Research in migration route of hatchery released Chinese shrimp (Fenneropenaeus chinensis) in the Bohai Bay using method of SSR marker

This study provides new insights for the hatchery released Chinese shrimp(Fenneropenaeus chinensis), including proportion, dynamic migration route, after they were released into nature for stock enhancement using a new strategy quite different than ever. Chinese shrimp were sampled at 22 survey stations during two investigation voyages acrossing 74 survey stations in the Bohai Sea from July 16 to August 9 in 2015. Among 289 sampled individuals during the second voyage, totally 155 shrimps were i...     

中国城市生活垃圾处理能力的时空格局及影响因素

基于2003-2017年中国30个省份的数据,探究城市生活垃圾处理能力的时空格局,并构建动态面板数据模型实证检验中国城市生活垃圾处理能力的影响因素.研究结果表明,考察期内城市生活垃圾处理能力存在空间发展不平衡问题;进一步利用Dagum基尼系数测算城市生活垃圾处理能力的空间差距并将其进行分解,其中,东部地区的地区内差距最...     

Calculation of groundwater head distribution with a close barrier during excavation dewatering in confined aquifer

When pumping is conducted in confined aquifer inside excavation pit(waterproof curtain),the direction of the groundwater seepage outside the excavation changes from horizontal to vertical owing to the existence of the curtain barrier.There is no analytical calculation method for the groundwater head distribution induced by dewatering inside excavation.This paper first analyses the mechanism of the blocking effects from a close barrier in confined aquifer.Then,a simple equation based on analytical solution is proposed to calculate groundwater heads inside and outside of the excavation pit with waterproof curtain(hereafter refer to close barrier)in a confined aquifer.The distribution of groundwater head is derived according to two conditions:(i)pumping with a constant water head,and(ii)pumping with a constant flow rate.The proposed calculation equation is verified by both numerical simulation and experimental results.The comparisons demonstrate that the proposed model can be applied in engineering practice of excavation.     

Trace element composition of magnetite from the Xinqiao Fe–S(–Cu–Au) deposit,Tongling, Eastern China: constraints on fluid evolution and ore genesis

The Xinqiao deposit is one of several polymetallic deposits in the Tongling ore district. There are two types of mineralization in the Xinqiao: skarn-type and stratiform-type. The skarn-type mineralization is characterized by iron oxides such as magnetite and hematite, whereas stratiform-type mineralization is characterized by massive sulfides with small amounts of magnetite and hematite. We defined three types of ores within the stratiform-type mineralization by the mineral assemblages and ore structures. Type I ore is represented by magnetite crosscut by minor calcite veins. Type II is a network ore composed of magnetite and crosscutting pyrite. Type III is a massive ore containing calcite and hematite. Type I magnetite is characterized by highly variable trace element content, whereas Type II magnetite has consistently higher Si, Ti, V, and Nb. Type III magnetite contains more In, Sn, and As than the other two types. Fluid–rock interaction, oxygen fugacity (fO₂), and temperature (T) are the main factors controlling element variation between the different magnetite types. Type I magnetite was formed by more extensive fluid–rock interaction than the other two types at moderate fO₂ and T conditions. Type II magnetite is thought to have formed in relatively low fO₂ and high-T environments, and Type III in relatively high fO₂ and moderate-T environments. Ca?+?Al?+?Mn and Ti?+?V discrimination diagrams show that magnetite in the Xinqiao deposit is hydrothermal in origin and is possibly linked with skarn.     

New Record of Palaeoscolecids from the Early Cambrian of Yunnan, China

A new palaeoscolecid, Guanduscolex minor Hu, Luo et Fu gen. et sp. nov., with preserved soft parts of introvert and intestines comes from the Lower Cambrian Guanshan fauna of Yunnan, South China. Microstructural details of the cuticle revealed by scanning electron microscopy （SEM） show that each annulation bears three rows of plates and each plate bears 9-10 marginal and 4-5 central nodes. This discovery sheds new light on the relationships and evolutionary pathway of the palaeoscolecids and other early priapulids.     

