New insights from low-temperature thermochronology into the tectonic and geomorphologic evolution of the south-eastern Brazilian highlands and passive margin

The South Atlantic passive margin along the south-eastern Brazilian highlands exhibits a complex landscape,including a northern inselberg area and a southern elevated plateau,separated by the Doce River valley.This landscape is set on the Proterozoic to early Paleozoic rocks of the region that once was the hot core of the Aracuai orogen,in Ediacaran to Ordovician times.Due to the break-up of Gondwana and consequently the opening of the South Atlantic during the Early Cretaceous,those rocks of the Araquai orogen became the basement of a portion of the South Atlantic passive margin and related southeastern Brazilian highlands.Our goal is to provide a new set of constraints on the thermo-tectonic history of this portion of the south-eastern Brazilian margin and related surface processes,and to provide a hypothesis on the geodynamic context since break-up.To this end,we combine the apatite fission track(AFT)and apatite(U-Th)/He(AHe)methods as input for inverse thermal history modelling.All our AFT and AHe central ages are Late Cretaceous to early Paleogene.The AFT ages vary between 62 Ma and90 Ma,with mean track lengths between 12.2μm and 13.6μm.AHe ages are found to be equivalent to AFT ages within uncertainty,albeit with the former exhibiting a lesser degree of confidence.We relate this Late Cretaceous-Paleocene basement cooling to uplift with accelerated denudation at this time.Spatial variation of the denudation time can be linked to differential reactivation of the Precambrian structural network and differential erosion due to a complex interplay with the drainage system.We argue that posterior large-scale sedimentation in the offshore basins may be a result of flexural isostasy combined with an expansion of the drainage network.We put forward the combined compression of the Mid-Atlantic ridge and the Peruvian phase of the Andean orogeny,potentially augmented through the thermal weakening of the lower crust by the Trindade thermal anomaly,as a probable cause for the uplift.

Knowledge and Practice of Breast Self-Examination among Female Undergraduates in South-Eastern Nigeria

Breast disease often presents as palpable masses (lumps), inflammatory lesions, nipple secretion, or mammography abnormalities;and this can be easily treated when discovered early. Breast Self-Examination (BSE) is the quickest and cheapest means of early breast cancer detection. The objective of this study was to determine the knowledge and practice of breast self-examination among female undergraduates in Owerri, south eastern Nigeria. A multi-stage sampling design was used to select participants. Interview using structured questionnaire was conducted on randomly selected respondents in six faculties from each tertiary institution. Questionnaire was prepared in English and was self-administered. Permission to conduct the survey was requested and obtained from the university ethical review board. Informed verbal and written consent was obtained from participants. Confidentiality of information was maintained throughout the study. Knowledge and practice of BSE was examined among 720 randomly selected female undergraduates aged 16 to 28 years. It was found that 98.9 percent have heard of BSE but only 32.5 percent of them performed this examination accurately and monthly as required. There is a statistically significant relationship between knowledge of risk factors for breast cancer and practice of BSE (χ2 = 31.17, P χ2 = 86.75, P χ2 = 75.94, P < 0.001). These female undergraduates had a poor knowledge of the right procedure and practice of BSE;therefore there is need for awareness creation on the risks of breast cancer and benefits of early detection among female undergraduates through breast self-examination.

An Assessment of Trends of Monthly Contributions to Seasonal Rainfall in South-Eastern Zimbabwe

Trends in the proportional contribution to the seasonal rainfall of each month were analyzed for the meteorological stations of Buffalo Range, Masvingo Airport and Zaka in South-Eastern Zimbabwe. Results found indicate the existence of some trends for all the stations and months. However, when subjected to a Mann-Kendel trend analysis, all the trends were found to be statistically not significant for all instances except for the month of October at the Zaka station. This month showed a significant trend of increasing proportional rainfall.

Assessment of Seed-Borne Plant Pathogenic Fungi Associated with Rice Crop in South-Eastern Nigeria

This study was conducted to assess the incidence of seed-borne fungi on rice seeds sourced from the major rice growing areas of South-Eastern Nigeria. The rice seeds were collected during the dry seasons between 2009 and 2010. Four hundred rice seeds randomly collected and surface sterilized by washing in 3% sodium hypochlorite and rinsed two times with sterile distilled water were placed in three circular rings inside the Petri dishes. The incubation was done one after the other for each variety from all the locations. Ten fungi species from eight genera were isolated from the rice seeds in all the rice growing areas of South-Eastern Nigeria. The fungi pathogens vary from one locality to another, as well as the frequency of occurrence. The pathogens isolated include： Fusarium moniliforme, F. solani, F. oxysporium, Aspergillus spp., Botridiploidia spp., Helminthosporium spp., Penicillium spp., Trichoconis padwickii, Curvularia oryzae and Phoma oryzae. Though, there was the presence of some seed-borne fungi in the rice seeds from the areas studied, most of the cultivars experienced up to 90% germination. But some cultivars had very low germination. IR 1416 from Arochukwu and GB90 from Arondiuzogu had less than 1% germination. This study shows that seed-borne organisms are major constraint in rice production in the South-Eastern states of Nigeria as a result of low seed germination stemmed from infestation of fungi organisms in the seeds.

