extremely strong magnetic-field environment,the screened a-decay half-lives of the a emitters with proton number Z = 52–105 are systematically calculated.In the external environment,the decay energy and the interaction potential between a particle and daughter nucleus are both changed due to the electron screening effect and their variations are both very important for the electron screening effect.Besides,the electron screening effect is found to be closely related to the decay energy and its proton number. 相似文献
7.
The information needs of a complex society are not met by an information-flow technology invented and developed in traditional societies. This article provides a theoretical framework derived from modern systems theory by which to understand the technology of public opinion policy formation in guidance operations of a complex society. Qualitative models of information flow systems are presented together with a discussion of the kind of society each information flow technology produces. Three are considered: tradition-based information-flow societies, managed information-flow societies (Utopian and elitist), and cybernetic issue-based information-flow societies. 相似文献
8.
《Journal of Nuclear Science and Technology》2013,50(6):577-580
A calculational model for a modified diffusion coefficient has been developed to incorporate the neutron streaming effect in heterogeneous low-density channels accurately into diffusion theory calculations. The model uses a supercell, and the axial and radial diffusion coefficients of the heterogeneous inner cell are so defined that they can reproduce Benoist's axial and radial diffusion coefficients of the supercell when the diffusion coefficient of the outer cell is given as 1/3 Σtr . In the case of the axial diffusion coefficient, the axial buckling effect is taken into account by modifying the neutron path length within the streaming channel in calculating the collision probabilities. This model has been applied to an RZ fast reactor Core model with a gas expansion module (GEM). By using the axial diffusion coefficient obtained with the presented model, calculational error of GEM worth was reduced to less than 1/7 compared to the formula of Rowlands and Eaton. 相似文献
9.
10.
中性常压条件下研究了不同因素对CuO-H2O2矿化模型底物苯酚的影响。引入H2O2矿化指数(X)、矿化半衰期(t1/2)概念,结合总碳(TOC)去除及氧化剂分解规律,对催化矿化进行分析。结果表明:温度、催化剂、氧化剂、初始TOC质量浓度的增加均能不同程度地加速TOC去除,矿化半衰期t1/2更短。随温度、氧化剂浓度提高,H202矿化指数X先增加后减小,随初始TOC及催化剂质量浓度提高X分别增加和减小。提出了羟基自由基矿化机理,紫外可见分光光谱分析表明底物先被氧化为某些中间产物,再被矿化为CO2和H2O。 相似文献