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Analysis of factors influencing carbon emissions in the Yangtze River Delta region and projections of carbon peak scenarios
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作者 SHI Xiong-tian WU Feng-qing +1 位作者 CHEN Yang DAI Li-li 《Ecological Economy》 2024年第1期2-24,共23页
Based on the supply-side perspective,the improved STIRPAT model is applied to reveal the mechanisms of supply-side factors such as human,capital,technology,industrial synergy,institutions and economic growth on carbon... Based on the supply-side perspective,the improved STIRPAT model is applied to reveal the mechanisms of supply-side factors such as human,capital,technology,industrial synergy,institutions and economic growth on carbon emissions in the Yangtze River Delta(YRD)through path analysis,and to forecast carbon emissions in the YRD from the baseline scenario,factor regulation scenario and integrated scenario to reach the peak.The results show that:(1)Jiangsu's high carbon emission pattern is the main reason for the YRD hindering the synergistic regulation of carbon emissions.(2)Human factors,institutional factors and economic growth factors can all contribute to carbon emissions in the YRD region,while technological and industrial factors can generally suppress carbon emissions in the YRD region.(3)Under the capital regulation scenario,the YRD region has the highest level of carbon emission synergy,with Jiangsu reaching its peak five years earlier.Under the balanced regulation scenario,the YRD region as a whole,Jiangsu,Zhejiang and Anhui reach the peak as scheduled. 展开更多
关键词 Yangtze River delta carbon peaking scenario forecasting STIRPAT model
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单边双通道内镜与Delta大通道内镜技术治疗L5/S1椎间盘突出并椎管狭窄的临床疗效分析
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作者 唐晓栋 张建文 +3 位作者 李昭成 赵庆 齐兵献 雍清锋 《中国现代手术学杂志》 2024年第1期42-48,共7页
目的 探讨Delta大通道内镜技术与单边双通道内镜技术(unilateral biportal endoscopy, UBE)治疗L5/S1单节段椎间盘突出并椎管狭窄的疗效。方法 回顾性分析2018年1月至2022年8月手术治疗的60例L5/S1单节段腰椎间盘突出并椎管狭窄患者的... 目的 探讨Delta大通道内镜技术与单边双通道内镜技术(unilateral biportal endoscopy, UBE)治疗L5/S1单节段椎间盘突出并椎管狭窄的疗效。方法 回顾性分析2018年1月至2022年8月手术治疗的60例L5/S1单节段腰椎间盘突出并椎管狭窄患者的临床资料,其中32例采用Delta大通道内镜技术行经皮椎板间入路内镜下椎间盘切除术(Delta内镜组),28例采用UBE内镜技术行椎管减压髓核摘除术(UBE组)。比较两组围手术期指标、腰腿痛VAS评分、 ODI及并发症情况,末次随访时按Macnab标准评价疗效。结果 两组患者均顺利完成手术。Delta内镜组术中出血量少于UBE组,手术时间、住院时间短于UBE组(P<0.001)。两组患者术后腰腿痛VAS评分及ODI均较术前明显降低,且Delta内镜组术后3 d腰痛VAS评分及术后1月腿痛VAS评分均低于UBE组(P<0.05)。术后随访6个月,末次随访按Macnab标准评价疗效:Delta内镜组优30例,可2例,优良率为93.75%;UBE组优27例,可1例,优良率为96.43%;组间比较差异无统计学意义(P>0.05)。Delta内镜组硬膜撕裂1例,因撕裂处较小仅严密缝合手术切口;UBE组出现腿部疼痛加重1例。结论 Delta大通道内镜技术与UBE治疗L5/S1单节段椎间盘突出并椎管狭窄均可获得良好的近期效果,但Delta内镜手术术中出血少,软组织损伤小,操作时间短,术后短期疼痛缓解明显,患者恢复快,而UBE适应证范围相对广泛。 展开更多
关键词 椎间盘突出 椎管狭窄 delta大通道内镜手术 单边双通道内镜手术
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Delta型FDM打印设备结构参数设定及运动学研究
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作者 祝洲杰 蔡彬 +2 位作者 海豫杭 张旭 方一仁 《机电工程技术》 2024年第7期126-129,184,共5页
FDM打印设备的扫描路径、打印速度、温度、层厚等问题是影响制件外形精度和成型效率的工艺参数的重要因素。Delta型结构作为最常用的FDM设备结构型式之一,其末端打印头的运动由多杆共同作用,运动分析较繁琐,为设备的参数设定增添了很大... FDM打印设备的扫描路径、打印速度、温度、层厚等问题是影响制件外形精度和成型效率的工艺参数的重要因素。Delta型结构作为最常用的FDM设备结构型式之一,其末端打印头的运动由多杆共同作用,运动分析较繁琐,为设备的参数设定增添了很大的难度,存在参数设定和运动分析难的问题。从Delta型的结构分析出发,重点研究了各结构尺寸之间的关联,总结了参数设定和计算的依据。考虑到Delta结构的打印头与3个滑车之间坐标的对应关系并不能通过简单推算得出,需要大量的三角函数运算,建立了Delta型结构的正、逆解运动学模型,结合几何的方式详细推导了运动学反解和正解的解法,分析和求解的结果为设定Delta型设备参数和确定控制程序算法提供了理论依据。经过分析与计算,基于并联机构内核的Delta结构采用正运动求解更便于规避正解集合中的不合理结果。 展开更多
关键词 熔融层积成型 delta结构 参数 运动学
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基于Delta分位数映射法的青藏高原中东部IMERG卫星降水误差订正
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作者 杜娟 于晓晶 +1 位作者 黎小东 敖天其 《高原气象》 CSCD 北大核心 2024年第2期366-380,共15页
可靠的降水资料对理解青藏高原水量平衡和水循环过程尤为重要。IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)是新一代卫星降水产品,具有更广的覆盖范围与更高的时空分辨率,但在高原复杂地形条件... 可靠的降水资料对理解青藏高原水量平衡和水循环过程尤为重要。IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)是新一代卫星降水产品,具有更广的覆盖范围与更高的时空分辨率,但在高原复杂地形条件下仍然存在较大的不确定性。鉴于此,本研究应用Delta分位数映射法(Quantile Delta Mapping,QDM),对IMERG日降水数据进行偏差订正,使用2001-2010年的中国区域地面气象要素数据集(China Meteorological Forcing Dataset,CMFD)降水数据和IMERG日降水产品分季节建立传递函数,对2011-2014年的IMERG逐日降水进行订正。研究结果表明:(1)Delta分位数映射法能够有效订正IMERG的降水频率、数值和空间分布,对极端降水和负偏差较大区域的订正效果更为明显。订正后的IMERG降水概率分布更加接近观测概率分布,降水偏差也更符合正态分布,改进了对全年和季节降水空间分布的刻画,提高了月降水的精度。(2)订正后日降水量均方根误差由1.49 mm·d^(-1)降低到1.26 mm·d^(-1),精度提高了15.44%;订正后的日降水在不同降水量级的临界成功指数CSI、命中率POD、误报率FAR、准确率Precision和F评分Fscore均有提高,降低了微量和暴量降水的空报率。(3)对极端降水的订正效果显著,降水强度SDII以及极强降水量R95p和R99p的均值更接近观测值;有效提高了对极端降水空间分布的表征,极端降水偏差从30%以上降低到5%以内;SDII、R95p和R99p的均方根误差从1.59 mm·d^(-1)、6.54 mm·d^(-1)、14.89 mm·d^(-1)降为0.65 mm·d^(-1)、3.01 mm·d^(-1)、8.99 mm·d^(-1),精度分别提高了59.12%、53.98%和39.62%。本研究验证了Delta分位数映射法在青藏高原的适用性,有利于为青藏高原气象和水文研究获取更精确的降水数据。 展开更多
