Preface to the Special Issue on Summer 2020: Record Rainfall in Asia — Mechanisms,Predictability and Impacts     

Robin T.CLARK  Xiquan DONG  Chang-Hoi HO  Jianhua SUN  Huiling YUAN  Tetsuya TAKEMI 《大气科学进展》2021,38(12):1977-1979

Throughout vast areas of Asia, the summer of 2020 was extraordinarily wet. After an exceptionally wet May in North-east India and Bangladesh, excessive rainfall hit at least 10 provinces in central and southern China in June and July, caus-ing extensive flooding in many rural and urban locations. Long standing rainfall, lake and river level records were con-sequently broken in several parts of the region with the Yangtze-Huaihe river valleys, particularly badly impacted, with con-sequential economic losses. Floods and landslides also affected parts of Japan with at least one location in Kumamoto province even experiencing a record-breaking 1000 mm of rainfall in just 3 days in early July. The 2020 wet season in South Korea was also exceptionally long, lasting 54 days, compared to their more usual 32.  相似文献   

The Role of Aerosol in Climate Change, the Environment, and Human Health   总被引：1，自引：0，他引：1       下载免费PDF全文

ZHANG Ren-Jian  HO Kin-Fai  SHEN Zhen-Xing 《大气和海洋科学快报》2012,5(2):156-161

Aerosol is an important component of the atmosphere, and its source, composition, distribution, and effects are highly complicated. Governments and scientists have given much attention to aerosol problems, and it has become a hot topic due to the important role it plays in climate change and the Earth’s environment. In this paper, 1) the importance of aerosol in climate change, the atmospheric environment, and human health is summarized; 2) the recent serious problems of aerosol pollution and the shortage of current aerosol research in China are pointed out; and 3) the necessity to enhance aerosol research in China is emphasized.  相似文献   

Offshore aquaculture legislation designed to balance production and protection     

Halvorson HO  Duff J 《Marine pollution bulletin》2008,56(10):1673-1675

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东部苏丹埋藏玄武岩／沉积界面的地球物理图     

Ali.  HO 韩再军 《地学工程进展》1999,16(2):36-40

东部苏丹的ＥＬ－Ｓｈａｗａｋ地区位一知的Ｇｅｄａｒｅｆ大的问斜盆地之内,此盆地主要由Ｎｕｂｉａｎ砂岩的碎屑沉积物组成,砂岩组的上覆地层为席状玄武岩和粒玄岩,下伏地层则为变质基底杂岩。作为该区水文地质研究的项目的一部分,利用重力和地震反射 结合来圈定玄武岩流的范围,并确定沉积岩组的厚度。研究结果表明,基底杂岩的地形呈波状起伏,并以地下山脊分离的两个波谷为特征。Ｎｕｂｉａｎ组的沉积厚度从５０ｍ到超过２  相似文献   

Analysis of effects of operating parameters on rate of penetration in drilling process with air down-the-hole hammer     

HO Yinchol  PAK Kumdol  PENG Jianming  RI Jaemyong  KIM Yongnam  CHOE Cholho 《世界地质(英文版)》2021,24(1):64-70

Air down-the-hole(DTH)hammer drilling has long been recognized to have the potential of drilling faster than conventional rotary drill,especially in some hard rocks such as granite,sandstone,limestone,dolomite,etc.with the same weight on bit(WOB)and rotations per minute(RPM).So,it has been widely used in many drilling fields including mineral resource exploration drilling,oil and gas drilling and geothermal drilling.In order to reduce drilling cost by selecting optimal drilling parameters,rate of penetration(ROP)should be estimated accurately and the effects of different factors on ROP should be analyzed.In this research,ANN model with several multi-layer perception back propagation(BP)networks for predicting ROP of air DTH hammer drilling was developed using controllable parameters such as impact energy,impact frequency,WOB,RPM and bit operating time for the formations with a certain drillability index of rock.Several BP neural networks with the different neurons in hidden layers were developed and compared for selecting optimal architecture of ANN.The effects of the drilling parameters such as impact energy,impacting frequency,WOB,RPM and bit operating time on the ROP of air DTH hammer drilling were investigated by trained ANN.From the analyses,the optimum range of drilling parameters for providing high ROP were determined and analyzed for a formation with a certain drillability index of rock.The methodology proposed in this study can be used in many mathematical problems for optimization of drilling process with air DTH hammer.  相似文献   

Petrogenesis of Cenozoic Basaltic Rocks from Jiangsu Province,China:Evidence from Geochemical Constraints     

Yung-Tan LEE  Ju-Chin CHEN  Jyh-Yi SHIH  Kung-Suan HO  Huai-Jen YANG  Meng-Lung LIN  Yen-Tsui HU  Ching-Hsing CHIU 《《地质学报》英文版》2013,87(1):102-117

