延边天宝山矿集区晚古生代岩浆-热液成矿的年代学证据——以新兴铅锌(银)矿床为例

延边天宝山矿集区已发现矽卡岩型铅锌铜矿床(立山和选厂后山)、隐爆角砾岩型铅锌(银)矿床(新兴)、沉积变质-热液改造型铜铅锌矿床(东风南山)和斑岩型钼矿床(东风北山)等四种成因类型、十余个矿床(点)。为确定矿集区内多金属成矿作用的期次,在已有工作基础上,本文首次采用LA-ICP-MS锆石U-Pb法和金属硫化物Rb-Sr法,对新兴铅锌(银)矿床开展了同位素年代学研究。结果表明,与角砾岩型铅锌(银)矿化密切相关的新兴花岗闪长岩的16个锆石测点的206Pb/238U年龄加权平均值为261. 1±3. 5Ma(MSWD=0. 46),角砾岩型矿石6件金属硫化物的Rb-Sr等时线年龄为259±3Ma(MSWD=1. 05),锶同位素初始值ISr=0. 71359,表明新兴矿床的成岩成矿时代为中二叠世晚期。结合矿集区内其它矿床的同位素测年资料分析认为,天宝山矿集区至少发生过晚古生代和早中生代两期岩浆-热液成矿事件,在中-晚二叠世形成了立山、选厂后山和新兴等多金属矿床,在早侏罗世则形成了东风北山斑岩型钼矿床。新兴矿床6件金属硫化物的Rb、Sr含量分别介于0. 1238×10-6～0. 7536×10-6和0. 3786×10-6～3. 247×10-6之间,初始Sr同位素比值(87Sr/86Sr)i介于0. 71350～0. 71371之间,均值为0. 71361,表明成矿物质以壳源为主,并有少量幔源物质的加入。综合研究表明,在中-晚二叠世(255～265Ma),受古亚洲洋俯冲作用的影响,天宝山矿集区发生了深源岩浆侵入,引发地壳物质同熔,形成富含Cu、Pb、Zn、Ag等金属元素的花岗闪长质岩浆,沿着构造裂隙上升至地壳浅部,侵位形成了矿集区内的立山、新兴、东风北山等多个晚古生代成矿(含矿)中酸性岩体。在花岗闪长岩与大理岩接触带附近,通过含矿热液交代作用,形成了立山、选厂后山等矽卡岩型铅锌铜矿床;随着岩浆期后热液在岩浆房顶部的不断聚集,挥发分的增加,当内压大于上部围岩压力时,发生隐爆作用,形成隐爆角砾岩,压力骤减引起流体不混溶,导致铅、锌、银等金属组分沉淀富集,形成新兴隐爆角砾岩型铅锌(银)矿床。

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Resistivity in Formation and Decomposition of Natural Gas Hydrate in Porous Medium

A new one-dimensional system for resistivity measurement for natural gas hydrate(NGH)exploitation is designed,which is used to study the formation and decomposition processes of NGH.The experimental results verify the feasibility of the measurement method,especially in monitoring the nucleation and growth of the NGH. Isovolumetric formation experiment of NGH is performed at 2°C and 7.8 MPa.Before the NGH formation,the initial resistivity is measured to be 4-7Ω·m,which declines to the minimum value of 2-3Ω·m when NGH begins to nucleate after the pressure is reduced to 3.3 MPa.As the NGH grows,the resistivity increases to a great extent,and finally it keeps at 11-13Ω·m,indicating the completion of the formation process.The NGH decomposition experiment is then performed.When the outlet pressure decreases,NGH begins to decompose,accordingly,the resistivity declines gradually,and is at 5-9Ω·m when the decomposition process ends,which is slightly higher than the resistivity value before the formation of NGH.The occurrence and distribution uniformity of NGH are determined by the distribution and magnitude of the resistivity measured on an one-dimensional sand-packed model.This study tackles the accurate estimation for the distribution of NGH in porous medium,and provides an experimental basis for further study on NGH exploitation in the future.

