Oxygen isotope variation in the water cycle of the Yamzho lake Basin in southern Tibetan Plateau

Given the potential use of stable isotope in the paleoclimate reconstruction from lacustrine records as well as in the local hydrology cycle, it is crucial to understand the processes of stable isotope evolution in catchment in the Tibetan Plateau region. Here we present a detailed study on the water oxygen isotope based on 2 years observation including precipitation, river water and lake water in the Yamzho Lake, south of the Tibetan Plateau. Temporal variation of local precipitation 5180 shows an apparent ＂monsoon cycle＂. In monsoon season, 5180 in waters is lower. In non-monsoon season, δ^18O in precipitation and lake water is higher and higher river δ^18O exists in spring, probably reflecting the effect of land surface evaporation, together with the higher δ^18O values in spring precipitation. It is also found that the surface lake water δ^18O varies seasonally and annually. The lower lake water δ^18O in the late summer is apparently related to the summer monsoon precipitation. The mean δ^18O value of lake water in 2007 is 1.2‰ higher than that in 2004, probably due to the less monsoon precipitation in summer of 2007, as can be confirmed from the precipitation data at the Langkazi meteorological data. It is also found that an obvious shift of vertical lake water δ^18O reflects the fast mixture of lake water. δ^18O values of lake water are over 10‰ higher than those of precipitation and river water in this region due to the evaporation fractionation. The modeled results show that the evaporation process of the lake water is sensitive to relative humidity, and the present lake water δ^18O reflects a relative humidity of 51% in the Yamzho Lake. It shows that the lake will take 30.5 years to reach present lake water δ^18O given a large shift in the input water δ^18O. The modeled results also reveal that surface lake water temperature and inflow δ^18O have slight effect on the isotopic balance process of lake water in the Yamzho Lake.     

Processes and mechanism of effects of sludge dredging on internal source release in lakes

Simulated research of internal loading and collecting and analyzing the samples from the lakes were carried out before and after dredging in polluted suburb lakes, Wuli Lake (Wuxi City) and Xuanwu Lake (Nanjing City). The research results showed that dredging can inhibit internal loadings in a certain degree in a short term. The discrepancy of dredging effect and technical level, namely dredging quality, by different dredging methods will result in a difference of control of lake internal loadings. The internal loadings‘ reversion will gradually appear along with the biogeochemical processes, including suspended particle precipitation, hydrodynamic disturbance and microbio-transformation. The reversion rate mainly depends on the dredging method and the change of interfacial processes on the newborn surface layer. The higher nutrient contents and organic matter in the sediment will enhance water-sediment interfacial processes and nutrients regeneration. It is very important to study the physicochemical and biological character of lacustrine sediments before dredging for determining the dredging methods and predicting their environmental effect.     

Preliminary research on Megalake Jilantai-Hetao in the arid areas of China during the Late Quaternary

We identified geomorphological, sedimentary and biological evidence of high lake levels around the current Jilantai Salt Lake through field investigations and through analyses of regional remote sensing images. There are four groups of shorelines at elevations of around 1060, 1050, 1044 and 1035 m a.s.l., being 37, 27, 21 and 12 m above the current salt lake surface, respectively. Littoral deposits of sand and gravels are found at elevations between 1070 and 1080 m a.s.l., 47 to 57 m higher than the current salt lake surface, although palaeoshoreline landforms are only preserved at several sites. At Herimuxini, on the northern margin of the Ulan Buh Desert, typical lacustrine sediments and sand-gravel littoral deposits also occur at elevations of 1080 m a.s.I, and below. A 11-km-long typical spit extends eastward from this shoreline gradually reducing in elevation from 1050 to 1035 m a.s.I. In some sand-gravel quarries along the southern bank of the Yellow River on its Great Bend, such as those located near the Hydrological Gauge Station and Shilazhao Town, shoreline features were identified. Littoral deposits overlying the alluvial-diluvial layers occur in a sand quarry near Balagong in Hangjin County. There are also beachrock and littoral deposits preserved on the cut-and-built terraces at several sites along the southern piedmont of Langshan-Yinshan Mountains. In addition, a profile revealing subaqueous delta sediments was identified near Wuhai, where the Yellow River enters the basin. Typical lake sediments also exist at the Togtoh Platform on the eastern end of the Hetao Plain. Aquatic Mollusk shells are common in the littoral deposits, including several species of Corbicula, Radix lagotis, R. xauricularia and Gyraulus convexiusculus. Ostracode shells can also be identified in finer sediments. Typical ver- tical prograding sequences are evident in outcrops where lacustrine sediments were well preserved. Wave-rolled cobbles and beachrock are very commonly preserved on the top of profiles in the embankments at     

