10kV配电线路杆塔接地装置冲击特性研究

分析10kV配电线路杆塔接地装置的冲击接地电阻特性对于提高配网的供电可靠性起着十分重要的作用。本文采用了考虑土壤火花放电的时域传输线优化模型计算接地装置计算分段导体的电气参数,并建立PSCAD仿真土壤火花效应的等效计算模型：通过对10kV配电线路的水平一垂直型和方格放射型两种常见的接地装置在经过雷电流时．冲击电阻随土壤电阻率,雷电流幅值以及接地装置埋深大小变化的关系,提出在10kV配电线路中根据地质条件、雷电参数和技术经济要求选择合适的接地装置。     

高温-超压-高CO2背景下致密砂岩储层成岩作用特征——以莺歌海盆地LD10区新近系梅山组-黄流组为例

利用薄片鉴定、扫描电镜、阴极发光及碳氧同位素分析等手段,对莺歌海盆地LD10区新近系梅山组-黄流组高温-超压-高CO₂背景下的储层成岩作用特征及其对孔隙的影响进行了系统研究。研究结果表明: ①莺歌海盆地LD10区新近系梅山组-黄流组储层发育重力流沉积,岩性以中-细粒长石岩屑石英砂岩为主,储层物性以特低-低孔、特低渗特征为主。②压实、胶结和溶蚀作用是研究区主要的成岩作用类型。超压对黏土矿物的转化及石英次生加大具有明显抑制作用,并在一定程度上保护了原生孔隙。富含CO₂的高温流体不仅造成了黏土矿物的异常转化,同时促进了溶蚀作用发生,增加了次生孔隙。③研究区黄二段储层的成岩演化序列为: 菱铁矿胶结→石英次生加大→绿泥石胶结→长石淋滤溶蚀→高岭石形成→早期方解石胶结→早期白云石胶结→长石溶蚀→方解石溶蚀→伊利石大量生成→晚期铁方解石、铁白云石形成。④总体上,压实作用使孔隙度减少了45.30%～62.93%,胶结作用使孔隙度减少了1.65%～35.01%,溶蚀作用使孔隙度增加了0.72%～8.00%。其中,黄流组中下部砂岩储层受到了超压保护和CO₂溶蚀作用的双重影响,物性较好,钻井过程中应考虑高CO₂风险。     

Phase evolution,crystal structure,and microwave dielectric properties of gillespite-type ceramics

A gillespite-structured MCuSi₄O₁₀ (M = Ba_1-xSr_x, Sr_1-xCa_x) ceramics with tetrahedral structure (P4/ncc) were prepared by solid-state reaction method. X-ray diffraction and thermogravimetry with differential scanning calorimetry (TG-DSC) were employed to study the phase synthesis process of BaCuSi₄O₁₀. Pure BaCuSi₄O₁₀ phase was obtained at 1075°C and decomposed into BaSiO₃, BaCuSi₂O₆, and SiO₂ when calcined at 1200°C. The relationships between the crystal structure and microwave dielectric properties of MCuSi₄O₁₀ ceramics were revealed based on the Rietveld refinement and P-V-L complex chemical bond theory. The dielectric constant (ε_r) decreased linearly with decreasing total bond susceptibility and ionic polarizability. Quality factor (Q × f) was closely dependent on bond strength and lattice energy. The temperature coefficient of resonant frequency (τ_f) was controlled by the stability of [CuO₄]⁶⁻ plane in MCuSi₄O₁₀. Optimum microwave dielectric properties were obtained for SrCuSi₄O₁₀ when sintered at 1100°C for 3 hours with a ε_r of 5.59, a Q × f value of 82 252 GHz, and a τ_f of −41.34 ppm/°C. Thus, SrCuSi₄O₁₀ is a good candidate for millimeter-wave devices.     