基于大规模围填海和陆源排污压力下的广西钦州湾环境容量变化及损失评估

在2004–2019年间,人类通过大规模围填海以及陆源排污等活动对钦州湾造成了不可逆转的深远影响。本文基于卫星遥感影像和海图资料,利用非结构网格有限体积海洋模型建立的高精度钦州湾水动力–水质模型,分析了十几年来人类活动的累积效应对钦州湾水质的影响。受围填海和陆源排污两者的影响,钦州湾内化学需氧量（COD）的浓度略有下降（0.976 mg/L下降到0.909 mg/L）,但湾内无机氮（DIN）和无机磷（DIP）的浓度分别从0.146 mg/L和0.023 mg/L增加到0.230 mg/L和0.027 mg/L,无机氮的浓度增加较为显著;统计结果表明,湾内超四类水质海域面积和重度富营养化水域面积大幅度增加,水质环境状况不容乐观。此外根据钦州湾内排污的特点,利用分担率法计算了不同时期下钦州湾的环境容量,结果表明湾内排污量远超最大允许排污量,茅岭江、钦江两条河流的排污量亟需削减;由于围填海导致的海湾面积减小和水交换能力降低,钦州湾环境容量较2008年有明显下降。对茅尾海局部采用排海通量最优法的计算表明,茅岭江应当分担比钦江更多的排污量,才能有利于茅尾海内的水质改善。通过估算发现双重人为压力共同对钦州湾造成了约每年26.95亿元的环境容量价值损失,因此在开发利用海洋前应慎重考虑环境容量损失的补偿方案。     

宁芜盆地玢岩型铁矿床的成矿时代：金云母40Ar-39Ar同位素年代学研究

宁芜盆地是长江中下游成矿带的重要组成部分,盆地内广泛产出玢岩型铁矿床,但其精确的成矿时代及其形成构造背景研究仍十分薄弱.本文在详细野外地质工作的基础上,选择与磁铁矿密切共生的金云母为对象,利用40Ar-39Ar阶段加热同位素定年方法,对盆地内典型玢岩型铁矿床进行了成矿时代研究,确定了盆地内主要玢岩型铁矿床陶村、白象山和...     

基于卫星通信的海洋气象数据采集系统设计

根据我国海洋综合气象监测装备建设网点不继扩大和加密的现状,依靠现有的卫星通信网络,利用其覆盖范围广、通信稳定、实时在线和维持经费等优势,设计一种基于卫星通信网络的海洋气象数据采集系统.介绍该系统的数据采集结构和功能,智能处理终端的硬件组成,硬件电路芯片选型与使用;介绍系统软件的控制和编制方法,简述在可视化编程语言Microsoft Visual Studi0 6.0集成包环境下开发海洋气象数据采集系统软件的步骤;讨论基于我国北斗卫星通信网络的海洋气象数据采集系统的实际应用情况.     

台风“灿鸿”、“莲花”和“浪卡”共存期间路径、强度及相互作用分析

利用NCEP1°×1°再分析资料,对2015年7月西太平洋洋面上台风"莲花""灿鸿""浪卡"三者共存期间的路径特征、强度变化及相互作用进行了分析。结果表明:1)台风"莲花"与"灿鸿"发生互旋,导致强度较弱的"莲花"路径发生逆时针转向;"灿鸿"与"浪卡"发生明显的相互作用。2)"莲花"的低层水汽通道在互旋过程中被"灿鸿"夺走,后者产生反馈气流补充前者;"浪卡"与"灿鸿"在对流层高层通过水汽"连体"通道进行水汽交换。3)与"莲花"互旋过程中"灿鸿"产生的反馈气流远比相互作用过程中"浪卡"对"灿鸿"的补充气流强,因此相互作用过程结束后"莲花"暖心与涡度继续维持,而"灿鸿"迅速衰弱。4)两个台风相互作用过程的水汽"连体"通道高度不同,台风"莲花"与"灿鸿"相互作用位于对流层低层,而台风"灿鸿"与"浪卡"相互作用发生在对流层高层。     

基于SPEI的1961—2015年淮北地区干旱时空分布特征

基于标准化降水蒸散指数（SPEI）,利用淮北地区108个气象站逐月气温、降水观测资料,采用线性趋势、M K突变检验等方法,从不同时间尺度（年、季）和干旱程度（轻旱、中旱、重旱和特旱）分析了淮北地区1961—2015年干旱频率和时空变化特征。结果表明：淮北地区1961—2015年总体呈干旱略加强趋势,其中1998—2001年干旱发生最频繁,干旱强度、极端干旱及中等干旱的频次均呈增加趋势。2011年淮北地区干旱程度发生了突变性增强;20世纪90年代起淮北地区夏季经历了先湿后干的转变,2013年是夏季转向干旱化的突变点。秋冬两季是淮北地区发生干旱频率较高的季节。秋季干旱分布广、旱情最为严重,淮北地区北部是秋季干旱的高发区;冬季发生中旱以上干旱的地区分布较广,主要位于淮北地区内的安徽片西部和江苏片中部。春夏季发生高频率干旱的区域相对较小。