Effect of long-term grazing on soil organic carbon content in semiarid steppes in Inner Mongolia

To clarify the response of soil organic carbon (SOC) content to season-long grazing in the semiarid typical steppes of Inner Mongolia, we examined the aboveground biomass and SOC in both grazing (G-site) and no grazing (NG-site) sites in two typical steppes dominated by Leymus chinensis and Stipa grandis, as well as one seriously degraded L. chinensis grassland dominated by Artemisia frigida. The NG-sites had been fenced for 20 years in L. chinensis and S. grandis grasslands and for 10 years in A. frigida grassland. Above-ground biomass at G-sites was 21-35% of that at NG-sites in L. chinensis and S. grandis grasslands. The SOC, however, showed no significant difference between G-site and NG-site in both grasslands. In the NG-sites, aboveground biomass was significantly lower in A. frigida grassland than in the other two grasslands. The SOC in A. frigida grassland was about 70% of that in L. chinensis grassland. In A. frigida grassland, aboveground biomass in the G-site was 68-82% of that in the NG-site, whereas SOC was significantly lower in the G-site than in the NG-site. Grazing elevated the surface soil pH in L. chinensis and A. frigida communities. A spatial heterogeneity in SOC and pH in the topsoil was not detected the G-site within the minimal sampling distance of 10 m. The results suggested that compensatory growth may account for the relative stability of SOC in G-sites in typical steppes. The SOC was sensitive to heavy grazing and difficult to recover after a significant decline caused by overgrazing in semiarid steppes.

领导行为的复杂性、角色结构及其有效性研究

As the social and organizational environment become more and more complex, the topic of leadership complexity is gaining more and more attention. So far, some critical issues in this field need further exploration, such as clarifying the theoretical framework, developing and validating the measurments and exploring the mechanism of the its effectiveness. Using BEI(Behavioral Event Interview), content analysis and EFA/CFA, ANOVA, regression analysis and other qualitative/quantitative methods, this research explored the leadership structure of Chinese enterprise managers, developed a new leadership questionnaire, investigated the differences of the leadership roles among various managerial areas and on different hirachical levels, and examined the impacts of the leadership roles and leadership complexity on different indicators of leadership effectiveness in various organizational contexts. 1,020 managers were surveyed. The followings are the main findings： First，the structure of leadership behaviors of Chinese enterprise managers included ethical model, authoritarian, producer, director, monitor, mentor, strategist, enterpriser, among which ethical model and authoritarian are the new findings in Chinese cultural context. Ethical model was characterized by presenting honesty, setting an example to others, being just and diligent. Authoritarian was characterized by showing power and arbitrariness. In addition, mentor, strategist and enterpriser incarnated some cultural features of present China. The new developed leadership questionnaire’s reliability and validity reached the criterion of standardized measurement. Second, there were significant differences of frequency of leadership behaviors among the managers at different managerial postions and hirachical levels, while the impacts of different leadership roles on different leadership effectiveness indicators were also singnificantly different. Ethical model had positive impacts on the whole performance and three indicators across task and context performance, and authoritarian’s impacts on the whole performance and department performance were negatively significant. Third, the impact of leadership complexity on the whole leadership effectiveness was positively significant, while the moderating effects of organization level and position function was not significant.

交易型领导的结构和作用机制研究

The Multifactor Leadership theory developed by Bass (1985) has become the new paradigm of leadership research. The empirical results of the effectiveness of transformational and transactional leadership in the literature, however, are not consentient. Researchers in China found the different structure of transformational leadership, but have not developed the transactional leadership. This study attempts to investigate three key questions in the unique Chinese socio-economic context: 1) what is the structure of transactional leadership in China? 2) What are the differences between western countries and China? And 3) what is the relationship between the transformational and transactional leadership mechanism? This study examines data collected from 3,500 participants, using Explored Factor Analysis (EFA), Confirmed Factor Analysis (CFA), Hierarchical Regression Analyses, partial correlations and other statistics methods. The major finings are listed as follows： Firstly, inductive methods was used to explore the structure of transactional leadership and the result show that transactional leadership is a four dimensions structure which includes contingent reward, contingent punishment , process control and anticipated investment. Reliability analysis, item analysis, EFA and CFA show the reliability and validity of the transactional leadership questionnaire we designed is good enough, the design of the item is effectively and properly. Contrast to other researches, anticipated investment emphasis on the leader’s recessive investment for subordinate, and this kind of transaction is quite special under the Chinese culture. While the content of the contingent reward with the contingent punishment is wider than the contingent reward in the western country, and the process control is wider than the management by exception and including goal setting and the management during the process. Secondly, hierarchical regression analyses showed that transformational and transactional leadership were significant positively related with in-role performance, extra-role performance, satisfaction and leadership effectiveness while negatively related to intention to leave. The effects of transactional and transformational leadership are different. Transactional leadership could significantly predict intention to leave controlling for transformational leadership, while transformational leadership could significantly predict in-role performance, extra-role performance, satisfaction and leadership effectiveness controlling for transactional leadership. Thirdly, the income level and the rank of subordinates are the moderators between the transformational, transactional leadership and leadership effectiveness. The leadership effectiveness of transactional leadership would decrease as the rank of subordinates increased, while the leadership effectiveness of transformational leadership would increase as the rank of subordinates increased. Transactional leadership is positively related to the effectiveness when the level of the subordinate income is low, but negatively related to the effectiveness when the level of the subordinate income is high. However the income level of the subordinate could not influence the leadership effectiveness of transformational leadership.

Post-grafting preparation of large-pore mesoporous materials with localized high content titanium doping

A new post-grafting process, consisting of two steps of substrate preparation and sol - gel post-grafting, has been developed to prepare titanium-doped mesoporous SBA-15 material with a double-layered structure and locally concentrated titanium content at the inner pore surface. With this novel technique, the single phased and originally ordered mesostructures can be well conserved; in the conventional direct synthesis they can be partially damaged when the frameworks are doped with high content heteroatoms. Titanium species exist in an isolated, tetrahedral structure and are localized at the pore surface; this is beneficial to both reactant access and product release. Characterization with XRD, N-2 adsorption/desorption isotherms, HREM/ EDS, ICP, UV - Vis, and the newly developed UV - Raman spectroscopy confirm these results. Preliminary catalytic tests with the selective epoxidation of cyclohexene show good catalytic activity. Among them, sample TiSBA-15-10 with a Si : Ti molar ratio of 10 shows a TON value of 75 and a highest product ( epoxide) yield of 55%.