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分析了脉冲X光与电子束和化爆模拟引起的结构响应的冲量等效性原则。并以脉冲X光与柔爆索化爆作用硬铝圆柱壳的结构响应测量结果为实例,对其进行了定量的等效性分析,得出了较好的等效性结果。 相似文献
13.
面向无线个人局域网应用设计了一种高吞吐量、低复杂度的2 048点快速傅里叶变换处理器。提出了新型改良基-26算法用于降低硬件实现复杂度,采用多路径负反馈架构来提高数据吞吐量。为了减少硬件成本,采取正则有符号数常数乘法器替代布斯乘法器完成除旋转因子W2048外所有旋转因子的复数乘法运算。另外,采用了一种减少存储旋转因子W2048系数只读存储器空间的方法,将其存储空间减少为原来的一半。基于QUARTUS PRIME平台的仿真结果显示,工作频率为320 MHz时,最高数据吞吐速率达到了2.6 Gsample/s,而且对比以往的研究方案至少可节约逻辑单元使用量23%,记忆体单元使用量12%。 相似文献
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Part 2 of this paper details an experimentally-based method to evaluate the power distribution for both CW and PM cutting. Variations in power distribution with different cutting speeds, material thickness and pulse ratios are presented. The paper also provides information on both the cutting efficiency and absorptivity index for MDF, and comments on the beam dispersion characteristics after the cutting process. 相似文献
15.
MDF机房遭遇强电入侵是机房安全的重大隐患,如何有效地将MDF机房告警信号上传至有人值守的地方成为关键。文章介绍了如何利用通信机房现有的动力环境监控系统将MDF机房告警信号上传至网监中心的方法。 相似文献
16.
Microsoft Query技术在PSMS二次开发中的应用 总被引:1,自引:0,他引:1
程少珠 《电信工程技术与标准化》2005,(5):36-39
动力及环境集中监控系统(PSMS,Power and Surroundings Monitoring System)的用户在使用过程中,往往会结合自身维护实践的需要提出一些特定的需求,但监控产品厂家目前所提供的软件却又不足以支持这些功能.本文结合实例,介绍了如何充分利用Microsoft Query技术并结合结构化查询语言(SQL,Structured Query Language),自行定义报表,从动力监控系统的大型数据库中获取数据,自动生成报表的方法.实践证明该方法对于加强配线架的例行维护管理具有现实的重要意义. 相似文献
17.
Weidong Wang Xiwei Shen Siqi Zhang Ruixue Lv Ming Liu Wang Xu Yu Chen Huiyu Wang 《Molecules (Basel, Switzerland)》2022,27(11)
Very volatile organic compounds (VVOCs) are a group of important odor pollutants affecting indoor air quality that have been shown to be harmful to human health. A 15 L environmental chamber, combined with multi-bed tube was used to collect gases. Fifteen very volatile organic compounds (VVOCs), including 12 odor compounds, were identified from veneered medium density fiberboard coated with water-based lacquer (WB-MDF) using gas chromatography–mass spectrometry/olfactometry (GC-MS/O). The total very volatile organic compound (TVVOC) and total odor intensity (TOI) showed a decreasing trend over time, reaching equilibrium on day 28. TVVOC showed an overall slow-fast-slow emission profile, from day 3 to day 7, with a maximum decay rate of 29.7%. TOI showed the greatest rate of decline from day 1 to day 3, at approximately 12%. Alkane and alcohol VVOCs were the more abundant compounds, accounting for at least 60% and even up to 80% of the total. The major odor impression was fruity, with a highest odor rating of 6.6, followed by sweet, with an odor rating of 6.1. Although the odor impression changed from sweet to fruity over time, it seemed pleasant overall. The odor contributors were mainly alkanes, alcohols, esters, and ethers, which had relatively high odor intensities. The main odor-contributing substances were dichloromethane, ethanol, ethyl acetate, 2-methylacrylic acid methyl ester, and tetrahydrofuran. When WB-MDF is used for furniture or other decorative materials, it is strongly recommended that it be stored under ventilation for at least 28 days and the adoption of substitute solvents of lacquers, modified adhesives, and low-odor wood raw materials is recommended. These possible initiatives would contribute to the aim of building an environmentally friendly indoor environment. 相似文献
18.
Mojumdar S. C. Chowdhury B. Varshney K. G. Mazanec K. 《Journal of Thermal Analysis and Calorimetry》2004,78(1):135-144
The results, presented here discusses the Macro-Defect-Free (MDF) cements prepared from the blends of sulfoaluminate ferrite
belite (SAFB) clinkers, ordinary Portland cement (OPC), Al2O3 and poly(butyl acrylate) (PBA), styrene/acrylonitrile co-polymer (SACP) or sodium polyphosphate (poly-P). Though MDF cements
have several attractive properties, their utilization has been limited due to the insufficient moisture resistance. It is
a very challenging task for scientists and technologist to improve the moisture resistance of MDF cements. Therefore, the
new MDF cements were subjected to various moist atmospheres to investigate their moisture resistance. The most significance
of this work is the improvement of moisture resistance of the studied MDF cements. The aim of this work was to understand
the effects of polymers, Al2O3, OPC and SAFB clinkers in the raw mix and delayed drying on MDF cements and also on their subsequent moisture resistance
and thermal stability as well as to discover the new properties of these materials. Their chemical, thermal and scanning electron
microscopic (SEM) analysis was also carried out before and after exposure to moisture. PBA was found to be the most suitable
polymer for MDF cement synthesis, since the samples containing PBA showed the highest resistance to moisture. There are three
main temperature regions on TG curves of both series of MDF cement samples. The significant differences in SEM of MDF cements
before and after moisture attack and with different polymers were observed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
A. Myburgh 《Journal of Thermal Analysis and Calorimetry》2006,85(1):135-139
MDF cements
using the blends of sulfoaluminate ferrite belite (SAFB) clinkers and ordinary
Portland cement (OPC) in mass ratio 85:15 with Al2O3,
and starch, polyphosphate (poly-P) or butylacrylate/acrylonitrile were subjected
to moist atmospheres (ambient, 52 and 100% relative humidity (RH)) to investigate
their moisture resistance. Their chemical, thermal, electron microscopic and
magnetic properties were also studied before and after moisture attack. Butylacrylate/acrylonitrile
(BA/AN) copolymer was found to be the most suitable for MDF cement synthesis
since the sample containing BA/AN showed the best moisture resistant. There
are significant differences in scanning electron microscopy (SEM) of MDF cements
before and after moisture attack and with different polymers. New data on
the paramagnetic nonhysteresis magnetization curves for all the samples are
observed. The MDF cements synthesized from SAFB clinker with dissolved poly-P
give the best signal/noise (S/N) ratio. Three main temperature regions on TG curves
of both series of MDF cements are observed. In the inter-phase section of
MDF cements, the content of classical cement hydrates decomposing by 250°C
is increased. Combustion of organic material took place by 550°C. In the
temperature range 550-800°C, the decomposition of CaCO3
occurs. 相似文献