Identifying the Hydrochemical Characteristics,Genetic Mechanisms and Potential Human Health Risks of Fluoride and Nitrate Enriched Groundwater in the Tongzhou District,Beijing,North China

Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.

Effects of drip and flood irrigation on carbon dioxide exchange and crop growth in the maize ecosystem in the Hetao Irrigation District,China

Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.

Properties and Characterization of Two Clays Raw Material from Mountain District (West of Côte d’Ivoire) for Use in Low-Carbon Cements

This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.

Evaluation of the Resuscitation of the Newborn in the Birth Room of the Maternity Ward of the Gynecology-Obstetrics Department of Reference Health Center (RHC) of the District V of Bamako, Mali

Birth is the transition from fetal life to ectopic life. This transition is usually smooth. Only 10% of newborns will need birth assistance. Successful resuscitation is linked to the skills of the health worker. It is to assess their skills that this work was undertaken with the objective of evaluating the practice of neonatal resuscitation in the delivery room of the RHC maternity hospital in District V of Bamako. Methodology: This was a descriptive cross-sectional study over a four-month period. We included in the study all live newborns who had a gestational age greater than or equal to 32 weeks and who had an Apgar score at the first minute of less than 7. At each birth, we observe the health agent responsible for the care of the newborn by observing the preparation of resuscitation and compliance with the neonatal resuscitation algorithm. We have excluded all newborns who met our inclusion criteria, were reanimated outside of our collection time and had visible or diagnosed anomalies or malformations in the prenatal period, and those whose parents refused to give their consent to participate in the study. Data were collected from the survey sheet and analyzed with the Statistical Package for Social Sciences (SPSS) software version 25. Results: We observed a 24.66% frequency of neonatal resuscitation. Pregnancies were too close in 15% (less than one year). Caesarean section delivery represented 34% of the sample. They were at term in 93% of cases. All newborns were well dried (98.5%), with wet linen change only at 49.5%. Apgar was less than 3 in 7.5% of newborns at first. The resuscitation needs were for the absence of a scream in 78.5% of cases and or heart rate Conclusion: The study evaluated neonatal resuscitation practices at a maternity hospital in Bamako, Mali. It found a 24.66% resuscitation rate, with a 95.5% success rate despite technical limitations. Most steps were correctly applied, though some improvements are needed in areas like preventing hypothermia and equipment preparation.

Optimization of Agricultural Industrial Structure in Changping District of Beijing Based on Grey Relational Analysis

In the economic development of Beijing,although the share of the total amount of agricultural industry in the overall economy is relatively low,it has an important impact on the daily life of residents,social stability and the development of other industries.Changping District,as an important agricultural production base of Beijing,its agricultural development has an indispensable strategic significance for the stability and growth of the entire regional economy.Therefore,it is very important to study the structure of agricultural industry in Changping District.Based on the detailed analysis of the agricultural industrial structure of Changping District,this paper uses the grey relation theory to analyze the different industries in the agricultural industrial structure of Changping District,including planting,forestry,animal husbandry,fishery and agricultural,forestry,service industries,in order to reveal the impact of these industries on the agricultural industrial structure of Changping District.Through this study,it comes up with specific and feasible suggestions for the optimization of agricultural industrial structure in Changping District,and provides valuable reference for the agricultural development of other areas in Beijing.

Spectral matching based remote sensing identification of two main crop rotation patterns in a large irrigation district

The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.

Improving the Quality of Public Space in Old Residential Areas Based on Superposition and Intervention:A Case Study of Baihuazhou District of Nanchang City

With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new standards have been put forward for the quality of public spaces for living.This paper analyzes and sorts out the characteristics and problems of the public space in the old residential areas of Baihuazhou district.Combining superposition and intervention techniques,the spatial,historical,cultural and other characteristic elements of the residential areas are preserved to the greatest extent.The public space in the old residential areas of Baihuazhou District is updated and reconstructed in order to achieve the goal of improving the quality of its public space.

Analysis of Characteristics and Meteorological Influencing Factors of Air Pollution in Luojiang District,Deyang City

Based on the monitoring data of ambient air quality and meteorological observation data,the characteristics and meteorological influencing factors of air pollution in Luojiang District of Deyang City from 2018 to 2022 were analyzed.The results show that from 2018 to 2022,the main air pollutants affecting the air quality of Luojiang District of Deyang City were PM_(2.5) and PM_(10),and the primary pollutant on heavy pollution days was basically PM_(2.5).PM_(2.5) and PM_(10) pollution showed obvious seasonal differences,and PM_(2.5) concentration exceeded the limit mainly in spring and winter,among which it was the most serious in early spring,especially in January and February,followed by December.PM_(10) exceeding the standard had a high seasonal correlation with PM_(2.5) exceeding the standard,mainly in spring and winter,among which it was the most serious in winter,especially in December,followed by January.PM_(2.5) and PM_(10) pollution showed an overall weakening trend.PM_(2.5) and PM_(10) concentration were closely related to meteorological factors such as temperature,relative humidity,wind speed,precipitation and air pressure,and were mainly affected by rainfall.

