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1.
基于Philips公司的一体化芯片SAA7130HL,提出一种以其为核心的CPCI接口视频采集卡的设计方法。此视频采集卡采用8块一体化芯片SAA7130HL,通过PCI-to-PCI桥芯片PCI2050BI扩展成8路设备,实现了8路视频采集,可在恶劣条件下工作。  相似文献   
2.
调度自动化系统PAS高级软件的应用   总被引:1,自引:0,他引:1  
PAS应用软件基本功能的实用化在国内外已经成为一种必然发展趋势,根据哈尔滨地区电网的实际应用情况综述了其结构、功能,提出了该软件的实用性和有待改进与完善的地方。  相似文献   
3.
The mutual confinement of ceramics and metals in laminated composites tends to change the original properties of ceramics and metals. In this study, two kinds of laminated composites, Al2O3/Ti and Al2O3/Ti/Ni, were prepared. Three-point bending experiments revealed that Al2O3/Ti underwent brittle fracture after elastic deformation. The fracture morphology analysis revealed that the Ti in Al2O3/Ti became brittle due to the formation of columnar crystals. The temperature gradient perpendicular to the direction of laminations during preparation was responsible for the formation of columnar crystals. The force–displacement curves of the Al2O3/Ti/Ni combine the properties of elastic deformation of ceramics and plastic deformation of metals. The reason why the Al2O3/Ti/Ni did not fracture completely in the bending experiments is that Ni maintained the toughness, and there is a good interfacial bond among Al2O3, Ti, and Ni. The indentation crack analysis revealed that cracks have long transverse propagation and short longitudinal propagation in both laminated composites. Finite element analysis revealed that this was due to compressive stress in the Al2O3 layer and tensile stress in the metal layer. This compressive stress consumes the crack energy in the longitudinal direction and stops the crack in the metal layer. The brittle to ductile gradient transition among Al2O3, Ti, and Ni, combined with the guidance of crack propagation direction by the interfacial layer, enhances the ability of Al2O3/Ti/Ni to resist damage.  相似文献   
4.
A transgenic rice line (TRS) enriched amylose and resistant starch has been developed by antisense RNA inhibition of starch branching enzymes. In this study, gelatinisation and crystalline properties, swelling power, water solubility, morphological and structural changes of starches from TRS and its wild-type Teqing (TQ) were carefully investigated during heating. Compared to TQ, TRS starch showed higher gelatinisation temperatures, lower gelatinisation enthalpy and swelling power. Morphological and structural changes showed that TQ starch drastically swelled after 70 °C, then gradually disrupted with increasing heating temperature. The surrounding band of TRS starch restrained granule swelling, though the subgranules disrupted to form the cavity. The results of spectroscopic analyses indicated that A-type crystalline of TQ changed to amorphous starch after 75 °C, while C-type crystalline of TRS gradually changed to B-type crystalline after 75 °C, then became amorphous starch at 95 °C. These results add to our understanding of the effect of heating on the high-amylose rice starch.  相似文献   
5.
《Ceramics International》2020,46(3):2624-2629
TaC/SiC composites with 5 wt% SiC addition were densified by plasma-activated sintering (PAS) at 1500–1800 °C for 5 min under 30 MPa. The effects of plasma-activated sintering on microstructures, densification and mechanical properties of the composites were investigated. The results showed that TaC/SiC composites achieved a relative density more than 99% of the theoretical density at 1600 °C. A low eutectic liquid phase generated by the oxide on the particle surface was observed in the composite to realize a relatively low temperature sintering densification. While the TaC particle size decreased insignificantly with increasing sintering temperature, the transformation of morphology of SiC particles changing from equiaxed to elongated grain was activated, accompanying with a slight particle size decreasing of the SiC phase, thus promoting a relatively high flexural strength of 550 MPa under 1800 °C. Besides, some ultra-fine 2 nm Ta2Si was observed in the glassy pockets, strengthening the amorphous phase and thus increasing the flexural strength.  相似文献   
6.