Calorimetric Determination of Enthalpy of Formation of Natural Gas Hydrates

This paper reports the measurements of enthalpies of natural gas hydrates in typical natural gas mixture containing methane, ethane, propane and iso-butane at pressure in the vicinity of 2000 kPa (300 psi) and 6900 kPa(1000psi). The measurements were made in a multi-cell differential scanning calorimeter using modified high pressure cells. The enthalpy of water and the enthalpy of dissociation of the gas hydrate were determined from the calorimeter response during slow temperature scanning at constant pressure. The amount of gas released from the dissociation of hydrate was determined from the pumped volume of the high pressure pump. The occupation ratio (mole ratio) of the water to gas and the enthalpy of hydrate formation are subject to uncertainty of 1.5%.The results show that the enthalpy of hydrate formation and the occupation ratio are essentially independent of pressure.

Cap rock blast caving of cavity under open pit bench

A laser technique based scanning system was employed to make a comprehensive scanning through borehole forunmapped cavity under open pit bench,then the three-dimensional data will be obtained,and these data were used for theoreticalanalysis and numerical simulation to analyze the stability of cap rock.Acoustic emission techniques were also adopted to carry outlong term real time rupture monitoring in cap rock.Therefore,a complete safety evaluation system for the cap rock was establishedto ensure safe operation of subsequent blasting processes.The ideal way of eliminating collapse hazard of such cavity is cap rockcaving through deep-hole blasting,thus,two deep-hole blasting schemes named as vertical deep-hole blasting scheme and one-timeraise driving integrated with deep-hole bench blasting scheme were proposed.The vertical deep-hole blasting scheme has moreexplosive consumption,but the relatively simple blasting net work structure can greatly reduce workloads.However,the one-timeraise driving integrated with deep-hole bench blasting scheme can obviously reduce explosive consumption,but the higher technicalrequirements on drilling,explosive charging and blasting network will increase workloads.

Greenhouse gas emissions from shallow uncovered coal seams

This study discusses a method of quantifying emissions from surface coal mining that has been trialled in Australia. The method is based on direct measurement of surface emissions from uncovered coal seams in mine pits, concurrent measurement of residual gas content of blasted coal in mine pits, and measurement of pre-mining gas content of the same seam from cores retrieved from exploration boreholes drilled away from active mining. The results from one of the mines studied are presented in this paper. In this mine,the pre-mining gas content of the target seam was measured using cores from an exploration borehole away from active mining. Gas content varied from 0.7 to 0.8 m3/t and gas composition varied from16% to 21% CH4(84–79% CO2). In-pit measurements included seam surface emissions and residual gas content of blasted and ripped coal. Residual gas content varied from 0.09 to 0.15 m3/t, less than twofold across the mine pit. Composition of the residual gas was in general 90% CO2and 10% CH4, with slight variation between samples. Coal seam surface emissions varied from 1.03 to 7.50 mL of CO2-e per minute and per square meter of the coal seam surface, a sevenfold variation across the mine pit.

MODIS BRIGHTNESS TEMPERATURE DATA ASSIMILATION UNDER CLOUDY CONDITIONS Ⅱ: IMPACTS ON RAINSTORM FORECASTING

Satellite observations provide large amount of information of clouds and precipitation and play an important role in the forecast of heavy rainfall.However,we have not fully taken advantage of satellite observations in the data assimilation of numerical weather predictions,especially those in infrared channels. It is common to only assimilate radiances under clear-sky conditions since it is extremely difficult to simulate infrared transmittance in cloudy sky.On the basis of the Global and Regional Assimilation and Prediction Enhanced System 3-dimensional variance(GRAPES-3DVar),cloud liquid water content, ice-water content and cloud cover are employed as governing variables in the assimilation system.This scheme can improve the simulation of infrared transmittance by a fast radiative transfer model for TOVS (RTTOV)and adjust the atmospheric and cloud parameters based on infrared radiance observations.In this paper,we investigate a heavy rainfall over Guangdong province on May 26,2007,which is right after the onset of a South China Sea monsoon.In this case,channels of the Moderate Resolution Imaging Spectroradiometer(MODIS)for observing water vapor(Channel 27)and cloud top altitude(Channel 36)are selected for the assimilation.The process of heavy rainfall is simulated by the Weather Research and Forecasting(WRF)model.Our results show that the assimilated MODIS data can improve the distribution of water vapor and temperature in the first guess field and indirectly adjust the upper-level wind field.The tendency of adjustment agrees well with the satellite observations.The assimilation scheme has positive impacts on the short-range forecasting of rainstorm.