关键词 青藏高原 IMERG卫星降水 偏差订正 delta分位数映射法
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一种具有1~128倍可变增益放大器的低功耗Sigma⁃Delta ADC
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作者 聂勇 吴旦昱 +2 位作者 王丹丹 唐朝 吴霖真 《半导体技术》 CAS 北大核心 2024年第5期476-482,共7页
为满足传感器应用的低功耗需求,设计并实现了一种低功耗Sigma⁃Delta模数转换器(ADC)芯片。该ADC采用一阶全差分开关电容Sigma⁃Delta调制器,且集成了可编程增益放大器(PGA)和Bandgap;使用1.5 bit量化结构,相较于1 bit量化结构减小了3 dB... 为满足传感器应用的低功耗需求,设计并实现了一种低功耗Sigma⁃Delta模数转换器(ADC)芯片。该ADC采用一阶全差分开关电容Sigma⁃Delta调制器,且集成了可编程增益放大器(PGA)和Bandgap;使用1.5 bit量化结构,相较于1 bit量化结构减小了3 dB的量化误差;使用优化的反馈电路,减小了电容失配引入的误差;PGA采用轨到轨的运放电路拓扑,增大了整个芯片的电压适应范围。基于180 nm CMOS工艺对该ADC进行了设计和流片。测试结果表明:该Sigma⁃Delta ADC在采样频率512 kHz、过采样率(OSR)为256时,峰值信噪谐波失真比(SNDR)和有效位数(ENOB)分别为75.29 dB和12.21 bit,芯片功耗仅为0.92 mW。芯片能在2.3~5.5 V宽电源电压范围内正常工作,可实现最大128 V/V的增益。适用于小型传感器的信号测量应用,可以满足小型传感器低功耗、高精度的需求。 展开更多
关键词 模数转换器(ADC) 全差分开关电容器 Sigma⁃delta调制器 1.5 bit量化 低功耗 可编程增益放大器(PGA)
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油茶果动态抓取Delta机器人正运动学特性研究
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作者 傅雄辉 李立君 +2 位作者 范子彦 李宇航 吕辉 《农机化研究》 北大核心 2024年第3期14-20,29,共8页
针对传统D-H参数法求解机械臂运动学时过程比较复杂的问题,为满足油茶果动态抓取的要求,提出了一种基于旋量理论构建3-R(SS)2Delta机器人正运动学方程的方法。针对3-R(SS)2Delta机器人的结构进行分析;通过旋量理论的指数积公式对该机器... 针对传统D-H参数法求解机械臂运动学时过程比较复杂的问题,为满足油茶果动态抓取的要求,提出了一种基于旋量理论构建3-R(SS)2Delta机器人正运动学方程的方法。针对3-R(SS)2Delta机器人的结构进行分析;通过旋量理论的指数积公式对该机器人的正运动学特性进行研究,获得机器人的位姿变换矩阵;最后,通过搭建的Delta机器人试验平台运行标准门型轨迹,结果表明:Delta机器人末端执行器能够精准地对传送带上移动的油茶果进行抓取。对比分析正运动学方程的计算值和Delta机器人试验平台试验测量值,得到末端执行器位置值的位置误差为±0.3mm,验证了所提出方法对构建油茶果动态抓取Delta机器人正运动学方程的正确性及可行性,旨在为后续进行油茶果动态抓取的轨迹规划研究奠定基础。 展开更多
关键词 delta机器人 油茶果动态抓取 旋量理论 正运动学
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基于事件触发的Delta算子网络控制系统故障检测
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作者 葛晓伟 周颖 《电子科技》 2024年第5期79-87,94,共10页
针对网络控制系统在高速采样情况下,网络中由于通信网络带宽受限发生时延和丢包所引起的故障问题,文中采用了基于事件触发机制和Delta算子相结合的故障检测方法。在对故障检测滤波器和控制器进行协同设计的同时,在Delta算子滤波器模型... 针对网络控制系统在高速采样情况下,网络中由于通信网络带宽受限发生时延和丢包所引起的故障问题,文中采用了基于事件触发机制和Delta算子相结合的故障检测方法。在对故障检测滤波器和控制器进行协同设计的同时,在Delta算子滤波器模型中加入构造向量,避免了参数设计时双线性项的产生。构造δ域的Lyapunov-Krasovskii泛函,对残差系统的稳定性和H∞性能进行分析。数值仿真实例验证了文中所提事件触发机制的有效性,并通过残差评价函数证明了其对故障的灵敏度较高。 展开更多
关键词 网络控制系统 故障检测 delta算子 网络时延 网络丢包 事件触发机制 残差系统 H∞性能 残差评价函数
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Construction and Application of a Regional Kilometer-Scale Carbon Source and Sink Assimilation Inversion System(CCMVS-R) 被引量:1
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作者 Lifeng Guo Xiaoye Zhang +8 位作者 Junting Zhong Deying Wang Changhong Miao Licheng Zhao Zijiang Zhou Jie Liao Bo Hu Lingyun Zhu Yan Chen 《Engineering》 SCIE EI CAS CSCD 2024年第2期263-275,共13页
CO_(2)is one of the most important greenhouse gases(GHGs)in the earth’s atmosphere.Since the industrial era,anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere,resulting in climate ... CO_(2)is one of the most important greenhouse gases(GHGs)in the earth’s atmosphere.Since the industrial era,anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere,resulting in climate warming since the 1950s and leading to an increased frequency of extreme weather and climate events.In 2020,China committed to striving for carbon neutrality by 2060.This commitment and China’s consequent actions will result in significant changes in global and regional anthropogenic carbon emissions and therefore require timely,comprehensive,and objective monitoring and verification support(MVS)systems.The MVS approach relies on the top-down assimilation and inversion of atmospheric CO_(2)concentrations,as recommended by the Intergovernmental Panel on Climate Change(IPCC)Inventory Guidelines in 2019.However,the regional high-resolution assimilation and inversion method is still in its initial stage of development.Here,we have constructed an inverse system for carbon sources and sinks at the kilometer level by coupling proper orthogonal decomposition(POD)with four-dimensional variational(4DVar)data assimilation based on the weather research and forecasting-greenhouse gas(WRF-GHG)model.Our China Carbon Monito ring and Verification Support at the Regional level(CCMVS-R)system can continuously assimilate information on atmospheric CO_(2)and other related information and realize the inversion of regional