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1.
Supergene mobility of noble metal elements in black rock series   总被引:2,自引:0,他引:2  
In order to discuss the supergene mobility of noble metal elements in black rock series, measurements have been conducted with ICP-MS method for the contents of Ru, Rh, Pd, Ir, Pt, Au and Ag in the primary jordisite-rich black shale ore, in the supergene leached jordisite-rich black shale ore, in the pyrite-rich black shale ore and in the water of pit, well and stream of the mining area near Zhongnan Village, Zunyi District of Guizhou Province. The temperature, pH, electric conductivity, dissolved oxygen of the water were also measured. The pit water is acidic with high electrical conductivity and low dissolved oxygen. The total content of platinum group elements in the primary pyrite-rich black shale ore is only 1/13 of that in the primary jordisite-rich black shale ore. The Ag content in the former is only a half of that in the latter while the Au contents in the two kinds of ores are almost the same. Being leached under supergene condition, the contents of most of the noble metal elements except Au in the jordisite-rich black shale ore greatly decrease; the leaching rates of Rh, Pd, Pt, the total platinum group elements and Ag reach as high as 66.72%~74.79%, revealing that under supergene condition, platinum group elements and Ag can migrate along with water; the ratios of Ag/Au, Pd/Ru, Pt/Ir and(Pt+Pd)/(Ru+Rh+Ir) are remarkably decreased, displaying that Pt and Pd relative to Ru, Rh and Ir, Ag relative to Au bear more active mobility. The noble metal elements in the black rock series near Zhongnan Village might be mobilized and migrate under the procession of "cold water" rich in [SO4]2- with pH value being about 2.4 at a temperature below 50 ℃.  相似文献   

2.
Scientific big data and Digital Earth   总被引:6,自引:0,他引:6  
Big data has been a focus of research in sci- ence, technology, economics, and social studies. Many countries have already incorporated big data research into their national strategies. This paper elaborates upon the origin, connotation, and development of big data from both a spatial and temporal perspective. It proposes that scien- tific big data will become a new solution in scientific research as the paradigm changes from being model-driven to data-driven. This paper defines the concept of "scientific big data" and proposes strategies for solving "big data problems". Theoretical frameworks and data systems for Digital Earth are discussed with a clear conclusion that scientific big data is a prominent feature of Digital Earth. As an example, spatial cognition of the formation mecha- nism of China's Heihe-Tengchong Line--a geo-demo- graphic demarcation line dividing China into two parts--is discussed within the context of big data computation and analysis for Digital Earth.  相似文献   

3.
A tiny ultrasonic motor was constructed by using a piezoelectric ceramic cylindrical rod as a vibration generator of the stator. The fabricated tiny motor has a diameter of 1 mm, a length of 5 mm and a weight of 36 mg. The resonant frequency is 32 kHz with one fixed boundary or 83 kHz with two free boundaries. Four silver electrodes were deposited on the cylindrical surface. The spacing between two adjacent electrodes was carefully designed. A method was developed for the polarization of the stator. By using the bending vibration mode of the stator, the motor shows a performance with a speed of 1800 rpm and a stalled torque of 4μNm, and can bear a high driving voltage up to 350 Vpp. The motor was used to drive an optical prism for circular scanning in an endoscopic OCT system. The tomographic images of the inner cavities of a plastic tube and a scallion were obtained, and the resolution was of the order of micrometer-scale.  相似文献   

4.
The formation of the black patina induced by soil humic asid under different conditions was studied, the black, grey and brown colored shiny surfaces prepared in laboratory were analyzed. As a result the formation of tin-rich shiny black surface on bronze mirrors is the product of soil corrosion of the bronze mirrors. The patina is formed by reection between the alloy and the humic acid in soil, and leaching of copper and lead oxides through a long period time when the mirrors were buried under the ground leaving a dense compact corrosion-resistant layer consisted predominantly of stannic oxide microcrystal.  相似文献   

