检索结果-南通市图书馆

Positive carbon isotope excursions:global correlation and genesis in the Middle-Upper Ordovician in the northern Tarim Basin,Northwest China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2016年第2期13卷 192-203页

作者： Cun-Ge liu li-Xin Qi yong-li liu Ming-Xia Luo Xiao-Ming Shao Peng Luo Zhi-li Zhang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of Technology Northwest Oilfield Company China Petroleum & Chemical Corporation Institute of Petroleum Exploration and Development Petroleum & Chemical Corporation

Stable carbon isotope ratio （δ13Ccarb） analysis has been widely applied to the study of the inter-conti- nental or global marine carbonate correlation. Large-scale Cambrian-Ordovician carbonate platforms were developed in the Tarim Basin. But research on fluctuation character- istics and global correlation of δ13Ccarb is still weak. Based on conodont biostratigraphy and whole-rock δ13Ccarb data in the Tahe oil-gas field of the northern Tarim Basin, the global correlation and genesis of positive carbon isotope excursions in the Darriwilian--Early Katian was exam- ined. Three positive excursions were identified in the Tahe oil-gas field including the middle Darriwilian carbon iso- tope excursion （MDICE）, the Guttenberg carbon isotope excursion （GICE）, and a positive excursion within the Pygodus anserinus conodont zone which is named the Early Sandbian carbon isotope excursion （ESICE） in this paper. Furthermore, these positive excursions had no direct relation with sea level fluctuations. MDICE and GICE could be globally correlated. The Middle-Upper Ordovi- cian Saergan Formation source rocks of the Kalpin outcrops were in accordance with the geological time of MDICE and ESICE. GICE had close relationship with the source rock of the lianglitag Formation in the *** organic carbon burial was an important factor controlling the genesis of these positive excursions.

关键词： Tarim Basin Tahe oil-gas field - Middle-Upper Ordovician Carbon isotope Darriwilian Sandbian Katian source rock

Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region,Tarim Basin,NW China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2017年第4期14卷 662-675页

作者： Rong-Hui Fang Mei-Jun li Hai-Tao Lü T.-G.Wang Yuan Yuan yong-li liu Zhi-yong Ni State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing 102249China Exploration and Development Research Institute Northwest Oilfield Branch CorporationSINOPECUrumqi 830011XinjiangChina Research Institute of Shaanxi Yanchang Petroleum(Group)Co.Ltd Xi'an 710075ShaanxiChina

Geochemical analysis of 64 oils sampled from an Ordovician carbonate reservoir in the Tuoputai region was undertaken to study the composition of molecular markers. All the oils have similar geochemical characteristics and belong to a single oil family. They are presumed to derive from the same source kitchen and have similar oil charging history. A histogram of homogenization temperatures(Th) of aqueous inclusions in reservoir rocks shows a bimodal distribution pattern, indicating that the Ordovician reservoir has been charged twice. Coupling the measured Th(°C) with the burial and geothermal histories reconstructed using 1D basin modeling, we relate the homogenization temperature to the relevant geological ages: i.e.,425–412 and 9–4 Ma, corresponding to the Middle to Late Silurian and the Miocene to Pliocene, respectively. The oil filling orientation and pathways are traced using molecular indicators related to alkyldibenzothiophenes and benzo[b]naphthothiophenes. The oil charging orientation is from south to north generally. It can be predicted that the Ordovician reservoirs were sourced from a kitchen located to the south of the Tuoputai region, most probably between the Awati and Manjiaer Depressions. Traps located in the southern side of the Tuoputai region, along the oil charging pathways, should therefore be preferred oil exploration targets.

关键词： Oil population Oil charging events Fluid inclusion 1D numerical modeling Oil filling pathway

Seeing measurements for the Guoshoujing Telescope (LAMOST) site with DIMM

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2010年第10期10卷 1061-1070页

作者： li-yong liu yong-Qiang Yao Yi-Ping Wang Jiang-Long Ma Bo-liang He Hong-Shuai Wang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

We present seeing measurements of the Guoshoujing Telescope （formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope- LAMOST） site at Xinglong station during the period from 2007 March 12 to April 25. The measurements were carried out with the Differential Image Motion Monitor （DIMM）, and a total of 9259 data sets was obtained. The median seeing was measured to be 1.1″, with 25% being better than 0.8″and 75% better than 1.5″. The experiment shows that the DIMM exposure time has significant effects on the results of seeing measurements. An SBIG Polaris seeing monitor, which had been planned to be installed on the LAMOST site for long-term monitoring, was also employed during the DIMM observations. The results show that the SBIG seeing monitor is easily affected by gusty wind, resulting in larger seeing values. Considering the previous seeing measurements at Xinglong station over the last 15 yr, we conclude that an acceptable seeing condition at Xinglong station is around 1″-2″.

关键词： techniques atmospheric turbulence seeing -- instrumentation DIMM -- site testing LAMOST

Grain Composition and Erosive Equilibrium of Debris Flows

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2007年第1期4卷 71-76页

作者： li yong liu Jingling CHEN Xiaoqing WEI Fangqiang Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences Institute of Mountain Hazards and Environment Chinese Academy of Sciences ＆ Ministry of Water Conseruancy Chengdu 610041

Debris flows consist of grains of various sizes ranging from 10^(-6) m ～1 m. Field observations in the Jiangjia Gully (JJG) and other sites throughout China indicate that the grain size distribution of sediment in debris flows can be characterized by an exponential function fit to the cumulative distribution. The exponent value for the function varies by location and may be useful in distinguishing between debris flows from different valleys. For example, minimum values and ranges of the exponent are associated with the high frequency of debris flows in the JJG. Furthermore, the distribution presents piecewise fractality (i.e. scaling laws hold in various ranges of the grain size) and we propose that the fractal structure determines the matrix and that the fractal dimension plays a crucial role in material exchange between a debris flow and the substrate it flows over. Finally, the empirical data support an exponential relation between grain composition and non-dimensional shear stress for the critical state of the channel. Overall we propose a material-determinism approach to studying debris flows which contrasts with the enviro-determinism that has dominated much recent work in this field.