and local anthropogenic carbon emissions and natural terrestrial ecosystem carbon exchange.Atmospheric CO_(2)data were collected from six ground-based monito ring sites in Shanxi Province,China to verify the inversion effect of regio nal anthropogenic carbon emissions by setting ideal and real experiments using a two-layer nesting method(at 27 and 9 km).The uncertainty of the simulated atmospheric CO_(2)decreased significantly,with a root-mean-square error of CO_(2)concentration values between the ideal value and the simulated after assimilation was close to 0.The total anthropogenic carbon emissions in Shanxi Province in 2019 from the assimilated inversions were approximately 28.6%(17%-38%)higher than the mean of five emission inventories using the bottomup method,showing that the top-down CCMVS-R system can obtain more comprehensive information on anthropogenic carbon emissions. 展开更多
关键词 CCMVS-R regional carbon assimilation system Anthropogenic carbon emissions CO_(2) POD 4DVar
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Leave or Stay?Antecedents of High-level Talent Migration in the Pearl River Delta Megalopolis of China:from a Perspective of Regional Differentials in Housing Prices
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作者 SHEN Chen WANG Yang +1 位作者 ZUO Jian Raufdeen RAMEEZDEEN 《Chinese Geographical Science》 SCIE CSCD 2023年第6期1068-1081,共14页
Rapid urbanization and population growth have triggered an increase in urban housing demand and rising housing prices,which can influence the migration intention of high-level talents.Much work within the literature h... Rapid urbanization and population growth have triggered an increase in urban housing demand and rising housing prices,which can influence the migration intention of high-level talents.Much work within the literature has focused more on the migration of the general public.However,antecedents of migration intention and the impact of housing prices on the migration of high-level talents remain unclear.Therefore,based on the push-pull theory,this study investigates the influencing factors of talent migration intention and explores the role of housing prices.This study reveals a complex mechanism underlying migration decisions by using logistic regression models and survey data of high-level talents in the Pearl River Delta(PRD)megalopolis of China.The results indicate that:1)in high house-price regions,social integration is the primary push factor,and the main factors for retaining talents are the expectation of future work and intimate family relationships;2)in medium house-price regions,the main factors that attract talents are the current salary level and close family ties;3)in low house-price regions,living convenience is a determining factor in retaining talents.This study provides a new perspective for talent mobility research and offers valuable inputs for retaining and attracting talents in different economic development regions.Findings are of great significance for formulating talent introduction policies and forming a new pattern of rational spatial docking and effective allocation of human resources. 展开更多
关键词 destination choice migration intention high-level talents house-price pressure push-pull theory the Pearl River delta megalopolis of China
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中国ETF期权Delta对冲收益的日夜特征研究
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作者 刘彦初 汤昊文 钱潮阳 《管理科学学报》 CSCD 北大核心 2024年第2期136-158,共23页
期权市场是现代金融市场的重要组成部分,研究期权市场Delta对冲收益的日夜特征,对于理解期权市场运行机制以及降低金融市场风险具有重要意义.本文使用我国2015年—2021年股票ETF期权数据,研究了期权Delta对冲收益的日夜特征.研究结果表... 期权市场是现代金融市场的重要组成部分,研究期权市场Delta对冲收益的日夜特征,对于理解期权市场运行机制以及降低金融市场风险具有重要意义.本文使用我国2015年—2021年股票ETF期权数据,研究了期权Delta对冲收益的日夜特征.研究结果表明,总体上Delta对冲的隔夜收益为负、日内收益不显著;认购期权和认沽期权的Delta对冲收益具有非对称性,即认购期权日内为负、隔夜为正,而认沽期权恰好相反.即使替换为基于波动率和标的资产价格关系的对冲模型,非对称性异象仍然存在.这些发现不同于美国期权市场的Delta对冲收益日内为正、隔夜为负的特征.本文进一步探讨了可能的成因:从风险溢价看,波动率风险溢价可以解释总体上负的隔夜对冲收益,但是不能解释Delta对冲收益的非对称性;从模型误差看,模型误差与标的资产收益共同作用影响了Delta对冲收益;从交易制度看,T+1交易制度约束造成了标的资产日夜收益反转,进而导致了对冲收益的非对称性,并且T+1交易制度约束越强,对冲收益的非对称性越明显.本文将丰富我国期权市场Delta对冲效率、交易制度对金融市场影响的相关研究,有利于提高投资者的风险管理水平、增进监管者对市场行为的理解,从而推动中国多层次资本市场的高质量发展. 展开更多
关键词 ETF期权 delta对冲收益 日内和隔夜 风险溢价 模型误差 T+1交易制度
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Does digitalization mitigate regional inequalities?Evidence from China
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作者 Haimeng Liu Xinyang Wang +1 位作者 Zheye Wang Yu Cheng 《Geography and Sustainability》 CSCD 2024年第1期52-63,共12页
