Probability-based location anonymity algorithm

As one of the most effective location privacy preservation technologies, the k-anonymity model provides safeguards for location privacy of the mobile client against vulnerabilities for abuse by constructing an anonymous area of k users including the protected one. However, most existing k-anonymity models only utilize the users who are sending requests at recent time. If there are not enough requesting users, the generated anonymous area of the k-anonymity model will be larger than expected. In this paper, a Probability-based Location Anonymity (PLA) algorithm is proposed for protecting location privacy of the mobile users in a road network. The PLA model takes advantage of the historical path track of the users who are not sending the request currently, and then computes the probability into the anonymous section so that it can greatly reduce the size of the anonymous area. Experimental results show that the PLA algorithm is superior to the k-anonymity and it increases its anonymous efficiency enormously.     

Ca2+对悬浮培养HEK293细胞的细胞团形成、细胞生长和代谢的影响

利用HEK293细胞在悬浮培养中具有聚集成团的体外培养特性,在250ml的Bellco的搅拌培养体系中,以细胞团粒径、细胞粒径、细胞数、细胞活力、葡萄糖比消耗速率 (qglc)、乳酸比生产速率 (qlac) 和乳酸对葡萄糖得率 (Ylac/glc) 为观察指标,考察了HEK293细胞在Ca2 浓度设置为0μmol/L、250μmol/L、500μmol/L、750μmol/L和1000μmol/L的搅拌培养体系中的细胞团形成、细胞生长和代谢.实验发现:培养基中的Ca2 浓度决定着HEK293细胞在悬浮培养中能否形成细胞团并影响着细胞团的粒径分布和细胞团内细胞相互连接的紧密程度;在250～1000μmol/L的Ca2 浓度范围内,HEK293细胞团的平均粒径与培养基中的Ca2 浓度成正比;Ca2 浓度对以细胞团的形式悬浮培养的HEK293细胞的生长和代谢无明显的影响.实验结果提示,Ca2 浓度是调节HEK293细胞团粒径分布、维持悬浮细胞团中HEK293细胞正常生长和代谢的有效控制参数.     

Ti-Al-B系统自燃烧合成TiB_2的研究

本文较系统地研究了Ti、B以及Al粉末混合自燃烧合成TiB_2/Al体系,探讨了在Al基中TiB_2粒子的形成机理,讨论了Al、B元素、合成温度以及含H体系对Ti-Al-B系反应产物相组成的影响。结果表明,Ti-Al-B系燃烧合成TiB_2的最佳温度为≥900℃;合成产物的相组成主要取决于Ti和B在反应物中的比例,并且受处理工艺的影响;Al和H的存在可以延缓TiB_2合成反应;TiB_2粒子的平均粒度主要取决于Al在反应物中的比例,一般地,TiB_2粒子的大小在0.5～5μm的范围内。     

An Optimized Combination of Mine Water Control,Treatment, Utilization,and Reinjection for Environmentally Sustainable Mining: A Case Study

This paper presents a case study of an optimized combination of mine water control, treatment, utilization and reinjection to achieve the zero discharge of mine water. Mine water has been considered a hazard and pollution source during underground mining, so most mining enterprises directly discharge mine water to the surface after simple treatment, resulting in a serious waste of water. Moreover, discharging a large amount of mine water can destroy the original groundwater balance and cause serious environmental problems, such as surface subsidence, water resource reduction and contamination, and adverse impacts on biodiversity. The Zhongguan iron mine is in the major groundwater source area of the Hundred Springs of Xingtai, which is an area with a high risk of potential subsidence. To optimize the balance between mining and groundwater resources, a series of engineering measures was adopted by the Zhongguan iron mine to realize mine water control, treatment, utilization, and reinjection. The installation of a closed grout curtain has greatly reduced the water yield of deep stopes in the mine; the effective sealing efficiency reaches 80%. Nanofiltration membrane separation was adopted to treat the highly mineralized mine water; the quality of the produced water meets China’s recommended class II groundwater standard. Low-grade heat energy from the mine water is collected and utilized through a water-source heat pump system. Finally, zero mine water discharge is realized through mine water reinjection. This research provides a beneficial reference for mines with similar geological and hydrogeological conditions to achieve environmentally sustainable mining.

     

MPM-700光学零件抛光平台的研制与改进

论述了用于激光陀螺仪、旋光片抛光的MPM-700光学零件抛光平台的主要结构及特点。介绍了该设备在传动方式、台面选型优化、抛光头装载结构方面较原PG-710抛光设备的技术改进;并通过运用有限元软件对该抛光平台架进行受载情况仿真,消除了抛光过程中抛光盘变形对抛光效果的影响,进而在理论和实践两个方面确定了该设备已达到设计要求。     

Synthesis and antifungal activities of glycosylated derivatives of the cyclic peptide fungicide caspofungin

Diseases caused by systemic fungal infections have become a significant clinical problem in recent decades. A series of glycosyl derivatives of the approved cyclic peptide antifungal drug caspofungin conjugated with β‐D ‐glucopyranose, β‐D ‐galactopyranose, β‐D ‐xylopyranose, β‐L ‐rhamnopyranose, β‐maltose and β‐lactose units were designed, synthesized, and evaluated as new potential antifungal drugs. The compounds were obtained by coupling the corresponding glycosyl amines to the free primary amino groups of caspofungin through a bifunctional glutaryl linker. In contrast to caspofungin, these glycosylated derivatives are soluble in water, but are not hygroscopic and moreover, are more stable than caspofungin under high humidity and temperature. CD studies showed that glycosylation has very little impact on the conformation of the cyclic peptide of caspofungin. In vitro antifungal tests against seven human pathogenic fungi revealed that the caspofungin–monosaccharide conjugates, but not the disaccharide conjugates, have increased antifungal activities against the majority of tested fungus species relative to caspofungin. The β‐D ‐glucopyranosyl derivative 2 a showed the strongest and broadest antifungal activity, providing a lead for further studies.     

R22的替代问题及其探索与研究

臭氧层破坏仍是当前国际社会面临的主要环境问题之一,《蒙特利尔议定书》再次加速了ODS物质的淘汰和禁用,本文介绍R22的一些替代研究方案及其应用情况。     

三色线阵CCD高速信号处理系统的优化设计

为提高线阵CCD测量系统的测量精度和抗干扰性能同时保证系统信号处理速度,总结并试验了几种常见的CCD信号处理方案,并提出对应优化设计。阐述了线阵CCD传感器、CCD驱动电路的工作原理,着重分析研究了CCD测量系统中的信号采样和处理过程。详述了CCD输出电压特性,分压电路、滞回比较电路工作原理和MCU采样时序。试验结果表明,相比传统使用单比较器的方案,使用多滞回比较器的设计系统精度得到大幅提升,同时抗干扰性能也得到更好的保证。该设计已应用到印刷行业的纠偏控制器中。     

我国细胞技术类再生医学创新型技术产业发展战略研究

近十年来国内外再生医学创新型医疗技术产业显示出了巨大的潜力和发展前景。本文通过查阅、整理和分析美国、欧盟成员国、日本、澳大利亚等典型发达国家在细胞技术类再生医学创新型医疗技术产业的现状和相关的政策法规、管理机制及其面临的问题,研究了我国在该技术产业的发展现状和政府的监管政策及管理机制,分析和总结了该产业的发展趋势、特点和存在的问题,提出以大力发展我国细胞技术类再生医学创新型医疗技术产业为原则,以突破产业发展的瓶颈为出发点的系列专家建议和意见。