AHFO-based soil water content sensing technology considering soil-sensor thermal contact resistance

The actively heated fiber-optic(AHFO)technology has become emerged as a research focus due to its advantages of distributed,real-time measurement and good durability.These attributes have led to the gradual application of AHFO technology to the water content measurement of in situ soil.However,all existing in situ applications of AHFO technology fail to consider the effect of soilesensor contact quality on water content measurements,limiting potential for the wider application of AHFO technology.To address this issue,the authors propose a method for determining the soilesensor thermal contact resistance based on the principle of an infinite cylindrical heat source.This is then used to establish an AHFO water content measurement technology that considers the thermal contact resistance.The reliability and validity of the new measurement technology are explored through a laboratory test and a field case study,and the spatial-temporal evolution of the soil water content in the case is revealed.The results demonstrate that method for determining the soilesensor thermal contact resistance is highly effective and applicable to all types of soils.This method requires only the moisture content,dry density,and thermal response of the in situ soil to be obtained.In the field case,the measurement error of soil water content between the AHFO method,which takes into account the thermal contact resistance,and the neutron scattering method is only 0.011.The water content of in situ soil exhibits a seasonal variation,with an increase in spring and autumn and a decrease in summer and winter.Furthermore,the response of shallow soils to precipitation and evaporation is significant.These findings contribute to the enhancement of the accuracy of the AHFO technology in the measurement of the water content of in situ soils,thereby facilitating the dissemination and utilization of this technology.

Thinning intensity affects microbial functional diversity and enzymatic activities associated with litter decomposition in a Chinese fir plantation

Microbial functional diversity and enzymatic activities are critical to maintaining material circulation during litter decomposition in forests.Thinning,an important and widely used silvicultural treatment,changes the microclimate and promotes forest renewal.However,how thinning affects microbial functional diversity and enzymatic activities during litter decomposition remains poorly understood.We conducted thinning treatments in a Chinese fir plantation in a subtropical region of China with four levels of tree stem removal（0,30,50,and 70%）,each with three replicates,and the effects of thinning on microbial functional diversity and enzymatic activities were studied 7 years after treatment by collecting litter samples four times over a 1-year period.Microbial functional diversity and enzymatic activities were analyzed using Biolog Ecoplates（Biolog Inc.,Hayward,CA,USA）based on the utilization of 31 carbon substrates.Total microbial abundance during litter decomposition was lower after the thinning treatments than without thinning.Microbial functional diversity did not differ significantly during litter decomposition,but the types of microbial carbon-source utilization did differ significantly with the thinning treatments.Microbial cellulase and invertase activities during litter decomposition were significantly higher under the thinning treatments due to changes in the litter carbon concentration and the ratios of carbon and lignin to nitrogen.The present study demonstrated the important influence of thinning on microbial activities during litter decomposition.Moderate-intensity thinning may maximize vegetation diversity and,in turn,increase the available substrate sources for microbial organisms in litter and promote nutrient cycling in forest ecosystems.

A new high-performance AC/DC power factor correction switching converter based on one-cycle control technology and active floating-charge technology

A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed.Its operating prniciples and control methods were expounded.Based on these,a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein.The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.

Spatio-temporal Fragmentation of Leisure Activities in Information Era： Empirical Evidence from Nanjing, China

Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.

Extended activated sludge model no. 1 (ASM1) for simulating biodegradation process using bacterial technology

Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 （ASM1）, this study extended this model in order to determine the fate of phosphorus during the biodegradation processes. When some of the kinetics parameters are modified using observed data from the restoration project of the Xuxi River in Wuxi City, China, from August 25 to 31 in 2009, the extended model shows excellent results. In order to obtain optimum values of coefficients of nitrogen and phosphorus, the mass fraction method was used to ensure that the final results were reasonable and practically relevant. The temporal distribution of the data calculated with the extended ASM1 approximates that of the observed data.