Regional inequality significantly influences sustainable development and human well-being.In China,there exists pronounced regional disparities in economic and digital advancements;however,scant research delves into t... Regional inequality significantly influences sustainable development and human well-being.In China,there exists pronounced regional disparities in economic and digital advancements;however,scant research delves into the interplay between them.By analyzing the economic development and digitalization gaps at regional and city levels in China,extending the original Cobb-Douglas production function,this study aims to evaluate the impact of digitalization on China's regional inequality using seemingly unrelated regression.The results indicate a greater emphasis on digital inequality compared to economic disparity,with variable coefficients of 0.59 for GDP per capita and 0.92 for the digitalization index over the past four years.However,GDP per capita demonstrates higher spatial concentration than digitalization.Notably,both disparities have shown a gradual reduction in recent years.The southeastern region of the Hu Huanyong Line exhibits superior levels and rates of economic and digital advancement in contrast to the northwestern region.While digitalization propels economic growth,it yields a nuanced impact on achieving balanced regional development,encompassing both positive and negative facets.Our study highlights that the marginal utility of advancing digitalization is more pronounced in less developed regions,but only if the government invests in the digital infrastructure and education in these areas.This study's methodology can be utilized for subsequent research,and our findings hold the potential to the government's regional investment and policy-making. 展开更多
关键词 regional inequality regional disparities Digital divide DIGITALIZATION Sustainable development Economic growth Seemingly unrelated regression
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Assessment of plant diversity of endemic species of the Saharo-Arabian region in Egypt
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作者 Asmaa S ABO HATAB Yassin M AL-SODANY +2 位作者 Kamal H SHALTOUT Soliman A HAROUN Mohamed M EL-KHALAFY 《Journal of Arid Land》 SCIE CSCD 2024年第7期1000-1021,I0002-I0044,共65页
Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emira... Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert(the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone(SS1) distributes all the 126 endemic species, Arabian regional subzone(SS2) owns 79 taxa, and Nubo-Sindian subzone(SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis(TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., Ⅰ Asphodelus refractus group, Ⅱ Agathophora alopecuroides var. papillosa group, Ⅲ Anvillea garcinii group, Ⅳ Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, Ⅵ Scrophularia deserti group, and Ⅶ Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region. 展开更多
关键词 ENDEMISM phytogeographical regions Saharo-Arabian floristic region Egyptian flora plant diversity two-way indicator species analysis(TWINSPAN)
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Investigation of Groundwater Quality with Borehole Depth in the Basin Granitoids of the Ashanti Region of Ghana
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作者 Bernard Ofosu Augustine Kofi Asante +2 位作者 Festus Anane Mensah Umar-Farouk Usman Naa Korkoi Ayeh 《Journal of Water Resource and Protection》 CAS 2024年第5期381-394,共14页
The dependence of groundwater quality on borehole depth is usually debatable in groundwater studies, especially in complex geological formations where aquifer characteristics vary spatially with depth. This study ther... The dependence of groundwater quality on borehole depth is usually debatable in groundwater studies, especially in complex geological formations where aquifer characteristics vary spatially with depth. This study therefore seeks to investigate the relationship between borehole depth and groundwater quality across the granitoid aquifers within the Birimian Supergroup in the Ashanti Region. Physicochemical analysis records of groundwater quality data were collected from 23 boreholes of public and private institutions in the Ashanti Region of Ghana, and the parametric values of iron, fluoride, total hardness, pH, nitrate, and nitrite were used to study the