A Systematic Study on the Genus Aphytis Howard (Hymenoptera:Aphelinidae) from South Korea

The present paper deals with the systematic study on the genus Aphytis Howard from South Korea. Five species of Aphytis are recognized, including one new species (Aphytis albus sp. nov.) and four new records (A. diaspidis, A. japonicus, A. proclia and A. vandenboschi). A key to the female species of Aphytis from South Korea is provided. The type specimens are respectively deposited in Korea National Arboretum and the Insect Collection of Northeast Forestry University, Harbin, China.

The Stability Research for the Finite Difference Scheme of a Nonlinear Reaction-diffusion Equation

In the article, the fully discrete finite difference scheme for a type of nonlinear reaction-diffusion equation is established. Then the new function space is introduced and the stability problem for the finite difference scheme is discussed by means of variational approximation method in this function space. The approach used is of a simple characteristic in gaining the stability condition of the scheme.

Participatory and Integrated Research in Mountainous Regions of Thailand and Vietnam:Approaches and Lessons Learned

Participatory and integrated research approaches employed by a long-term Thai- Vietnamese-German collaborative research program, ‘The Uplands Program’, that address the vicious circles of resource scarcity, environmental degrada- tion and rural poverty in mountainous regions of northern Thailand and northern Vietnam are discussed in this paper. We present two examples from the Thai component of the research program to show how different disciplines and stakeholders need to cooperate at different scales to make meaningful scientific contributions towards sustainable land use and rural development in mountainous regions. The case of resource conservation in the Thai highlands shows that local and scientific knowledge, conven- tional surveys and participatory modeling can be creatively combined. Integrated research on the potential of integrating fruit trees and associated technologies into mountain farming systems suggests that natural scientists have to work alongsideeconomists and social scientists to avoid harmful effects of purely technology-driven and productivity- enhancing approaches. The success of new technologies cannot be measured solely by adoption rates and yield increases, but also needs to take into account their long-term impact on various groups of farmers and the ecological, economic and social trade-offs that they entail. Technical and institutional innovations need to go hand in hand to provide viable livelihood opportunities for smallholder farmers in mountain watersheds. The major lesson learned from the first six years of our research in the mountains of Thailand and Vietnam is that conventional and participatory approaches are not antagonistic; if scientists from various disciplines and research paradigms are open-minded, the combination of both approaches can produce meaningful results that cater for the needs of both the academic community and local stakeholders in mountain environments.

Reconciling Local and Global Agendas in Sustainable Development: Participatory Research with Indigenous Andean Communities

This paper discusses participatory research in the Andes and presents a case study in Cotacachi, Ecuador, where sustainability scientists and indigenous people seek common ground in their respective but drastically different research and social agendas. Participatory research based on Andean experiences pre-dated and inspired much of the later international movement in agriculture, health, and conservation. Andean communities have a long history in demanding that outsiders address the needs of the community as a condition for carrying out scientific or applied activities. What an Andean community, however, sees as relevant may or may not be within the rubric of ‘participatory research’ as it is practiced throughout much of the world. In fact, overzealous participatory researchers are just as bothersome as their predecessors bearing long questionnaires. More important to Andean people is an equitable relationship with researchers and developers in which exchanges of value are made. A distinction between ‘enriching’ and ‘extractive’ research is drawn. In the case of the SANREM project in Cotacachi, Ecuador, scientists carried out enriching research activities of interest to local people as a wayto generate social capital for conducting basic research which does not have an obvious, immediate local benefit. The requested research did not have a conventional participatory methodology but provided valuable products (educational opportunity, germplasm, community visualization tools, and information) to the indigenous community in exchange for time and resources to conduct research on more basic natural resource questions. We argue that in the Andean context the key to reconciling the needs of scientists and of local needs is seeking new forms of equitable collaboration which reach beyond the present and now somewhat tired discourse of ‘participation’.

Construction of a New Fractional Chaotic System and Generalized Synchronization

In this paper a new dynamic system with integer and fractional order is investigated. It is shown that determining the effect of quadratic coefficients to the systematic structure can be converted to determining that of coefficients of the linear part. Under some parametric conditions, the system can produce chaotic attractors similar as Lorenz attractor. A constructive theorem is proposed for generalized synchronization related to the fractional-order chaotic system and an application of this new system is demonstrated.

Experimental Research on Gas-Liquid Two-Phase Spiral Flow in Horizontal Pipe

In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.

Exact Solutions to Nonlinear Schr(?)dinger Equation and Higher-Order Nonlinear Schr(?)dinger Equation

We study solutions of the nonlinear Schroedinger equation （NLSE） and higher-order nonlinear Sehroedinger equation （HONLSE） with variable coefficients. By considering all the higher-order effect of HONLSE as a new dependent variable, the NLSE and HONLSE can be changed into one equation. Using the generalized Lie group reduction method （CLGRM）, the abundant solutions of NLSE and HONLSE are obtained.

Ultimate Load Capacity and Reinforcement of Circular-Hollow-Section N-Joint

Experimental research and numerical analysis were applied to study the ultimate load capacity(ULC) and reinforcement of circular-hollow-section N-joint.Four specimens were tested under static load.The ULC of each specimen was obtained and the detailed failure conditions were discussed.Based on the results, both welding a plate on the chord member and filling concrete in the chord member are effective to reinforce the N-joint, but it is suggested that these two methods should not be applied simultaneously.Mo...

Stability evaluation and protection of slope for Laosongling-Yanji Highway

The authors analyzed the engineering geological characteristics of the slope of the study area (K75+840-K76+340). Two typical cross-sections have been chosen to analyze the failure modes after the excavation of the highway. Different types of the failure modes have been calculated and analyzed. The results show that some dealing methods have been advised to ensure the stability of the slopes.

战国燕币综述

战国时期，燕国货币的品类包括刀币、布币以及圆钱三种，其中以刀币最为常见，数量也最多，圆钱次之，布币的数量最少。下面，我们将分别对这三种不同品类的燕币作一概括性说明。