Ag2CO3-derived Ag/g-C3N4 composite with enhanced visible-light photocatalytic activity for hydrogen production from water splitting

In this paper, Ag-based g-C₃N₄ composites have been successfully fabricated through two deferent synthetic methods: (i) a facile and efficient precipitation-calcination strategy (denoted as D–CN–xAg, x represents the dosage of Ag₂CO₃, the same below), (ii) a calcination method (denoted as Z–CN–xAg). All Ag-based g-C₃N₄ composites exhibit the enhanced photocatalytic activities under visible-light irradiation. Moreover, the optimal dosage of Ag₂CO₃ in the D–CN–xAg composite is found to be 5%, the corresponding hydrogen production capacity is 153.33 μmol g⁻¹ h⁻¹, which is 4.6 times higher than that of Z–CN–5%Ag composite. This might be attributed to appropriate content of metallic Ag and more active sites exposed on the surface of D–CN–5%Ag composite. Meanwhile, combining with photoelectrochemical results, it could be inferred that LSPR effect and the intimate interfacial between metallic Ag and g-C₃N₄ in the system play also important role for the improvement of photocatalytic activity. These results demonstrate that the appropriate loading of metallic Ag originated from Ag₂CO₃ into g-C₃N₄ could accelerate the separation and transfer of photogenerated electron-hole pairs, leading to the improvement of photocatalytic activity for hydrogen production from water splitting. Finally, a possible photocatalytic mechanism is proposed.     

港澳城市水土保持管理模式分析

城市水土流失的日益严重对城市水土保持管理提出了更高的要求,该文研究了香港、澳门的城市水土保持管理模式,并将其与内地城市水土保持管理模式进行对比,指出了内地城市水土保持管理的优势及有待加强的部分,以期为内地水土保持管理的改进提供参考。     

广东珠江流域建设节水减污型城市的对策

介绍了珠江三角洲属于水质型缺水和资源缺水城市的情况，提出建设节水减污型城市、确保水资源可持续利用应采取的基本对策及关键技术。     

猎德污水处理厂化学除磷设施的改造

猎德污水处理厂为适应《城镇污水处理厂污染物排放标准》（GB18918-2002）对磷排放指标的严格要求以及方便全厂的生产运行管理，对化学除磷设施进行了全面改造，新建了1套液态硫酸铝投加装置，重新设计了投加点，控制系统采用手动和PLC自动控制两种方式。改造后出水总磷可以稳定达到GB18918-2002的一级B标准，但污泥产量明显增加。     

猎德污水处理厂UNITANK工艺的运行效果

广州市猎德污水处理厂二期工程采用UNITANK处理工艺,一年多的运行实践表明,UNITANK工艺在进水浓度较低的大型城市污水处理厂的应用是可行的,关键在于找到适合于实际生产的工艺控制参数和运行模式.     

催化型活性炭除臭系统对污水泵站臭气的净化效果

采用催化型活性炭除臭装置对污水泵站产生的臭气进行净化。结果表明，催化型活性炭除臭系统对泵站的主要恶臭污染物H2S和NH3的平均去除率分别为97．9％和86．7％，对臭气浓度的平均去除率为87．4％；厂界的H2S及NH3浓度均可达到《城镇污水处理厂污染物排放标准》（GB18918-2002）的要求，反冲洗再生频率、压降和气体停留时间是影响除臭效果的主要因素。     

Determinates of EIS acceptance

The large number of organizations developing executive information systems (EISs) highlights the importance of understanding why executives use these systems. This survey investigated how ease of use, the number of features, and support staff characteristics are related to EIS acceptance. Acceptance was measured by the percentage of the targeted users who incorporate the EIS into their daily routine. High usage was not associated with ease of use, a large number of features, or the staff being physically close to the users. However, rapid development time was positively correlated with acceptance. Higher numbers of available features were associated with larger support staffs and larger user groups. The number of users was positively correlated with both staff size and EIS age. Existing EISs place a stronger emphasis on reporting internal rather than external data.     

Creep behavior of copper at intermediate temperatures—II. Surface microstructural observations

Detailed microstructural observations reveal the formation of three types of slip features during creep of copper at intermediate temperatures between 0.46–0.72 T_m, where T_m is the absolute melting point. Single slip occurs at the higher temperatures and lower stresses with the slip lines being inhomogeneously distributed among the grains at the lower strains. Complex wavy slip features are observed at the higher temperatures, higher stresses and with increasing strains, thereby suggesting that cross-slip mechanisms may be important under these conditions. The absence of these slip patterns at the lower temperatures and higher stresses, when mainly multiple slip morphologies are observed, suggests that cross-slip mechanisms are likely to control the creep of polycrystalline copper only in a limited range of stresses and temperatures.