自持续HIRS辅助的MU-MISO系统公平性研究

针对自持续智能反射面(Intelligent Reflecting Surface,IRS)存在牺牲系统性能和实施难度大等问题,提出了一种包含被动元件和主动元件的混合IRS(Hybrid IRS,HIRS)自持续辅助多用户多输入单输出(Multi-User Multiple Input Single Output, MU-MISO)系统的公平性传输方案。为了实现多用户通信的公平,联合考虑基站的主动波束成形和HIRS系数矩阵,建立了以最大化最小用户速率为目标的优化问题。然而,由于约束条件和目标问题中存在多变量耦合,导致优化问题是非凸的。因此,将原始问题分解为2个单变量的子问题,然后利用逐次凸近似和半正定松弛方法获得每个子问题的近似解,最后利用交替优化算法迭代求解每个子问题。仿真结果表明,所提优化方案可有效提高系统的最小速率。

液晶弹性体单摆在光刺激下的自持续振动研究

液晶弹性体(LCE)在光刺激下,由于其能够直接从环境中获取能量,无须额外人为控制即可维持自持续振动的优点,被广泛用于设计光驱动的多功能机械。本研究提出一种LCE单摆在光刺激下振动的动力学模型,通过LCE纤维的收缩和伸展来达到自持续振动的目的,对此进行力学分析和理论推导。通过数值计算后发现调节参数可以得到两种振荡模式,以此控制系统物理参数,来实现主动机械不同的功能用途,拓展了LCE自持续振动的设计应用。

基于聚类的能量自持续可见光定位算法

将Kmeans聚类算法和传统的K近邻(KNN)算法相结合,提出一种适用于能量自持续室内可见光定位(VLP)系统的融合算法。该算法兼顾低复杂度和高精度,在使用Kmeans聚类算法对专门设计的指纹库进行划分实现粗定位的基础上,使用KNN定位算法进行精准定位。将所提Kmeans-KNN融合算法引入到搭建的能量自持续VLP系统,分析不同条件下系统的定位性能。结果表明,与传统KNN定位算法相比,采用Kmeans-KNN融合算法后,系统的平均定位误差位为0.141 m,定位精度明显提高,同时算法计算量减少了94.7%,系统耗能因此大幅降低,利于VLP系统高精度能量自持续定位的实现。

神经元集群自持续放电活动的层次网络仿真模型与分析方法

神经元集群的自持续放电活动是大脑内广泛存在的现象,其被证实在大脑的工作记忆与目标导向等行为中有重要体现。作者以非线性的整合发放(integrate-and-firing,IF)神经元模型为网络节点,构建了具有小世界特征的层次网络仿真模型,以研究自持续活动中神经元发放的一些特性。在合适的模型参数下,层次网络能产生自持续放电活动,其整体发放频率在撤掉外部刺激之后的20 s内比较稳定,而层次内部发放频率的高低与层次顺序无关。整体发放频率关于突触连接数量与短路径密度都呈现出先正关系增长再达到饱和的趋势,同时,规模越大的神经元网络的整体发放频率对短路径密度更为敏感。研究结果对揭示大脑神经元功能性核团之间的相互作用机制具有重要意义。

几例乌托邦式建筑实例剖析

建筑需要创造力,更需要深刻地揭示和探索更本质的东西,需要从更高角度和更广阔的视角进行乌托邦式的构想;而这些构想源于社会、科技和城市问题,源于对自然要素的体验.

A Study on the Relationships of Ecological Civilization Construction with Natural Conservation and Sustainable Resources Use

Ecological Civilization Construction and natural conservatiorl and sustain- able resources use are three aspects of same object proposed from various angles of theory and practice. The paper intends to simply deal with some problems of this aspect and to propose corresponding suggestions for related departments.

