首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   117篇
  免费   30篇
  国内免费   9篇
电工技术   22篇
综合类   10篇
化学工业   29篇
金属工艺   9篇
机械仪表   11篇
建筑科学   9篇
矿业工程   3篇
能源动力   7篇
轻工业   7篇
石油天然气   4篇
武器工业   3篇
无线电   9篇
一般工业技术   15篇
冶金工业   5篇
自动化技术   13篇
  2024年   2篇
  2023年   6篇
  2022年   13篇
  2021年   16篇
  2020年   18篇
  2019年   8篇
  2018年   9篇
  2017年   10篇
  2016年   7篇
  2015年   9篇
  2014年   7篇
  2013年   9篇
  2012年   8篇
  2011年   4篇
  2010年   6篇
  2009年   4篇
  2008年   1篇
  2007年   4篇
  2006年   4篇
  2005年   3篇
  2001年   1篇
  1999年   2篇
  1998年   1篇
  1993年   2篇
  1992年   1篇
  1979年   1篇
排序方式: 共有156条查询结果,搜索用时 15 毫秒
81.
季登辉 《上海节能》2020,(2):155-159
针对燃煤电厂输煤系统传统转运站设计存在的粉尘大、落煤管堵煤等问题,介绍了一种曲线落煤管及无动力除尘导料槽组合的新型转运站设计。该落煤管设计通过对物料的汇集,实现了运输物料的可控化,从而降低落煤管堵煤现象的发生,减少对下游皮带的冲击。通过与无动力除尘导料槽组合达到控制诱导风,降低粉尘浓度。  相似文献   
82.
83.
新一轮的战略性油气地质调查工作在南黄海盆地崂山隆起新近系之下发现了疑似海相地层的有效地震反射,但因针对海相地层的勘探程度低(无井、地震测线稀)等原因,其地层属性至今依然不清楚。本文利用青岛坳陷有限的钻井资料,结合新采集有限的二维地震资料,对青岛坳陷二叠系、三叠系进行了地震属性提取及分析,认为其地震属性特征为:上二叠统龙潭组和大隆组总体表现为中-强振幅、偏低频、平行-近平行较密集地震反射;下三叠统下青龙组为中振幅、中-高频、平行-近平行密集地震反射;下三叠统上青龙组则为弱振幅或空白反射、低-中频、平行-近平行地震反射。预测上二叠统及中-下三叠统主要残存分布于青岛坳陷东侧靠近崂山隆起及勿南沙隆起的部位,并据此推测在崂山隆起及勿南沙隆起区可能残存,是值得探索的勘探领域。对于钻井稀少的低勘探程度区,利用地震多属性分析技术及地震属性特征来识别与预测勘探目的层的分布,对于早期勘探评价具有重要现实意义。  相似文献   
84.
Permanent control of environment by using remote sensing images requires effective techniques. Two new methods for remote sensing image change detection are proposed. The first method is based on the notion of difference image and image histograms. A complementary pair of images is proposed as the main presentation of a difference image which allows automatic separation of the changes of ground objects without loss or distortion. The use of the histograms in accordance with variations of image brightness (increasing and decreasing) provides opportunities for the assessment and experimental verification of existing approaches in the selection of automatic detection thresholds. The second method for change detection is based on energy moments for image rows and/or columns. It allows one to find image changes even in one pixel and differs from the existed methods by a more simple algorithm and possibility to extract even small changes. The proposed image representation can be considered as an integral feature of the whole image. The methods have been tested in real images. Comparing to start-of-the-art methods, our methods can detect changes in real-time with high accuracy when deployed on a standard computer.  相似文献   
85.
在LXI自动测试系统中,通过计算机控制程序的调用,波形发生器能够根据测试对象的不同,输出多种形式的激励信号;进而,测试系统软件对控制程序的通用性、可维护性及可移植性也提出了更高要求;由此,在测试软件的开发中,采用了模块化技术,不同仪器的控制程序得以并行开发,同时也方便了同一仪器接口间的互换;以上所述在使用图形化编程语言LabVIEW,实现Agilent 33220A程序化控制的过程中得到了验证;此外,模块化编程技术很容易推广到系统中其它仪器,为整个测试系统软件的构建和升级创造条件.  相似文献   
86.