5.
We extend the classical newsvendor problem by introducing a downside risk constraint from the perspective of inventory control. At the beginning of a replenishment period the newsvendor will place an order, then he will review the inventory level at the end of the period. If the inventory level is positive then he will bear the holding cost and if the inventory level is negative then he will bear the backorder cost. The optimal order quantity has a simple form. We analyze the form of the optimal order quan-tity when we restrict that the probability that the cost level is larger than or equal to a fixed cost constant is less than a fixed value of probability. At last, we analyze the case that the fixed cost constant is equal to the expected cost.  相似文献   

6.
X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 2θ angle, while their matixes does not.These results indicate that those diffuse peaks were produced by the SnO2, microcrystals of 3~5 nm size contained in the black or brown patina.The matrix of unearthed black patina bronze mirror numbered 223, gives strong XRDA diffraction peaks, indicating that there are a large amounts of non-oxidized bronze alloy particles surrounded by SnO2,which shows that the black patinas are not wholly metallic oxides (mainly SnO2),there are also a lot of original alloys of different sizes in grain in the patina.The bright-field image of the black patina sample gives the same result.  相似文献   

7.
郑颖 《科技信息》2009,(16):96-97
Beloved,one of the representative works of Toni Morrison,was published more than a decade after the Emancipation Proclamation was issued.Although many years went by,the evil slavery still had an impact on the black people's internal world,because the condition of the enslavement of the external world,especially the denial of one's status as a human subject.The black people couldn't get out of the bondage of the past experience to gain the real freedom.In Beloved,Morrison emphasizes on gaining the internal freedom of the black people.She tries to tell the readers about the evil impact of slavery on the black people and she also wants to call up her fellow men to get out of the bondage and gain the internal freedom.  相似文献   

8.
Estimation and prediction of black carbon emissions in Beijing City   总被引:1,自引:0,他引:1  
Black carbon is a by-product of incomplete combustion of carbon containing fuels. It can alter atmospheric radiation property and make adverse impacts on human health. The energy consumption in Beijing City depends largely on coal burning. Recently, Beijing City has been performing the municipal energy structure adjustment as a tool for air pollution abatement, aiming at the air quality goal for the Beijing 2008 Olympic Games. Based on Beijing energy use data in 2000, combined with emission factors of major sources of black carbon, the emission of black carbon in Beijing City is estimated to be 7.77 Gg. Coke, raw coal and biomass as non-commercial energy are the main contributors to municipal black carbon emissions. Based on Beijing energy planning in the year 2008, the emission of black carbon in 2008 will be 2.97 Gg if the contribution from biomass is not taken into account. Assuming that the black carbon emission from rural biomass in 2008 is the same as that in 2004, the biomass burning will be the largest emitter of black carbon to Beijing City in 2008.  相似文献   

9.
A series of researches on mechanical behaviors of big pipe roof for shallow large-span loess tunnel were carried out based on the Wenxiang tunnel in Zhengzhou -Xi' an Special Passenger Railway. The longitudinal de- formations of the pipe roofs were monitored and the mechanical behaviors of the pipe roofs were analyzed at the test section. A new double-parameter elastic foundation beam model for pipe roof in shallow tunnels was put for- ward in Wenxiang tunnel. The measured values and the calculation results agreed well with each other, revealing the force-deformation law of big pipe roof in loess tunnel: At about 15 m in front of the excavating face, the pipe roof starts to bear the load; at about 15 m behind the excavating face, the force of the pipe roof tends to be stabi- lized; the longitudinal deformation of the whole pipe roofs is groove-shaped distribution, and the largest force of pipe roofs is at the excavating face. Simultaneously, the results also indicate that mechanical behaviors of pipe roof closely relate to the location of the excavation face, the footage of the tunnelling cycle and the mechanics pa- rameters of pipe roof and rock. The conclusions can be reference for the design parameter optimization and the con- struction scheme selection of pipe roofs, and have been verified by the result of numerical analysis software FLAC3D and deformation monitoring.  相似文献   