A Beam Stabilization Algorithm Based on Nonlinear Observer for Low Cost Satcom-on-the-Move

A beam stabilization algorithm was proposed for low cost satcom-on-the-move （SOTM） to stabilize the vehicle-mounted antenna beam. The proposed algorithm utilizes the nonlinear observel to estimate the vehicle＇s attitude information based on inertial measurement unit. Then the estimated angles and angular velocities are used to stabilize the antenna beam. Experiment results show tha｜ the proposed algorithm can stabilize the antenna beam when the tracking information is available, indicating that it is competent to the SOTM system.

Erasing the Asian Longhorned Beetle with Determined Actions, but at High Costs--A Case Report

In 2012, an infestation of Asian Longhomed Beetle （ALB） was detected in Winterthur （Canton Zurich, Switzerland）. With more than 140 adult beetles and several hundred eggs and larvae, the infestation was by far the most extensive in Switzerland. Based on long-term experiences made in Braunau （Austria）, where the first ALB infestation in Europe occured, the beetle was fought with extensive actions： removal of all infested trees, preventive removal of potential host trees and installation of a focus- and a buffer zone. Transport of plant material out of these zones was banned and a close monitoring regime including specialised dogs put in place. As a result of these efforts, there were no adult beetles and only a few living larvae detected 2013. Neither larvae nor beetles were found in 2014. However, costs are high： 700,000 Swiss francs were spent in 2012 alone, not including hundreds of working hours spent by employees of the Canton Zurich. The previewed monitoring programme between 2013 and 2017 is estimated to cost another 2.8 million Swiss francs, if no more living beetles are detected. The experiences from Winterthur thus show that elimination of a relatively small ALB infestation with determined actions is likely possible in short time. However, the high costs demonstrate the need for strong boarder controls or alternative packaging materials for imports from infested regions （China）. In addition, a concept for small communities with limited resources is needed.

Contribution of Ground-Based Cloud Observation to Satellite-Based Cloud Discrimination

One of the biggest factors to deteriorate the satellite product quality is cloud coverage. Therefore, cloud masking process is important to improve the quality of various satellite products. However, satellite-based cloud discrimination algorithm has been developing and efficient ground-based cloud observations are necessary to validate satellite-based cloud discrimination. The purpose of this study is to develop the efficient ground-based cloud observation methodology using whole sky camera. This paper deals with methods how to discriminate cloud portions on whole sky image, how to apply the ground-based cloud observation to the validations for satellite products. For the cloud discrimination on whole sky image, we propose SI （sky index） and BI （brightness index） calculated from RGB （red, green and blue） channels. SI shows the extent of the blueness and gray scale and BI indicates the extent of the brightness. Sun, cloud and blue sky portions are divided by SI and BI threshold. As an application of ground-based cloud observation for the validation of satellite products, clouds portions discriminated from whole sky image are projected onto ground surface with map coordinate. We also examine to compare with cloud portions on whole sky images and MODIS （MODerate resolution Imaging Spectroradiometer） image as one of experiments. The proposed ground-based cloud observation method and its extension to satellite-based cloud discrimination should be connected to improve the quality of satellite products.

OPTIMAL ANTENNA SUBSET SELECTION AND BLIND DETECTION APPROACH APPLIED TO ORTHOGONAL SPACE-TIME BLOCK CODING

An approach combining optimal antenna subset selection with blind detection scheme for Orthogonal Space-Time Block Coding (OSTBC) is proposed in this paper. The optimal antenna sub- set selection is taken into account at transmitter and/or receiver sides, which chooses the optimal an- tennas to increase the diversity order of OSTBC and improve further its performance. In order to en- hance the robustness of the detection used in the conventional OSTBC scheme, a blind detection scheme based on Independent Component Analysis (ICA) is exploited which can directly extract transmitted signals without channel estimation. Performance analysis shows that the proposed ap- proach can achieve the full diversity and the flexibility of system design by using the antenna selec-tion and the ICA based blind detection schemes.

