Hydrochemical Characteristics and Evolution of Underground Brine in Lop Nur,Northwestern China

Lop Nur is located at the eastmost end of the Tarim Basin in Xinjiang,Northwestern China.This study reviews the hydrochemical characteristics and evolution of underground brine in Lop Nur,based on analytical data from 429 water samples(mainly brine).It is found that in the NE-SW direction,from the periphery to the Luobei sub-depression,while the hydrochemical type varies from the sodium sulfate subtype(S)to the magnesium sulfate subtype(M),the corresponding brine in the phase diagram transfers from the thenardite phase(Then)area,through the bloedite phase(Blo),epsomite phase(Eps),picromerite phase(Picro),finally reaching the sylvite phase(Syl)area.As for the degree of evolution,the sequence is the periphery<Luobei horizontally and the overlying glauberite brine<the underlying clastic brine vertically.It is concluded that the oxygen and hydrogen isotopic compositions of the brine have evidently been affected through the effects of evaporation and altitude,as well as the changes in local water circulation in recent years.Boron and chloride isotopic compositions show that the glauberite brine is formed under more arid conditions than the clastic one.The strontium isotopic composition indicates that the Lop Nur brine primarily originates from surface water;however,deep recharge may also be involved in the evolution of the brine,according to previous noble gas studies.It is confirmed that the brine in Lop Nur has become enriched with potassium prior to halite precipitation over the full course of the salt lake's evolution.Based on chemical compositions of brine from drillhole LDK01 and previous lithological studies,the evolution of the salt lake can be divided into three stages and it is inferred that the brine in Lop Nur may have undergone at least two significant concentration-dilution periods.

The paleoclimatic environment reconstruction of Lop Nur in NW China in UAV spectroscopy

The change in the ecological environment in the arid core area is a critical issue in the context of global warming.To study the paleoclimate evolution,precise identification of minerals deposited in Asia’s arid hinterland,Lop Nur Salt Lake,NW China was conducted.The hyperspectral data of the salt crust was sampled to identify the species and content of sedimentary minerals,and the multispectral photos were used to reconstruct the salt crust morphology using the unmanned aerial vehicles platform.The SUnSAL(sparse unmixing by variable splitting and augmented Lagrangian)method was employed to inverse the sedimentary mineral components along the shoreline.The heterogeneity of salt and clay minerals in bright and dark ear-shaped strips was evaluated.The paleoclimatic environment associated with salt lake extinction was reconstructed by analyzing paleoclimate records of sediments,spectral reflectance and morphology of the salt crust.Results show that:(1)the variations in the micro-geomorphology of the salt crust are obviously the reason for the formation of bright and dark ear-shaped strips and the differences in the species and relative content of the sedimentary minerals are the microscopic reason.The high ratio of sedimentary salt minerals to clay minerals(RS/C)contributes to the high reflectivity,and the salt crust presents a bright texture.The low RS/C results in the low reflectivity,salt crust presents a dark texture;(2)the bright and dark ear-shaped strips represent warm-arid and cold-humid climates.The shape of the Lop Nur Lake shoreline evolved due to alternating warm-dry and cold-humid paleoclimate changes.

基于LOP模型的事故隐患分类分级研究

为构建科学有效的事故隐患(AP)排查治理长效机制,基于防护层(LOP)模型,建立统一的、便于执行和管理的事故隐患分类分级框架。讨论分析事故隐患及危险源的几种定义,将事故隐患分为设计建造、基本过程控制、超限报警、安全控制、主动防护、被动防护和应急等新7大类,并定为严重、中等、一般等新3级。提出设置事故隐患排查治理指标,建立事故隐患分类分级标准备案机制。结果表明,事故隐患是事故的必要但不充分条件,是LOP安全防护功能下降或失效的充要条件,所建立的事故隐患分类分级框架是促进事故隐患排查治理工作的基础。

CT-LOP硫磺回收反应器堵塞原因分析及解决措施

硫磺堵塞是络合铁工艺存在的主要问题之一,络合铁工艺的各设备及管线均存在不同程度的堵塞情况。针对中国石油西南油气田公司天然气研究院自主研发的络合铁(CT-LOP)液相氧化还原工艺装置反应器堵塞进行讨论,CT-LOP工艺在运行过程中出现环流式反应器、吹扫风管线、硫浆通道等堵塞情况,就堵塞现状对原因进行全面分析,并提出脉冲风管线优化、定期更换鸭嘴分布器和优化加药操作等解决措施,为液相氧化还原工艺或单井脱硫的堵塞问题提供解决思路和借鉴方案。

