Understanding the impact of High Speed Railway on urban innovation performance from the perspective of agglomeration externalities and network externalities

Transportation infrastructure and innovation play an important role in promoting regional economic growth. However, previous studies have mainly focused on the economic agglomeration by increased accessibility, but ignored the important on inter-city economic linkages and the network externalities it generated. Based on the externality perspective, this paper uses the propensity score matching model (PSM-DID) and spatial econometric model to analyze the heterogeneous impact of HSR opening on urban innovation performance and compare the differential effects of agglomeration externalities and network externalities on knowledge spillovers. The empirical results suggest the following: (1) The opening of HSR significantly improves urban innovation performance, but there is significant spatial heterogeneity. (2) The opening of HSR not only promotes the agglomeration of production factors to cities, but also strengthens inter-city economic connections, thus improving urban innovation performance through agglomeration externalities and network externalities. However, compared to agglomeration externalities, network externalities have a superior strength of impact on urban innovation performance. (3) From the dynamic effect perspective, the opening of HSR has a hysteresis effect on urban innovation of 2–3 years, and differences exist between cities.     

A novel intelligent approach for yaw position forecasting in wind energy systems

Yaw control systems orientate the rotor of a wind turbine into the wind direction, optimize the wind power generated by wind turbines and alleviate the mechanical stresses on a wind turbine. Regarding the advantages of yaw control systems, a k-nearest neighbor classifier (k-NN) has been developed in order to forecast the yaw position parameter at 10-min intervals in this study. Air temperature, atmosphere pressure, wind direction, wind speed, rotor speed and wind power parameters are used in 2, 3, 4, 5 and 6-dimensional input spaces. The forecasting model using Manhattan distance metric for k = 3 uncovered the most accurate performance for atmosphere pressure, wind direction, wind speed and rotor speed inputs. However, the forecasting model using Euclidean distance metric for k = 1 brought out the most inconsistent results for atmosphere pressure and wind speed inputs. As a result of multi-tupled analyses, many feasible inferences were achieved for yaw position control systems. In addition, the yaw position forecasting model developed was compared with the persistence model and it surpassed the persistence model significantly in terms of the improvement percent.     

Improved dispersibility of multi‐wall carbon nanotubes with reversible addition–fragmentation chain transfer polymer modification

A non‐covalent approach is used to modify multi‐wall carbon nanotubes (MWCNTs) via a block polymer that can be synthesized in aqueous solvent through reversible addition–fragmentation chain transfer polymerization. The block polymer consists of oligo(ethylene glycol) methyl ether acrylate and acrylic acid. The hydrophobic backbone is significantly adsorbed on hydrophobic MWCNT surfaces, which is verified using transmission electron microscopy, thermogravimetric analysis and X‐ray photoelectron spectroscopy. The coated block polymer can prevent the aggregation of MWCNTs and improve their dispersibility in water. The MWCNTs after modification are stable in water even after standing in a long‐term test. © 2015 Society of Chemical Industry     

利奈唑胺致乳酸酸中毒研究进展

利奈唑胺是噁唑烷酮类抗菌药物，用于耐甲氧西林金黄色葡萄球菌、青霉素耐药肺炎链球菌和耐万古霉素肠球菌等革兰阳性球菌引起的感染。乳酸酸中毒是利奈唑胺的不良反应之一。利奈唑胺致乳酸酸中毒的危险因素为长时间暴露、肝功能障碍、肾功能障碍、线粒体DNA A2706G多态性、合并使用影响线粒体功能的药物等。利奈唑胺引起乳酸酸中毒的症状为恶心、呕吐、嗜睡、呼吸急促、心动过速和血压下降等，可通过密切监测血乳酸、pH、血药浓度等实验室指标以早期识别。利奈唑胺引起乳酸酸中毒机制可能与线粒体毒性相关。利奈唑胺发生乳酸酸中毒可通过减少药物剂量、停药甚至体外肾脏替代治疗，必要时加强对症支持治疗。本文对此开展综述，以期为临床防治利奈唑胺致乳酸酸中毒提供思路。     

