Quantitative relationship between surface sedimentary diatoms and water depth in North-Central Bohai Bay,China

To study the quantitative relationship between surface sedimentary diatoms and water depth,67 surface samples were collected for diatom analysis on eight profiles with water depth variation from the muddy intertidal zone to the shallow sea area in North-Central Bohai Bay,China.The results showed that the distribution of diatoms changed significantly in response to the change in water depth.Furthermore,the quantitative relationship between the distribution of dominant diatom species,their assemblages,and the water depth was established.The water depth optima for seven dominant species such as Cyclotella striata/stylorum,Paralia sulcata,and Coscinodiscus perforatus and the water depth indication range of seven diatom assemblages were obtained in the study area above the water depth(elevation)of-10 m.The quantitative relationship between surface sedimentary diatoms and water depth provides a proxy index for diatom-paleo-water depth reconstruction in the strata in Bohai Bay,China.

Diagnostic Analysis on a Regional Rainstorm Weather in North-central Henan Province

[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.

Latest Zircon U-Pb Age of the Baiyingaolao Formation Volcanic Rocks in the Keyihe Area of North-Central Da Hinggan Mountains

Objective Mesozoic volcanic rocks are mainly distributed in the Da Hinggan Mountains.The Baiyingaolao Formation is the main stratum in this area and has been considered to be formed in the Late Jurassic.Many scholars have researched these Mesozoic volcanic rocks in this area,which have been much debatable（Zhang Xiangxin et al.,2017）.A series of studies focusing on the Baiyingaolao Formation volcanic rocks in the middle-south section of

Genetic diversity of Plasmodium falciparum isolates from naturally infected children in north-central Nigeria using the merozoite surface protein-2 as molecular marker

Objective: To characterize the genetic diversity of Plasmodium falciparum ( P. falciparum ) field isolates in children from Lafia, North-central Nigeria, using the highly polymorphic P. falciparum merozoite surface protein 2 (MSP-2) gene as molecular marker. Methods: Three hundred and twenty children were enrolled into the study between 2005 and 2006. These included 140 children who presented with uncomplicated malaria at the Dalhatu Araf Specialist Hospital, Lafia and another 180 children from the study area with asymptomatic infection. DNA was extracted from blood spot on filter paper and MSP-2 genes were genotyped using allele-specific nested PCR in order to analyze the genetic diversity of parasite isolates. Results: A total of 31 and 34 distinct MSP-2 alleles were identified in the asymptomatic and uncomplicated malaria groups respectively. No difference was found between the multiplicity of infection in the asymptomatic group and that of the uncomplicated malaria group ( P >0.05). However, isolates of the FC27 allele type were dominant in the asymptomatic group whereas isolates of the 3D7 allele type were dominant in the uncomplicated malaria group. Conclusions: This study showed a high genetic diversity of P. falciparum isolates in North-central Nigeria and is comparable to reports from similar areas with high malaria transmission intensity.

Geospatial Technology Potentials in Reawakening the Consciousness of Soil Distribution in Nigeria’s North-Central Region and Mediating the Herdsmen-Farmers Conflicts

The pervasive herdsmen-farmers conflicts in the north-central region of Nigeria have changed the narrative of Nigeria’s enduring ethnic crises to ideologies, which are in-controvertibly sinister. The consequences of this tension, which has defied possible military responses, political, religious and cultural strategies are potentially devastating, not just for Nigeria, but the whole of West African region. Since the particular nature of these conflicts increasingly highlights the significance and inevitability of land resources for crops farming and cattle rearing, it is imperative to create awareness of the elemental nature of soils, especially their diversities in these conflict-prone areas. This study’s objective was to produce a Geographic Information System (GIS) based digital soil map (DSM) of the north-central region of Nigeria, and to delineate soil distribution and unique properties. Based on this study, the DSM offers a quick access to quantitative soil data covering the study area. It indicates that soil mapping units 15d, 18d and 24b are dominant, and constitute about 40% of the local arable lands. The broad pattern of distribution of these soils reflects both the climatic conditions and the geological structure of the region. The soils are highly weathered with limited capacities to supply essential nutrients needed by crop plants. These issues raise a number of questions, most of which focuses on the best possible way to maximize these soils to accommodate both crop farming and cattle rearing. It is our hope that taking the advantage of GIS to stimulate the knowledge and consciousness of soil distribution in the region will place the weight where it is appropriate in terms of food security through crops production and cattle rearing, and hence forge a more realistic pathway to reconciliation and conflict resolution.

