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   7篇
  免费   2篇
电工技术   1篇
武器工业   2篇
无线电   1篇
一般工业技术   2篇
原子能技术   3篇
  2023年   1篇
  2022年   2篇
  2021年   1篇
  2020年   1篇
  2013年   1篇
  2011年   1篇
  2009年   1篇
  2006年   1篇
排序方式: 共有9条查询结果,搜索用时 31 毫秒
1
1.
为研究和考证现行枪械定型试验国军标中规定的枪械射击方法的合理性,从最典型的战斗类型——进攻战与防御战出发,经实战分析与研究,结合部队、院校广泛调研情况,确定了既可满足试验要求也可指导实战的各种枪械射击方法。  相似文献   
2.
针对传统春节效应影响时期按经验选取以及物理意义模糊的问题,提出了一种适于用电量春节效应调整新方案,以估计和消除春节效应对电量的影响。首先提出一种确定春节效应影响时期的方法;然后基于X-12-ARIMA模型形成一种春节效应调整新方案,对原始电量序列进行修正,以减小春节效应影响月份的预测误差;最后利用支持向量机模型, 进行某省月度负荷用电量预测算例分析,验证该春节效应调整方法的正确性和有效性。算例表明,所提出的春节效应调整方法可有效改善用电量数据质量,有助于对中期负荷用电量做出更为精准的预测。  相似文献   
3.
密肋壁板结构简化计算模型对比分析   总被引:7,自引:3,他引:4  
提要:密肋壁板结构中多种材料及构件的使用与嵌套,使实体计算模型比较复杂,在结构计算中需要提出简化计算模型。结合课题组前期研究成果及现代高层结构计算理论,提出密肋壁板结构弹性阶段简化数值模型与解析模型。利用前期1/10比例振动台试验研究结果,采用刚架-复合弹性板模型对结构进行时程分析,并验证简化数值模型的正确性;利用解析模型和数值模型对实际工程进行对比分析,验证解析模型的合理性。理论与试验表明:采用刚架-复合弹性板模型作为密肋壁板结构在弹性阶段的数值模型具有一定的理论依据和可行性;提出的框架-复合墙模型作为密肋壁板结构在弹性阶段的解析模型较为合理,为实际工程提供了一种较为简化、实用的手算解析方法。  相似文献   
4.
The power conversion efficiency (PCE) of organic solar cells (OSCs) has reached high values of over 19%. However, most of the high-efficiency OSCs are fabricated by spin-coating with toxic solvents and the optimal photoactive layer thickness is limited to 100 nm, limiting practical development of OSCs. It is a great challenge to obtain ideal morphology for high-efficiency thick-film OSCs when using non-halogenated solvents due to the unfavorable film formation kinetics. Herein, high-efficiency ternary thick-film (300 nm) OSCs with PCE of 15.4% based on PM6:BTR-Cl:CH1007 are fabricated by hot slot-die coating using non-halogenated solvent (o-xylene) in the air. Compared to PM6:BTR-Cl:Y6 blends, the stronger pre-aggregation of CH1007 in solution induces the earlier aggregation of CH1007 molecules and longer aggregation time, and thus results in high and balanced crystallinity of donors and acceptor in CH1007-based ternary film, which led to high-carrier mobility and suppressed charge recombination. The ternary strategy is further used to fabricate high-efficiency, thick-film, large-area, and flexible devices processed from non-halogenated solvents, paving the way for industrial development of OSCs.  相似文献   
5.
蒋兴  翁羽  王海军 《核动力工程》2021,42(5):119-122
我国非能动系列压水堆将应急冷却系统冷却水的注入管道直接连接于压力容器上,与传统的冷管段安注不同,这种安注方式被称之为反应堆压力容器直接安注。本文以安注条件下的反应堆压力容器为研究对象,采用物理实验与数值分析结合的方法,对安注流体在压力容器表面形成的热分布形态进行研究。研究发现,不同于传统的主管道冷段斜接管安注方式,直接安注条件下安注流体在下降环腔中的分布形态接近于等腰三角形。以实验结果为基础,结合数值计算验证,发现了压力容器热分布角与流速比成正比关系,并进一步提出了安注流体分布计算模型,从而为反应堆安全设计提供参考。   相似文献   
6.
Surface charge accumulation and transport on cellular polypropylene play an important role in nanogenerators, which could have a potential impact on energy harvesting and wearable devices for zero carbon energy systems and the internet of things. Different shapes have different charge accumulation and decay characteristics of the polymer. Therefore, we studied the influence of the sample's shape on the surface charge decay by experiment and modeling. The surface potential of square and circular cellular polypropylene was measured by a two-dimensional surface potential measurement system with electrostatic capacitive probe. The experimental result shows that the surface potential distribution of the square sample dissipates non-uniformly from the bell shape to a one-sided collapsed shape, while that of the circular sample dissipates uniformly from the bell shape to the crater-like shape. Moreover, the simulated results of the initial surface potential distributions of the square and circular cellular polypropylene are consistent with the experimental results. The investigation demonstrates that the charge transport process is correlated with the shape of the sample, which provides significant reference for designing electret material used for highly efficient nanogenerators.  相似文献   
7.
为实现半球壳内外表面缺陷的高精度、非接触测量,在一种新型非正交系坐标测量机的基础上,提出了球壳内外表面缺陷的光学复合式测量方法.该方法将激光测量的点扫描与视觉测量的面扫描相结合,不仅可以测量表面缺陷的覆盖面积和分布,还可以测量缺陷的深度/高度.实际测量结果表明了该方法是可行的,具有较高的精度和效率.  相似文献   
8.
A fundamental T-branch in one-dimensional photonic crystal waveguides based on the omnidirectional reflection is constructed. Numerical simulations of this T-branch indicate that without any structural optimization, four high reflectance peaks and three high transmittance peaks appear alternately within a wide enough frequency band. The T-branch with the unique transmission characteristics can be used as a wavelength splitter. Combining the fundamental T-branch with flexible bends of one-dimensional photonic crystal waveguides, we construct simple and compact wavelength splitters with arbitrary branching angles. Those wavelength splitters are expected to be applied to high density photonic integrated circuits.  相似文献   
9.
An array of 30 plasma synthetic jet actuators (PSJAs) is deployed using a modified multichannel discharge circuit to suppress the flow separation over a straight-wing model. The lift and drag of the wing model are measured by a force balance, and the velocity fields over the suction surface are captured by a particle imaging velocimetry system. Results show that the flow separation of the straight wing originates from the middle of the model and expands towards the wingtips as the angle of attack increases. The flow separation can be suppressed effectively by the PSJAs array. The best flow control effect is achieved at a dimensionless discharge frequency of F+ = 1, with the peak lift coefficient increased by 10.5% and the stall angle postponed by 2°. To further optimize the power consumption of the PSJAs, the influence of the density of PSJAs on the flow control effect is investigated. A threshold of the density exits (with the spanwise spacing of PSJAs being 0.2 times of the chord length in the current research), below which the flow control effect starts to deteriorate remarkably. In addition, for comparison purposes, a dielectric barrier discharge (DBD) plasma actuator is installed at the same location of the PSJAs. At the same power consumption, 4.9% increase of the peak lift coefficient is achieved by DBD, while that achieved by PSJAs reaches 5.6%.  相似文献   
1
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