10.
Aqueous ammonia mixed with caustic potash as wheat straw pulping liquor was investigated.The caustic potash not only reduced the NH3 usage and cooking time,but also provided a potassium source as a fertilizer in the black liquor.Excessive NH3 in black liquor from wheat straw NH4OH-KOH pulping process was recovered by batch distillation with a 98% recovery rate of free NH3 under atmospheric pressure and constant reflux.The temperature at the bottom of the column was controlled at 104-105℃.After removal of free NH3,the black liquor contained 8.4 g/L NH3-N and 7.04 g/L total potassium,with a substantial amount of ammoniacal lignin,and it could be used as a liquid fertilizer for farming.The height equivalent to a theoretical plate (HETP) of a rectifier for recovering free NH3 was calculated.The diameter and height of packing of the rectifier based on a daily consumption of 75 t oven-dry wheat straw were estimated.  相似文献   

11.
It is now the era of big data. Massive volumes of complex and dynamic data exist in a variety of indus- tries, including internet finance. This paper briefly describes the current big data situation and its significance, discusses the big data resource service platform architec- ture that includes three levels: data resource identification and access, data resources storage and analysis, and net- work information service platform, and then introduces some work undertaken by our project team on big data analysis research and application of trusted transactions for internet finance.  相似文献   

12.
Since 2004, three excavations have been carried out at a late Pleistocene human fossil site of Huanglong Cave in Yunxi County, Hubei Province of China, which unearthed seven human teeth, dozens of stone tools, mammal fossils and other evidence indicating human activities. During the third excavation in 2006, in the same layer as the human teeth, we found some patches of black materials embedded in the deposit. We doubted that this black deposit layer is the remains of burning or even human use of fire at the cave. To further explore the possibility of human fire use at the Huanglong Cave, we examined samples directly taken from the black deposit layer and compared them with samples taken from several places in the cave using three methods: micromorphology, element content determination and deposit temperature analysis. Our results indicate that the contents of carbon element in the black deposit reach 64.59%―73.29%. In contrast, contents of carbon element of the comparative samples from other parts in the cave are only 5.82%―9.49%. The micromorphology analysis of the black deposit samples reveals a plant structure like axial parenchyma, fibrocyte, uniseriate ray and vessel. High-temperature magnetic susceptibility measurements suggest that the stratum possibly underwent a high temperature in the nature. Based on these lab analyses, we are sure that the black layer in the Huanglong Cave is the remains of fire and combustion did occur in the cave 100000 years ago. Taking other evidence of human activities found in the Huanglong Cave into consideration, we believe that the evidence of fire from the Huanglong Cave was caused by the human activities of controlled use of fire.  相似文献   

13.
INTRODUCTIONKraft black liquor composition is very complicated. Generally, it is a complex and multiphase fluid, which consists of organic and inorganic components. The total solids content in black liquors has a great effect on its fluidity and deformation. To the wood black liquor, there have already been detailed researches on their flow properties and many theoretic or practical results have been concluded in the literatures [1-8]. But to non-wood black liquor, the previous researches…  相似文献   

14.
Au nanotubules (channels) can be electrolessly plated within the pores of polycarbonate microporous filtration membranes. When an electric field was applied on the cell consisting of the membrane and Pt electrodes, the response current decreased due to a baffle effect from big molecules when the electrolyte ion and big molecules passed through the channels modified with chemical groups. Based on this principle, a nanotubules-based sensing technique has been developed. This method can be applied to the determination of human IgG with a detection limit of 0.34 ng/mL.  相似文献   

15.
The design and implementation of a scalable parallel mining system target for big graph analysis has proven to be challenging. In this study, we propose a parallel data mining system for analyzing big graph data generated on a Bulk Synchronous Parallel (BSP) computing model named BSP-based Parallel Graph Mining (BPGM). This system has four sets of parallel graph mining algorithms programmed in the BSP parallel model and a well-designed workflow engine optimized for cloud computing to invoke these algorithms. Experimental results show that the graph mining algorithm components in BPGM are efficient and have better performance than big cloud-based parallel data miner and BC-BSP.  相似文献   