Knowledge, Attitude and Practice of Physicians in the Treatment of Hypertension in North-Central Nigeria

Background and Objectives: Hypertension is a global health hazard and most cases are first attended to by the physicians. Achieving a control will depend on the knowledge, attitude and practice of the physicians. We therefore determined the knowledge, attitude and practices of physicians on the detection and treatment of arterial hypertension in north-central Nigeria. Design and Methods: A cross-sectional study of 100 of the 250 physicians attending a continuing medical education lecture series in Bida was conducted using a pre-validated self administered questionnaire. Results: The mean age of the physicians was 41.05 ± 8.71 years and 59 (73.8%) were males. Forty-one (51.2%) of them have practiced for more than 10 years. Arterial hypertension was considered an important health problem by 93.8% of the physicians, 30% of them believed that it should not be referred to a specialist. Majority of the physicians request for urinalysis (96.2%), electrocardiogram (95.0%), fasting blood glucose (88.8%), blood urea nitrogen (98.8%) and fasting lipid profile (97.5%) to either assess target organ damage or associated co-morbid conditions. Fifty-seven (71.2%) of the physicians prescribe diuretics as the initial drug. However, the knowledge of the other drugs on initiation of therapy of mild uncomplicated hypertension was poor. The sources of information on arterial hypertension by physicians were scientific programs (73.8%), drug companies (38.8%) and journals in 11.3%. Conclusion: The knowledge, attitude and practice of physicians in the detection and management of hypertension were modest. Educative programs like continuing medical education, seminars, and conferences on cardiovascular disorders are advised to be organized regularly to strengthen these and update the physicians.

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-Central Nigeria

The Precambrian basement complex in the southernmost part of North-Central Nigeria is underlain by migmatitic banded gneisses, granitic intrusions and dykes of dolerite, rhyolite porphyry and pegmatite. The rocks are generally felsic, containing modal and normative hypersthene, as well as normative corundum. The basement complex has experienced high-grade regional metamorphism as indicated by the presence of hypersthene and plagioclase of andesine composition. Anatectic melting is suggested by the occurrence of ptygmatic folds, folded gneissose foliation, numerous quartzo-feldspathic veins and lenses of dark-colured, micaceous schistose rocks. Geochemically, the rocks have magnesian, calc-alkalic and strongly peraluminous characteristics. Their overall characteristics suggest derivation from progressive (fractional) partial melting of pelitic rocks during high-grade regional metamorphism, possibly associated with intense hydrothermal activities. The magnesian characteristics reflect close affinity to relatively hydrous, oxidizing melts and source regions in settings broadly related to subduction.

A hydrochemical study of the Hammam Righa geothermal waters in north-central Algeria

This study focuses on the hydrochemical characteristics of 47 water samples collected from thermal and cold springs that emerge from the Hammam Righa geothermal ?eld, located in north-central Algeria. The aquifer that feeds these springs is mainly situated in the deeply fractured Jurassic limestone and dolomite of the Zaccar Mount. Measured discharge temperatures of the cold waters range from 16.0 to 26.5 °C and the hot waters from 32.1 to 68.2 °C. All waters exhibited a near-neutral p H of 6.0–7.6. The thermal waters had a high total dissolved solids(TDS) content of up to 2527 mg/l, while the TDS for cold waters was 659.0–852.0 mg/l. Chemical analyses suggest that two main types of water exist: hot waters in the up?ow area of the Ca–Na–SO_4type(Hammam Righa) and cold waters in the recharge zone of the Ca–Na–HCO_3type(Zaccar Mount). Reservoir temperatures were estimated using silica geothermometers and?uid/mineral equilibria at 78, 92, and 95 °C for HR4, HR2,and HR1, respectively. Stable isotopic analyses of the δ^(18)O and δD composition of the waters suggest that the thermal waters of Hammam Righa are of meteoric origin. We conclude that meteoric recharge in?ltrates through the fractured dolomitic limestones of the Zaccar Mount and is conductively heated at a depth of 2.1–2.2 km. The hot waters then interact at depth with Triassic evaporites located in the hydrothermal conduit(fault), giving rise to the Ca–Na–SO_4water type. As they ascend to the surface,the thermal waters mix with shallower Mg-rich groundwater, resulting in waters that plot in the immature water?eld in the Na–K–Mg diagram. The mixing trend between cold groundwaters from the recharge zone area(Zaccar Mount) and hot waters in the up?ow area(Hammam Righa) is apparent via a chloride-enthalpy diagram that shows a mixing ratio of 22.6 \ R \ 29.2 %. We summarize these results with a geothermal conceptual model of the Hammam Righa geothermal ?eld.

