我国北方沙尘暴年代际变化与北大西洋海气系统年代际变率的联系

分析了近50年我国北方沙尘暴的年代际变化和热盐环流(THC)的年代际变率的演变特征,发现沙尘暴与THC存在一定的联系.这种相互联系的演变过程大致是:THC与北大西洋涛动(NAO)有联系,NAO与西伯利亚冷高压有联系,而西伯利亚高压又影响北半球冷空气活动,最终影响我国北方沙尘暴的发生.结果表明,THC强(弱)→NAO弱(...     

Electron-positron annihilation lines and decaying sterile neutrinos

If massive sterile neutrinos exist, their decays into photons and/or electron-positron pairs may give rise to observable consequences. We consider the possibility that MeV sterile neutrino decays lead to the diffuse positron annihilation line in the Milky Way center, and we thus obtain bounds on the sterile neutrino decay rate Γ _e ≥10⁻²⁸ s⁻¹ from relevant astrophysical/cosmological data. Also, we expect a soft gamma flux of 1.2×10⁻⁴–9.7×10⁻⁴ ph cm⁻² s⁻¹ from the Milky Way center which shows up as a small MeV bump in the background photon spectrum. Furthermore, we estimate the flux of active neutrinos produced by sterile neutrino decays to be 0.02–0.1 cm⁻² s⁻¹ passing through the earth.     

安徽沿江地区铜金多金属矿化系列及其相互关系

安徽沿江地区是长江中下游成矿带的主要地段之一，矿产资源十分丰富。本文在系统划分该区矿床类型和矿化系列的基础上，分析了矿化系列的演化及其间的相互关系。     

内蒙古呼和浩特市承压地下水水位监测网优化

定量评价地下水监测网的合理性对于准确、经济地获取高质量的监测数据尤为重要。本文针对呼和浩特市平原区现行承压水监测网, 以估计误差标准差作为衡量监测网合理与否的特征参数, 借助ArcGIS地学统计模块, 利用普通Kriging插值模型, 对待测点进行插值, 获取估计误差标准差等值线图。结果表明: 监测水位估计误差标准差范围由优化前的0.47~4.44变为优化后的0.5~0.8(除研究区西南边界附近外), 研究区整体估计误差标准差显著减小, 且全区范围内变幅较小。优化后的监测网在满足监测精度需要的同时, 能够较大程度节省监测网的运行费用。研究成果为呼和浩特市平原区承压水水位监测提供一个较优化的监测网布设方案, 进而为研究区承压地下水的合理开发利用以及相关环境地质问题提供真实可靠的数据支撑, 具有重要的应用价值。     

Removal of Aromatic Volatile Organic Compounds in the Sequencing Batch Reactor of Petroleum Refinery Wastewater Treatment Plant

This paper presents a field investigation of aromatic volatile organic compounds (AVOCs) emissions from a sequence batch reactor (SBR) with powdered activated carbon (PAC) to treat the wastewater in a large petroleum refinery plant. AVOC with high Henry's constant preferred to transfer from liquid‐phase into air‐phase so that might cause the emission and odor problem. During SBR operation, AVOC concentrations and distributions in wastewater, sludge and off‐gas were analyzed. The total AVOC removal from wastewater was >99% under the kinetic parameters of SBR operated. Batch experiments were carried out in the laboratory to obtain the adsorptive characteristic of AVOC onto PAC, but the results showed that bio‐degradation was the main removal mechanism (85%). Nevertheless, off‐gas emission (<1%) and AVOC in the sludge (<0.1%) remained a stable level. Oxidation/reduction potential (ORP) was correlated to the logarithm of the dissolved oxygen (DO) concentration in a linear relationship so that ORP profile could indirectly reflect the DO and biomass concentrations. Since the influent AVOC concentration was varied and difficultly to measure, ORP could be used as real‐time parameter for optimizing SBR operation. The results provided useful information for future evaluation of AVOC emissions from wastewater treatment plants.     

US-Russian Civilian Research and Development Fund Project： An origin of microdiamonds in metamorphic rocks of the Kokchetav Massif, Northern Kazakhstan

The Kokchetav Massif of northern Kazakhstan is a typelocality of occurrence of microdiamonds in ultrahighpressure metamorphic“ rocks. It records continental subduction and exhumation from depths greater than 120 km and provides unparalleled insights into mantle dynamics, global material recycling and the processes responsible for the genesis and destruction of continent. Through the support of a US Civilian Development and Research Fund, a group of Russian, US, Taiwanese and Kazakhstan geologists visited the reconstructed 800-m underground gallery to conduct field survey and sample collections. This gallery provides a useful geologic laboratory for international community to undertake similar geotectonic or different ecological and environmental studies.     

PRIMARY ANALYSIS ON GROUNDWATER, SOIL MOISTURE AND SALINITY IN FUKANG OASIS OF SOUTHERN JUNGGAR BASIN

１INTRODUCTIONSoilandlandformarethemoreimportantenviron－mentalfactorsaffectingthedistributionofvegetationinabasinwhenthemeteorologicconditionissimilaronalargescale，especiallyspatialandtemporalvariationsofthesoilmoistureandsaltcontent．Inaridareasthesoil…     

Fossil fluid reservoir beneath a duplex fault structure within the Central Range of Taiwan: implications for fluid leakage and lubrication during earthquake rupturing process

In order to understand the kinematics which likely facilitated the speedy rupturing process of the 1999 Mw 7.6 Taiwan Chi-Chi earthquake, we examined exposed rocks in the Taiwan Slate belt, where the pressure and temperature conditions most resembled the hypocentre of the Chi-Chi earthquake, i.e. sub-greenschist facies. Field observations and composition analyses of the silicified vein-rich zones beneath the duplex structure suggest that impermeable slate layers may serve as cap rocks for confining deep-seated fluids. These fluids most likely come from the Taiwan metamorphic complex at deeper depths by the dehydration and decarbonation reactions (or partial melting). In addition, the gouge zone of a link fault above the detachment also indicates the presence of overpressured fluids during faulting. It is probable that episodic leakage of the confined fluid reservoirs may provide essential fluids for fault lubrication during earthquake ruptures.     

Impact of the El Nino on the Variability of the Antarctic Sea Ice Extent

1　IntroductionManymeteorologistsandoceanographerspaidmuchattentiontothestudyofthemechanismofENSOformanyyears,suchasBjerknes(1 966) ,Wyrtki(1 975) ,McCreary(1 983 ) ,Philander(1 984) ,ZhangandChao(1 993 )andMcCPhaden(1 998)havemadegreatdevelopmentinthestudyofENSO .Especiallyinthe 1 990’s,withtheincreasingofthedatainthedeepocean ,thesomeonearguedthattheENSOepisodehadcloserelation shipwiththeeasterntransportationoftheanomalousseasurfacetemperatureinthewestPacific(LiandMu 1 999;Huang 2…