消化性溃疡患者血SOD、NO及LOP水平变化研究

目的:探讨消化性溃疡患者血SOD、NO及LOP水平变化的变化规律,为消化性溃疡的治疗和诊断提供依据。方法:选取2006年12月～2009年1月于本院进行治疗的125例消化性溃疡患者为研究对象,将其设为观察组,同时选取同期的100例健康人为对照组,并对对照组及观察组治疗前后的血SOD、NO及LOP水平进行检测研究,并加以研究统计。结果:经研究比较发现,对照组与观察组治疗前SOD、NO及LOP水平比较,P<0.05,差异有统计学意义;观察组治疗前与治疗后4周差异较大,P<0.05,差异有统计学意义;观察组治疗前与治疗后8周差异较小,P>0.05。结论:消化性溃疡患者的血SOD、NO及LOP水平变化对于患者的诊断及治疗有着积极的意义,值得临床进一步研究及探讨。

The Greening Construction and Technology of the Management in the Lop Nur Potash Mine

Lop Nur potash mine greening projects is located in the heart of the Lop Nur, known as the ＂green zone ban＂. The project overcomes the extreme drought, high temperature, gale and dust salt and salt, and many other adverse environmen- tal factors. Adopted the suitable salt improvement measures and management tech- nology, the artificial green has emerged in the sea of death. At the same time the greening project improved the office environment of mining area, and shaped ex- treme environment greening projects successful cases.

CT-LOP液相氧化还原脱硫工艺核心反应器热量衡算方法探析

利用化工数据手册中收录的物性数据,采用常用的化工计算公式,根据质量守恒定律和能量守恒定律,形成了一种可对CT-LOP液相氧化还原工艺核心反应器进行热量衡算的计算方法。将计算结果与现有天然气净化装置的设计参数进行对比,数据吻合度较好。该方法可为新建CT-LOP液相氧化还原工业装置的设计提供技术支撑。

函数的epi-和lop-收敛性

利用Painleve-Kuratowski关于集列的收敛性研究函数的上图(epi-)收敛性,进而讨论二元函数的lop-收敛性,给出函数的max inf点的特性及其收敛性的有关特征,并对Fanky不等式进行了推广.

基于LOP的分布式数据存储与查询技术

当今已经进入了云计算时代,其中,数据的分布式存储和查询也已成为大数据管理的关键技术之一.分布式数据管理在数据存储层面需要进行数据的分片和配置,在查询方面需要进行各节点查询子结果的配置与整合.对于结构化数据例如关系型数据已经具有了成熟有效的相关技术,但对于主要是半结构化、无结构化以及多种数据模式混杂的大数据而言,其分布式数据分片和配置还是一个具有需要深入研究的课题.本文针对具有广泛应用的具有时间标签的非结构化数据,提出了一种按照时间标签进行分片与配置的分布式存储与处理方案,相应的仿真实验表明本文的工作是可行的和有效的.

Features and Formation Mechanism of Faults and Potash-forming Effect in the Lop Nur Salt Lake,Xinjiang,China

The Lop Nur Salt Lake, located in the eastern part of the Tarim Basin, Xinjiang, China, has become a playa in the Quaternary. Rhombic in shape, the Lop Nur depression is mainly controlled by the NE-striking and nearly N-S-striking sets of faults. Since 1995, a superlarge brine potash deposit with potash resources of 2.50×10^8s t has been found in the Luobei subbasin in the northeastern part of the Lop Nur. We intensively studied the features and formation mechanism of faults inside the Lop Nur through satellite images, geomorphologic survey and continuous conductivity imaging and found seven subparallel graben faults formed under the action of nearly N 10° E principal compressional stress during deposition of the Lop Nur Salt Lake. These faults are up to 〉60 km long and 1-4 km wide and may extend downward for 1000 m or more. It is just under the action of these tensional faults that potash subbasius formed. The largest subbasin is the Luobei subbasin and the smaller ones are the Luoxi hollow, Erbei hollow and Tienan hollow. Investigation also indicates that the graben faults in the Lop Nur not only control the origin of the potash subbasins, but they themselves are also good brine reservoir structures, in which abundant potash-rich brines are stored. Therefore, The faults had played an important role in the potash formation of the Lop Nur.