川中地区北部下寒武统沧浪铺组一段风暴岩特征及沉积地质意义

川中地区北部下寒武统沧浪铺组风暴岩发育,但对该风暴岩沉积以及该区早寒武世沉积环境、古地理和沉积古地貌的研究较为薄弱。通过详细岩心观察及镜下薄片鉴定,研究了沧浪铺组风暴沉积序列和沉积模式,并揭示其地质意义。研究区沧浪铺组发育砾屑层、粒序段、平行层理和丘状交错层理等风暴沉积构造,可划分出5个风暴沉积序列,即:序列Ⅰ由砾屑段(A)、平行层理段(C)和丘状交错层理段(D)组成,在正常浪基面之上沉积;序列Ⅱ由平行层理段(C)、丘状交错层理段(D)和水平层理泥岩段(E)组成,位于风暴浪基面附近;序列Ⅲ由底冲刷面和砾屑段(A)和粒序段(B)构成,于正常浪基面和风暴浪基面之间;序列Ⅳ由粒序段(B)和平行层理段(C)组成,距离风暴中心远,沉积环境更靠近风暴浪基面附近;序列Ⅴ由底冲刷面和砾屑段(A)构成,位于平均海平面与正常浪基面之间且靠近正常浪基面。川中地区北部风暴岩的发现证实,沧浪铺组一段为陆棚—斜坡—台地边缘沉积,指示上扬子板块在沧浪铺组沉积期处于低纬度地区,这为岩相古地理恢复提供了约束;同时风暴作用形成连片分布的颗粒滩,有效提升储集相带的规模,有助于对颗粒滩相带的分布进行预测。

鄂尔多斯盆地中北部重力场及基底特征分析

鄂尔多斯块体是我国华北地区在新生代和现代构造活动中重要的活动块体,处于华北、华南和青藏3个板块的交接部位,其构造活动和动力学问题一直在基础地质问题领域中备受关注。同时,鄂尔多斯盆地作为我国重要的能源基地,查明基底特征对于区内沉积盖层构造变形、挠曲与次级断裂形成、深部物质和能量的交换、后期深部流体上升运移通道、中新生代盖层沉积碎屑物质来源、油气分布与富集、后期铀成矿铀源分析等也具有重要指示作用(王晓鹏等,2023)。

四川盆地中北部DB1井区灯影组四段沉积相及储层特征

四川盆地中北部(川中北部)灯影组四段(灯四段)储层岩性复杂,非均质性较强,限制了灯影组四段气藏的勘探。为了进一步深化川中北部DB1井区的沉积相及储层特征认识,通过钻井岩心及薄片资料的观察,并结合测井、录井、物性测试以及钻探成果等资料的综合分析,对川中北部DB1井区灯四段沉积相及储层特征进行研究。结果表明:研究区灯四段主要发育台地边缘和局限台地2种沉积亚相,进一步可识别出藻丘、颗粒滩和滩间海等沉积微相,其中藻丘微相主要发育藻凝块云岩和藻叠层云岩,颗粒滩微相主要发育砂屑云岩,滩间海微相主要发育泥晶云岩和粉晶云岩;藻丘和颗粒滩沉积主要发育在台缘一侧,向台内藻丘和颗粒滩沉积逐渐减少,以滩间海沉积为主;藻丘发育呈纵向叠置特征,横向延伸较近,且集中发育在灯四段上亚段,单体厚度较大,下亚段发育较少且厚度较薄;储集岩类型主要为藻凝块云岩、藻叠层云岩和砂屑云岩,储集空间主要为藻黏结格架孔、粒间溶孔和晶间溶孔;研究区岩心孔隙度分布在2.02%~6.03%,总体平均孔隙度为3.11%,岩心渗透率分布在0.00704~9.78 mD,总体平均渗透率为0.69264 mD,整体物性具有低孔特低渗透特征,部分样品由于受到裂缝的影响呈现低孔高渗透特征。

中国区域创新创业指数构建与空间格局(1990-2020)

创业和创新对于中国构建新发展格局,实现高质量发展至关重要。本文围绕企业家、资本与技术三大核心要素,运用北京大学企业大数据中心构建的包含全量企业信息的企业大数据资源,从新建企业数量、吸引外来投资、吸引风险投资、专利授权数量和商标注册数量五个维度,构建兼具客观性、实时性与多维性的中国区域创新创业指数,以反映中国各地区的创新创业活力与绩效。研究表明:第一,1990-2020年,中国各地区创新创业指数不断提高,创新创业绩效显著提升。第二,广东省、浙江省、江苏省、山东省、北京市和上海市创新创业绩效最强,西部省份创新创业活力严重不足。第三,1990-2020年间,南北方地区创新创业绩效的差距呈现U形态势,“南热北冷”形势不断加剧;与此同时,中部地区创新创业活力不断增强,呈现出“中部崛起”态势。

