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Large storage dam projects may modify geo-environmental conditions in many ways. The reservoir impoundment of the 285.5 m high Xiluodu arch dam located on the Jinsha River (China) caused large-scale canyon deformations, including significant canyon contraction and uplift movements from reservoir to downstream valley. The dam experienced subsequent tilting towards upstream and raised a safety concern of the project. A Thermo-Hydro-Mechanical (THM) mechanism is proposed for this extraordinary behavior. Due to reservoir impounding and seepage, significant temperature drops and fluid pressure increase within the underlying geothermal limestone aquifer in a synclinal basin are primary root causes. Finite element THM simulations successfully reproduce these unique deformations. Recent observations of large quantities of thermalized discharge water downstream and high pore pressure in the limestone layer provide further support for the proposed mechanism. Furthermore, refined numerical modeling is adopted to evaluate the safety of Xiluodu dam subjected to potential larger canyon contractions. We conclude that these unprecedented phenomena are dominantly the consequence of THM response to regional hydrogeological evolution following the build-up of a large reservoir. The accumulated canyon contractions at the current stage would not pose a direct threat to the dam safety, but a tripled situation may cause severe safety issues.

In this work, the same formulations of Nano-Silica/intumescent fire retardant polypropylene nanocomposites were prepared via a novel vane extruder and a tri-screw extruder, which represented elongational flow field and shearing flow field, respectively. Not only the synergistic combustion mechanisms of Kissinger method and Flynn-Wall-Ozawa method were revealed, but also the combustion effect and efficiency were compared. Both two methods proved specimens that processed by TE exhibited higher thermal stability. The smaller aggregates of physical initial Nano-Silica, the better dispersivity of aggregates in specimens that processed by VE. Such property broke the compactness degree of char layer.

In the field of polymer processing, disperse phase exhibited better dispersion and distribution performance in elongational field rather than shearing field. This property commonly brought a better functional feature for polymer composites. It could also be applied to Nano-ZnO/IFR synergetic flame retarded polypropylene/ ethylene-propylene-diene monomer composites. An experiment was designed to study the mechanism of improving flame retardant properties. In the experiment, the same formulas of composites were extruded by vane extruder (represents elongational field) and three-screw extruder (represents shearing field). Then Kissinger method and Flynn-Wall-Ozawa method were used to mutually proved that Nano-ZnO with better dispersion condition catalysed a more intense esterification of IFR in the whole thermal degradation process.

利用磁控溅射方法改变氧气含量制备了一系列NiO∶Cu/ZnO异质pn结。实验结果表明,氧含量对NiO∶Cu/ZnO异质pn结电学影响很大。相对于纯氩溅射,引入一定氧气（O2/（Ar＋O2）比例为30%）后,NiO∶Cu/ZnO异质pn结的整流特性明显得到改善。与此同时,NiO∶Cu/ZnO异质pn结的光透过率也从40%增大到80%。这可能是由于氧气的轻量引入致使NiO∶Cu/ZnO异质pn结的结晶得到改善,薄膜内缺陷减少所致。进一步提高氧气含量,直到O2/（Ar＋O2）比例至80%后,异质结的整流特性有所削弱,这可能是由于过多氧气的引入造成薄膜缺陷再次增多,进而影响到异质结的整流特性。这一结论得到了EDS、XRD、AFM和UV结果的支持。

The vane plasticating extruder (VPE) is a novel polymer processing equipment which is based upon elongational rheology. According to the basic structural analysis and movement interpretation, generation mechanism of elongational flow field was derived. Elongational effects during the controlled recovery of immiscible polymer blends, containing polystyrene (PS) matrix and linear low density polyethylene (LLDPE) as dispersed phase, were studied. The morphological results revealed the elongational effect of vane extruder. LLDPE morphology evolution was precisely predicted by a mathematical model. Elongational ratio and elongational strain via VPE were calculated separately, both of which established that the VPE does imposed elongational force field on polymer blends. DOI: http://dx.doi.org/10.5755/j01.mech.23.6.19855

Effective management and evaluation of on-site supervision staffs in large hydropower project is a key method to strengthen management, improve efficiency, and ensure the progress and quality of projects. A new method based on smart phones and real-time tracking technology was developed to manage and evaluate on-site supervision staffs. The location information of supervisors at the construction site is collected and uploaded to the server by smart phones containing a GPS data uploading application. The server stores and processes the data, and displays the location and the track of staffs on the web page to achieve real-time monitoring. The collected GPS data is deeply analyzed to identify the specific work context of supervisors and to build 3 indicators: Field Work Time, Effective Work Time and Effective Work Scope which are effective indicators to measure the workload. The feasibility of the method was verified by simulation experiments. Experimental results show that the proposed method can determine the real-time position of supervisors accurately, and identify their work contexts effectively. Extracted indicators meet the realities of situation. The method possesses abroad potential in large hydropower construction management.