groundwater quality-depth relationship. The results showed that the depth-to-groundwater quality indicated a marginal increase in water quality in the range of 30 to 50 m, which is mathematically represented by the low-value correlation coefficient (r<sup>2</sup> = 0.026). A relatively significant increase occurs in the depth range of 50 to 80 m, which is given by a correlation coefficient of r<sup>2</sup> = 0.298. The mean percent parameter compatibility was 74%, 82%, 89%, and 97% at 50, 60, 70, and 80 m depths, respectively. The variations in groundwater quality per depth ratio ranged from 1.48, 1.37, 1.27, and 1.21 for 50, 60, 70, and 80 m depth, respectively. The recommended minimum borehole depth for excellent groundwater quality is suggested with a compatibility per meter depth ratio of 1.37. This results in a range between 50 and 70 m as the most desirable drilling depth for excellent groundwater quality within the granitoids of the Birimian Supergroup of the Ashanti Region in Ghana. 展开更多
关键词 Groundwater Quality Borehole Depth Birimian Supergroup Granitoid Aquifers Ashanti region
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Management of autoimmune hepatitis induced by hepatitis delta virus
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作者 Eleni Gigi Vasileios Lagopoulos Aris Liakos 《World Journal of Gastroenterology》 SCIE CAS 2024年第8期799-805,共7页
Approximately 12-72 million people worldwide are co-infected with hepatitis B virus(HBV)and hepatitis delta virus(HDV).This concurrent infection can lead to several severe outcomes with hepatic disease,such as cirrhos... Approximately 12-72 million people worldwide are co-infected with hepatitis B virus(HBV)and hepatitis delta virus(HDV).This concurrent infection can lead to several severe outcomes with hepatic disease,such as cirrhosis,fulminant hepatitis,and hepatocellular carcinoma,being the most common.Over the past few decades,a correlation between viral hepatitis and autoimmune diseases has been reported.Furthermore,autoantibodies have been detected in the serum of patients co-infected with HBV/HDV,and autoimmune features have been reported.However,to date,very few cases of clinically significant autoimmune hepatitis(AIH)have been reported in patients with HDV infection,mainly in those who have received treatment with pegylated interferon.Interestingly,there are some patients with HBV infection and AIH in whom HDV infection is unearthed after receiving treatment with immunosuppressants.Consequently,several questions remain unanswered with the challenge to distinguish whether it is autoimmune or“autoimmune-like”hepatitis being the most crucial.Second,it remains uncertain whether autoimmunity is induced by HBV or delta virus.Finally,we investigated whether the cause of AIH lies in the previous treatment of HDV with pegylated interferon.These pressing issues should be elucidated to clarify whether new antiviral treatments for HDV,such as Bulevirtide or immu-nosuppressive drugs,are more appropriate for the management of patients with HDV and AIH. 展开更多
关键词 Autoimmune hepatitis Hepatitis delta virus Bulevirtide PREDNISOLONE
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Enhancing Autonomy Capability in Regional Power Grids:A Strategic Planning Approach withMultiple Autonomous Evaluation Indexes
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作者 Jie Ma Tong Zhao +8 位作者 Yuanzhao Hao Wenwen Qin Haozheng Yu Mingxuan Du Yuanhong Liu Liang Zhang Shixia Mu Cuiping Li Junhui Li 《Energy Engineering》 EI 2024年第9期2449-2477,共29页
After the integration of large-scale DistributedGeneration(DG)into the distribution network,the randomness and volatility of its output result in a reduction of spatiotemporal alignment between power generation and de... After the integration of large-scale DistributedGeneration(DG)into the distribution network,the randomness and volatility of its output result in a reduction of spatiotemporal alignment between power generation and demand in the distribution network,exacerbating the phenomenon of wind and solar power wastage.As a novel power system model,the fundamental concept of Regional Autonomous Power Grids(RAPGs)is to achieve localized management and energy autonomy,thereby facilitating the effective consumption of DGs.Therefore,this paper proposes a distributed resource planning strategy that enhances the autonomy capabilities of regional power grids by considering