Research on Program-controlled Power Source Based on DDS

Direct Digital Synthesis （DDS） chip was used in the design of program controlled power source in this paper. With the accurate control of Dual DDS chips by Micro Controller Unit （MCU）, illter and power amplifier, this power source can generate voltage and corrent output with variable frequency, amplitude and phase. There are several advantages of this power source such as high power, high accuiracy, output stable, light and conveaient.

Metamerism Appreciation of Jadeite-Jade Green under the Standard Light Sources D_(65),A and CWF

We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism colors were highly consistent of L＊D65∈（43.47, 46.75）, C＊D65∈（65.20, 68.80） and ho＊D65∈（138.10, 140.23）. We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the color of jadeite-jade green might be slightly influenced by alternating of the light sources.

Assessing the role of forest resources in improving rural livelihoods in West Bengal of India

Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consumed locally,supporting numerous rural communities relying on forests for essential resources,such as firewood,timber,and NTFPs.This study focuses on two forest-dominant districts in West Bengal of India,namely,Jhargram District and Paschim Medinipur District.Furthermore,this study aims to enhance the understanding of forest-dependent communities by comparing the standard of living among different village classes.Thus,we categorized villages into three classes based on the distance from home to forests,including inner villages,fringe villages,and outer villages.Through focus group discussions and household surveys,we explored the sources of local economy,income sources of household,and reasons for economic diversification in different village classes.The study findings confirm that substantial variations existed in the income sources and the standard of living in these villages.Forest income varied dramatically among the three village classes,with inner villages having greater forest income than fringe villages and outer villages.Meanwhile,households in outer villages depended on forests and engaged in diverse economic activities for their livelihoods.Compared with inner and fringe villages,households in outer villages derived a significant portion of their income from livestock.This discrepancy can be attributed to challenges,such as inadequate transportation,communication,and underdeveloped market chains in inner villages.Moreover,these findings emphasize the need to develop sustainable forest management practices,create alternative income-generation opportunities,and improve infrastructure and market access in inner villages,as well as promote economic diversification in outer villages.Through targeted policy measures,these forest-rich regions can achieve improved livelihoods,enhanced standard of living,and increased resilience for their communities.

Complying with Coding Standards or Retaining Programming Style: A Quality Outlook at Source Code Level

In order to make most software engineers and managers pay more attention to software quality at source level, two confusing terms-coding standard and programming style-were reviewed and compared. An evolutionary model of quality assurance at source code level was proposed, which implies that coding standard should be better accepted and more emphasized than programming style. Our current researches on evaluating the compliance with coding standards will likely make the strategy of quality assurance at source code level more operable.

Response of Vegetation Cover Change to Drought at Different Time-scales in the Beijing-Tianjin Sandstorm Source Region,China

Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional vegetation protection and drought prevention,we assessed the relations between vegetation cover change(measured by the Normalized Difference Vegetation Index,NDVI)and the Standardized Precipitation Evapotranspiration Index(SPEI)at different time-scales,in different growth stages,in different subregions and for different vegetation types based on the Pearson's correlation coefficient in the BTSSR from 2000 to 2017.Results showed that 88.19%of the vegetated areas experienced increased NDVI in the growing season;48.3%of the vegetated areas experi-enced significantly increased NDVI(P<0.05)and were mainly in the south of the BTSSR.During the growing season,a wetter climate contributed to the increased vegetation cover from 2000 to 2017,and NDVI anomalies were closely related to SPEI.The maximum correlation coefficient in the growing season(Rmax)was significantly positive(P<0.05)in 97.84%of the total vegetated areas.In the vegetated areas with significantly positive Rmax,pixels with short time-scales(1-3 mon)accounted for the largest proportion(33.9%).The sensitivity of vegetation to the impact of drought rose first and then decreased in the growing season,with a peak in July.Compared with two subregions in the south,subregions in the north of the BTSSR were more sensitive to the impacts of drought variations,especially in the Xilingol Plateau and Wuzhumuqin Basin.All four major vegetation types were sensitive to the effects of drought variations,especially grasslands.The time-scales of the most impacting droughts varied with growth stages,regions,and vegetation types.These results can help us understand the relations between vegetation and droughts,which are important for ecological restoration and drought prevention.