Cenozoic（Miocene to Pleistocene） basaltic rocks in Jiangsu province of eastern China include olivine tholeiite and alkali basalt.We present major,trace element and Sr-Nd isotopic data as well as Ar-Ar dating of these basalts to discuss the petrogenesis of the basalts and identify the geological processes beneath the study area.On the basis of chemical compisitions and Ar-Ar dating of Cenonoic basaltic rocks from Jiangsu province,we suggest that these basalts may belong to the same magmatic system.The alkali basalts found in Jiangsu province have higherΣFeO,MgO,CaO,Na₂O, TiO₂ and P₂O₅ and incompatible elements,but lower Al₂O₃ and compatible elements contents than olivine tholeiite which may be caused by fractional crystallization of olivine,pyroxene and minor plagioclase.In Jiangsu basaltic rocks the incompatible elements increase with decreasing MgO/ΣFeO ratios.The primitive mantle-normalized incompatible elements and chondrite-normalized REE patterns of basaltic rocks found in Jiangsu province are similar to those of OIB.Partial loss of the mantle lithosphere accompanied by rising of asthenospheric mantle may accelerate the generation of the basaltic magma.The ¹⁴³Nd/¹⁴⁴Nd vs.⁸⁷Sr/⁸⁶Sr plot indicates a mixing of a depleted asthenospheric mantle source and an EMI component in the study area.According to Shaw’s equation,the basalts from Jiangsu province may be formed by l%-5%partial melting of a depleted asthenospheric mantle source.On the basis of Ar-Ar ages of this study and the fractional crystallization model proposed by Brooks and Nielsen（1982）,we suggest that basalts from Jiangsu province may belong to a magmatic system with JF-2 as the primitive magma which has undergone fractional crystallization and evolved progressively to produce other types of basalts.  相似文献   

Characteristics of Atmospheric Circulation Associated with Cold Surge Occurrences in East Asia： A Case Study During 2005/06 Winter   总被引：1，自引：0，他引：1  

Tae-Won PARK  Jee-Hoon JEONG  Chang-Hoi HO  Seong-Joong KIM 《大气科学进展》2008,25(5):791-804

The characteristics of the upper-level circulation and thermodynamical properties for the period when two distinct cold surges broke out over East Asia during the 2005/06 winter are investigated. From early December 2005 to early January 2006, exceptionally cold weather lasted for approximately one month due to two successive cold surges that took place on 2 December 2005 and 2 January 2006, respectively. This study reveals that both involve the upper-tropospheric circulation, which induces the amplification and expansion of the surface Siberian high toward East Asia, but arose from different causes： the former is caused by the upper-level blocking originated from the North Pacific and the latter is caused by the upper-level wave train across the Eurasian Continent. In particular, it is suggested that the lower-tropospheric anomalous wind caused by upper-level circulation anomalies and a steep meridional temperature gradient amplified by phase-locked annual cycle combined to induce very strong cold advection in East Asia, which resulted in exceptionally cold weather that lasted for several weeks. The present results emphasize that the characteristics of the upper-tropospheric circulation can be considered as important precursors to cold surge occurrences in East Asia.  相似文献   

黄海、渤海底层盐度预报方法的研究     

王宗山  徐伯昌  孙卫阳  邹娥梅  李繁华 《海洋科学进展》1996,(3)

根据二维流体动力学方程和深度平均盐度扩散方程在河口径流量以及蒸发和降水之差为已知情况下构成的闭合方程组，预报出深度平均盐度，然后利用底层盐度与深度平均盐度、水深和时间（月）之间的经验关系，给出底层盐度的二维预报。为了检验试报结果的可靠性，文中将黄渤海底层盐度的试报结果（１９７年７月１１日，时效为３ｄ）与标准断面观测资料（７月１１日观测，１２４．５°Ｅ以西，共１０４站）作一粗略比较。比较表明，试报结果与实测值的相关系数为０．９６，均方误差为σ＝０．２６，绝对误差小于０．２和０．３的站数分别占总站数的６３．５×１０－２和７７．０×１０－２，而总均绝差为０．１９。由此可见，试报的效果是令人满意的。  相似文献   

1990年热带海洋状况的诊断     

王宗山  邹娥梅  徐伯昌 《海洋学报》1991,13(5):592-599

文中根据“中美热带西太平洋海气相互作用联合研究”第8航次的考察结果结合美国NOAA提供的SST图以及L.J.Mangum提供的锚碇测温链和K.Wkrtki提供的水位资料,对1989年10月以来的热带太平洋的物理海洋状况进行了诊断分析。结果表明,1990年是一个类似于1980的年弱的埃尔尼诺事件;西太平洋暖水向中、东太平洋的输送,类似于1976埃尔尼诺——主要是北赤道逆流的贡献;这次事件行将消衰。  相似文献   

海洋上准均匀层纯风混合加深理论     

Г.  НГ 徐伯昌 《海岸工程》1996,15(2):66-75

基于积分上混合层涡动能平衡参数化方法[1]（该方法保证了理论与实验室试验相吻合），发展了旋转层化流体中上涡动层加深的理论。这里，当确定无维函数和常系数时，理论结果与混合过程的实验室模拟的比较给予了很大关注。指出，当不存在通过海面的热通量时，风混合的平衡深度Dst由式Dst=（u／Ω）F（N／Ω）确定，式中函数F（N／Ω）由文中所采用的涡动能平衡闭合的假定来求得（Ω为柯氏参量；N为温跃层下面的维萨拉-普朗特特征频率；u2为风对表层水作用的功应力）。根据上述理论，F（N／Ω）≈（Ω／N），不同于文献[7，11]所得出的理论结果。还指出，N／Ω在75～150范围内，整个模式中Dst的大小为相同的量级。因此，函数F（N／Ω）应该在实验室里或用现场试验来确定。  相似文献