寒区引水隧洞保温层设置比选及保温效果研究

为了研究寒区引水隧洞开挖完成后保温层的设置方式及保温效果的问题,以新疆某寒区引水隧洞为依托,通过有限元数值模拟研究了引水隧洞保温层的设置方式、设计厚度参数的比选.结果表明:寒区引水隧洞保温层设置在二衬表面的效果优于设置在初衬与二衬之间的,保温层设置在二衬表面;随着保温层、衬砌厚度增加,对应围岩的温度逐渐升高,厚度与温度呈线性相关.该研究结果可以提高引水隧洞的保温效果,同时节约材料成本,可为相关工程设计提供参考.     

Plasmonic coupling-enhanced in situ photothermal nanoreactor with shape selective catalysis for C-C coupling reaction

Carbon-carbon (C-C) coupling reactions represent one of the most powerful tools for the synthesis of complex natural products, bioactive molecules developed as drugs and agrochemicals. In this work, a multifunctional nanoreactor for C-C coupling reaction was successfully fabricated via encapsulating the core-shell Cu@Ni nanocubes into ZIF-8 (Cu@Ni@ZIF-8). In this nanoreactor, Ni shell of the core-shell Cu@Ni nanocubes was the catalytical active center, and Cu core was in situ heating source for the catalyst by absorbing the visible light. Moreover, benefiting from the plasmonic resonance effect between Cu@Ni nanocubes encapsulated in ZIF-8, the absorption range of nanoreactor was widened and the utilization rate of visible light was enhanced. Most importantly, the microporous structure of ZIF-8 provided shape-selective of reactant. This composite was used for the highly shape-selective and stable photocatalysed C-C coupling reaction of boric acid under visible light irradiation. After five cycles, the nanoreactor still remained high catalytical activity. This Cu@Ni@ZIF-8 nanoreactor opens a way for photocatalytic C-C coupling reactions with shape-selectivity.

     

论如何提高学校的市场竞争力

论述了中国加入WTO后,教育系统应完善制度,建立相应激励机制,提高学校的市场竞争力-校长要有市场竞争意识,教师队伍应有竞争实力,学校以质量求生存,求发展,走教研兴校,特色兴校之路.     

全尾砂结构流体胶结充填的理论与实践

随着对矿产资源不可再生性的认识加深及环境保护要求的日趋严格,全尾砂充填在金属矿山的应用越来越普遍。论述了国内外全尾砂充填现状,提出了全尾砂结构流体充填方法。在实验室试验的基础上,进行了全尾砂结构流体流变参数的测定及输送性能的理论分析计算。结合矿山充填实践,介绍了该种充填方式的工艺流程及其应用效果。     

宽厚煤柱煤岩体流变力学特性试验研究

煤柱煤岩体的流变试验是确定煤柱长期强度的基础 ,也是评价煤柱长期稳定性的重要依据。本次试验以兴隆庄煤矿的深部宽厚煤柱为研究对象 ,详细分析了煤岩体的蠕变特征、长期强度、破坏特征 ,以及煤岩体结构和围压等因素对流变特性的影响     

尖山铁矿矿体地质特征新认识及找矿方向

尖山铁矿床产于下元古界尖山群袁家村组含铁岩系中，矿体受尖山向斜构造控制，同时断裂构造对矿亦有较大的影响，使主矿体向下延伸和错移。     

A novel multi-electrode system for electrolytic and biological water treatments: electric charge transfer and application to denitrification

A novel multi-electrode system is proposed for electrolytic and biological water treatments. The multi-electrode system is comprised of multiple working electrodes and their counter electrode, where electric current or potential applied to each electrode is controlled independently. Experimental result for different electrolyte solutions showed that electric charge in the system was efficiently carried by dissociative electrolytes such as carbonate ions. This transfer mechanism is regarded as being effective both in keeping pH level around neutrality and in passing certain amounts of electric current especially in dilute solutions such as groundwater and surface water. A long-term (over 500 days) experiment also showed the enhanced and stable denitrification performance of biofilm-electrode reactor (BER) equipped with the multi-electrode system, comparing to former BERs. This superior performance was thought to be attributable to large effective surface area of electrode, the charge transfer mechanism by dissociative electrolyte, and the formation of highly reducing (or oxidizing) zones. From these results, we conclude that the multi-electrode system is useful for electrolytic and biological treatments of groundwater and surface water.     

Determination of labile and strongly bound metals in lake water

Differential pulse anodic stripping voltammetry is applied to differentiate and determine the labile and strongly bound forms of Zn, Cd, Pb and Cu in lake water without preconcentration of the sample. The sensitivities as established for an oxidation peak current of 0·020 μA are: 0·2 ppb for Zn. 0·4 ppb Cd. 0·7 ppb Pb and 0·5 ppb for Cu. For the analysis of a lake water containing 5·0–24·5 ppb of the four metals, the relative S.D. ranged from 1·6 to 10 per cent. Interferences of cations and anions and the choice of a buffer system have been discussed. The method has been applied to study a number of small lakes in the Sudbury area. Ontario.     

Fluid filling of a membrane tube with self-weight

The filling of a membrane tube with self-weight by a fluid is studied theoretically for the first time. The fundamental problem depends on two non-dimensional parameters, $\beta$ and $\gamma$ which represent the importance of internal pressure and membrane self-weight respectively. The nonlinear equations are solved by an efficient numerical integration method. It is found that membrane self-weight has considerable effect on the tube geometry and the tension of the membrane at low filling pressures.     

带热水供应的家用空调器的探讨

针对余热回收技术在国内外的研究和应用状况，分析了夏季家用空调器和热水器运行存在的弊端，提出了将两者合二为一的新系统，并分析了该系统的意义。详细阐述了新设备运行的原理及三种工作模式，以及与常规系统比较所具备的特点。同时，本文对于该系统的今后应用，提出了几个应注意的问题。