1949年华北解放区南下干部集中整训之研究

抽调大批干部南下是中共中央为夺取全国胜利而制定的重大战略决策,华北解放区的干部南下工作则构成全国“南下”战略中的关键性环节。在南下干部的动员、抽调等工作完成之后,华北解放区下辖各区的南下干部分别在石家庄、武安、菏泽、威县、开平和正定等地开展了为期一个月左右的集中整训。此次集中整训目标明确,兼顾思想性与实用性,为南下干部适应从北方到南方、从老区到新区、从乡村到城市的工作实践转移奠定了基础。华北解放区南下干部集中整训过程中的组织整编、学习教育和军事训练,亦暗含着中国共产党理论与实践相结合、常规与运动相融合的干部生成与养成机制。

南水北调中线工程突发水污染生态补偿机制研究

突发水污染已成为制约南水北调中线工程可持续调水的重大安全隐患,亟须解决南水北调中线工程突发水污染的生态补偿机制设计问题。针对应由中线局承担责任的南水北调中线干渠突发水污染场景,从多利益相关者合作视角出发,明确了中线局向纳污地政府提供生态补水的突发水污染生态补偿机制,基于合作博弈理论,构建了中线局与纳污地政府合作联盟的纳什议价模型,并以河南省邓州市为例开展研究,主要研究结果表明:①生态补水天数与纳污总损失呈现出显著的正向相关关系,且伴随纳污总损失逐步增大,中线局议价能力对补水天数的影响能力呈现出边际递减特征。②中线局生态补水成本与生态补水天数具有显著的正向关系,随着中线局议价能力的增强,生态补水成本的规模效益呈现一定的弱化趋势。③在一定的生态补水规模范围内,中线局与纳污地政府能够达成有效的合作联盟。

山西义兴寨金矿床铁塘硐矿段原生晕地球化学与深部找矿预测

义兴寨金矿床是山西省规模最大的金矿床,其深部成矿潜力如何及是否发育隐伏矿体,是矿山亟待解决的实际问题。在对成矿特征、控矿因素和矿床成因有比较全面认识的基础上,采用矿床原生晕地球化学法对义兴寨金矿床铁塘硐矿段开展了深部找矿预测研究。原生晕异常显示,在6勘探线深部400~550 m标高和0 m标高附近存在2个主要Au异常中心,且0 m标高附近金矿化规模最大,异常区即推测矿体范围。原生晕元素轴向分带序列自上而下为:Sb-Mn-Mo-W-Ni-B-Sn-P-Au-Hg-Cr-Co-Cu-Pb-Zn-Ag-Bi-As-Ba。因此,认为铁塘硐矿段深部具有很好的成矿潜力,推测在深部-400~-500 m标高附近区域存在规模较大的富矿段。预测成果得到了近期布置钻探工程的验证,新增金资源量8 t,为进一步深部找矿工作提供了可靠支撑。

川中古隆起北斜坡蓬莱气区上震旦统-下寒武统海相碳酸盐岩天然气多层系立体成藏

2022年9月,西南油气田部署于川中古隆起北斜坡(蓬莱气区)的东坝1井在下寒武统龙王庙组取得重大勘探突破,标志着川中古隆起北斜坡上震旦统—下寒武统超深层古老海相碳酸盐岩多层系立体成藏的确立。针对蓬莱气区上震旦统—下寒武统的多个含气目的层的沉积相、岩相、储层特征进行分析,进而从烃源岩及源-储配置、沉积相及成岩作用、多层系含气特征及圈闭等3个方面着手,对斜坡区多层系含气的有利条件进行解剖,建立了立体成藏模式。结果表明:分布广泛的厚层、优质烃源岩(灯三段泥页岩和筇竹寺组黑色页岩)为多层系天然气成藏提供了良好的物质保障,上生下储、旁生侧储的源-储配置关系保证了天然气的高效充注;震旦系灯影组受多期桐湾运动海平面升降旋回影响发育厚层叠置丘滩体,寒武系沧浪铺组和龙王庙组受古地貌控制发育白云石化的高能颗粒滩相,丘滩体和高能颗粒滩构成储层形成的物质基础,而后期广泛发育的岩溶作用进一步改善了储层的物性条件,直接控制了优质储层的形成和分布;局部发育的小型构造圈闭和斜坡背景下的岩性圈闭、构造-岩性复合圈闭共同控制上震旦统—下寒武统多层系含气。