multiple evaluation indexes for autonomy.First,a regional Energy Storage(ES)configuration strategy is proposed.This strategy can select a suitable reference value for the upper limit of ES configuration based on the regional load andDGoutput to maximize the elimination of source load deviations in the region as the upper limit constraint of ES capacity.Then,a control strategy for regional ES is proposed,the charging and discharging reference line of ES is set,and multiple autonomy and economic indexes are used as objective functions to select different proportions of ES to control the distributed resources of the regional power grid and establish evaluation indexes of the internal regional generation and load power ratio,the proportion of power supply matching hours,new energy consumption rate and tie line power imbalance outside the region to evaluate changes in the regional autonomy capabilities.The final simulation results showthat in the real regional grid example,the planning method in the planning year in the region of the overall power supply matching hour ratio and new energy consumption rate increased by 3.9%and 4.8%on average,and the power imbalance of the tie line decreased by 7.8%on average.The proposed planning approach enables the maximization of regional autonomy while effectively smoothing the fluctuation of power exchange between the regional grid and the higher-level grid.This presents a rational and effective planning solution for the regional grid,facilitating the coordinated development between the region and the distribution network. 展开更多
关键词 regional autonomous power grid distributed generation distributed energy storage regional planning strategy evaluation index
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Assessment of Groundwater Physico-Chemical Quality in the Ouémé Delta (Southern-Benin)
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作者 Aoulatou Alassane Zakari Dadja Toyou Masamaéya Gnazou +5 位作者 Abdoukarim Alassane Kodjo Apelete Raoul Kpegli Ousmane Touré Boukari Bio Guidah Chabi Bénito Didier Koukpohounsi Daouda Mama 《Journal of Environmental Protection》 2024年第3期298-317,共20页
Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural ... Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural and industrial activities have resulted in a deterioration in the quality of these resources. To assess the quality of the delta’s groundwater and its suitability for human consumption and irrigation, a total of fourteen (14) physico-chemical parameters were analyzed in some forty existing water points between September 2020 and March 2021, using standard water analysis techniques. The values obtained were compared with the potability standards recommended by the World Health Organization (WHO) and the Republic of Benin and were subjected to statistical analysis (principal component analysis (PCA)). In addition, methods for determining the suitability of water for irrigation were used. The results showed that the waters are acidic to slightly neutral and influenced by ambient temperature. In addition, the waters are moderately mineralized, with conductivities (24 - 1205 μS/cm) in line with WHO standards. A comparison of the analytical results of the WHO (2017) and Benin (2001) standards indicates that the majority of the waters studied are of good quality for all the chemical parameters considered. Nevertheless, some samples show levels of nitrates (21%), potassium (14% to 16%), calcium (13%), ammonium (12%), nitrites (8%) and bicarbonates (10%) over their respective standards. The Wilcox and Riverside diagrams indicate that the majority of waters (90%) have excellent suitability for irrigation and no negative effect on soil fertilization. 展开更多
关键词 BENIN Ouémédelta GROUNDWATER Physico-Chemical Quality Consumption IRRIGATION
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Uncertainties of ENSO-related Regional Hadley Circulation Anomalies within Eight Reanalysis Datasets
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作者 Yadi LI Xichen LI +3 位作者 Juan FENG Yi ZHOU Wenzhu WANG Yurong HOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期115-140,共26页
