Characteristics,Current Status and Strategy on Exploitation of Agricultural Natural Resources in China

This paper formulated the present characteristics, current status and the problems of agricultural natural China. Measures of preservation and strategy about exploitation of agricultural natural resources were put forward, provide a scientific basis for the government to make policies .

Energy-efficient methods for production methane from natural gas hydrates

Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the aspects of energy efficiency. Different exploiting methods and different types of hydrate reservoir were selected to study their effects on energy efficiencies. Both laboratory studies and field tests have shown that the improved technologies can help to increase efficiency for gas hydrate exploitation. And it also showed the trend that gas hydrate exploitation started to change from permafrost to marine. Energy efficiency ratio （EER） and energy return on energy invested （EROI） were introduced as an indicator of efficiency for natural gas hydrate exploitation. An energy-efficient hydrate production process, called ＂Hydrate Chain Energy System （HCES）＂, including treatment of flue gas, replacement of CH4 with CO2, separation of CO2 from CH4, and storage and transportation of CH4 in hydrate form, was proposed for future natural gas hydrate exploitation. In the meanwhile, some problems, such as mechanism of C02 replacement, mechanism of CO2 separation, CH4 storage and transportation are also needed to be solved for increasing the energy efficiency of gas hydrate exploitation.

Study on fish life history traits and variation in the Taiwan Strait and its adjacent waters

Large portions of the world＇s fishery resources are overexploited. Life history traits of fish species are important indicators to reveal different life history strategies and to indicate population responses to fishing pressures. For this study, empirical data on fishing grounds located in the coastal area between Fujian Coast and Taiwan Island were collected. These areas have experienced severe overfishing in the past 30 years, leading to changes in the structure and function of the fish communities. Fifty-one commercial fish species in this fishing ground were selected to study the life history traits. Using the life history traits, all the species were grouped into five different life history strategies by principle component analysis. More than 60% of the species were categorized in Group 5 that was similar to r-strategists. Twenty-five commercial species were selected for further analysis of changes in life history variables, and to discuss the population responses to exploitation. Results showed that most of the species appeared to become smaller size, shorter life, earlier maturation and faster growing under long-term exploitation. The exploitation rate of each species was also calculated to further discuss the impacts of fishing pressures to fish populations. Four species were found with the severest changes on life history traits indicating some of the species might be more susceptible to exploitation. This study on fish life history traits and their long-term variations under fishing pressures could provide important scientific implications for fishery management and conservation.

Meta-synthesis management framework of a complex project： A case study of the deck pavement project of the Hong Kong-Zhuhai-Macao Bridge

Innovative technology and deep uncertainty during the design and construction process of complex projects introduce great challenges to their organization and management.The traditional methods,represented in the project management body of knowledge(PMBOK)guide,can solve systematic problems;however,they cannot solve complex problems.Based on the management practice implemented in the deck pavement project of the Hong Kong-Zhuhai-Macao Bridge(HZMB),in this work,we propose a meta-synthesis management framework for a complex project from the perspective of the science of complexity.The method deems that the complexity of the project has the characteristic of being multi-scale both in the design phase and the construction phase.These problems can be classified into different categories,each of which requires a different strategy.As a result,it is first necessary to adopt the"exploration"strategy to reduce project complexity and to transform the deep uncertainty problems into systematic problems.Then,the"exploitation"strategy should be used to apply the PMBOK and other traditional methods to achieve the design and construction goals of the project and to improve its efficiency.More specifically,in the design phase of a complex project,the"innovative integration"process is used for the exploration of the new engineering technology and knowledge;then,the"functional integration"process is employed to define the system architecture,the interface relationship,the technical index,and other functions.In the construction phase,the"adaptive integration"process is used for the construction of the engineering organization system;next,the"efficient integration"process is employed to improve the actual construction performance.The meta-synthesis management framework proposed in this work reveals the multi-scale principle of solving complex problems in the management practice of a complex project,and develops the methodology of metasynthesis.