期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
翡翠玉件的表面组构及其在鉴定中的应用 被引量:3
1
作者 苏文宁 《云南地质》 2001年第4期385-391,共7页
表面组构是指在微观条件下翡翠玉件表面所呈现的物质组分和形貌特征 ,它们是一定内部组构在不同加工条件下的必然反映。不同质地 ,不同加工性质所制成的翡翠玉件 ,表面组构各异 ,因此可以利用表面组构 ,判断内部组构 ,进而评价玉件质地 ... 表面组构是指在微观条件下翡翠玉件表面所呈现的物质组分和形貌特征 ,它们是一定内部组构在不同加工条件下的必然反映。不同质地 ,不同加工性质所制成的翡翠玉件 ,表面组构各异 ,因此可以利用表面组构 ,判断内部组构 ,进而评价玉件质地 ,并为确定玉件加工条件提供一定依据。此外 ,还可为大型精密仪器测试提供有效靶区 。 展开更多
关键词 内部组构 伴生组分 翡翠玉件 正常充填 异常充填 表面组构
下载PDF
“当X时”与“在X时” 被引量:2
2
作者 王耿 《汉语学报》 CSSCI 北大核心 2014年第4期74-80,共7页
介词短语"当X时"与"在X时"是现代汉语中表达时间的重要方式,本文从句法功能、内部组构、语用价值三个方面探讨"当X时"和"在X时"的区别。我们认为,介词"在"和"当"的语义特... 介词短语"当X时"与"在X时"是现代汉语中表达时间的重要方式,本文从句法功能、内部组构、语用价值三个方面探讨"当X时"和"在X时"的区别。我们认为,介词"在"和"当"的语义特征是造成二者差异的重要原因。 展开更多
关键词 “当X时” “在X时” 句法功能 内部组构 语用价值 区别
下载PDF
Effects of Different Nitrogen Fertilizer Rates on Soluble Sugar,Starch and Root Tissue Structure of the Peach Trees
3
作者 潘春香 肖艳辉 +1 位作者 新居直祐 中尾義則 《Agricultural Science & Technology》 CAS 2011年第12期1861-1863,共3页
[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental... [Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental nitrogen fertilizer.Three nitrogen levels,0,3,6 g per pot respectively were set to study the effects of different nitrogen fertilizer on the contents of soluble sugar,starch and internal structure of the root of the peaches.[Result] The contents of soluble sugar of roots and leaves increased with the increase of nitrogen fertilizer level,and the level of 6 g per pot was the highest,which showed extreme differences between the level of 3 g per pot and the control.However,starch contents showed opposite results,which decreased as the level of nitrogen fertilizer increased.Compared with the 3 g per pot level of nitrogen fertilizer and the control,the internal structure of root applied with nitrogen fertilizer of 6 g per pot level had larger fibrovascularcylinder,advanced vascular bundle,small-spaced thin-walled cells,smooth and full cells with smooth cell wall.[Conclusion]Appropriate nitrogen levels can accelerate the accumulation of soluble sugar and the growth of root tissue structure. 展开更多
关键词 PEACH Nitrogen fertilizer rate Soluble sugar STARCH Root tissue structure
下载PDF
Security Analysis and Enhanced Design of a Dynamic Block Cipher 被引量:3
4
作者 ZHAO Guosheng WANG Jian 《China Communications》 SCIE CSCD 2016年第1期150-160,共11页
There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution o... There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix transformation.Then,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity function.The dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of iteration.The safety performance of proposed algorithm was analyzed by simulation test.The results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the security.Meanwhile,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement. 展开更多
关键词 cryptography block cipher encryption algorithm safety analysis
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部