Synthesis of the dl-ξ-Thiotocopherol： Newest Derivative of the dl-a-Tocopherol

Tocopherol is the most active vitamin and natural antioxidant existing in the nature known as vitamin E. Lacking of this vitamin makes drastic exchanges on the health of the living organisms. Their active chemical form is l-α-tocopherol substance. In this article, α-thiotocopherol a tocopherol derivative was synthesized via a precursor like dl-α-tocopherol, which has better antioxidant than natural α-tocopherol. And the last compound after separation and purification via TLC and PC procedures was analyzed by FTIR, GC-MS and elemental analysis, oxidative stability is tested with TGA method in air showing roughly antioxidant effect. Another approach is measurment of redox potential against a reference electrode under inert nitrogen atmosphere.

Exotic Beam for Direct Measurement of the 22^Mg＋a

The scattering and resonance reactions of ^22Mg＋p and ^22Mg＋α play crucial roles for studying deeply not only in the structure of proton-rich nuclei of ^23A1 and ^26Si but also for the interest of astrophysics. It is believed that ^22Mg nucleus is a waiting point in the αp-process of nucleosynthesis in novae. We supposed to perform direct measurement the ^22Mg＋α system in invert kinematics using radioactive ion （RI） beam. The ^22Mg beam of 3.73 MeV/u was produced at CRIB facility of the University of Tokyo located at RIKEN, Japan in 2011. In this paper, we report the results the scattering and resonance reactions with the alpha target. of the ^22Mg beam production used for the direct measurement of

3 m Twin-Segment Solid Rocket Engine Tested Successfully

On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aerospace Solid Propulsion Technology（AASPT）under CASC.

First result from the Jinping Underground Nuclear Astrophysics experiment JUNA:precise measurement of the 92 keV ^(25)Mg(p,γ)^(26)Al resonance

The ^(25)Mg(p,γ)^(26)Al reaction plays an important role in the study of cosmic 1.809 MeV γ-ray as a signature of ongoing nucleosynthesis in the Galaxy.At astrophysical temperature around 0.1 GK,the ^(25)Mg(p,γ)^(26)Al reaction rates are dominated by the 92 keV resonance capture process.We report a precise measurement of the 92 keV ^(25)Mg(p,γ)^(26)Al resonance in the day-one experiment at Jinping Underground Nuclear Astrophysics experiment(JUNA)facility in the China Jinping Underground Laboratory(CJPL).The resonance strength and ground state feeding factor are determined to be 3.8±0.3×10^(-10) eV and 0:660:04,respectively.The results are in agreement with those reported in the previous direct underground measurement within uncertainty,but with significantly reduced uncertainties.Consequently,we recommend new ^(25)Mg(p,γ)^(26)Al reaction rates which are by a factor of 2.4 larger than those adopted in REACLIB database at the temperature around 0.1 GK.The new results indicate higher production rates of ^(26g)Al and the cosmic 1.809 MeV γ-ray.The implication of the new rates for the understanding of other astrophysical situations is also discussed.

Integrated Optical Waveguide Sensor for Lighting Impulse Electric Field Measurement

A Lithium niobate （LiNbO3） based integrated optical E-field sensor with an optical waveguide Mach-Zehnder interferometer （MZI） and a tapered antenna has been designed and fabricated for the measurement of the pulsed electric field. The minimum detectable E-field of the sensor was 10kV/m. The sensor showed a good linear characteristic while the input E-fields varied from 10kV/m to 370kV/m. Furthermore, the maximum detectable E-field of the sensor, which could be calculated from the sensor input/output characteristic, was approximately equal to 1000kV/m. All these results suggest that such sensor can be used for the measurement of the lighting impulse electric field.