关键词： Grain composition fractal erosion equilibrium debris flow

Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第3期30卷 149-159页

作者： yong-li liu Qing-Xian Zhang Jian Zhang Hai-Tao Bai liang-Quan Ge The College of Applied Nuclear Technology and Automation Engineering Chengdu University of Technology

The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid *** on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.

关键词： Energy-dispersive X-ray fluorescence analysis Full-spectrum least-squares method Effective atomic number Mass attenuation coefficient Fundamental parameter method

Dysprosium Modification of Cobalt Ferrite Ionic Magnetic Fluids

在线全文

学校读者我要写书评

暂无评论

Journal of China University of Mining and Technology 2005年第4期15卷 354-356页

作者： JIANG Rong-li liu yong-chao GENG Quan-rong ZHAO Wen-tao School of Chemical Engineering and Technology China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Dysprosium composite cobalt ferrite ionic magnetic fluids were prepared by precipitation in the presence of Tri-sodium citrate. Influence of dysprosium modification on magnetic property is studied. The result shows that magnetic response toward exterior magnetic field can be improved by adding Dy3+. Studies also show that the increase of reaction temperature may improve the modification effect of dysprosium. By adding dysprosium ions, the average diameter of the magnetic nanoparticles will be decreased evidently. It is clear that the particles appear as balls. Cobalt ferrite with sizes of 12-15 nm, rare earth composite cobalt ferrite with sizes of 6-8 nm.

关键词： cobalt ferrite magnetic fluids dysprosium modification mechanism magnetic property

Characterization of Porcine Reproductive and Respiratory Syndrome Virus Deletion Mutant

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2008年第11期7卷 1379-1386页

作者： CHEN Hao-tai ZHANG Jie MA li-na liu yong-sheng State Key Laboratory of Veterinary Etiological Biology/Key Laboratory of Animal Virology Ministry of Agriculture/Key Laboratory of Veterinary Public Health Ministry of Agriculture/Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou 730046 P.R.China

The genome of the isolate of porcine reproductive and respiratory syndrome virus （PRRSV） from China, designated HPBEDV, was sequenced and analyzed. The size of the genome of HPBEDV was 15 334 nucleotides （nt）. Comparative analysis of HPBEDV with the genomic sequences of the domestic and other isolates （JXA 1, HUN4, CH-1 a, B J-4, VR2332, and LV） revealed that HPBEDV shared 98.4, 98.0, 89.0, 88.7, and 88.6% identity with the American strain JXA1, HUN4, CH- 1a, BJ-4, and VR2332, respectively, but only 54.7% identity with the European reference strain Lelystad virus. The NSP2 gene had 2 850 nt and encoded 950 amino acids （aa）, with two discontiguous deletions of 1 aa and 29 aa at positions 482 and 534-562, respectively, relative to VR-2332. Also, phylogenetic analysis with the published PRRSV genomic sequences indicated that the newly emerging isolate form a clade with the VR-2332 isolates. Therefore, HPBEDV was a novel strain with deletions in NSP2 gene.

关键词： porcine reproductive and respiratory syndrome virus deletion mutant genome phylogenetic tree

Fractal Structure of Debris Flow

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2007年第4期12卷 595-598页

作者： li yong liu Jingjing HU Kaiheng CHEN Xiaoqing Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China

One of the most remarkable characteristics of debris flow is the competence for supporting boulders on the surface of flow, which strongly suggests that there should be some structure in the fluid body. This paper analyzed the grain compositions from various samples of debris flows and then revealed the fractal structure. Specifically, the fractality holds in three domains that can be respectively identified as the slurry, matrix, and the coarse content. Furthermore, the matrix fractal, which distinguishes debris flow from other kinds of flows, involves a hierarchical structure in the sense that it might contain ever increasing grains while the total range of grain size increases. It provides a possible mechanism for the boulder suspension.

关键词： debris flow fractal structure grain composition

Site testing campaign for the Large Optical Telescope at the Ali site

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2020年第6期20卷 141-150页

作者： li-yong liu yong-Qiang Yao Jia Yin Hong-Shuai Wang Jun-Rong li Yun-He Zhou Xian-Long You Peng Tang Xi-Yue Zhao De-Qiang Ma Jian Dong National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The Large Optical/infrared Telescope(LOT)is a ground-based 12 m diameter telescope which is proposed to be built in western *** site selection for LOT in China began in 2016,and Ali was listed as one of the three candidate *** studies and local surveys have been carried out for more than 15 years in western China,and the results show that Ali is a promising site with comprehensive quality in terms of atmospheric and supporting *** overview of the site testing campaign at the Ali site from 2016 to 2019 is *** the two years of data collection,the overall median seeing value is found to be 1.17 arcsec,the observable nights are 81.71%and the good observable nights are 71.76%.The weather conditions as follows,the median night temperature value is-5.18℃,the median night relative humidity value is 41.25%,the median night atmospheric pressure value is 540.92 hPa,the median night wind speed value is 7.41 m s-1 and the mainly wind direction is southwestern(SW).The median night sky background value is 22.07 *** also discuss the wind speed at different locations on-site,the possibility of light pollution and the effect of wind speed on differential image motion monitor(DIMM)seeing measurements.

关键词： large optical telescope site testing Ali site cloudiness seeing