The Human Sustainable Development under Biologically Evolutionary Background

Evolution,adaptation and selection always exist in the evolutionary process of any species,which is the result of interrelation and interaction between living things and their environments,and the incarnation of natural laws in the evolutionary process of any species. Only if accurately understanding their connotation and interrelation among them,taking the evolution of living things as the line with centralizing the human sustainable development,dialectically unifying the active adaptation of the human being to their environments and oriented selection of nature and the society to species,we can acquire a better understanding of evolution of living things and a deeper understanding of the human sustainable development under biologically evolutionary background and uphold the true Darwinism,modern evolutionary point of view and the concept of current sustainable development in theory and in practice.

Discussion on Sustainable Urbanization in Tibet

After 1995, Tibet entered the stage of accelerated urbanization. The large floating population fi＇om outside Tibet has become the driving force for urban expansion and the rising of urbanization rate. After analyzing the changes of urban functions and spatial structure of urban system in Tibet, this paper argues that before 1995 the urbanization in Tibet was mainly driven by administrative function, resulting in certain population migration, whereas in the past decade economic function has become the key factor accelerating urban expansion with the market mechanism creating large-scale inflow of population. The floating population-based urbanization and high population growth in the agricultural and pastoral areas of Tibet has promoted the regional economic prosperity, but exerted resources and environmental pressure and brought some problems for Tibetan culture protection at the same time. The conflicts and contradictions between urbanization and the sustainability of natural resources, environment and social development have been intensified. Addressing these problems, this paper proposes some countermeasures for improving the sustainability of Tibetan urbanization.

An efficient methodology for utilization of K-feldspar and phosphogypsum with reduced energy consumption and CO2 emissions

The issues of reducing CO_2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO_2 with reduced CO_2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the hightemperature co-reaction significantly facilitated the reduction of phosphogypsum to SO_2 and the exchange of K^+(K-feldspar) with Ca^(2+)(CaSO_4 in phosphogypsum). The reaction parameters were systematically investigated with the highest sulfur recovery ratio of ~ 60% and K extraction ratio of ~ 87.7%. This novel methodology possesses an energy consumption reduction of ~ 28% and CO_2 emission reduction of ~ 55% comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.

Research Progress on Evaluation Frameworks of Regional Ecological Sustainability

As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.

Addressing the trade-climate change-energy nexus: China's explorations in a global governance landscape

We have arrived at a critical juncture when it comes to understanding the numerous ways in which trade interacts with climate change and energy(trade-climate-energy nexus).Trade remains crucial for the sustainable development of the world's greatest trading nation:China.After clarifying the linkages within the trade,climate change and energy nexus,this article delves into China's specific needs and interests related to trade,climate change and energy.Then it explores the ways in which trade can contribute to China's needs,to sustainable energy development and to the goals of the global climate agreement that is under negotiation.One main findings are China is a key participant in negotiations on trade liberalization of environmental technologies and services.These negotiations are in China's interests in terms of innovative industries,technological upgrading,employment and public health.China could stand up for the interests of other emerging and developing countries and serve as an example in terms of transitioning to a low-carbon economy.Beyond trade barriers issues of domestic(energy)regulation such as fossil-fuel subsidies as well as investment,competition-policy,tradefacilitation and transit issues related to clean energy need to be addressed.Building trust between relevant actors across sectors and national borders will be of the essence in order to foster long-term cooperation on technological innovation.As a way forward,different approaches towards the governance of trade and climate change will be highlighted.Besides discussing the specific aspects of Chinese participation in global trade and climate change governance,this paper aims at offering broader insights into the nexus between trade,energy and climate governance in China.

