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排序方式: 共有179条查询结果,搜索用时 15 毫秒
1.
Edwin Ramaroson Gilbert Blanchard Michel Che Jean-Michel Tatibouët 《Catalysis Letters》1992,15(4):393-400
The oxidative dimerisation of propene to 1,5-hexadiene has been investigated on Bi-Zn-O catalysts. The Bi48ZnO73 phase, observed in the catalysts calcined at 700 ° C is an active and selective catalyst for the formation of 1,5-hexadiene. The best catalytic performance (1,5-hexadiene selectivity 7352l0v7/xxlarge8776.gif" alt="ap" align="MIDDLE" BORDER="0"> 64%) has been obtained at 525 ° C, with a propene to oxygen ratio of 26, on a catalyst formed by Bi48ZnO73 with a small excess of ZnO. 相似文献
2.
Miguel Martínez-Espronceda Jesús D. Trigo Santiago Led H. Gilberto Barrón-González Javier Redondo Alfonso Baquero Luis Serrano 《Computer methods and programs in biomedicine》2014
Experiences applying standards in personal health devices (PHDs) show an inherent trade-off between interoperability and costs (in terms of processing load and development time). Therefore, reducing hardware and software costs as well as time-to-market is crucial for standards adoption. The ISO/IEEE11073 PHD family of standards (also referred to as X73PHD) provides interoperable communication between PHDs and aggregators. Nevertheless, the responsibility of achieving inexpensive implementations of X73PHD in limited resource microcontrollers falls directly on the developer. Hence, the authors previously presented a methodology based on patterns to implement X73-compliant PHDs into devices with low-voltage low-power constraints. That version was based on multitasking, which required additional features and resources. This paper therefore presents an event-driven evolution of the patterns-based methodology for cost-effective development of standardized PHDs. The results of comparing between the two versions showed that the mean values of decrease in memory consumption and cycles of latency are 11.59% and 45.95%, respectively. In addition, several enhancements in terms of cost-effectiveness and development time can be derived from the new version of the methodology. Therefore, the new approach could help in producing cost-effective X73-compliant PHDs, which in turn could foster the adoption of standards. 相似文献
3.
The influence of externally located platinum on the isothermal stability of 73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al2O3 scales formed at high temperatures has been examined. It has been observed that a nickel-base alloy forms an external scale of 73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al2O3 during oxidation at 1200°C, but this scale breaks down isothermally, enabling a faster-growing Cr2O3-rich scale to develop. However, in the presence of platinum metal alongside the specimen in the furnace hot zone, the breakdown of the 73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al2O3 scale is postponed for a substantial period of time. It appears that platinum, as the volatile species PtO2, is incorporated into the growing 73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al2O3 scale where it either influences the stress relief mechanism at temperature or reduces oxidation growth stress generation and thus significantly enhances the isothermal stability of the scale. 相似文献
4.
5.
基于无线数据传输的钢丝绳张力监测系统 总被引:3,自引:0,他引:3
介绍了一种用PICl6C73单片机控制的钢丝绳张力监测系统,由于矿井提升机工作环境的特殊性,检测的数据需要进行无线传输。给出了控制系统组成和工作原理.重点介绍了发送系统控制部分,给出了设计流程。该系统实现了低压无电缆线环境下的压力监测,提高了信号传输的可靠性和灵活性。它只需更换传感器和修改控制软件,就可以扩展到其他监控系统中。 相似文献
6.
针对国产7050高强铝合金铆钉丝材,采用室温拉伸、室温剪切、镦粗试验的方法,研究了经177~182℃不同二级时效时间后7050铝合金丝材的性能。利用扫描电镜(SEM)、透射电镜(TEM)观察合金不同时效工艺下断口组织和析出相形貌特征。结果表明,拉伸强度和剪切强度随二级时效温度的升高、二级时效时间的延长逐渐降低,剪切强度低于330 MPa时镦粗试样不开裂。TEM微观组织显示,随二级时效温度的升高、时间的延长析出相形貌变化不大,但析出相的尺寸随时效温度的升高逐渐长大、间距逐渐增大;拉伸断口形貌显示,二级时效的断裂方式均为韧窝断裂和沿晶断裂的混合断裂模式,随二级时效温度的升高和保温时间的延长,断口中韧窝数量逐渐增加且尺寸变大,沿晶断裂逐渐减少。 相似文献
7.
针对G73循环切削指令在生产和教学应用中存在的由于程序编辑时参数选择不合适造成的首次过切、首次空刀等问题,采用数学分析方法对相关要素单一分析,筛选出各单一要素的控制方法;通过对车削复合循环指令G73使用过程中单一要素的控制的分析与应用,阐述G73的使用方法,解决G73在使用中遇到的一些难题. 相似文献
8.
E.F. Riebling 《Materials Research Bulletin》1975,10(11):1135-1142
The molar volumes of MO/Bi2O3/2 GeO2 glasses () vary directly with cation volume and inversely with cation field strength. Small needles of ZnBi2Ge2O8 (up to 0.75 mm) & SrBi2Ge2O8 (up to 0.20 mm) can form during slow cooling of the parent melts. Al2O3 (or Ga2O3) additions expand these glasses by introducing AlO4 Tetrahedra. Precipitation of spinel-like arrays from such molten polyhedral jumbles requires more Al2O3 (or Ga2O3) with larger cations for solubility reasons. This is confirmed by the nuclei concentrations. 相似文献
9.
Genetically modified (GM) canola is the most widely grown oilseed crop in Canada. At this time, commercially produced GM canola cultivars in Canada have the events GT73/RT73 and Ms8xRf3. Commercial seed sale of canola cultivars containing the GM events such as OXY235 and T45 has been discontinued. Adventitious presence of GM seeds and grains in non-GM grains is a concern for international grain trade, and development of effective detection methods is important. A multiplex qualitative PCR procedure was established for the detection of the GM canola events OXY235, Ms8xRf3, T45 and GT73. The presence of the GM canola events was also successfully detected in ground spiked wheat and barley grain samples prepared at 0.1%, 0.5% and 1.0% levels (w/w). The GT73 real-time PCR assay was successfully used to quantify DNA extracted from spiked ground canola samples consisting of 5%, 1%, 0.5% and 0.1% GT73 (w/w). 相似文献
10.