Cardiovascular Risk Factors in South-Eastern Nigeria: A Community Based Survey

Background: Cardiovascular risk factors play a major role in cardiovascular disease burden worldwide. The prevalence is known to be in the increase especially in the developing countries. There is need for timely community based studies in order to keep tab with the current scope. It is against this background that we embarked on this cross-sectional community based study of the prevalence of selected cardiovascular risk factors in semi-urban community in Abakaliki Southeastern part of Nigeria in October 2016. Method: The consecutive consenting persons of 18 years and above were screened for selected cardiovascular risk factors in October 2016. Results: A total of 1074 adults were seen (males-567, females-507) with age range of 18 - 80 years and mean age of 35.63 ± 12.45 years. They were predominantly farmers, petty traders and artisans. The identified CVD risk factors were hypertension 285 (26.4%), alcohol abuse 131 (12.1%), obesity 122 (11.3%), diabetes 97 (9%), family history of stroke 87 (8.1%), smoking 74 (6.9%) and previous stroke 29 (2.7%). Conclusion: The cardiovascular risk factors were quite prevalent with male preponderance of alcohol abuse and smoking.

The Prevalence of Cigarette Smoking and Knowledge of Its Health Implications among Adolescents in Owerri, South-Eastern Nigeria

Despite the growing problem of global cigarette use, accurate information on the prevalence and pattern in Nigerian adolescents’ remains sparse. The aim of this study was to determine the prevalence of cigarette smoking among in-school male adolescents in Nigerian population and to assess their level of knowledge on the health effects of cigarette smoking. A descriptive cross-sectional study was carried out among 944 randomly selected in-school male adolescents in Owerri, south-east Nigeria, between September and November 2013. Information was obtained using a self-administered questionnaire. The findings indicated a prevalence of 15.3% for ever smoked adolescents and 11.2% for current smokers. The mean age at cigarette smoking initiation was 14 years. Sixty-three percent had good knowledge of health problems associated with cigarette smoking. Lung cancer was the most reported associated health problem. Fifty-two (36.1%) indicated that they were initiated by their friends who offered them their first stick of cigarette. The major reason for smoking cigarette the first time was to be like their friends/role model and out of curiosity. Poor knowledge of health effects of smoking was statistically associated with cigarette smoking (X2 = 26.82, p-value < 0.001). Knowledge of health problems associated with smoking proved to be the major reason for not smoking by never smoked adolescents, which means that awareness creation on health problems associated with cigarette smoking through health education in schools coupled with stiff legislative ban on sale of cigarette to adolescents will, to a reasonable extent, reduce the high prevalence of adolescent cigarette smoking in our society.

Micronutrient dynamics in some wetland soils of south-eastern Nigeria

The inventory of profile distribution of total iron (Fe), zinc(Zn), manganese(Mn) and copper(Cu) were determined in three different soil horizons each of the wetland soils selected form Mbiabet(MB), Nkari(NK) and Nkana(NA) in Ini Local Government Area of Akwa Ibom State. Total Fe ranged between 3 25 and 4 15 ppm. The average contents were 3 72, 3 91 and 3 62 ppm in Mbiabet(MB), Nkari(NK) and Nkana(NA) soils respectively. The total value of Zn also ranged between 2 4 and 4 9 ppm with the average content in each soil being 28.27, 17 73 and 36 53 ppm respectively. The amount of Fe and Zn in these soil profiles were strongly correlated with the clay content and high levels of organic matter of 3 70%, 2 47% and 2 5% respectively. The content clearly reflected a poor drainage conditions.In all the soil profiles Mn and Cu were detected in at least one of the soil horizons. However, Mn and Cu were not detected in the soil horizons at Nkari.Generally, the relative inventory of these micronutrients appeared to be influenced by pH, drainage pattern, organic matter and clay contents of these soils.The inventory of total values of the wetland soils considered are assessed in the light of establishing a baseline information.