El Nino-Southern Oscillation(ENSO),the leading mode of global interannual variability,usually intensifies the Hadley Circulation(HC),and meanwhile constrains its meridional extension,leading to an equatorward movement... El Nino-Southern Oscillation(ENSO),the leading mode of global interannual variability,usually intensifies the Hadley Circulation(HC),and meanwhile constrains its meridional extension,leading to an equatorward movement of the jet system.Previous studies have investigated the response of HC to ENSO events using different reanalysis datasets and evaluated their capability in capturing the main features of ENSO-associated HC anomalies.However,these studies mainly focused on the global HC,represented by a zonal-mean mass stream function(MSF).Comparatively fewer studies have evaluated HC responses from a regional perspective,partly due to the prerequisite of the Stokes MSF,which prevents us from integrating a regional HC.In this study,we adopt a recently developed technique to construct the three-dimensional structure of HC and evaluate the capability of eight state-of-the-art reanalyses in reproducing the regional HC response to ENSO events.Results show that all eight reanalyses reproduce the spatial structure of HC responses well,with an intensified HC around the central-eastern Pacific but weakened circulations around the Indo-Pacific warm pool and tropical Atlantic.The spatial correlation coefficient of the three-dimensional HC anomalies among the different datasets is always larger than 0.93.However,these datasets may not capture the amplitudes of the HC responses well.This uncertainty is especially large for ENSO-associated equatorially asymmetric HC anomalies,with the maximum amplitude in Climate Forecast System Reanalysis(CFSR)being about 2.7 times the minimum value in the Twentieth Century Reanalysis(20CR).One should be careful when using reanalysis data to evaluate the intensity of ENSO-associated HC anomalies. 展开更多
关键词 regional Hadley circulation ENSO atmosphere-ocean interaction reanalysis data
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Evaluation of formation susceptibility and sand production potential in an offshore field,Niger Delta Basin,Nigeria
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作者 David O.Ubuara Yinka A.Olayinka +1 位作者 Godwin O.Emujakporue Geoffrey C.Soronnadi-Ononiwu 《Energy Geoscience》 EI 2024年第1期1-11,共11页
Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil facilities.The vulnerability of lithologic for... Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil facilities.The vulnerability of lithologic formations to wellbore instability and resultant sand production is investigated in the four delineated reservoirs of the“Areo”field,western part of Niger Delta Basin.The foundation for establishing the geomechanical properties in this study was a 1-dimensional mechanical earth model,using gamma ray(GR),density(RHOB),compressional slowness(DTC),and shear slowness(DTS)logs.Within the Areo oil field,two wells(well 001 and well 002)were correlated.The evaluated formations are still primarily composed of compacted shale and unconsolidated sandstone,with reservoir sand units exhibiting lower elastic and rock strength properties than shale units.High compressibility and porosity make sand more brittle,while low compressibility and porosity make shale stiffer due to high moduli.The maximum force that can be applied to a shale unit without causing it to fail is 17.23 MPa,which is the maximum average rock strength of the shale.It means that shale requires more vertical stress or pressure than sand does in order to deform it(15.06 MPa).The three sand prediction approaches used in the analysis of sand production predictions have cut-off values that are higher than the average values of the formations.The Schlumberger sand production index method(S/I)indicates that the reservoir has potential for sand influx in the two wells,with the average of the four reservoirs studied in wells 001 and 002 being 1.551012 psi and 1.141012 psi respectively.However,when a formation's sand production index is less than 1.241012 psi,as it is in this study,the formation is likely to produce sand.These findings support the notion that the defined sandstone units are highly unconsolidated and have a high potential for producing sands;therefore,sand control techniques must be factored into process optimization and cost reduction plans. 展开更多
关键词 Wireline log Stress Geo-mechanicanical characterization Sand prediction Niger delta
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Regional economic assessment of a novel place-based model for sustainable food systems