Calibration of a neutron dose rate meter in various neutron standard fields

This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and five simulated workplace fields with241Am-Be moderated sources).The calibration in standard fields with bare sources was conducted by following the recommendations of the ISO 8529 standard.The measured total neutron ambient dose equivalent rates,denoted as H*(10)tot,were analyzed to obtain direct components,denoted as H*(10)dir,using a reduced fitting method.The CF was then calculated as the ratio between the conventional true value of the neutron ambient dose equivalent rate in a free field,denoted as H*(10)FF,and the value of H*(10)dir.In contrast,in the simulated workplace neutron fields,the calibration of the neutron dose rate meter was conducted by following the ISO 12789 standard.The CF was calculated as the ratio between the values of H*(10)totmeasured by a standard instrument(i.e.,Bonner sphere spectrometer)and the neutron dose rate meter.The CF values were obtained in the range of 0.88–1.0.The standard uncertainties(k=1)of the CFs were determined to be in the range of approximately 6.6–13.1%.

基于多源数据的长江流域1982—2022年骤旱事件时空演变

骤发性干旱(简称骤旱)是一种突发性高且强度大的极端干旱现象,会对农业生产和生态系统构成严重威胁。近年来,长江流域骤旱频发,然而其骤旱时空演变格局及规律尚不明晰。本研究基于GLEAM、GLDAS和ERA5-Land数据,以标准化蒸发胁迫比及其变化值作为识别指标,开展1982—2022年长江流域骤旱识别,全面分析长江流域骤旱空间分布和时间演变特征;并鉴于2022年旱情的严重性和特殊性,重点分析该年长江流域骤旱事件。研究结果表明:①在空间分布上,长江流域上游的金沙江水系和中下游的大型水库湖泊骤旱发生频率最高且强度最大;②在时间演变上,骤旱发生频率、平均持续时间和强度均在长江流域整体上呈现出非显著上升趋势,而有显著变化趋势的区域在2001年前后表现出明显的趋势反转现象;③2022年夏季受极端高温热浪影响,长江流域遭遇大规模骤旱事件,具有波及范围广、持续时间长的特点,且骤旱在空间上呈现出从上游向下游传递的态势。

面向设计研发的核能大数据系统架构及标准化研究

结合核能设计研发基本流程和全生命周期数据特点,开展基于多源异构数据集成的采集、存储、处理、管理、应用等功能需求分析,按照“分层设计”思想和以数据应用为目标的路线,建立核能大数据系统技术架构和数据架构,对架构中的层级、模块、功能进行分析。考虑大数据技术持续应用的特点,基于核能大数据系统架构和技术发展需求,开展标准化研究,提出核能大数据标准体系。该研究为大数据技术在核能设计研发应用提供基础,并为后续开展系统性的核能大数据标准化工作提供技术参考。

关于优化税制结构及相关问题的分析与思考

构建高水平社会主义市场经济体制,经济发展阶段不断跨越,数字经济、人工智能等新产业、新业态、新模式快速发展,税制结构随之发生变化,优化税制结构、适当提高直接税比重,成为我国深化税制改革的必然要求。我国经济管理部门应根据经济增长的动力结构变化适时调整、优化税源结构,正确处理投资和消费在税源结构中的关系,以确保税收收入的可持续、稳定性;在稳定宏观税负前提下应更加强化税制调控功能(特别是在社会公平领域的调控功能),不断强化直接税在调节收入分配方面的功能作用,促进社会适度流动,有效调节数据要素相关收入分配问题,更加有效调控区域税收分配、维护全国统一大市场。

知识产权国际平行诉讼禁诉令的适用:理念与方略

禁诉令在知识产权案件尤其是标准必要专利纠纷中频频出现,催生了全球禁诉令大战。禁诉令制度与涉外司法中管辖权的争夺是相伴相生的,客观上对于恰当解决国际平行诉讼冲突,维护司法主权,以及作为体现一定导向性的公共政策,都具有积极的意义。我国当前立法缺乏关于禁诉令的直接规定,法院在数起知识产权诉讼案件中能动地扩张解释和适用行为保全规定,取得了一定的效果,但也面临着质疑。站在国家利益的高度来看,未来我国法院在涉及禁诉令的案件时,应从诉源治理的理念出发,树立慎用的态度,严格审查路径、限定适用范围,充分尊重国际礼让原则,充分发挥我国司法制度中重视调解的特色和优势,为禁诉令国际难题提供中国式的解决方案。