跨流域调水前后白洋淀淀区水资源短缺风险分析

跨流域调水深刻改变了白洋淀淀区下垫面的供水条件,揭示淀区下垫面供水量与实际蒸散发量(ET a)的关系对于淀区用水安全和水资源管理具有重要意义。采用基于Budyko理论的傅抱璞经验公式对白洋淀淀区的ET a进行计算,然后运用Archimedean Copula函数对淀区不同供水组合与ET a的联合分布进行研究。结果表明:跨流域调水前后白洋淀淀区多年平均ET a分别为547.24、583.96 mm,且ET a变化趋势与下垫面的供水变化趋势相同;不同Archimedean Copula函数均可较好地描述下垫面供水量与ET a的相依关系和联合概率分布特性;同时段“P+R+Q与ET a”与“P+R与ET a”的联合概率相比下降了0.06,条件概率下降了0.04,条件重现期增加了6.67年,在二者均值所构建的联合分布中,联合概率下降了0.10,条件概率下降了0.26。以上结果表明,实施跨流域调水工程以来,白洋淀淀区水资源短缺风险有所降低。

易地扶贫搬迁脱贫人口的人力资本、生计模式与脱贫脆弱性——基于凉山彝区大型易地扶贫搬迁安置点的调研分析

基于凉山彝区大型易地扶贫搬迁安置点1034户脱贫家庭的调研数据,实证分析人力资本对脱贫脆弱性的影响及作用机制。研究发现:部分脱贫户的脱贫较为脆弱,但能够守住不发生规模性返贫的底线;人力资本对脱贫脆弱性具有显著的负向影响,引入工具变量后其结论仍然成立,采用因变量替换法检验后其结论仍然稳健;人力资本对脱贫脆弱性的作用没有安置点类型差异,但有家庭收入差异;生计模式在人力资本对脱贫脆弱性的影响中起到中介作用。因此,建议高度重视脱贫脆弱性高风险的家庭,持续强化脱贫家庭人力资本的提升,创新推动脱贫家庭的生计模式转型。

区域市场一体化与产业链韧性——基于“撤县设区”改革的准自然实验

以“撤县设区”改革的制度冲击作为区域市场一体化的指标表示,基于2009—2021年中国内地地区278个地级市的样本数据,采用广义双重差分方法,实证检验了区域市场一体化是否有助于提升产业链韧性。研究结果表明,市场一体化对产业链韧性有显著的促进作用,创新要素集聚、产业结构优化升级和市场规模扩大是市场一体化正向影响发挥的主要渠道。相比较而言,市场一体化对产业链韧性的促进作用在营商环境更优越、数字经济发展程度更高、规模更大的城市表现更为突出。并且,市场一体化的正向影响效应随着政府和市场关系的改善存在非线性递增特征,发育良好的要素市场和公平公正的法律制度环境更能充分释放市场一体化对产业链韧性的强化作用。

有机生态型废旧基质还田利用对辣椒生长及产量和经济效益的影响

通过探索有机生态型废旧基质的资源化、无害化利用新途径,使河西灌区有机生态型废旧基质得到资源化循环再利用。以辣椒品种美国红为指示作物,在河西绿洲灌区灌漠土区研究了有机生态型废旧基质还田对辣椒生长的影响。结果表明,施用废旧基质30 t/hm^(2)+80%常规施肥(N 300.0 kg/hm^(2)、P_(2)O_(5)96.0 kg/hm^(2)、K_(2)O 72.0 kg/hm^(2))时,辣椒折合产量最高,为32340 kg/hm^(2),较不施肥对照增产27.31%,较常规施肥处理(N 375.0 kg/hm^(2)、P_(2)O_(5)120.0 kg/hm^(2)、K_(2)O 90.0 kg/hm^(2))增产12.84%;产值、净产值均最高,分别达到71148.0、45742.0元/hm^(2),较不施肥对照分别增加15261.4、7705.4元/hm^(2),较常规施肥处理分别增加8096.0、4360.0元/hm^(2)。该有机生态型废旧基质还田配施化肥模式能有效提高辣椒产量、产值,建议在河西灌区灌漠土区辣椒生产上加以推广应用。

重大应急事件封闭管理下的城乡政区边界治理逻辑

重大传染病等应急公共卫生事件的肆虐常常始料未及,如何及时有效控制疫情的快速扩散,切断传导或传播途径的“封城”“封区”等空间封闭管理,成为重大疫情防控中的关键举措。作为具有中国特色的应急管理举措,空间封闭管控与政区边界紧密相关,然而依托政区边界进行封闭管理还存在诸多实践困境,尤其对以高复杂性与高流动性等为主要特征的超大特大城市而言,挑战更大。在阐释政区边界的属地化和一体化功能及其效应基础上,辨析了行政管控和社会主导的驱动机制,划分了政区边界治理的四类模式并提出了优化路径。

Soil vanadium pollution and microbial response characteristics from stone coal smelting district

A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.