烃相态录井在南海东部A井中的应用

近年来,南海东部引入烃相态录井,该录井技术主要通过检测钻井液中气态烃类对红外光的吸收变化规律来定性定量的快速评价储层流体性质。该技术采集时间短,检测范围宽,能够在8 s内识别出地层中C1~C5的含量变化,满足在快速钻井条件下,准确识别出油气水层的技术要求,同时该技术采用谱图形式直观表达解释成果,可视化程度高,在南海东部应用效果良好。

南水北调东线江苏段工程供水成本核算研究

围绕南水北调东线江苏段工程,基于规划与实际调水量、淮水利用比例、泵站开机等基本情况,探讨工程最新成本构成与核算方法,核算南水北调东线江苏段工程供水成本。通过分析各项费用、各个区段在单方水总成本中的占比,明晰供水成本结构特征,并对最易影响固定成本与可变成本变化的费用进行了敏感性分析,为相关供水成本体系研究提供参考。

南水北调东线一期工程受水区生态环境效益演变

研究南水北调东线一期工程通水以来受水区生态环境效益的演变态势,对南水北调后续工程高质量建设、加快构建国家水网以及促进工程综合效益发挥有决策参考作用。以定性定量相结合的方式分析东线一期工程在优化水资源配置、保障饮水安全、复苏河湖生态环境和畅通南北经济循环等方面的作用,进而结合层次分析法,从直接效益和间接效益2个方面,筛选构建东线一期工程受水区生态环境效益评价指标体系,主要包括工程年供水量、水质改善度、生态补水量、地下水压采量、地下水水位、水域面积、绿地面积和涵养水源等,并采用VlseKriterijumska Optimizacija I Kompromisno Resenje(VIKOR)多准则妥协解排序方法对南水北调东线一期工程通水以来即2013-2022年受水区生态环境效益演变态势进行分析。结果表明:南水北调东线一期工程通水的10年以来,受水区的生态环境整体复苏效果明显,近3年排序值保持在0.8以上;受降水偏枯进而影响地下水开采量和地下水水位等因素影响,2019年间接生态环境效益下降29.2%,之后迅速恢复并保持稳定。在分析直接效益和间接效益演变的基础上,从工程提质增效、提高工程水质状况以及完善体制机制建设等方面提出东线一期工程进一步促进受水区生态环境持续改善的策略和建议,以期为东线工程及受水区生态环境保护及高质量发展相关研究、决策制定等提供参考。

粤东连平—河源—汕尾地震测深剖面地壳速度结构及其意义

为适应防灾减灾工作的需要,广东省地震局联合中国地震局地球物理勘探中心、河南省地球物理空间信息研究院于2021年在粤东地区实施了人工地震宽角反射/折射探测,以期获得粤东地区深部地壳速度结构.本文采用地震射线走时正演对粤东地区NW向连平—河源—海丰测线数据进行了处理解释,构建了该剖面的二维壳幔速度结构模型.该模型表明,沿剖面自NW向SE,莫霍面深度由32 km缓慢抬升至29 km,广州—恩平断裂带、河源—邵武断裂带和政和—大埔断裂带的对应位置都显示莫霍面有抬升现象;研究区存在多条NE向展布深大断裂;中地壳发育低速异常区域(低速体)受断裂控制,主要分布于政和—大埔断裂带NW内陆方向,可能与中生代早期岩浆活动形成的花岗岩质岩浆相关.我们认为壳内低速区域(低速体)可能是影响研究区深部孕震环境的重要因素.

南海东部底水油藏水平井控水完井技术研究进展

南海东部底水油藏分布广泛,水平井开发方式可大幅度降低底水锥进速度,但由于水平段距离长,储层非均质性和水平井跟趾效应造成的点状见水易导致油井含水率大幅上升,降低生产效益。针对上述问题,南海东部油田采用ICD、AICD、C-AICD等控水工具,结合控水颗粒充填、智能分段分流等控水工艺,开展了底水油藏水平井控水完井技术研究与应用,取得显著效果。围绕南海东部底水油藏水平井控水完井技术研究进展,综合分析了不同控水方式的控水原理、技术特点和不同控水完井工具的特性曲线数学模型,总结了不同生产预测技术的应用规模和不同控水完井技术的应用效果。在此基础上提出了底水油藏水平井控水完井技术挑战和发展趋势,可为南海东部底水油藏水平井控水完井的进一步发展提供参考。

地层压力预测技术在南海东部高温高压井中的应用

近几年南海东部钻探高温高压井数逐渐增多,严重影响安全钻井和资料录取。文章介绍了惠州某构造A1探井因钻遇超压地层而提前完钻及高压成因分析,重新部署A2,开展钻前地层压力精细预测分析,预测目的层压力系数在1.500~1.600之间,指导A2井成功钻井,MDT实测压力系数为1.595,实现勘探目的。