A rapid approach to convective aeroheating prediction of hypersonic vehicles

A rapid approach to hypersonic aeroheating predictions in the stagnation region and downstream is developed in the present paper.The engineering method is used to calculate inviscid hypersonic flowfields to reduce time cost,and a combination of the mass flow balance technique and the axisymmetric analog is proposed to account for the entropy swallowing effects.A three-dimensional linear method is derived to fit the vehicle surface flowfields.Then a new axisymmetric analog method based on linear flowfields and linear surface equations is developed,with the complexity and computational cost reduced dramatically.In the stagnation region,an implicit surface fitting is introduced to approximate the primary curvatures and a robust aeroheating prediction method is constructed.The proposed approach is verified on a variety of configurations including spherically blunted cone,double ellipsoid and aerospace vehicle.Numerical results indicate the followings:1)The approach predicts aeroheating in about one second and the results agree well with CFD simulations and wind-tunnel measurements;2)with the help of entropy correction,the precision is further improved in the streamline diverging regions on the vehicle surface,while little improvement is found after entropy correction in the regions where the streamlines do not diverge.

Extracting predictable components and forecasting techniques in extended-range numerical weather prediction

This paper refers to the CNOP-related algorithms and formulates the practical method and forecast techniques of extracting predictable components in a numerical model for predictable components on extended-range scales.Model variables are divided into predictable components and unpredictable chaotic components from the angle of model prediction error growth.The predictable components are defined as those with a slow error growth at a given range.A targeted numerical model for predictable components is established based on the operational dynamical extended-range forecast(DERF)model of the National Climate Center.At the same time,useful information in historical data are combined to find the fields for predictable components in the numerical model that are similar to those for the predictable components in historical data,reducing the variable dimensions in a similar judgment process and further correcting prediction errors of predictable components.Historical data is used to obtain the expected value and variance of the chaotic components through the ensemble forecast method.The numerical experiment results show that this method can effectively improve the forecast skill of the atmospheric circulation field in the 10–30 days extended-range numerical model and has good prospects for operational applications.

Mining of a streptothricin gene cluster from Streptomyces sp.TP-A0356 genome via heterologous expression

Streptothricins (STs) are used commercially to treat bacterial and fungal diseases in agriculture. Mining of the sequenced microbial genomes uncovered two cryptic ST clusters from Streptomyces sp. C and Streptomyces sp. TP-A0356. The ST cluster from S. sp. TP-A0356 was verified by successful heterologous expression in Streptomyces coelicolor M145. Two new ST analogs were produced together with streptothricin F and streptothricin D in the heterologous host. The ST cluster was further confirmed by inactivation of gene stnO, which was proposed encoding an aminomutase supplying -lysines for the poly-β-Lys chain formation. A putative biosynthetic pathway for STs is proposed based on bioinformatics analyses of the ST genes and experimental evidence.

Factors influencing the porosity of gas hydrate bearing sediments

Porosity is a key parameter in calculating the velocity of gas hydrate bearing sediments and quantifying the amount of gas hydrate. The variation of porosity is affected by many factors. The influences of different factors on porosity are distinct. The purpose of this paper is to analyze the main factors that affect the overall and local change of porosity in marine sediments where gas hydrate was sampled. Porosity logs were collected from ODP Leg 164, Blake Ridge, ODP Leg 204, Hydrate Ridge, and IODP expedition 311, Cascadia Margin. Based on the characteristic of porosity variation in depth, porosity was divided into three components: low frequency component, middle frequency component, and high frequency component. The factors influencing each component were discussed. From the analysis, we observed that the porosity of unconsolidated sediment was very high, and the decreasing trend of low frequency component versus depth was affected by compaction. In addition, the initial porosity and slope of low frequency component variation were affected by the content of fine grain and geothermal gradient respectively. The middle component could reflect the variation of lithology, which was affected by the content variation of different sized grains and gas hydrate. The high frequency component was affected by the frequent change of grain size. The existence of volcanic ash-rich sand caused a high value to the high frequency component. The results are applicable to porosity evaluation in gas hydrate bearing sediments.