银屑病患者中医体质类型地区差异性分析

目的了解不同地区银屑病患者中医体质类型分布的差异性,为本地区银屑病预防及治疗提供新思路和方法。方法选择天津市中医药研究院附属医院、沈阳市第七人民医院和武汉市第一医院收治的银屑病患者进行中医体质类型的流行病学调查,填写“中医体质分类量表”,采用Epidata3.1软件建立数据库,SPSS 13.0软件分析华北地区银屑病患者中医体质类型。结果共入选1740例患者,男性985例,女性755例。华北地区500例、东北地区740例和华中地区500例。不同地区的银屑病患者中医体质类型的差异有统计学意义(P<0.001)。结论银屑病患者中医体质类型与其所处的地域位置相关,临床医生要依据其具体的体质类型进行辨证论治,指导治疗用药。

川中北斜坡地区沧浪铺组一段颗粒滩特征及分布

基于岩心、薄片、测井及地震资料的综合分析,围绕川中北斜坡地区寒武系沧浪铺组一段颗粒滩特征及分布规律开展研究,认为:1)区内滩体岩性以鲕粒灰岩及在此基础上受不同程度白云石化作用改造的残余鲕粒云岩、云质鲕粒灰岩、灰质鲕粒云岩为主;颗粒滩在自然伽马曲线上以箱形、漏斗形响应为主,地震反射上以丘状杂乱、中弱振幅、中低频的a类地震相响应最优,b类地震相次之。2)纵向上,沧一段颗粒滩单体厚度不大,表现为多套频繁叠置、累计厚度具有一定规模的特征;横向上,滩体连续性较好,可对比追踪;平面上,三维地震资料精细刻画显示滩体北西—南东向展布,呈现整体连片、局部分异的特征。3)滩体发育受到海平面及古地貌的双重控制,位于研究区东侧的相对古地貌高带及裂陷槽边缘地带是沧浪铺组颗粒滩发育的主要区域,也是下一步勘探工作的主要方向。

华北克拉通中西部地壳S波速度结构及其地质意义

华北克拉通是世界上最古老的克拉通之一.我们利用布设于华北中部的ChinArray计划461个宽频带地震台阵的连续波形资料,基于背景噪声成像技术,获得了克拉通中西部5~45 s的Rayleigh波群速度频散曲线,并利用线性反演方法获得了研究区地壳上地幔顶部的S波速度结构.密集流动地震台阵使我们能够揭示研究区精细的地壳上地幔顶部速度变化,以深入探讨华北克拉通中西部深部结构及其对岩浆和地震的控制作用.8 km深度的S波速度切片显示低速与高速异常分别与地表的盆地和山脉对应良好.不同经度和纬度方向的S波速度剖面均表明,西部克拉通地壳大致可以分为上、中、下地壳三层.克拉通西部鄂尔多斯块体的下地壳S波速度介于3.7~3.8 km·s^(-1),暗示其下地壳以长英质岩石为主.大同火山区下方的S波低速异常从中地壳延伸至上地幔顶部,推测源自软流圈的地幔热流提供了近垂直的主干上涌通道,并控制了该区新生代岩浆活动.强震集中分布在上地壳高速体内部或高低速相间区,其下地壳乃至上地幔顶部都呈现明显的低速异常,推测源自上地幔/下地壳的深部热流沿地壳尺度的陡深断裂上侵,诱发上覆高应力刚性块体发生蠕动破裂与应力释放,进而诱发大震.

川中北部须家河组烃源岩测井解释及评价

基于烃源岩地球化学实验成果和常规测井资料,通过拟合地球化学参数敏感测井值,建立了可靠性较高的总有机碳含量以及生烃潜量测井解释模型,同时结合研究区实际,制订了相应的烃源岩分级评价标准,并对其平面展布进行了初步刻画,结果表明:1)川中北部须家河组烃源岩在测井曲线上具有高自然伽马,高声波时差,较高电阻率以及低补偿密度响应特征;2)声波时差和电阻率曲线对烃源岩总有机碳含量、生烃潜量的响应较为敏感,基于二者与实测地球化学参数间的多元回归,可以得到较为可靠的烃源岩总有机碳含量以及生烃潜量解释模型;3)研究区须家河组烃源岩总有机碳含量多在0.75%~1.50%,生烃潜量多在0.60~1.00 mg/g,以差烃源岩为主;4)纵向上,须五段是本区须家河组烃源岩发育的主力层段,其次为须二段;平面上,须五段烃源岩厚度具有自西向东减薄的趋势,而须二段烃源岩厚度呈北西至南东向减薄。