一种2050铝锂合金薄板的微观组织与力学性能   总被引:1,自引:0,他引:1  
通过力学性能测试和微观组织观察研究了不同热处理工艺对一种2050铝锂合金薄板力学性能和组织结构的影响。结果表明:2050铝锂合金主要强化析出相为T1相和θ′相,并可能存在少量S′相析出。在T6态(175℃)、T8态(6%预变形+155℃)时效时合金具有不同的时效析出特征;相比于T6态时效,由于时效前预变形的引入,T8态时效时合金中T1相和θ′相析出密度提高,尺寸减小,其对应的强度及延伸率均提高,T8峰时效(32 h)时σ_b、σ_(0.2)和δ分别为531MPa、488 MPa和11.4%。T8态时效(155℃/32 h)时,2%~10%预变形均可促进T1相形核,2%~6%预变形可促进θ′相形核,过大的预变形(如10%)并不能促进θ′相进一步形核,但可显著抑制θ′相长大。  相似文献   
7.
通过拉伸试验、晶间腐蚀试验以及透射电镜(TEM)等方法对固溶处理后不同预拉伸变形量处理并人工时效后2050铝锂合金厚板室温拉伸性能、抗晶间腐蚀性能以及合金的微观组织形貌进行了研究。结果表明,随预拉伸变形量的增加,合金L向和LT向的屈服强度和抗拉强度逐渐增大,变形量>4.0%后趋于平稳,伸长率逐渐降低后趋于稳定;随预拉伸变形量增加,腐蚀形貌由晶间腐蚀变为点蚀,点蚀深度逐渐减小。预拉伸变形促进了人工时效过程中晶内T1相的弥散析出,降低了晶界处T1相含量,因此提高了合金的强度和抗晶间腐蚀性能。预拉伸变形量为5.0%时,合金的强度和抗晶间腐蚀性能最佳。  相似文献   
8.
电网调度自动化系统的开发应用   总被引:1,自引:0,他引:1  
电网调度自动化系统是利用现代化先进的电子技术,计算和网络技术和通信技术,将网上的实时数据,离线数据、电网结构、设备参数和地理信息等多种信息进行综合处理和集成,形成调度自动化系统。从结构上分为变电所数据采集(RTu)、通信通道、计算机系统主站三个部分。目前、盘曙电网35座变电所已经实现电网调度自动化,其中微机综合自动化变电所10座,老式变电站25座。运行可靠稳定,安全运行水平显著提高,实现了调度管理自动化。  相似文献   
9.
基于神经网络理论与传统分析方法,采用改进的BP网络算法,利用黄河陕县水文站531 a天然年径流时间序列,建立了黄河中下游年径流长期变化的BP网络预测模型,并以此模型对2001—2050年黄河中下游天然年径流变化趋势进行了预测分析,结果表明:①中下游天然年径流在未来50 a变化的大趋势是丰水时段比枯水时段略占优势,要经历2001—2020年相对丰水时段、2021—2026年相对枯水时段、2027—2037年相对丰水时段及2038—2050年相对枯水时段;②黄河中下游与上游的天然年径流变化的大趋势基本一致,但中下游出现连续枯水时段的时间较上游长。  相似文献   
10.
With the European Strategic Energy Technology Plan (SET Plan) expiring in 2020, the EU needs to revisit its energy technology policy for the post-2020 horizon and to establish a policy framework that fosters the achievement of ambitious EU commitments for decarbonization by 2050. We discuss options for a post-2020 EU energy technology policy, taking account of uncertain technology developments, uncertain carbon prices and the highly competitive global market for energy technologies. We propose a revised SET Plan that enables policy makers to be pro-active in pushing innovation in promising technologies, no matter what policy context will be realized in the future. In particular, a revised SET Plan should include a more technology-specific focus, provide the basis for planning and prioritization among decarbonization technologies, and should be based on a comprehensive approach across sectors. Selected technology targets and EU funding of innovation should be in line with the SET Plan prioritization.  相似文献   
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