International Conference on Sustainable Rice Production - Policy, Technology and Extension Celebration Activity for International Year of Rice and World Food Day 2004

Rice is the staple food of more than half of the world’s Population.The production,processing and management of paddy rice have provided the basic conditions for the living of mankind.The production of rice has not only created

Application of Green Technology Using Biological Means for the Adsorption of Micro-Pollutants in Water

It is true that the world we have today is not the world we use to know. The Covid-19 pandemic has paralyzed all sector, hence the need for safety and enabling environment for mankind is of high importance. Adsorption technology is far the best and cheapest treatment technology for water and has extensively proven its worth for the uptake of micro-pollutant from surface, ground and water which are the major channels of home water. Over the years activated carbon is considered as the most common and universally used adsorbent for the eradication of different types of micro-pollutants from water. The contamination of surface water by micro-pollutant is a potential threat for the production of high quality and safe drinking water. Adsorption operation onto granulated activated carbon (GAC) in fixed-bed filters is often applied as a remedying step in the synthesis of safe and drinkable water. Activated carbon actively tends to act as a carrier material for a thin usually resistant layer of microorganisms (mostly bacteria) that forms on the coat of various surfaces (biofilm), hence biological simplification can be an alternative removal approach that can be adopted in granulated activated carbon filters. To evaluate the capacity of biofilm to biologically simplify micro-pollutants, it is very imperative to distinguish adsorption from biological simplification (biodegradation) as a removal mechanism. Experiment was carried out under the operating condition of a temperature range of 6?C to 20?C with biologically activated and autoclaved GAC to assess the biological simplification by the biofilm adsorbed on the GAC surface. Five micro-pollutants were selected as model compounds, of which some of them were biologically simplified by the GAC biofilm. Additionally, we observed that temperature can increase or decrease adsorption. Conclusively, comparison was made on the adsorption capacity of granulated activated carbon used for more than 50,000 beds.

Superfast and solvent-free core-shell assembly of sulfur/carbon active particles by hail-inspired nanostorm technology for high-energy-density Li-S batteries

The demand on low-carbon emission fabrication technologies for energy storage materials is increasing dramatically with the global interest on carbon neutrality.As a promising active material for metal-sulfur batteries,sulfur is of great interest due to its high-energy-density and abundance.However,there is a lack of industry-friendly and low-carbon fabrication strategies for high-performance sulfur-based active particles,which,however,is in critical need by their practical success.Herein,based on a hail-inspired sulfur nano-storm(HSN)technology developed in our lab,we report an energy-saving,solvent-free strategy for producing core-shell sulfur/carbon electrode particles(CNT@AC-S)in minutes.The fabrication of the CNT@AC-S electrode particles only involves low-cost sulfur blocks,commercial carbon nanotubes(CNT)and activated carbon(AC)micro-particles with high specific surface area.Based on the above core-shell CNT@AC-S particles,sulfur cathode with a high sulfur-loading of 9.2 mg cm^(-2) delivers a stable area capacity of 6.6 mAh cm^(-2) over 100 cycles.Furthermore,even for sulfur cathode with a super-high sulfur content(72 wt%over the whole electrode),it still delivers a high area capacity of 9 mAh cm^(-2) over50 cycles in a quasi-lean electrolyte condition.In a nutshell,this study brings a green and industryfriendly fabrication strategy for cost-effective production of rationally designed S-rich electrode particles.

Development of piezoelectric-based technology for application in civil structural health monitoring

Piezoelectric material,as one of the great potential materials,had attracted lots of attention all over the world due to its distinguish advantages.In this paper,the development of piezoelectric-based technology for application in the field of civil structural health monitoring(CSHM),was summarized and discussed.Based on the different identification mechanisms,the piezoelectric transducer-based technology can be divided into two main approaches as the active or passive sensing and detection methods.This paper summarized the development of these two approaches and discussed their applications in the area of civil structural health monitoring,such as structural and concrete engineering,bridge engineering,pipeline engineering,protection engineering for geological hazards and earthquake disasters,and so on.In addition,the electrical mechanical impedance(EMI)technique,as one of the active identification methods,was also detailly presented.Finally,its great potential for the piezoelectric-based technique was presented based on the detail discussion,especially in the areas of civil structural health monitoring.