16.
Davidius triangulus Chao et Yang,sp.nov.Davidius fruhstor feri junior(Navas),Yang et Li,1992,Journal of Hanzhong Teachers College(Natural Science),1992(2):72,(?),(?).Shaanxi.(misidentification)COLORATION-Male:Head:Anterior aspeet and rear of head black except forbrown anteclypeus and transverse yellow stripe on frons,the latter stripe pointed on bothends.Prothorax:anterior lobc extensively orange,middle lobe with a large round yellowspot on each side,posterior lobe not marked.Synthorax:dorsal stripe narrow,ventrallyconfluent with collar stripe to form a pair of opposed and inverted 7-marks.Antehumeralstripe absent.Side of synthorax greatly yellow,with 2nd lateral stripe represented by a blackline from spiraele downwards,3rd stripe represented by a very narrow black line above.Ab-domen:extensively black,marked with yellow.Segment i yellow,dorsally with a pair oflarge transverse light brown marks.Segment ii dorsally with median stripe extending thewhole 1ength of the segment,laterally with two very large y  相似文献   

17.
Much attention has been paid to the development of dye-sensitized solar cells (DSCs) during the past decade. In general, a DSC comprises a nanocrystalline titanium dioxide (TiO2) electrode modified with a dye fabricated on a transparent conducting oxide (TCO), a platinum (Pt) counter electrode, and an electrolyte solution with a dissolved iodide ion/tri-iodide ion redox couple between the electrodes. Although a DSC using black dye with high efficiency of 10.4%, which was measured by NREL(U. S. A. ), was reported by Graetzel et al. , the efficiency of DSCs should be further improved for practical use in comparison with silicon so- lar cells.  相似文献   

18.
Anisotropic nanopatterns have potentials in constructing novel plasmonic structures which have various applications in such as super-resolution microscopy, medicine, and sensors. However, it remains challenging to build big anisotropic nanopatterns that are suitable for big noble metal nanoparticles. Herein, we report a simple and reliable strategy for constructing DNA origami-based big anisotropic nanopatterns with controlled size and shape, nanoscale resolution, and fully addressability. Two kinds of basic DNA origami nanoblocks-cross-shaped and rectangular DNA origami units were used. We have demonstrated that by encoding nanoblocks’ edges, anisotropic higher-order nanopatterns, such as dimer, trimer, tetramer and mini "windmill" like pentamer nanopatterns could be constructed. To show the potential use as template to direct the assembly of anisotropic nanoparticles arrays, a proof of concept work was conducted by anchoring streptavidin nanoparticles on the "windmill" template to form a chiral array. Significantly, these nanopatterns have the sizes of hundreds of nanometers, which are in principle also suitable for big noble metal nanoparticles arrays.  相似文献   

19.
China Unicorn, the largest WCDMA 3G operator in China, meets the requirements of the historical Mobile Internet Explosion, or the surging of Mobile Internet Traffic from mobile terminals. According to the internal statistics of China Unicom, mobile user traffic has increased rapidly with a Compound Annual Growth Rate (CAGR) of 135%. Currently China Unicorn monthly stores more than 2 trillion records, data volume is over 525 TB, and the highest data volume has reached a peak of 5 PB. Since October 2009, China Unicom has been developing a home-brewed big data storage and analysis platform based on the open source Hadoop Distributed File System (HDFS) as it has a long-term strategy to make full use of this Big Data. All Mobile Internet Traffic is well served using this big data platform. Currently, the writing speed has reached 1 390 000 records per second, and the record retrieval time in the table that contains trillions of records is less than 100 ms. To take advantage of this opportunity to be a Big Data Operator, China Unicom has developed new functions and has multiple innovations to solve space and time constraint challenges presented in data processing. In this paper, we will introduce our big data platform in detail. Based on this big data platform, China Unicom is building an industry ecosystem based on Mobile Internet Big Data, and considers that a telecom operator centric ecosystem can be formed that is critical to reach prosperity in the modern communications business.  相似文献   

20.
Thermal energy storage (TES) can increase the energetic efficiencies and, in many cases, the exergetic efficiencies of thermal energy systems. Steam boiler plant with a violently fluctuating load is a typical example when a steam accumulator is added to it. While the comparatively big first cost constitutes a barrier to the wide use of TES, the cost will notably be reduced through minimizing the necessary thermal capacity of it. The structure and illustrations are given for the computer program designed for performing the optimization. This program was applied to an existing boiler plant equipped with a steam accumulator. The results show that there would have been a big reduction in the necessary capacity, if the design of this steam accumulator had been optimized. Four conclusions have been reached.  相似文献   

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