期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
^(137)Cs应用于我国西部风蚀地区土地退化的初步研究─—以新疆库尔勒地区为例 被引量:46
1
作者 濮励杰 包浩生 +1 位作者 彭补拙 DavidLHiggitt 《土壤学报》 CAS CSCD 北大核心 1998年第4期441-449,共9页
本文以新疆库尔勒地区为例,首次运用137Cs示踪分析法对我国西部风蚀地区土壤侵蚀的强度与区域分布进行了研究,分别计算出该地区荒地、耕地、草地等土地利用类型的土壤侵蚀模数的平均值为5987.21吨/平方公里·年、3537.29吨/... 本文以新疆库尔勒地区为例,首次运用137Cs示踪分析法对我国西部风蚀地区土壤侵蚀的强度与区域分布进行了研究,分别计算出该地区荒地、耕地、草地等土地利用类型的土壤侵蚀模数的平均值为5987.21吨/平方公里·年、3537.29吨/平方公里·年和317131吨/平方公里·年,其土壤侵蚀强度依次为荒地>耕地>草地。并据此探讨了不同土地利用类型与土地退化之间的相关关系及空间特征。这对于丰富风蚀地区土地退化研究的理论和方法,制订准确的土地退化防治对策,进一步合理利用土地资源具有理论和实践意义。 展开更多
关键词 ^137CS 土地退化 风蚀 土壤侵蚀强度
在线阅读 下载PDF
Effect of Heat Treatment on Luminescent Properties of White Organic Light Emitting Device
2
作者 LIJuan HUAYu-lin +1 位作者 WANGChang-sheng XIONGShao-zhen 《Semiconductor Photonics and Technology》 CAS 2004年第1期41-43,47,共4页
The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated.Heat treatment is used to control the ratio between the intensities of main electrol... The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated.Heat treatment is used to control the ratio between the intensities of main electroluminescent spectral peaks.The electroluminescent spectrum of our device is quite similar to that of white inorganic LED produced by Nichia Corporation after being annealed,and its turn-on voltage can be decreased by 1 V. 展开更多
关键词 White OLED Heat treatment Electroluminescent spectrum
在线阅读 下载PDF
LFTOP: An LF-Based Approach to Domain-Specific Reasoning 被引量:1
3
作者 庞建民 PaulCallaghan 罗朝晖 《Journal of Computer Science & Technology》 SCIE EI CSCD 2005年第4期526-535,共10页
A new approach to domain-specific reasoning is presented that is based on a type-theoretic logical framework (LF) but does not require the user to be an expert in type theory. The concepts of the domain and its relate... A new approach to domain-specific reasoning is presented that is based on a type-theoretic logical framework (LF) but does not require the user to be an expert in type theory. The concepts of the domain and its related reasoning systems are formalized in LF, but the user works with the system through a syntax and interface appropriate to his/her work. A middle layer provides translation between the user syntax and LF, and allows additional support for reasoning (e.g., model checking). Thus, the complexity of the logical framework is hidden but the benefits of using type theory and its related tools are retained, such as precision and machine-checkable proofs. This approach is investigated through a number of case studies: here, the authors consider the verification of properties of concurrency. The authors have formalized a specification language (CCS) and logic (μ-calculus) in LF, together with useful lemmas, and a user-oriented syntax has been designed. The authors demonstrate the approach with simple examples. However, applying lemmas to objects introduced by the user may result in framework-level objects which cannot be translated back to the user level. The authors discuss this problem, define a notion of adequacy, and prove that in this case study, translation can always be reversed. 展开更多
关键词 LFTOP 逻辑结构 网络图 代码规范 逻辑推理 计算机
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部