Pathway and policy analysis to China's deep decarbonization

The Paris Agreement marks the beginning of a new era in the global response to climate change, which further clarifies the long-term goal and underlines the urgency addressing climate change. For China,promoting the decoupling between economic growth and carbon emissions as soon as possible is not only the core task of achieving the medium-and long-term goals and strategies to address climate change, but also the inevitable requirement for ensuring the sustainable development of economy and society. Based on the analysis of the historical trends of the economy and social development, as well as society, energy consumption, and key end-use sectors in China, this paper studies the deep carbon emission reduction potential of carbon emission of in energy, industry, building, and transportation and other sectors with "bottom-up" modeling analysis and proposes a medium-and long-term deep decarbonization pathway based on key technologies' mitigation potentials for China. It is found that under deep decarbonization pathway, China will successfully realize the goals set in China's Intended Nationally Determined Contributions of achieving carbon emissions peak around 2030 and lowering carbon dioxide emissions per unit of gross domestic product(GDP) by 60-65% from the 2005 level.From 2030 onward, the development of nonfossil energy will further accelerates, and the share of nonfossil energies in primary energy will amounts to about 44% by 2050. Combined with the acceleration of low-carbon transformation in end-use sectors including industry, building, and transportation, the carbon dioxide emissions in 2050 will fall to the level before 2005, and the carbon dioxide emissions per unit of GDP will decreases by more than 90% from the 2005 level. To ensure the realization of the deep decarbonization pathway, this paper puts forward policy recommendations from four perspectives, including intensifying the total carbon dioxide emissions cap and strengthening the related institutional systems and regulations, improving the incentive policies for industrial lowcarbon development, enhancing the role of the market mechanism, and advocating low-carbon life and consumption patterns.

Urban Expansion in China Based on Remote Sensing Technology：A Review

Urban areas and its evolution are important anthropogenic indicators and human ecological footprints, and play decisive roles in environmental change analysis, global geo-conditional monitoring, and sustainable development. China has the highest rate of urban expansion and has emerged as an urban expansion hotspot worldwide. In this paper, the progress of studies on Chinese urban expansion based on remote sensing technology are summarized and analyzed from the aspects of urban area definition, remotely sensed imagery applied in urban expansion, monitoring methods of urban expansion, and urban expansion applications. Existing issues and future directions of Chinese urban expansion are discussed and proposed. Results indicate that: 1) The fusion of multi-source remotely sensed imagery is imperative to meet the needs of urban expansion with various monitoring terms and frequencies on different scales and dimensions. 2) To guarantee the classification accuracy and efficiency and describe urban expansion and its influences on local land use simultaneously, the combination of visual interpretation and automatic classification is the tendency of future monitoring methods of urban areas. 3) Urban expansion data have become the prerequisite for recognizing the urban development process, excavating its driving forces, simulating and predicting the future development directions, and also is conducive to revealing and explaining urban ecological and environmental issues. 4) In the past decades, Chinese scholars have promoted the application of remote sensing technology in the urban expansion field, with data construction, methods and models developing from the quotation stage to improvement and innovation stage; however, an independent and consistent urban expansion data on the national scale with long-term and high-frequency(such as annual monitoring) monitoring is still lacking.

Remote Sensing and Landscapes in Sahelian Africa

For decades, Africa has undergone many crisis, affecting economy, climate, food, politics as well as society with irreparable consequences on the environment. The protection of the latter, being one of the cornerstones of sustainable development, is only possible if it＇s based on a reliable and rigorous diagnosis and inventory. This study suggests a method to characterize natural resources, in particular agricultural ones, by showing their landscape context. In this perspective and in the absence of any pre-existing mapping, as it is often the case in Africa, this work provides a simple and reproducible approach that merely uses Landsat Thematic Mapper （TM） （free） images, with the only constraint of the cross-checking of several images at different times of the plant cycle.

Eco-mindfulness in Buddhism

Many of those involved in the ecological movement have found inspiration and parallels within the Buddhist tradition. The Buddhist philosophy of karmic causality and dependent origination （pratitya-samutpada） convey the notion of interdependence of humans and nature. Today, especially in the United States, there are many movements, such as the Buddhist Peace Fellowship, to promote eco-living and sustainable communities, which call for humans to be mindful of the environment and make conscientious choices for the benefit of all sentient beings and non-sentient entities. Just as humans have been the cause of the gradual deterioration of Nature, we can also be the solution towards an coo-conscious living, which not only fosters a healthy environment, but also enables us to build good merit. The core Buddhist teaching, which must be embraced by all eco-minded practitioners is the notion of interdependence, which has been expounded by notable Japanese Buddhist figures in the eighth century, such as Kukai （774-835） of the Shingon School and Dogen （1200-1253） of the Soto Zen sect, who both viewed that non-living life forms--trees, plants, and the earth--could also achieve enlightenment. Their view is based on the ontological notions of Buddha-nature （tathagata-garbha） and Indra＇s Jewel Net, which is a powerful image found in Huayen＇s （Jpn. Kegon） Avatamsaka Sutra. This paper examines Buddhist teachings and sutras, which support eco-friendly and sustainable movements in our society and world today.

