ICP-AES法测定六氟化铀中的微量钽

以TBP-萃淋树脂萃取分离基体铀,通过对发生器功率、雾化气流量、样品提升量等进行条件试验,建立了六氟化铀中杂质元素钽的ICP-AES测定方法。在取样量为250 mgU时,方法的检出限为0.60μg/gU,方法的加标回收率为86.6%~113.4%,相对标准偏差小于12%。     

B2O3-K2O-Sb2O3系统玻璃的光学折射率及带隙

高折射率和非线性光学玻璃可以用于高速光开关、光学存储器、新型光纤和光学运算元件等，其研究受到各国科技工作者的高度重视，本文采用熔融淬冷法制备了组成为(85-x)B₂O₃-15K₂O-xSb₂O₃(x=70, 75, 80, 85)的4组玻璃，测试了玻璃样品的密度、折射率、热学性能、拉曼光谱和吸收光谱，利用玻璃样品的吸收光谱计算了其直接允许光学带隙、间接允许光学带隙及Urbach能量。结果表明：随着Sb₂O₃含量的增加，玻璃样品的密度从4.445g/cm³逐渐增加到4.767g/cm³，折射率从1.9438增加到2.0058，玻璃转变温度从291℃降低到260℃，玻璃析晶温度从463℃降低到370℃，直接光学带隙从3.2775eV降低到3.1379eV，间接光学带隙从3.1444eV降低到3.0256eV，Urbach能量从0.137eV逐渐减小到0.107eV。说明Sb₂O₃-K₂O-B₂O₃系统玻璃可以作为新型的非线性光学玻璃候选材料之一。     

浅谈城镇开发边界外村庄的规划编制思路——以厦门市同安区五显镇三秀山村的规划编制为例

通过总结厦门市城镇开发边界外村庄的发展困境和规划编制不足之处,以三秀山村为例,探讨新时期乡村振兴战略背景下城镇开发边界外村庄的规划编制思路。     

高压大流量不可控探水钻孔注浆封堵技术

万福煤矿-820 m水平井底车场首次探查三灰含水层时,单孔最大出水量达到350 m~3/h。由于钻孔孔身靠近已掘巷道、岩层结构差、水压高、出水量大等原因,钻孔出水处于不可控状态,造成安全隐患。设计采用泄压注浆法来封堵高压大流量不可控探水钻孔。通过向探水孔三灰区块施工3个疏降钻孔,对高承压水进行疏导、降压,减小探水孔的水压及流量后,直接注水泥-水玻璃双液浆,实现了不可控探水孔的有效封堵,彻底消除了安全隐患。     

综采长壁工作面推进速度对优势瓦斯通道的诱导与控制作用

基于采动裂隙椭抛带理论，确定了采动优势瓦斯通道带的上、下边界，构建了采动优势瓦斯通道带的时空形态理论模型。以淮北祁南矿34下采区为原型，开展了上覆岩采动瓦斯通道扩展数值仿真研究，发现优势瓦斯通道在上覆岩的空间位置随推进速度的增加而降低，发育高度、宽度和范围随推进速度的增加而减小等特征。以此为依据，对综采工作面推进速度加快后的高位钻孔参数进行了相应调整，并在祁南矿34下2工作面开展了卸压瓦斯抽采人工导流试验，现场试验结果验证了高位钻孔参数依据推进速度而进行的优化是合理的，从而也验证了本文提出的推进速度对优势瓦斯通道的诱导与控制规律是正确的。     

M1080B无心外圆磨床改进

M1080B无心外圆磨床砂轮及导轮宽度较窄,磨削轴承套圈外圆时,磨削效率低,托板架调整较为繁琐、皮带打滑、磨损较为严重。针对上述问题,提出了相应的解决办法,提高了磨削效率。     

Robust user equilibrium model based on cumulative prospect theory under distribution-free travel time

The assumption widely used in the user equilibrium model for stochastic network was that the probability distributions of the travel time were known explicitly by travelers. However, this distribution may be unavailable in reality. By relaxing the restrictive assumption, a robust user equilibrium model based on cumulative prospect theory under distribution-free travel time was presented. In the absence of the cumulative distribution function of the travel time, the exact cumulative prospect value(CPV) for each route cannot be obtained. However, the upper and lower bounds on the CPV can be calculated by probability inequalities.Travelers were assumed to choose the routes with the best worst-case CPVs. The proposed model was formulated as a variational inequality problem and solved via a heuristic solution algorithm. A numerical example was also provided to illustrate the application of the proposed model and the efficiency of the solution algorithm.