Enhanced electrocatalytic properties in dye-sensitized solar cell via Pt/SBA-15 composite with optimized Pt constituent.

The Low utilization and high cost of platinum counter electrode (CE) in the application of dye-sensitized solar cells has limited its large-scale manufacturing in the industry. Herein, a facile pyrolysis combination of Pt and SBA-15 molecular sieve (MS) formed 1.6-1.9 times higher amount and 2-3 times reduced dimension of Pt distributed within porous structure of SBA-15. The composite CE with 20 % of SBA-15 exhibited an enhanced power conversion efficiency of 9.31 %, exceeding that of absolute Pt CE (7.57 %). This superior performance owed to the promoted oxidation-reduction rate of I3-/I- pairs at the CE interface and the increased conductivity of CE materials attributed from well distributed Pt particles. This work has demonstrated the significance of utilizing porous molecular sieves for dispersing catalytic sites when designing a novel type of counter electrode and their application in DSSCs.

CO2 flows in the inter-regional and inter-sectoral network of the Yangtze River Economic Zone.

As a significant economic region in China, the Yangtze River Economic Zone has close spatial and sectoral linkages and generates considerable CO2 emissions. Reducing CO2 emissions in the Yangtze River Economic Zone (YREZ) while considering both inter-regional and inter-sectoral connections has become an essential issue. Based on a multi-regional input-output model and complex network theory, this study constructed a network with inter-regional and inter-sectoral CO2 emission flows in the YREZ simultaneously to reveal sectoral and spatial transfer pattern and identify the key sectors at the provincial level. The results of density, connectedness, hierarchy, and efficiency showed that the CO2 flow network was vulnerable and sensitive. The key provincial sectors were identified through different network indicators, including degree centrality, betweenness centrality, and eigenvector centrality. According to their characteristics, the 66 sectors were categorized into different communities with the roles of suppliers, receivers, and intermediaries. The findings of this study provided an integral map of CO2 emission flows in the YREZ so that the specific and comprehensive policies could be designed from sectoral and provincial level to avoid the offset of different policies.

The influence of three diphenylpyran isomer co-sensitizers with different sterical structures on N719-based dye sensitized solar cells.

Aiming to explore the relationship between the molecular structure and photovoltaic performance, three pyran isomer dyes DO, DM and DP were synthesized and applied as a co-sensitizer with N719 dye in dye-sensitized solar cells (DSCs). These sensitizers were investigated by theoretical calculation, UV-vis absorption spectroscopy and cyclic voltammetry measurement to understand their structure, optical and electrochemical properties. The DSC devices based on N719 and the co-sensitizers were characterized using I-V tests, incident photon-to-current conversion efficiency and electrochemical impedance spectroscopy measurements. As compared to the standard N719-based DSCs, the co-sensitization system of N719 and DM with the most sterical structure exhibited an enhancement of the power conversion efficiency (PCE) by 18% from 7.60% to 8.96%. Both the short-circuit photocurrent density (J sc) and open-circuit voltage (V oc) of the co-sensitized systems were increased resulting from the better maintained N719 dye loading amount on TiO2 as well as the prevention of dye aggregation. Co-sensitization of the DO molecule with less steric hindrance reduced the desorbed N719 dye amount by half leading to a decline of the photo-harvesting ability and photocurrent generation in DSCs.

A retrospective analysis of thyroid cancer in China.

BACKGROUND: Thyroid nodules are a common clinical problem that require close attention to determine the risk of malignancy. This study was designed to investigate the diagnostic values of pathological characteristics, ultrasonographically-detected calcification, and serum TSH levels in thyroid cancer in Han Chinese. METHODS: A retrospective analysis was carried out using 1,685 patients with thyroid cancer or benign nodules, who had undergone thyroidectomy between 2008 and 2009 in our hospital. RESULTS: Among the 1,685 cases, 222 had thyroid carcinomas and, of those, 113 (50.9%) developed different benign thyroid diseases. The frequency of thyroid cancer showed a progressive decrease from the younger to the older patients. The frequency of malignancy was closely related to the level of calcification, with the lowest frequency occurring in patients with no calcification and the highest in those with micro-calcification. The frequency of malignancy was also closely related to serum TSH levels, with the lowest occurring in patients with TSH levels <0.40 uIU/mL, and the highest with >1.34 uIU/mL; in addition, <4.00 uIU/mL TSH showed a progressive increase from the lower to the upper of normal range. CONCLUSIONS: Thyroid malignancies often coexist with benign thyroid disease. Age, TSH levels, and calcification of the nodules are predictors of malignancy.

A new nortriterpenoid from Rostrinucula dependens.

A new nortriterpenoid rostrinucin (1), together with five known compounds were isolated from Rostrinucula dependens. The structure of 1 was elucidated by spectroscopic evidence.