RELATIVITY AND SUSTAINABLE DEVELOPMENT

From the realism of science, and taking the guide of EINSTEIN’s Relativity as guide, this article called in question the present theory of the sustainable development by the rational thinking of philosophy and a close logic inference. It is found that there are many paradoxes to the theory. Through more deepening and meticulous inference, we arrived at philosophic language of science about the sustainable development. The sustainable development is "non-sustainable development", and the non-sustainable development is "the best sustainable development". While carrying out philosophical principle thinking and repeating science demonstration for the sustainable development, this article got further confirmation that the existence of human being at the minimum environment cost may help them obtain motive power of the sustainable development. In fact, this foundation motive power exists in the flow of development in different organization levels, meanwhile it exists in strategy of intuition living of the ancient people. Only in relative lower environment cost to live can we get the support system of science for the sustainable development, and be able really to achieve the basic goal of the sustainable development.

Developing newly emerging high-end industries in the low-carbon economy

Global warming has exerted severe challenges on the sustainable development of economic society and the food security,resource security,energy security and ecological security of the world.Low-carbon economy has become the current trend of the global economic development.Thus,the industrial development of China must seek the institutional innovation and technological innovation so as to improve the efficiency of energy.High-end industry has become the main factor of the future development of the economic society.Thus,to develop the high-end industry is an important approach to realize low-carbon economy.This paper explores the strategies of the development of newly emerging high-end industries against the background of low-carbon economy form such perspectives as effective use of resources,the improvement of independent innovative ability,and leading the high-end,high quality and high efficiency industries to the important region.

Community Based Natural Resource Management, Tourism and Poverty Alleviation in Southern Africa： What Works and What Doesn＇t Work

Community based natural resource management （CBNRM） is perhaps the most important tool for driving community and rural development in southern Africa. The paper therefore analyses the CBNRM framework as a strategy for implementing sustainable tourism and poverty alleviation initiatives in Botswana, Namibia, and Zambia. The article specifically underscores the importance of local-level participatory management and utilisation of natural resources in the region. Paying special attention to the previous researches that have been conducted in Botswana, Namibia, and Zambia, the methodological approach employed in the paper centres on critical discourse analysis and review of literatures to highlight the interface existing between CBNRM and rural （tourism） development. The analytical framework of the paper is thus rooted in the Common Property Resource （CPR） theory Overall, the authors argue that tourism, poverty alleviation, rural development, and sustainable natural resource use are linked and interrelated in the process of enhancing community well-being. Findings indicate that CBNRM initiatives have had a significant and positive impact in achieving sustainable tourism, rural development, poverty alleviation, and natural resource management. Specifically, findings show that the CBNRM has contributed to the reduction in wildlife poaching. While other pertinent issues remain, national governments in the three southern African economies need to fully appropriate the benefits that CBNRM offers and improve on them for better implementation of developmental programs.

Study on Disturbances and Its Effects on Nature Reserves

As a widespread natural phenomenon, disturbances are considered a discrete event occurring in a natural ecosystem within various spatial and temporal scales. The present paper discusses the types of disturbances and their influence on the ecologic system in nature reserves. It is shown that nature reserves are facing a great challenge dealing with these disturbances. A rational control for disturbances should be improved in order to promote the healthy development of nature reserves this could be done by enhancing the publicity and training of environment protection, coupling management with communities around and other nature reserves, effective management methods, rational planning, and supporting nature servers.