南水北调东线江苏段典型泵站运行效率模拟模型

泵站机组运行受多种因素影响,导致泵站运行理论效率与实际效率误差较大。针对泵站机组运行效率精准模拟难题,运用基于高价多项式回归、回归树、多元线性回归、向量机回归、高斯过程回归、神经网络的10个回归算法,建立泵站机组效率模拟模型并开展对比分析,优选出有效的泵站运行效率模拟建模方法。讨论分析采用“上下游水位+流量”代替传统“扬程+流量”开展泵站运行模拟的效果。以南水北调东线邳州站和遂宁二站共8台机组的历史数据开展实例分析,相关实验结果表明:在所有方法中,高斯过程回归(Gaussian process regression,GPR)模型在均方根误差(ERMS)、平均绝对误差(EMA)、均方误差(EMS)、决定系数(R2)和最大个体误差(EMI)指标上综合表现最佳,R2逼近0.95;使用站上、站下水位代替传统的扬程对模型进行训练,所有模型的综合评价指标整体有所改善。综合来看,使用GPR模型并使用上游、下游水位代替扬程进行模拟效率表现最好,以邳州站4号机为例,可将模拟效率的EMA和EMI分别从16.49%和20.40%减少至0.41%和2.30%,研究成果具有一定实际意义,可为我国调水工程泵站经济运行提供有力支撑。

5月中国土壤湿度异常对7月华南-青藏高原东部偶极子型降水年际变化的影响

利用1979—2019年ERA5再分析资料和站点降水资料,研究了5月中国土壤湿度异常对7月华南和青藏高原东部偶极子型降水年际变化的影响及其可能的物理过程。结果表明,当5月青藏高原土壤湿度偏湿,华中地区土壤湿度偏干时,对应7月华南(高原东部)降水偏多(偏少),两地降水呈偶极子型分布。通过进一步的诊断分析发现,青藏高原(华中地区)土壤湿度正(负)异常可从5月持续至7月,使得7月中国北方地区地表湍流热通量正异常,进而使得对流层中低层大气增暖,中国北方与贝加尔湖之间经向温度梯度和大气斜压性增强,天气尺度的瞬变波活动增强。通过瞬变的涡度强迫有利于中国北方及蒙古地区准正压异常高压和Rossby波波源的形成,相关的Rossby波向东南方向传播至我国南方,使得华南地区出现准正压结构的异常低压,有利于西北太平洋副热带高压东移,南亚高压西移。对应中国北方及蒙古-华南地区对流层中低层为反气旋-气旋式环流异常,进而导致华南地区(高原东部)降水增多(减少)。此外,中国北方-蒙古地区的异常高压与局地偏干的土壤湿度之间的正反馈过程,有利于上述物理过程的维持和增强,进而有利于7月偶极子降水的异常,反之亦然。

冻融影响下生态系统服务价值和生态风险的时空演变特征及关联性——以南羌塘盆地东区为例

气候变化会显著影响冻土、冰川等对温度变化敏感的生态系统,造成区域生态系统服务价值和生态风险发生变化。为揭示气候变化对青藏高原典型冻土区域的生态系统服务价值的影响和可能造成的生态风险,基于2000-2020年土地利用数据,运用生态系统服务价值(Ecosystem Service Value,ESV)评估、生态风险指数(Ecological Risk Index,ERI)评估、双变量空间自相关、地理探测器等模型和方法,分析了南羌塘盆地东区ESV、ERI的时空演变、空间关联和空间分异特征。结果显示:(1)2000-2020年,南羌塘盆地东区ESV呈增长趋势,累计增长5.76%(276.98亿元),草地和水域贡献了超98.70%的ESV。研究区ESV总体呈中部高、四周低的分布格局,以中等价值区为主(面积约占研究区总面积的70.37%)。(2)研究区ERI整体呈上升趋势,总体呈东南低、西北高的分布格局,以极低风险区为主(面积约占研究区总面积的60.68%)。(3)研究区ESV和ERI具有空间负相关性(Moran s I<0),主要LISA聚类为低价值—低风险(面积约占研究区总面积的34.26%)。(4)区域ESV和ERI的空间分异受自然因子和经济因子共同作用影响,其中归一化植被指数为二者空间分异的主导因子(q值分别为0.55和0.19)。研究结果表明需根据研究区ESV和ERI的时空分布和变化特征,采取因地制宜的生态保护措施,推动区域生态环境的可持续发展。