The Impact of the Linked Factors of Provenance,Tectonics and Climate on Potash Formation:An Example from the Potash Deposits of Lop Nur Depression in Tarim Basin,Xinjiang,Western China

Potash deposits commonly accumulate in highly restricted settings at the final stage of brine evaporation. This does not mean that potash deposits are formed simply as a result of the evaporation concentration of seawater or lake water, but rather as a coupling result of particular provenance, tectonics and climate activities. In this paper, we focus on the formative mechanism of the potash deposits of Lop Nur depression in Tarim Basin to interpret the detailed coupling mechanism among provenance, tectonics and climate. In terms of the provenance of Lop Nur Lake, the water of the Tarim River which displays ＂potassium-rich＂ characteristics play an important role. In addition, the Pliocene and Lower-Middle Pleistocene clastic beds surrounding Lop Nur Lake host a certain amount of soluble potassium and thus serves as ＂source beds＂ for potash formation. During the late Pliocene, the Lop Nur region has declined and evolved into a great lake from the previous piedmont and diluvial fan area. Since the mid Pleistocene, the great-united Lop Nur Lake has been separated and has generated a chain system consisting of Taitema Lake, Big Ear Lake and Luobei Lake which has turned into the deepest sag in Lop Nur Lake. Dry climate in Lop Nur region has increased since the Pliocene, and became extreme at the late Pleistocene. The study implies that potash formation in Lop Nur Lake depends on the optimal combination of extreme components of provenance, tectonics and climate during a shorter-term period. The optimal patterns of three factors are generally characterized by the long-term accumulation and preliminary enrichment of potassium, the occurrence of the deepest sub-depression and the appearance of an extremely arid climate in Lop Nur region. These factors have been interacting synergistically since the forming of the saline lake and in the later stages strong ＂vapor extraction＂ caused by extremely arid climate is needed to trigger large scale mineralization of potash deposits.

Minerogenic Theory of the Superlarge Lop Nur Potash Deposit, Xinjiang, China

Located in the eastern part of the Tarim basin, Xinjiang, the Lop Nur was an ultimate water catchment area of the Tarim basin during the Quaternary. Through nearly ten years of investigation and research, the authors have found a superlarge brine potash deposit in the Luobei subbasin—a secondary basin of the Lop Nur depression. The deposit has been mined now. On that basis, the authors propose new theories on the genesis of the potash rock deposit. In the tectonic and geomorphologic contexts, the Tarim basin lies in a 'high mountain-deep basin' environment. At the beginning of the Quaternary, influenced by the neotectonic movement, the Lop Nur evolved into a 'deep basin' in the Tarim basin. At the end of the middle Pleistocene, neotectonic migration began to take place in the interior of the Lop Nur and a new secondary deep basin—the Luobei subbasin—formed gradually. Despite its small area, it is actually the deepest subbasin in the Lop Nur depression, where brines of the Lop Nur Salt Lake gather and evaporate, thus providing materials for the formation of a superlarge brine potash rock deposit. With respect to the phenomenon of brine concentration and change with deepening of the lake, the authors propose a model of 'high mountain-deep basin' tectonic migration for potash concentration. In the sedimentological context, the honeycomb-shaped voids developed in glauberite rock in the subbasin are good space for potash-rich brine accumulation. Study indicates that the deposition of glauberite requires recharge of calcium-rich water. In the Tarim area the calcium-rich water might come from deep formation water or oilfield water, and the river water recharging the Lop Nur Salt Lake was rich in sulfate radicals and other components; in addition, the climate in the area was very dry and the brine evaporated steadily, thus resulting in deposition of substantial amount of glauberite, potash accumulation in intercrystal brine and final formation of the potash deposit. Generally, potash formation in a salt lake undergoes a three-stage process of 'carbonates—?sulfates (gypsum and glauberite)—^chlorides (halite etc.)', but in the study area there only occurred a two-stage process of 'carbonates—>sulfates (gypsum and glauberite)'. The authors call this new geological phenomenon the 'two-stage potash formation' model. In conclusion, the superlarge Lop Nur potash deposit is the result of combined 'high mountain-deep basin' tectonism and 'two-stage potash formation'.