基于NWGISS的空间信息网格节点   总被引:1,自引:0,他引:1  
研究了空间信息服务节点的概念结构,分析了NWGISS的组成结构和工作机理,基于NWGISS设计了遵循OGC规范的空间信息服务节点结构和原型系统,结合SIG系统需求建立了节点实例,实验结果表明建立的数据节点可以提供有效的空间信息服务。  相似文献   
87.
CK1 casein kinases are well conserved in filamentous fungi. However, their functions are not well characterized in plant pathogens. In Fusarium graminearum, deletion of FgYCK1 caused severe growth defects and loss of conidiation, fertility, and pathogenicity. Interestingly, the Fgyck1 mutant was not stable and often produced fast-growing spontaneous suppressors. Suppressor mutations were frequently identified in the FgBNI4 gene by sequencing analyses. Deletion of the entire FgBNI4 or disruptions of its conserved C-terminal region could suppress the defects of Fgyck1 in hyphal growth and conidiation, indicating the genetic relationship between FgYCK1 and FgBNI4. Furthermore, the Fgyck1 mutant showed defects in polarized growth, cell wall integrity, internalization of FgRho1 and vacuole fusion, which were all partially suppressed by deletion of FgBNI4. Overall, our results indicate a stage-specific functional relationship between FgYCK1 and FgBNI4, possibly via FgRho1 signaling for regulating polarized hyphal growth and cell wall integrity.  相似文献   
88.
为检测PAE湿强剂中氯丙醇的含量,本研究建立了气相色谱-质谱联用法(GC-MS),检测PAE湿强剂中1,3-二氯-2-丙醇(1,3-DCP)与3-氯-1,2-丙二醇(3-MCPD)的含量,并进行了方法学验证,同时探究了PAE湿强剂中氯丙醇含量与纸张水提取液中氯丙醇含量之间的关系。本研究对4批次某款湿强剂进行检测,发现随着湿强剂制造工艺的改进,1,3-DCP与3-MCPD的含量均有明显的下降。调整湿强剂和助留剂的添加量,抄造不同批次的纸张,同时测定纸张水提取液中的氯丙醇含量与纸张的抗张强度。结果显示,纸张水提取液中的氯丙醇含量与湿强剂中氯丙醇含量呈正相关关系,与湿强剂添加量成正比;在助留剂实际添加量超过厂家推荐添加量的情况下,纸张水提取液中的氯丙醇含量与助留剂添加量无明显关系,但会导致纸张湿、干抗张指数下降。  相似文献   
89.
High-quality hosts are indispensable for simultaneously realizing stable, high efficiency, and low roll-off blue solution-processed organic light-emitting diodes (OLEDs). Herein, three solution processable bipolar hosts with successively reduced triplet energies approaching the T1 state of thermally activated delayed fluorescence (TADF) emitter are developed and evaluated for high-performance blue OLED devices. The smaller T1 energy gap between host and guest allows the quenching of long-lived triplet excitons to reduce exciton concentration inside the device, and thus suppresses singlet-triplet and triplet-triplet annihilations. Triplet-energy-mediated hosts with high enough T1 and better charge balance in device facilitate high exciton utilization efficiency and uniform triplet exciton distribution among host and TADF guest. Benefited from these synergetic factors, a high maximum external quantum efficiency (EQEmax) of 20.8%, long operational lifetime (T50 of 398.3 h @ 500 cd m−2), and negligible efficiency roll-off (EQE of 20.1% @ 1000 cd m−2) are achieved for bluish-green TADF OLEDs. Additionally introducing a narrowband emission multiple-resonance TADF material as terminal emitter to accelerate exciton dynamic and improve exciton utilization, a higher EQEmax of 23.1%, suppressed roll-off and extended lifetime of 456.3 h are achieved for the sky-blue sensitized OLEDs at the same brightness.  相似文献   
90.
A model of random particles constructed by the operation of self-similarity in fractalgeometry is presented.The correlation function of the number density has been obtained andcan be used conveniently in theoretical study and computer simulation for wave interaction withrandom media.As an example,this model has been applied to calculate analytically the rangedependence of volume scattering in radar echoes.The result agrees with that of Rastogi andScheucher's simulation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号