Trans-10 18:1 in ruminant meats: A review

Trans (t) fatty acids (TFA) from partially hydrogenated vegetable oils (i.e., industrial trans) have been phased out of foods in many countries due to their promotion of cardiovascular disease. This leaves ruminant-derived foods as the main source of TFA. Unlike industrial TFA where catalytic hydrogenation yields a broad distribution of isomers, ruminant TFA are enzymatically derived and can result in enrichment of specific isomers. Comparisons between industrial and ruminant TFA have often exonerated ruminant TFA due to their lack or at times positive effects on health. At extremes, however, ruminant-sourced foods can have either high levels of t10- or t11-18:1, and when considering enriched sources, t10-18:1 has properties similar to industrial TFA, whereas t11-18:1 can be converted to an isomer of conjugated linoleic acid (cis(c)9,t11-conjugated linoleic acid), both of which have potential positive health effects. Increased t10-18:1 in meat-producing ruminants has not been associated with negative effects on live animal production or meat quality. As such, reducing t10-18:1 has not been of immediate concern to ruminant meat producers, as there have been no economic consequences for its enrichment; nevertheless at high levels, it can compromise the nutritional quality of beef and lamb. In anticipation that regulations regarding TFA may focus more on t10-18:1 in beef and lamb, the present review will cover its production, analysis, biological effects, strategies for manipulation, and regulatory policy.     

机械合金化PM304粉末的烧结特性

采用高能球磨方法制备了PM304复合粉末。研究了纳米PM304粉末的真空烧结致密化和显微组织演化现象，并与未球磨粉末的烧结试样进行了比较。结果表明，提高烧结温度和延长烧结时间有利于提高相对密度，同时组织长大。1100℃，2h是最佳烧结工艺。机械合金化导致粉末纳米化，使真空烧结后的显微组织结构明显细化，使试样的相对密度和抗拉强度比未球磨粉末烧结后的试样有显著提高。     

Creep behavior and microstructure evolution of directionally solidified superalloy IC 10 at high temperature

The creep behavior of directionally solidified （DS） superalloy IC 10 was investigated under 192 MPa and 218 MPa at 980 ℃. Under the testing conditions, the marked creep characteristic of the superalloy is that the creep curve has a short primary and secondary stage and a long tertiary stage. Another creep characteristic is that the superalloy has excellent plasticity at high temperature. To study the creep behavior, the microstructure was observed by SEM and TEM. Different from other microstructure of Ni-base superalloys, superalloy IC10 forms incompletely rafted γ＇ phase during the creep processes. To understand the creep deformation mechanism of superalloy IC10, the movement of dislocations was analyzed. The results show that the dislocations moving in the γ matrix and climbing over the γ＇ precipitates is the main deformation mechanism under the experimental conditions.     

Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15合金的非晶和晶态薄带吸氢行为研究

研究两种不同成分具有较大过冷液相区的四元合金Zr65Al7.5Ni10Cu17.5和Zr65Al10Ni10Cu15，非晶和晶态薄带吸氢行为，结果表qt两种薄带的吸氢量均随着温度的升高而增大，非晶薄带的吸氢量要小于同等条件下的晶态薄带的吸氢量且只有在673K吸氢后形成了氢化物，Zr65Al7.5Ni10Cu17.5非晶和晶态薄带吸氢后分别生成了Zr2NiH4.7和ZrH2；而Zr65Al10Ni10Cu15非晶和晶态两种薄带最后生成的氢化物同为ZrH2。     

光通信用10 Gbit/s激光器模块及关键技术

由于芯片封装成器件后频率响应会降低,介绍了10 Gbit/s系统用的激光器和探测器的封装技术来封装芯片.通过研究发现,通过金丝电感可以补偿芯片和热沉的寄生电容,从而使封装后的器件频率响应有所改善.利用此封装技术,实现了3 dB调制带宽为10.5 GHz的TO封装激光器.并在此基础上,研发了10 Gbit/s Transponder,且此10 Gbit/s Transponder的测试性能完全满足MSA和ITU-T规范,符合应用要求.     

基于类等势场的粉末高温合金盘件等温锻造预成形设计

以体积成形工艺为例提出了一种新的预成形设计方法。通过静电场模拟选取适当的等势线作为预锻模型腔的基本形状，将选取的预成形形状通过频谱分析进行光顺处理，可以确定出六组预锻模型腔最终轮廓形状。利用有限元软件对粉末高温合金盘件两工步（预锻＋终锻）等温锻造过程进行模拟，进一步分析了相关场变量的分布，优选出预锻模型腔形状。分析表明，基于类等势场法的预成形设计和基于频谱分析的曲线曲面光顺处理方法适合体积成形工艺的预制坯设计。     

THERMAL STABILITY OF THE MECHANICALLY ALLOYED Al－10Ti NANOCRYSTALLINE ALLOY DURING CONSOLIDATION PROCESS

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