Holocene Yellow Silt Layers and the Paleoclimate Event of 8200 a B.P.in Lop Nur,Xinjiang,NW China

Many yellow silt layers have been identified in the Holocene sediments in the last lake of Lop Nur (playa), Xinjiang, northwestern China. Statistics of drill-hole cores have revealed more than one hundred layers, which exhibit regularity in time sequence. Study has further verified that these yellow silt layers were deposited through eolian processes. The time-frequency distribution diagram shows an obvious peak occurring at about 8200 a B.P., which is consistent with the dry, windy and cold climate event occurring at 8200 a in other places around the world. Therefore, this event is regarded as a response to the global climate change.

Quaternary Climate and Environment in the Lop Nur,Xinjiang

Since the middle Early Pleistocene (1.20 Ma B.P.), the desert steppe climate and environment have predominated in the Lop Nur area, Xinjiang, characterized by warm humid epochs interrupted by dry cold intervals. The grain-size and magnetic susceptibility curves record 30 climatic oscillations, each with a ca. 40 ka cycle, in the area since 1.2 Ma B.P., which reflects the controlling effects exerted by the astronomic factor on the environment. The Quaternary sedimentary environment in the Lop Nur gradually changed from a fresh lake through a brackish lake to a saline lake, showing a spiral evolution, and finally it evolved into a playa.

Growth and sustainability of Suaeda salsa in the Lop Nur,China

Extremely saline soils are very harsh environments for the growth and survival of most plant species, however, halophytes can grow well. The underlying mechanism of halophyte to resist high saline is not well understood by us. This study was conducted at the potash mine near the Lop Nur, China, where the effects of the halophyte Suaeda salsa L. on the saline-alkaline soils and its growth and sustainability were investigated. Four plots（in which the salt encrustation layers were removed）, with different soil treatments were evaluated：（1） undisturbed soil, with no additional treatment（T1）;（2） the slag soil zone, in which a 40-cm layer of slag was placed on the undisturbed soil surface（T2）;（3） slag＋sandy soil, in which a 20-cm layer of slag was placed in the lower layer and 20 cm of sandy soil, taken from an area about 70 km away from Lop Nur potash mine, where Tamarix species were growing, was placed in the upper layer（T3）; and（4） a 40-cm sandy soil layer taken from the area where Tamarix species were growing was placed on undisturbed soil（T4）. Soil nutrient contents increased in the four treatments, but salt content only decreased in the T1 treatment. Salt content in the T4 treatment increased over the two-year period, which may be partly attributed to salt deposition from wind-blown dust within the mine and salt accumulation within the surface soil（0–20 cm） in response to high evaporative demands. The S. salsa plants exhibited greater improvements in growth under the T4 treatment than under the T1, T2, and T3 treatments, which demonstrated that low levels of salinity are beneficial for the growth of this species. The T1 treatment was sustainable because of its low cost and superior soil improvement characteristics. Therefore, S. salsa plants not only reduced soil salinity and increased soil nutrient levels, but also ameliorated the plant growth environment, which would be beneficial for both the ecological restoration of the Lop Nur area and similar areas throughout the world.

The changes of Lop Nur Lake and the disappearance of Loulan

The causes of the disappearance of the ancient town of Loulan in Xinjiang, China have been generally agreed to derive from two factors: human activities and natural factors (environmental variations). In this paper, the Muzart Glacier was selected as an example, and found that the length of the glacier has been gradually decreasing and the snow line has been retreating to a higher altitude, both results contributing to a decrease in river flow below the Muzart Glacier. From the distribution of moraines in the Tianshan Mountains and adjacent areas in different periods, the paper speculates that there have been four minor glacial periods since the Quaternary. Although the durations and scales of the four minor glacial periods were different, they all indirectly influenced the formation and disappearance of the Lop Nur Lake. The events of the fourth minor glacial period are the important impact factors in the existence and disappearance of Loulan. Whether the disappearance of Loulan can be related to the events of the three previous minor glacial periods needs further investigation.