南水北调中线工程水源地水质安全问题与对策思考

南水北调中线工程是我国水资源优化配置的战略性基础工程,水源地水质安全保障工作至关重要。当前中线工程水源地水质状况总体良好,但水源地依然存在常规水质超标、富营养化、藻类异常增殖及尾矿库渗漏或溃坝等风险,需高度关注。系统梳理了水源地水质现状,总结了水质安全面临的主要风险,并从人为因素、工程因素、自然因素和管理因素等方面分析了影响因素,从产业发展、污染防治、监测监控、风险防范、科学研究、水质管理等方面总结了水源地水质安全保障管理现状及存在问题。基于现状和问题分析,提出构建水质综合管理体系框架,包含工业-农业-服务业生态产业与环境耦合协调的发展体系、源头减排-过程控制-末端治理的全过程水污染防治体系、全要素-全天候-全覆盖的现代化监测监控体系、识别评估-监测告警-预测预警-应急响应的全链条风险防控体系、理论研究-技术研发-平台建设-人才发展的全方位科学技术支撑体系、立法引领-机构健全-机制完善-规范建设-能力突出的全面化管理体系,为确保“一泓清水永续北上”提供强有力的管理策略与科学参考。

粮食安全与“双碳”视角下黄河流域农田生态补偿额度

[目的]测算从粮食安全和“双碳”两个视角下的农田生态补偿额度,并将流域上中下游的地理空间、经济贡献度等因素综合考虑在内划分生态补偿区域,为流域高标准农田建设、农业低碳发展、健全利益补偿机制提供理论参考。[方法]首先从粮食安全的角度对黄河流域内60个地级市进行了农田盈亏量的测算,基于机会成本法建立了粮食安全视角下的农田生态补偿标准;接着,计算黄河流域各市农业生产过程中,使用的农业资源与农作物生长过程所产生的碳排放量,估计农作物生长中通过光合作用吸收碳的总量。根据所得碳源、碳汇量计算该区域内农田的总净碳汇量。以2021年碳交易平均价格为补偿标准,求出“双碳”视角下区域内农田生态补偿标准。最后,在分别计算粮食安全与“双碳”视角下的农田生态补偿额度的基础上,得出双视角下黄河流域的农田生态补偿额度。[结果]青海、河南省内黄河流经的市大多都接受一定的补偿。部分省会城市如西安、郑州与太原市因城镇化与工业化水平较高,经济发展情况良好,需要支付的农田生态补偿额度较高,说明当地农田安全与粮食、生态安全间的矛盾问题更严重。[结论]在高标准农田的建设中,为更合理地进行农田生态补偿,应在保障粮食安全的前提下,结合考虑农业生产过程中的碳排放与碳吸收量,以实现中国的“双碳”目标,助力农业强国建设。

车路协同感知技术研究进展及展望

近年来,我国自动驾驶研究逐步从聚焦于单车智能技术向车路协同技术转变,为智能交通产业发展带来了重大机遇;我国在车路协同感知领域的研究虽处于起步阶段,但注重技术推动,未来发展前景广阔。本文致力于深入探讨车路协同感知技术的发展动态,梳理了车路协同感知基础支撑技术的特性和发展现状,厘清了车路协同感知技术的研究进展,探讨了其技术发展趋势,并针对推动车路协同感知技术发展提出了一系列建议。研究表明,车路协同感知技术正朝着多源数据融合方向发展,主要集中在纯视觉协同感知技术优化、激光雷达点云处理技术升级、多传感器时空信息匹配与数据融合技术发展以及车路协同感知技术标准体系构建等方面。为进一步促进我国车路协同自动驾驶产业的迅速成长,研究建议,加大对多模态车路协同感知技术的研发投入、深化行业间的合作、制定统一的感知数据处理技术标准并加速技术应用普及,以期推动我国在全球自动驾驶竞争中赢得主动,推动自动驾驶行业稳定持续发展。

