排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
统计分析畜牧兽医类5种中文核心期刊和5种非核心期刊的发文时滞,并参阅相关的文献资料,发现我国的科技期刊的发文周期相对过长,特别是较有名气的中文核心期刊,时效性相对较差.造成我国科技论文发文时滞过长的原因主要是稿源丰富,载文量少,审稿环节不畅,修改时间长和编辑加工流程落后.我国科技期刊编辑部可以采取建立来稿初步筛选机制,量化科技期刊论文审稿质量,增加期刊载文量,健全审稿专家队伍,利用网络资源建立现代化的编辑流程等措施来缩短发文时滞. 相似文献
2.
某大型水闸闸基以淤泥为主,设计采用围墩式沙体围堰进行基坑围护施工,效果较好。本文通过对围堰的结构形式、围堰的施工方法、堰体滑动与处理措施及处理效果进行分析、总结,说明围墩式沙体围堰在水利工程中的可行性。 相似文献
3.
The Fibonacci piezoelectric superlattices(FPSs) with an external dc electric field is presented, in which the dc electric field can tune the bandwidth of polaritonic band gaps(PBGs) continuously and reversibly via the electrooptic effect. The absolute bandwidths of two major PBGs of the FPSs around ω= 7.5 GHz and ω = 12.5 GHz can be broadened from 0.022 GHz to 0.74 GHz and from 0.02 GHz to 0.82 GHz with the dc electric field increasing from 0 to 1.342 × 10~6 V/m, respectively. The corresponding relative bandwidths of the two major PBGs are widened from 0.28% to 9.2% and from 0.18% to 6.35%, respectively. The general mechanism for the bandwidth tunability is that the coupling strength between the lattice vibration and electromagnetic waves is capable of being altered by the dc electric field via the electro-optic effect. Thus the properties can be applied to construct microwave switchings or field tunable bulk acoustic filters. 相似文献
4.
总结了湘南学院大学物理实验教学中存在的问题,探索了分层次实验教学改革的思路、内容和方法并部分付诸了实践,取得了良好的效果。 相似文献
5.
通过水泥粉喷桩加固技术在某大型水闸重建工程的成功运用事例,结合工程实际重点介绍了设计应注意事项、施工工艺、质量控制和检测等,说明水泥粉喷桩在沿海淤泥地区的适用性和可行性。 相似文献
6.
Boundary-Dependent Chaotic Regions for a Bose-Einstein Condensate Interacting with Laser Field
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Spatial chaos of a Bose Einstein condensate perturbed by a weak laser standing wave and a weak laser δ pulse is studied. By using the perturbed chaotic solution we investigate the new type of Melnikov chaotic regions, which depend on an integration constant co determined by the boundary conditions. It is shown that when the │co│ values are small, the chaotic region corresponds to small values of laser wave vector k, and the chaotic region for the larger h values is related to the large │co│ values. The result is confirmed numerically by finding the chaotic and regular orbits on the Poincarg section for the two different parameter regions. Thus, for a fixed co the adjustment of k from a small value to large value can transform the chaotic region into the regular one or on the contrary, which suggests a feasible method for eliminating or generating Melnikov chaos. 相似文献
7.
某大型水闸闸基以淤泥为主,设计采用围墩式沙体围堰进行基坑围护施工,效果较好.本文通过对围堰的结构形式、围堰的施工方法、堰体滑动与处理措施及处理效果进行分析、总结,说明围墩式沙体围堰在水利工程中的可行性. 相似文献
8.
9.
根据对该边坡的变形破坏特征及形成条件分析,认为该边坡在自重应力、卸荷变形、降雨、地下水等内外动力地质作用以及人类工程活动影响下,斜坡土体前缘崩塌滑移使上部失去支撑而发生破坏变形,尤其是暴雨饱水条件下,随着软弱结构面抗剪强度降低和自重应力增加,导致边坡失稳破坏。通过参数反演,对坡体3条剖面的稳定性进行了定量评价,为边坡治理设计提供,重要的地质依据。 相似文献
1