Magnetic mineral diagenesis in sediments of saline lake Lop Nur

Saline lakes are useful repositories for paleo-climatic records. In recent years, magnetic properties of saline lake sediments have been widely applied to establish paleo-climatic change. However,the influence factors of magnetic properties in saline lakes have not been fully understood, which complicates the paleoenvironmental interpretation.Here, we present a rock magnetic analyses result of LOP_1 profile(40°26′09″′N, 90°21′23″E) from Lop Nur, a well-known saline lake, located in the eastern Tarim Basin in northwestern China. We combined the particle size, total organic content, and mineral characteristics analysis to assess the influence factors of magnetic properties in Lop Nur and its environmental significance. The results indicate that early diagenesis is the major influence factor on magnetic properties of Lop Nur saline sediments.Authigenic greigite and pyrite are identified within organic-rich sediments, which produce zones with high and low magnetic susceptibilities, respectively.The different authigenic iron sulfide contents in different layers are related to sedimentary environment changes. Sufficient supplies of organic matter and sulphate and low sedimentation rates favour the pyritization process. Moreover, if pyritization was constrained, intermediate greigite formed and was preserved. In oxidizing environments, sediment magnetic properties are consistent with those of source materials from Tarim Basin and are mainly controlled by particle size and hydrodynamic sorting of mainly detrital magnetite is largely unaffected by early diagenesis. Our study demonstrates that magnetic properties can provide a robust approach for studying depositional environment change in saline lake. In addition, the information obtained in this study would also provide insights into the geochemical processes of iron element in saline lakes.

Sediment record of environmental change at Lake Lop Nur (Xinjiang, NW China) from 13.0 to 5.6 cal ka BP

Lake Lop Nur is located in the eastern part of the Tarim Basin in Xinjiang,northwestern China.A 220-cm-long sediment core was collected from the center of the ear-shaped depression forming the basin and dated with AMS^(14)C.Grain size,total organic matter(TOC),total nitrogen(TN),and TOC/TN(C/N)analyses were used to reconstruct climatic conditions from 13.0 to 5.6 cal ka BP.The results showed fi ve main climatic stages.Zone I(13.0–11.3 cal ka BP)was a wet–dry environment,whereas Zone II(11.3–8.9 cal ka BP)consisted of a primarily wet environment.Zone III(8.9–7.7 cal ka BP)was subdivided into Zone IIIa(8.9–8.2 cal ka BP)that indicated lake constriction and dry climate,and Zone IIIb(8.2–7.7 cal ka BP)in which the proxies indicated wet conditions.In Zone IV(7.7–6.6 cal ka BP),the climate presented a bit wet conditions.In Zone V(6.6–5.6 cal ka BP),abundant glauberite is present in the sediment and silt dominates the lithology;these results indicate the lake shrank and the overall climate was dry.Abrupt environmental events were also identifi ed,including six dry events at 11.0,10.5,9.3,8.6,8.2,and 7.6 cal ka BP and one fl ood event from 7.8 to 7.7 cal ka BP in the Early–Middle Holocene.

A study on historical location and evolution of Lop Nor in China with maps and DEM

Lop Sea,located at the east end of the Tarim Basin,Northwest China,dried up permanently,which is the terminal lake of the Tarim River.Lop Sea was considered as the lake basin of Lop Nor since Quaternary.However,the possibility that Lop Nor was away from the Lop Sea in historical time is crucial to be discussed to interpret the proxy records in sediment profiles.To obtain a general view of the evolution of Lop Nor and Lop Sea in a historical period,several approaches were adopted in this paper.First,the Qianlong Thirteen-Row Atlas,an ancient imperial atlas of the Qing Dynasty,which was completed around 1760,indicated that the Tarim River formed a relatively large lake at its modern upstream region.Second,a Digital Elevation Model(DEM)with a 10-m spatial resolution and a relative precision of 0.42 m was derived from TanDEM-X/Terra SAR-X satellite image pairs using the interferometry method,which was verified using ICESat-GLAS laser footprints and a local DEM acquired by a drone.Finally,based on the spatial analysis of historical documents,expedition reports,sediment profiles and archaeological evidence,it can be deduced that the lacustrine deposition was discontinued in the Lop Sea.Six episodes in the evolutionary history of the drainage system in eastern Tarim Basin were summarized.The proved depositional condition variations could be used for future interpretation of proxy records in sediment.The high-accurate DEM provided a reference for the location of further fieldwork in the Lop Sea.The method proposed in this paper may be efficient for the research of inland lakes or rivers in global arid regions.

Water Absorption Capcapability and Moisture Content Seasonal Changing of Salt-Crust in Lop Nur Dry Lake

The Lop Nur dry salt lake,Xinjiang province,is charactered by typical physiognomy salt-crust,located in39.6-41.3N.latitude and 89.6-91.4E.longitude.The thickness of salt-crust is about from 20 cm to 100 cm,and