澜沧江源区高山柏径向生长对气候变化的响应

为探究澜沧江源区气候变化对高山柏(Sabina squamata)径向生长的影响,在该区巴青县、杂多县和囊谦县分别对高山柏进行采样。运用树木年轮学方法测定3个样地高山柏逐年树轮宽度和胸高断面积增量(BAI),建立高山柏树轮宽度标准年表并分析其对气候变化的响应。研究结果表明,1986—2019年,澜沧江源区年平均温度呈快速上升趋势(0.43℃/10a,P<0.01),年平均最低气温(0.57℃/10a,P<0.01)的上升速率明显高于年平均最高气温(0.33℃/10a,P<0.01),而年降水量呈不显著的上升趋势(2.39mm/a,P>0.10)。气候变暖背景下,澜沧江源区高山柏树轮宽度呈上升趋势(P<0.01),2000—2019年生长速率((0.37±0.16) mm/a)较1986—1999年((0.20±0.09) mm/a)增加了85%;BAI亦上升显著,在1986—1999年一直呈上升趋势((12.16±5.16) mm^(2)/a),2000—2019年处于平稳快速生长阶段((22.49±8.84) mm^(2)/a),表现出稳定且持续的生长能力。高山柏树轮宽度标准年表与气候因素的相关性显示:澜沧江源区高山柏径向生长对温度的响应明显强于降水,与多数月份(上年6月—当年10月)的降水呈不显著正相关,而与多数月份的温度呈显著正相关。与月平均最高温度和平均温度相比,高山柏径向生长与月平均最低温度的相关性更为显著(P<0.01)。在气候暖湿化背景下,近30年澜沧江源区高山柏径向生长进入快速生长时期,树轮宽度和BAI均呈快速生长特征,表明该区域气候条件更加适宜高山柏生长。

IEC/TC1082024年春季工作组会议综述

介绍IEC/TC108 HBSDT工作组2024年春季虚拟会议情况,包括对IEC 62368-1:2023的新技术提案讨论、特别小组讨论、解释组文件讨论及相关决议讨论等。

不同介质环境样品的符合修正方法研究

使用γ能谱测量放射性核素活度时,级联发射的γ射线会发生符合效应,影响测量结果。为了得到不同环境介质样品的符合修正因子,研究了简单级联发射模式的核素在不同介质中符合修正因子之间的关系,提出了利用水代替其他环境介质的符合修正因子计算方法。实验结果表明,使用该方法所得结果的最大偏差为2.8%。使用此方法不需要逐一制备不同介质标准源,它为多介质的辐射环境监测提供了一种简单的符合修正方法。

Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in China from 2000 to 2020

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

国内外固定源大气挥发性有机物排放标准综述

系统综述了目前国内外涉及固定源大气挥发性有机物(VOCs)防控的政策法规与标准,全面梳理了当前发达国家与中国国家及地方VOCs标准体系,重点结合了几大主要行业的特征VOCs物种及对臭氧(O_(3))生成的贡献,提出固定源VOCs排放体系中指标设立存在管控模糊、缺乏针对性的问题。在此基础上,从借鉴国外管理方法及经验、及时修订现行标准和纳入更多O_(3)生成高贡献物种并分层管理等方面提出了进一步完善中国固定源VOCs排放标准体系的建议。

A new calibration method for radon detector in seismic systems

Radon observation is an important measurement item of seismic precursor network observation.The radon detector calibration is a key technical link for ensuring radon observation accuracy.At present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon sources.As a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in China.To solve this problem,a new calibration method for radon detectors was established.The advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector calibration.This method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in China.The comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new method.This new method can completely replace the traditional calibration method of using a radon source in seismic systems.

我国农村生活污水与农田退水面源氮磷污染生态净化技术现状与研究进展

当前,我国农村生活污水与农田退水面源氮磷污染尚未得到有效治理,解决此类污染的代表措施——“生态净化技术”的发展广受关注。本文从技术发展、技术标准、技术体系三个角度切入,对农村生活污水与农田退水氮磷污染生态净化技术进行梳理分析。技术发展从分析和介绍当前热门生态净化技术的研究进展开始,通过调研整理这些技术在我国的推广和应用,梳理其在我国不同区域的发展特征,归纳出当前生态净化技术应用所面临的困难。当前相关部门对生态净化工程的监管仅关注出水水质的达标率,缺乏有效的后期维护及意见调查反馈。在技术标准方面,本文梳理了关于已发布实施的生态净化工程的的系列标准,认为应引入综合效益评价方法,以完善我国生态净化工程的评价体系。在技术体系方面,以生态净化技术的拦截性和修复性为依据对单一技术进行分类,并分别针对农村生活污水、农田退水提出了对应的技术联用体系。