Actively Promoting Regional Space Cooperation——Vice Administrator, Loan Enjie headed a delegation to attend the Second Asia-Pacific Conference on Multilateral Cooperation in Space Technology and Applications

A Chinese delegation of 24 persons headed by Mr. Luan Enjie, Vice Administrator of China National Space Administration (CNSA) attended the Second Asia-Pacific Conference on Multilateral Cooperation in Space Technology and Applications held at Islamabad, the Capital of Pakistan from April 22 to 26, 1995. Following the First AsiaPacific Workshop held in Beijing in December, 1992, and the First Asia-Pacific Conference on Multilateral Cooperation in

Some Results of Direct FR Technology Applied to Study Methane Seepage Areas in the Arctic Region

The experimental study of the seepage processes’sources formation in structures of the Arctic Region was carried out using modified methods of frequency-resonance(FR)processing and decoding of satellite images and photographs with the vertical scanning of the cross-sections.The newly obtained results show that the intensity and dynamics of the methane seeps and pockmarks fields’formation depend on active deep degassing processes in the continental margin structures.The use of direct FR-sounding technologies allows for determining the probable origin and depth of geological sources of gas migration at marginal migration centers in Greenland,and Norwegian and Barents Seas.New results confirm the crust-mantle gas fluids’influence on the nature and degassing processes features in the scan points of polar marginal structures.These data are important arguments in favor of the“volcanic model”of various structural elements formation in this and other regions.The FR technologies data also showed a possibility of seeps use as shallow and deep hydrocarbon field indicators in gas emission areas.These independent data can be used in compiling models of the deep lithosphere structure and possible mechanisms of abiogenetic hydrocarbon formation in Arctic margin structures.The authors suppose that hydrocarbons through deep channels migrate(from 57 km deep)to the upper crustal horizons where their fields can form.During this migration,gas seeps and pockmarks are formed on the sea bottom and part of the gas can migrate into the atmosphere.Data show that basaltic volcanoes in Greenland scan points can be the real channels through which hydrogen migrates to the upper crustal horizons and further into the atmosphere.Active gas migration in Arctic seepage areas can be an important factor in the global climate change processes.

How to Design Key Activities in an Oral English Class

Analyzing the current situation of oral teaching and factors against students’progress in oral English of vocational and technological colleges,the essay focuses on three strategies to design key oral English activities,aimed at the improvement of students’oral competence.

《科技伦理审查办法(试行)》的解读与实施思考

当今,国际国内科技创新活动均面临不同类别和不同程度的伦理风险,给人类社会带来诸多负面影响,甚至威胁个人生命和财产安全。为进一步规范科技伦理审查,强化风险防控,促进负责任创新,2023年9月,十部委联合发布了《科技伦理审查办法(试行)》。《科技伦理审查办法(试行)》要求诸多领域的科技创新活动实施伦理审查,伦理审查应更加切实可行,加强了对重大突发公共事件的应急管理,提出研究机构应建立风险评估方法,新增无单位人员可申请委托伦理审查,建立伦理委员会认证制度等。《科技伦理审查办法(试行)》亮点突出、特色鲜明,明确了科技创新活动的责任主体,强化了责任主体对伦理审查的职责和管理,推出了科技活动清单管理制度,开创了针对较大伦理风险挑战的专家复核模式。对《科技伦理审查办法(试行)》进行解读和实施思考,为落实《科技伦理审查办法(试行)》提供参考,以期推动科技伦理审查成为规范性力量,促进科技创新活动向上向善发展以造福人类。

科技金融政策能否提升城市创业活跃度——基于“促进科技和金融结合试点”的准自然实验

科技金融政策能否促进经济社会包容性发展,其效应如何是一项值得关注的议题。本文基于2004—2021年中国280个地级及以上城市的面板数据,将“促进科技和金融结合试点”政策视为一项准自然实验,采用双重差分法考察了科技金融政策对城市创业活跃度的影响及作用机制。研究发现:科技金融政策显著提升了城市创业活跃度,该结论经过一系列稳健性检验后依然成立。机制检验表明,科技金融政策通过人才集聚效应、金融助推效应、科技创新效应和消费扩张效应提升城市创业活跃度。异质性分析表明,科技金融政策对东部地区城市、高市场化程度的城市,以及服务业尤其是非生产性服务业创业活跃度的提升作用更为明显。经济后果分析表明,科技金融政策所产生的创业效应能够有效转化为就业创造效应,但这一效应主要体现在第三产业。本文研究结论为有效发挥科技金融政策的创业效应,实现稳就业、促发展的目标提供了有益的政策启示。

