Design and construction of river crossing tunnel beneath Tachia River,Taiwan

Due to the impact of the 1999 Chi-Chi earthquake (ML = 7.3) and the following typhoon induced heavy rainfalls and floods, the tailrace tunnel of the Kukuan Hydropower Plant was severely blocked and must be realigned and rebuilt. The new tailrace tunnel is 1991 m long with a 140 m section passing underneath the Tachia River, where the shallowest rock cover is 3.5 m. In view of the common phenomenon that weak zone developed along river channel and debris accumulated on river bed, the ground improvement from the surface to the tunnel is difficult. Therefore, a construction shaft, a water sealing pre-grouting plan and a special supporting system were designed to prevent the potential water inflow when tunneling underneath the Tachia River. In the construction phase, adequate excavation cross sections, support elements, auxiliary treatments, and water sealing grouting methods were selected to overcome the difficult ground condition encountered. The experience learned from this successful case can be a valuable reference for the design and construction of similar river crossing tunnels in the future.     

Current states of coalbed methane and its sustainability perspectives in China

With the rapid development of China's economy in the recent years, the gap between energy supply and demand has been gradually enlarged. To solve the problem of insufficient reserves of natural gas, greenhouse effect, and safety of coal mines, coalbed methane (CBM) is considered as an effective substitute. First of all, CBM industry status is introduced, mainly including resource endowment, development status, technical conditions, and market environment. Then, the policy environment of CBM in China was summarized into 6 aspects: price policy, tax policy, financial subsidy policy, resource management policy, foreign cooperation policy, and other policies. Thirdly, through Politics, Economics, Society, and Technology analysis, Strength, Weakness, Opportunities, and Threats analysis, Politics, Economics, Society, and Technology‐Strength, Weakness, Opportunities, and Threats analysis, and Comparative Analysis, the influence of political factors, economic factors, social factors, and technological factors on CBM industry is analyzed, and the strengths, weaknesses, opportunities, and threats of CBM development are pointed out. Fourth, through the above analysis, development proposal is given from 3 aspects which include policy support, technical support, and market support. Finally, through the analysis of the industry, the related conclusions and the prospect of China's CBM are put forward.     

南宁吴圩国际机场新航站楼超大超厚分叉铸钢件安装技术

针对设计较为罕见的超大超厚分叉铸钢件,通过吊装软件模拟三维吊装,确保安装的安全性和可靠性,采取可靠的测量定位方法,严格按照对称焊接顺序保证铸钢件定位后的准确性和质量的保证性,解决了此超大超厚分叉铸钢件的施工难题。     

基于AquiferTest和FEFLOW求解水文地质参数

工程由于受地下各未知因素的影响,应用于工程计算的含水层水文地质参数与利用抽水试验及求参公式计算得出的结果有较大差距。本文利用AquiferTest软件对抽水试验结果进行模拟计算得出理想状态下区域水文地质参数,结合FEFLOW软件对小王家矿区进行了数值模拟,得出可以用于工程实际的水文地质参数,通过与实测值对比发现效果较好,模拟结果可以较好的应用于工程中的水文地质条件。     

A versatile chemical conversion synthesis of Cu2S nanotubes and the photovoltaic activities for dye-sensitized solar cell

A versatile, low-temperature, and low-cost chemical conversion synthesis has been developed to prepare copper sulfide (Cu₂S) nanotubes. The successful chemical conversion from ZnS nanotubes to Cu₂S ones profits by the large difference in solubility between ZnS and Cu₂S. The morphology, structure, and composition of the yielded products have been examined by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction measurements. We have further successfully employed the obtained Cu₂S nanotubes as counter electrodes in dye-sensitized solar cells. The light-to-electricity conversion results show that the Cu₂S nanostructures exhibit high photovoltaic conversion efficiency due to the increased surface area and the good electrocatalytical activity of Cu₂S. The present chemical route provides a simple way to synthesize Cu₂S nanotubes with a high surface area for nanodevice applications.