全自动陀螺经纬仪寻北技术研究

分析陀螺经纬仪工作原理,探索实现陀螺经纬仪自动化的关键技术,设计了陀螺仪数字测量单元、陀螺仪灵敏部自动升降单元、粗寻北自动控制单元,经DSP和CPLD的总体控制协调,结合全自动寻北算法方案,完成了一种与精寻北相结合的自动化寻北系统的实验装置,实现光标自动采集、仪器操作的自动化与智能化、寻北结果的计算与显示等功能,测量时间为12min时,寻北精度(1σ)为6.3";测量时间为4min时,寻北精度(1σ)为18.7".     

Preparation of monophasic titanium sub-oxides of Magnéli phase with enhanced thermoelectric performance

Titanium sub-oxides of Magnéli phase are considered as earth-abundant, non-toxic materials for thermoelectric application at high temperature, but very limited investigation has been reported mainly owing to the difficulty lying in obtaining monophasic material. Herein we describe a facile strategy to prepare monophasic Ti₉O₁₇ and Ti₄O₇ powder, in which the single Ti₉O₁₇ phase is obtained for the first time. After spark plasma sintering, the thermoelectric properties of monophasic Ti₉O₁₇ and Ti₄O₇ ceramics are studied comparatively. Despite the one magnitude lower electrical conductivity, Ti₉O₁₇ shows higher power factor compared with Ti₄O₇ due to the large Seebeck coefficient. Moreover, with the low electronic thermal conductivity, sub-micron scaled grain size and nano-scaled crystallographic shear plane, the Ti₉O₁₇ ceramic exhibits even lower thermal conductivity compared to Ti₄O₇, leading to a ZT of 0.16 at 764 K, which is the best thermoelectric performance among reported Magnéli phases.     

脉冲TIG焊熔宽动态过程模糊推理——神经网络控制方法

对脉冲ＴＩＧ焊工艺中焊接电流－正面熔宽动态过程提出了一种模糊神经网络控制方法，并研究了利用人工神经网络直接过程建模的控制仿真，从而回避了经典方法对过程建模控制和困难。将上述方法用于实际脉冲ＴＩＧ焊过程控制，结果表明模糊神经网络控制方案有效。     

双电层对碱矿渣胶凝材料氯离子传输的影响

描述了碱矿渣胶凝材料固液界面的双电层特性,测试分析了不同氯离子浓度及表面活性剂掺量下的Zeta电位,阐明了双电层效应对氯离子扩散和吸附的影响机理.结果表明：碱矿渣胶凝材料的Zeta电位为负值,随着氯离子浓度的增大Zeta电位绝对值减小;阳离子表面活性剂可使碱矿渣胶凝材料的Zeta电位转为正值,并提高氯离子吸附能力,减小有效氯离子扩散系数,而阴离子表面活性剂效果相反;碱矿渣胶凝材料孔隙表面双电层效应的改变可使氯离子吸附能力改变50%以上.     

Double-Lock Nanomedicines Enable Tumor-Microenvironment-Responsive Selective Antitumor Therapy

A hybrid nanocarrier for reducing the off-target adverse effects of chemotherapy via selective drug delivery to the tumor cells is reported. The model active agent, combretastatin A4 (CA4) phosphate is deposited onto the magnetite (Fe₃O₄) nanoparticles as the core, followed by lipid coating as the shell. Upon nanocarrier administration and biodistribution to the tumor site, the high level of adenosine triphosphate in the extracellular space of tumor induces the cargo release via phosphate displacement. Then, the CA4 phosphate is dephosphorylated by the alkaline phosphatase that is overexpressed at the plasma membrane of certain tumor cells, resulting in enhanced intracellular uptake of hydrophobic CA4. These sequential two-step unlocking processes enable the preferable accumulation of CA4 within tumor cells. Such approach is applicable to a wide range of chemotherapeutics and is promising for efficacy enhancement and side-effect reduction of antitumor chemotherapy.     

机械剥离法制备石墨烯及其在石墨烯／陶瓷复合材料制备中的应用

扼要介绍了石墨烯特殊的二维结构及因这种结构导致石墨烯所具有的极其优异的电学、光学和力学性质。回顾了石墨烯的研究历史以及微机械剥离法在其中所起到的重要作用,并对主要制备方法进行了简要的介绍。然后,阐述了以机械磨为剥离工具的新型机械剥离法的发展和已取得的成果。最后,对利用机械剥离法制备石墨烯／陶瓷复合材料粉体的探索进行了总结和概括。同时,展望了机械剥离法在制备石墨烯及其复合材料中的应用前景。     

引水改善平原感潮河网水质效果评估

以张家港市三大水循环体系为例,构建一维河网水动力水质数学模型,揭示了不同长江潮位与内河引水量的响应关系,不同引水量与河网水质改善效果、引水服务面积的响应关系。结果表明:随着长江高潮位的升高,内河引水量呈现线性增长趋势;当中部水系引水量达到1.4×10~7m~3时,氨氮浓度改善率达到50%以上,浓度变化指数达到0.6以上,且整体提升了1个水质类别;引水服务面积随着引水量的增大呈现线性增长趋势,而单位引水量服务面积呈现对数函数下降趋势,其中东北部水系单位引水量服务面积最大,为0.352～0.891 km~2/万m~3。     

Hierarchical under frequency load shedding scheme for inter-connected power systems

Severe disturbances in a power network can cause the system frequency to exceed the safe operating range. As the last defensive line for system emergency control, under frequency load shedding (UFLS) is an important method for preventing a wide range of frequency excursions. This paper proposes a hierarchical UFLS scheme of “centralized real-time decision-making and decentralized real-time control” for inter-connected systems. The centralized decisionlayer of the scheme takes into account the importance of the load based on the equivalent transformation of kinetic energy (KE) and potential energy (PE) in the transient energy function (TEF), while the load PE is used to determine the load shedding amount (LSA) allocation in diferent loads after faults in real-time. At the same time, the infuence of inertia loss is considered in the calculation of unbalanced power, and the decentralized control center is used to implement the one-stage UFLS process to compensate for the unbalanced power. Simulations are carried out on the modifed New England 10-generator 39-bus system and 197-bus system in China to verify the performance of the proposed scheme. The results show that, compared with other LSA allocation indicators, the proposed allocation indicators can achieve better fnadir and td. At the same time, compared with other multi-stage UFLS schemes, the proposed scheme can obtain the maximum fnadir with a smaller LSA in scenarios with high renewable energy sources (RES) penetration.