Improvement of sediment microbial fuel cell performances by design and application of power management systems

One of the ways to generate clean and non-destructive energy is to use the energy stored in the biomass resources by the microbial fuel cells (MFCs). Sediment Microbial Fuel Cells (SMFCs) are a special type of MFCs that use organic materials in aquifers sediment to generate electricity. In this research, the effects of an increase in the electrode surface are investigated. The results showed that the increase in cathode electrode surface had better efficiency than the multi-cathode mode (maximum power generated for a 3-cathode electrode (27 cm³) and 1-cathode electrode (27 cm³) was 526 mW/cm² and 800 mW/cm², respectively. Another parameter affecting the performance of these systems is temperature. In the next step, the power generation rate was measured in different step currents and at different sample times. In the final stage, a power management system (PMS) was designed to optimally utilize the output energy of the improved SMFC, leading to an increase in the output voltage to 3.3 V.     

Tuning and controlling photocatalytic performance of TiO2/kaolinite composite towards ciprofloxacin: Role of 0D/2D structural assembly

Lamellar kaolinite supported monodispersed TiO₂ was prepared through rational design and 0D/2D structural assembly, which showed significantly improved photocatalytic performance towards ciprofloxacin. After systematic evaluation, the pseudo-first-order kinetic constant rate of TiO₂/kaolinite composite can reach to 0.04549 min⁻¹, which was 6.90 and 1.81 times higher than that of pure TiO₂ and P25, respectively. The nano-TiO₂/kaolinite composite photocatalyst also displayed good reusability performance, only a slight decline occurred after four repeated experiments, which is beneficial for the large-scale application of photocatalysts. Various characterizations indicated that enhanced photocatalytic performance can be ascribed to the synergistic effect between natural kaolinite and the well distributed TiO₂, which enhanced the light absorption ability, assisted the dispersion of pure TiO₂, resulted in co-catalysis effect, improved the separation facilitation of photo-induced carriers and promoted the stronger adsorption capacity, etc. These merits effectively regulated the carriers’ lifetime and migration velocity of the photogenerated charge carriers. Considering the excellent properties of natural kaolinite (low cost, abundance, stability, etc.), our study provides a promising candidate for effective degradation of trace amounts of pharmaceutical and personal care product (PPCP) or contaminants with potential high-toxic risk.     

Self-healing and wearable conductive hydrogels with dynamic physically crosslinked structure

Traditional hydrogels are easily frozen or evaporated under colder or hotter temperatures, resulting in their performance degradation. In this paper, polyacrylic acid, sodium alginate, carbon nanotubes, water, and glycerol are used to synthesize self-healing, wearable, freezing resistance, and dry resistance conductive hydrogels with interpenetrating crosslinking network structure. The dynamic cross-linking network structure of the hydrogel can rapidly recover and restructure after damage. In addition, the conductive hydrogels exhibit excellent adhesion to various materials (including PTFE, iron, glass, plastic, and skin). Conductive hydrogel has excellent strain-electric sensing properties, and has high sensitivity, significant stability and repeatability. The conductive hydrogel can be used to test the movement of fingers and knee joints by strain sensing, and has excellent, sensitive, and stable resistance response. Therefore, the conductive hydrogel can be used as a wearable strain sensor for real-time detection of human joint movement. The hydrogel has better environmental adaptability and broad application prospects.

     

凹凸棒石黏土对Cd2+的吸附作用及影响因素

通过室内吸附实验，表明凹凸棒石黏土（凹土）对重金属离子Cd^2＋有很好的吸附作用，吸附作用受溶液pH值影响明显。增大镉离子初始浓度，有利于提高凹土对Cd^2＋吸附量，但是去除率降低。支持电解质对凹土吸附Cd^2＋也产生影响，Ca^2＋的影响比Na^＋和K^＋的大。