中东欧国家与中国公路隧道防火理念对比研究——以黑山南北高速公路项目为例

为指导中国企业在中东欧国家进一步开展公路隧道建设,以中国企业在欧洲建设的最大公路基建项目黑山南北高速公路为例,进行公路隧道防火理念对比研究。黑山南北高速公路具备各类长度隧道16座,全过程基本采用欧洲标准建造,由欧洲公司进行监理,所选设备基本都在欧洲当地生产,因此其隧道防火理念可反映中东欧国家乃至整个欧洲地区的技术水平和建设理念,具备典型代表意义。采用比较分析法对隧道火灾风险评估报告、防火主设计、实施情况等进行分析研究,其中隧道火灾风险评估报告由具备欧盟认可的防火资质且独立于公路建设业主的第三方进行评估。评估主要针对与火灾安全相关的隧道设施配置规模,评估结论需提交给业主,并要求设计单位严格依据评估结果开展设计。同时也对中东欧国家和中国在公路隧道火灾安全风险评估、疏散逃生、消防救援、防火安全设计等理念上的差异进行综合对比。结果表明:中东欧国家公路隧道关于整体防火、防火分区、消防救援等防火理念相比中国更具有安全性、智能性,因此可为中国隧道防火安全建设提供一定借鉴,同时也可用于指导中国企业在中东欧乃至整个欧洲开展公路隧道建设。

基于耦合协调性的区域洪水资源利用评价

为全面理解和优化区域水资源利用格局、提高区域水资源利用率,以南水北调东线工程江苏段主要涉及的徐州、宿迁、淮安3个城市为研究对象,以2010-2022年数据为基础从基于洪水资源开发利用的水资源利用、经济社会发展、生态环境保护3个维度,采用共23项指标在使用熵权法确定权重的基础上,构建基于洪水资源开发利用的水资源利用-经济社会-生态环境系统容量耦合协调发展模型,并结合匹配度模型进行比较分析,运用障碍度模型分析影响耦合协调发展的因素。结果表明:3个城市的综合系统发展水平均由初级阶段上升到良好阶段。徐州、宿迁和淮安市的耦合协调度变化分别为勉强协调到良好协调、初级协调到良好协调以及初级协调到中级协调,而3个城市耦合协调度在后期均超越匹配度,达到理想协调状态。影响协调度的主要障碍因子为洪水资源利用潜力、森林覆盖率以及洪水资源量,且对于3个系统的障碍度分析,3个城市各自有不同的主导影响因素,徐州市复合系统耦合协调度主要受水资源利用影响较大,宿迁市受经济社会影响较大,而淮安市则受生态环境影响较大,因此,各市应当合理利用水库及蓄滞洪区的削峰、调蓄能力,增加洪水资源可利用量,提高洪水资源利用效率,降低洪灾发生频率,在保证经济和生态用水效率的同时,减少因洪灾带来的经济及生态损失。

南海东部E油田钙质夹层特征及影响

钙质夹层研究对储层精细研究具有重要意义。通过动静态资料分析,对南海东部E油田钙质夹层岩性、测井、分布特征及其对油田动态的影响开展了研究。结果表明,E油田分为三类钙质夹层:生物碎屑灰岩、含生屑砂岩、钙质砂岩,夹层厚度在0.2~1.5m之间,小于0.5m厚钙质夹层测井特征不明显;单砂体间钙质夹层平面展布在100m以上,且发育较连续;单砂体内部厚度小于0.5m钙质夹层平面展布范围小于100m;利用垂向0.2m网格建立地质模型,模型更符合动态特征。

南水北调东线工程江苏段泵站安全监测现状及专业化管理探讨

泵站是南水北调东线工程的主要组成部分,在运行期对泵站进行监测是保障东线工程安全运行的重要手段。为提高东线工程泵站群的安全监测专业化管理水平,通过实地考察、现场调研等手段,对东线工程江苏段宝应站、邳州站、金湖站、泗洪站、解台站等14座泵站的安全监测设施状况进行系统性的排查,并分析东线工程江苏段泵站的历年年度监测资料整编情况,结果表明:当前东线工程江苏段泵站主要存在自动化监测水平低、扬压力设施损坏严重、监测资料整编分析不规范等问题,难以全面准确地掌握泵站真实的运行状况。针对当前存在的问题,建议管理单位加强安全监测作业标准化建设并提高设施养护水平,开展安全监测系统鉴定和自动化升级改造,建立泵站工程安全监测监督平台和泵站群安全管理数字孪生体系,以实时掌握各泵站工作状态,保障泵站群安全运行。