Study on Methods of Evaluating Visual Landscapes in Historic and Cultural Districts

This paper with the purpose of protecting visual landscape environment in historical and cultural districts,analyzes categories and characteristics of historical and cultural districts from the perspective of visual landscape,finally with the assessment basis of "landscape picture" proposes the classification of areas of 5 different levels,that is,the optimal viewing gallery,the secondary viewing gallery,the optimal viewing surface,the secondary viewing surface,and the common viewing surface,explores an approach of evaluating pollution indexes in historic and cultural districts by comprehensively evaluating "landscape pictures" in those areas of different levels.

Analysis on Vapour Field for the Drought Causes in Beijing,Tianjin and Hebei Districts in Recent Years

The monthly variation,temporal-spatial distribution,transportation characteristics of vapour field at middle and lower atmosphere and their effects on drought in Beijing,Tianjin and Hebei districts were studied,which have a guiding significance on predicting climate and arranging agricultural production in the district.

Waterfront Landscape Planning along the Yihe River in the New District of Luoyang City in China

General situation of the Yihe River in the new district of Luoyang City and its evolution history were introduced and evaluated from 4 perspectives of water,embankment,vegetation and traffic accessibility.On this basis,orientation of waterfront landscape planning of the Yihe River in the overall urban planning of Luoyang City was proposed,and it was proposed that waterfront landscape planning in the study area should follow the principles of "ecological,cultural and regional,public,accessible and human-centered".It was to provide references for the landscape planning and design of the Yihe River in the new district of Luoyang City,and to promote its waterfront landscape construction.

乡村全面振兴背景下数字农业节庆新路径探析——以广州市花都区数字农业直播节为例

在乡村全面振兴的背景下,文章着眼于数字农业节庆新路径对广州市花都区数字农业直播节进行了研究,基于区域、企业和产品这三个维度分析数字农业直播节的运行机理,并指出了数字农业直播节的不足,最后建议花都区数字农业直播节围绕“广东盆景花卉之都”来打造IP形象,从区域形象、企业形象和产品形象三个方面更好地体现出来,打造特色产业和乡土特色品牌,助推产业融合发展和乡村全面振兴。

RS and GIS-based Analysis on Dynamic Changes of Landscape Pattern on Urban-rural Fringe——A Case Study of Licheng District, Jinan City of China

By using GIS, RS and landscape ecology, LandsatTM (1993 and 2009) and ETM (2001) remote sensing images of Licheng District of Ji’nan City, Shandong Province were interpreted, and dynamic changes of landscape pattern in the district were analyzed at the levels of class and landscape. The results showed that during the 16 years the landscape pattern in the district had changed significantly. (a) From the perspective of patch category, areas of arable land, woodland and grassland decreased unceasingly, and arable land accounted for the largest reduction from 488.15 km 2 in 1993 down to 324.37 km 2 in 2009, witnessing a reduction rate of 33.56%. But the patch quantity and fragmentation increased, patch connectivity reduced. Spatial pattern of construction land expanded and its area witnessed a significant increase of 147.05%. Patch cohesion index increased and connectivity grew better. (b) From the perspective of overall landscape, patch quantity, contagion and perimeter-area fractal dimension decreased, patch shape became simple, the Shannon’s diversity index, Shannon’s evenness index and splitting index increased, landscape heterogeneity rose. With the rapid social and economic development, landscape pattern will be more and more influenced by human behaviors

Tourism Development Paths for the Leap-forward Development of Ecological Civilization—A Case Study of Northern Doumen District in Zhuhai City,China

A section more than 300 km2 in the Northern Domen District of Zhuhai City was designed to the Ecological Agricultural Zone of Zhuhai City,on the basis of introducing connotations of ecological civilization and basic conditions of this district,it was proposed that the leap-forward development pattern from agricultural civilization to ecological civilization should be applied,and 2 realization paths were summarized as developing urban agriculture and ecotourism.Ecotourism development was taken as the focus,tourist resources in the study area introduced,and bottleneck of its ecotourism development analyzed(lack of unified planning,poor consciousness of protecting historical and cultural resources;backward infrastructure,poor attractiveness for investment;insufficient propaganda and popularity;backward product development and insufficient integration of existing scenic spots.From the perspective of bottleneck of ecotourism development,the development of eco-culture and sightseeing tourism was proposed,specifically,to build a tourism spatial layout of "one axis,two wings and four centers";establish a functional circle of eco-cultural tourism,including cultural and recreational ecosphere centering on Mount Huangyang,tidal land water system ecosphere with key nodes of Dongjiao and Xijiao Villages,modern eco-agricultural sightseeing tourist circle,intangible cultural tourist circle of the waterfront Baijiao Township.