数字赋能技术促进智力与发展性残疾儿童身体活动和健康的系统综述

目的系统综述数字赋能技术(DET)促进智力与发展性残疾(IDD)儿童身体活动和健康的效益。方法从PubMed、Embase、Web of Science、PsycINFO和中国知网中,检索2014年至2023年DET在IDD儿童身体活动中的应用相关文献,对文献进行质量评价,对高质量随机对照研究(RCT)进行系统综述。结果最终纳入8项RCT,来自中国、美国、意大利、韩国4个国家,涉及376例儿童,主要来源于智力残疾应用、发展性残疾研究、临床医学等领域期刊。发表时间主要集中在2018年至2023年。研究对象年龄7~18岁,涵盖智力残疾(包括唐氏综合征)、孤独症和其他发展性残疾。采用的技术包括可穿戴技术、移动健康指导和监测的云计算技术、虚拟现实和增强现实,以及动感游戏技术,设备包括主动视频游戏、Fitbit智能设备、Wii Fit平衡游戏、Stepmania节奏视频游戏、Xbox Kinect系统、VZFit传感器和CoTras认知康复电脑游戏等,虚拟身体活动包括拳击、田径、保龄球、乒乓球、沙滩排球、足球、棒球、滑雪、网球、高尔夫、飞镖、美式足球、射击、跳跃、慢跑和跳绳等。干预频率为每次20~45 min,每周1~5次,持续4~12周;在家庭、特殊教育学校和康复机构中进行。健康效益主要体现在提高身体活动水平、改善身体功能,以及提高运动功能和日常生活活动能力。结论将DET应用到身体活动领域,能提高IDD儿童在虚拟环境下、学校、社区以及康复机构中的身体活动参与水平,改善上下肢活动功能、粗大运动功能和肌肉力量,提高静态平衡功能、运动协调和感觉运动功能,减少久坐行为发生,提升认知、日常生活活动能力和社交能力。

教育5.0时代:内涵、需求和挑战

数字化转型开启了教育5.0时代,为教育带来新的格局、多模态学习的新体验、人机协同的新范式。文章探讨了以学习者为中心、生成式人工智能为技术支撑、智慧教育生态环境建设为依托的教育5.0的内涵、需求及面临的挑战。教育5.0强调学习的主体性、包容性、公平性、可持续性与韧性、主观能动性和团结协作性。文章通过分析教育的演进过程与阶段特征,阐释了教育5.0时代的理念升级、内容更新和方式变革,指出未来教育更应注重人本主义,关注学习者学习体验,满足其个性化和多样化需求,促进其全面发展;将数字技术整合到教育各层面,推动全方位创新与变革,推进教育优质公平与支持终身学习,形成具有开放性、适应性、个性化、自主性等特征的教育新生态。

危岩崩塌防治技术体系及工程选型分析

危岩崩塌防治技术是保障危岩工程安全稳定的关键。通过对危岩崩塌防治技术的优缺点、适用条件、工程设置原则以及选型程序的分析,认为危岩崩塌防治技术可分为主动防治技术、被动防治技术和辅助防治技术,各项防治技术设计时应充分考虑其适用条件,按照工程设置原则采纳使用,适时选择多种技术组合方式的治理措施进行危岩崩塌工程防治;危岩崩塌防治技术选型应遵循查清危岩体基本情况→评价危岩体状态→选择危岩防治技术→分析防治技术选型结果的基本程序,确定危岩崩塌防治技术选型程序各环节的关键参数,以确定合适的崩塌防治技术。研究成果可为危岩崩塌防治工程设计提供理论依据和关键技术支撑。

变电站铅酸电池的失效及综合修复

铅酸电池是直流(DC)系统的重要储能设备,对变电站的安全稳定运行至关重要。站用铅酸电池寿命普遍低于理论寿命,大量电池的提前失效给电网企业带来巨大的经济和环境压力。针对变电站铅酸电池的特殊运行环境,对失效电池复杂的失效模式进行分析。采用化学和物理相结合的技术手段,针对性地选择合适的活化剂,同时使用“大电流-恒流-恒压”的充电方式,达到修复活化失效铅酸电池的目的,修复后的铅酸电池容量可达额定容量的80%以上。