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作者 Susanna Kujala Kari Koppelmäki 《Geography and Sustainability》 CSCD 2024年第2期220-229,共10页
Several actions from both the environmental and human viewpoints have already been made to meet the sustainability goals targeted at food systems.Still,new place-based ideas to improve sustainability are needed.Agroec... Several actions from both the environmental and human viewpoints have already been made to meet the sustainability goals targeted at food systems.Still,new place-based ideas to improve sustainability are needed.Agroecological symbiosis(AES),a novel food system model,is an example of a suggested system-level change to attain sustainability targets;it is a symbiosis of food production and processing using renewable energy that uses its own feedstock.AES has already been found advantageous from the ecological and biophysical viewpoints,but a regional economic evaluation of the model is still lacking.Thus,the aim of our paper is to assess the regional economic impact of a possible systemic change in the food system using the network of agroecological symbiosis(NAES)as an example.We applied scenarios representing different ways of moving towards envisioned NAES models in Mäntsälä,Finland,and a computable general equilibrium model to evaluate the regional economic impact.According to our results,both regional economy and employment would increase,and the regional production base would diversify with NAES implementation applied to the region,but the extent of the benefits varies between scenarios.The scenario that includes change in both public and private food demand,production of bioenergy and utilization of by-products would cause the largest impacts.However,realizing NAES requires investments that may influence the actual implementation of such models.Nonetheless,a change towards NAES can promote an economically and spatially just transition to sustainability,as NAES seems to be economically most beneficial for rural areas. 展开更多
关键词 SUSTAINABILITY regional economy Localized food system Renewable energy CIRCULARITY
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Factors of Adherence to Concurrent Tuberculosis Treatment and Antiretroviral Therapy among HIV-TB Co-Infected Individuals in the East Region, Cameroon in the COVID-19 Era: A Retrospective Cohort Study
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作者 François Anicet Onana Akoa Ulrich Dama +5 位作者 Jean Ndibi Abanda Alphonse Tedonge Asobochia Melkior Fobasso Dzeuta Pearl Nsom Mbu Yokyu Zachary Pangwoh Pierre Yassa Yoniene 《Health》 2024年第2期131-147,共17页
Context/Objectives: Tuberculosis (TB) and HIV co-infection is a serious health problem in Cameroon. The problems associated with poor adherence to treatment are on the increase worldwide. This problem can be observed ... Context/Objectives: Tuberculosis (TB) and HIV co-infection is a serious health problem in Cameroon. The problems associated with poor adherence to treatment are on the increase worldwide. This problem can be observed in all situations where patients are required to administer their own medication, whatever the type of illness. The general objective of this study was to assess the factors affecting adherence to treatment among HIV-TB co-infected patients in health facilities in the East Region in the COVID context. Method: A retrospective cohort study before and during COVID-19 was conducted in HIV care units in 13 health districts in the East Region of Cameroon. Data were collected using a questionnaire recorded in the Kobo Collect android application, analyzed using SPSS version 25 software and plotted using Excel. Results: The pre-COVID-19 cohort compared to the during-COVID-19 cohort had a 1.90 risk of not adhering to treatment (OR: 1.90, CI {1.90 - 3.37}) and the difference was statistically significant at the 5% level (p-value = 0.029). Frequency of adherence was 65.4% (140/214). Adherence before COVID-19 was 56.9% whereas during COVID-19, it was 74.3%. Conclusion: The implementation of targeted interventions in the COVID-19 context, using evidence-based data and integrating the individual needs of HIV-TB co-infected patients, improved adherence to concurrent anti-tuberculosis treatment and antiretroviral therapy during the COVID-19 Era. 展开更多
关键词 Factors of Adherence Tuberculosis Treatment Antiretroviral Therapy HIV-TB Co-Infection East region Cameroon
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