Coastal seafloor observatory at Xiaoqushan in the East China Sea

The seafloor observation system is becoming an important infrastructure for marine research because it is transforming oceanic research from temporal investigation to long term observation.The East China Sea coastal seafloor observatory,located between 30°31′44″N,122°15′12″E and 30°31′34″N,122°14′40″E,is constructed near the Xiaoqushan Island outside the Hangzhou Bay on the inner continental shelf of the East China Sea.The observatory is connected by a submarine optical fiber composite power cable that is more than one kilometer long and consists of a special junction box that transmits power and communication signals to different instruments.The special junction box has a variety of waterproof plugs and connects to three different instruments installed in a trawl preventer.The submarine optical fiber composite power cable is landed on the platform by The East China Sea Branch,State Oceanic Administration and the power is continuously supplied by the solar panels and solar battery on the top of the platform.The real time data are directly sent through the cable to the platform and are transmitted by CDMA wireless to the receiver at the State Key Laboratory of Marine Geology of Tongji University.Measurements at the observatory have been taken since April 20,2009 after installation and the results have been interpreted.The characteristics of the near bottom boundary are constrained by a sediment suspension model using portion of the observed data.In particular,discussion is provided on the sea surface height anomaly at Xiaoqushan Island influenced by the tsunami driven by the 2010 Earthquake in Chile.The successful establishment of the coastal seafloor observatory is the first step toward future development of seafloor observation systems in China.It not only accumulates experiences in technology and engineering,but also paves the way for performing important oceanic research using the long term continuous observation platform.     

Co-influencing mechanisms of physicochemical properties of blasting dust in iron mines on its wettability

This study explores the key physicochemical factors affecting the hydrophilic characteristics of iron mine blasting dust (BD). The BD is separated into an unwetted part (UWBD, hydrophobic part) and a wetted part (WBD, hydrophilic part). Its particle size, true density (TD), pore parameters, mineral composition, and surface compounds are comprehensively characterized and compared. The results indicate that a smaller particle size and more developed pore parameters are two key factors responsible for the strong hydrophobicity of the BD. The mineral composition of the BD has no direct effect on its wetting properties; however, it indirectly influences the deposition characteristics of the BD in water by affecting its TD. Unlike coal dust, the surface organic composition of the BD does not affect its wettability and the peak area of C-C/C-H hydrophobic groups in the C 1s X-ray photoelectron spectrum of the UWBD (45.03%) is smaller than that in the C 1s spectrum of the WBD (68.30%). Thus, eleven co-influencing processes of physicochemical properties of the BD on its wettability are summarized. This research sheds light on the key factors affecting the wettability of the BD.     

A nut-type ultrasonic motor and its application in the focus system

This article reports a screw-driven polyhedron linear ultrasonic motor （USM） of nut-type. It is comprised of a stator, which is a threaded metal nut bonded with piezoelectric plates on its external surface, and a rotor with external threads, which engage with the internal threads of the stator. A traveling wave in the plane is stimulated on the stator when harmonic electric signals are applied to the piezoelectric plates. The traveling wave drives the rotor to rotate, and the threads transform the rotation into a linear motion. The lens can be fixed in the rotor and realize the integrated design of the auto focus system. This structure can omit retarder and directly drive to obtain a high accuracy of positioning, and it is shockproof. A mini AF cellular phone module （8.5 mm×8.5 mm×5.9 mm） driven by this motor was made and an image resolution of 3-5 MP was obtained in the module prototypes of the cellular phone.     

High precision topographic data on Lop Nor basin＇s Lake ＂Great Ear＂ and the timing of its becoming a dry salt lake

High precision elevation measurements using DGPS were carried out along three representative tran-sects for the ＂Great Ear＂ area, a dry salt lake within the Lop Nor basin. Results indicate that the Lop Nor basin is only 5.2 m deep and its lowest point occurs at the center of the ＂Great Ear＂. In addition, the basin is asymmetric-steeper in the southwest （0.19‰） and gentler in the northeast （0.09‰）. Points along the same ＂Great Ear＂ ring were found to have an identical elevation value, but different when from different ones （lower towards the center）. The spacing of the ＂Great Ear＂ rings was found to be closely related with the surface steepness. The closer the ＂Great Ear＂ rings are spaced, the steeper the ground surface, and vice versa. These findings support the argument that the ＂Great Ear＂ rings are the former shoreline trails left behind by Lop Nor water during the last few episodes of recession towards its total dry up. A comprehensive analysis of the high precision elevation data, historical accounts, aerial and satellite photographs and imagery, and official topographic maps of the study area suggests that the ＂Great Ear＂ area in the Lop Nor basin was incorrectly mapped as being covered by a great body of water on the 1963 topographic maps. A re-interpretation of the 1958 aerial photographs and newer remote sensing imagery indicated that the ＂Great Ear＂ ring structure was already in place in 1958 and it continued to appear on the subsequent remote sensing data without any major changes. It is estimated that lake water in the ＂Great Ear＂ area of the Lop Nor basin disappeared between the late 1930s and early 1940s.     

Failure wave motion of 3D-C/SiC composites subjected to shock compression

The response and failure behavior of 3D-C/S軨 composites subjected to shock compression have been experimentally studied. With the help of a one-stage light gas gun, the 3D-C/SiC composite samples, which are subjected to the plane shock compression by LY-12 aluminum flyer sheets with different speeds become available. Based on the analysis of observation for the curve of pressure vs time, which has been measured from the tests as well as from the samples, it is found that when the shock speed is larger than a critical value, the material of 3D-C/SIC will be comminuted and the failure surface will move from the shock plane to its inward direction in the waveform.     

The temporal and spatial distribution of ancient rice in China and its implications

The relics of ancient rice have been regarded as the most important objective evidence of the origina- tion and spread of rice cultivation.Based on the records of 280 rice relics sites and the rice cropping regionalization as well as the distribution map of paddy soils,the current study compiled the temporal and spatial distribution map of ancient rice distribution in China.The map shows that the distribution of ancient rice is spatially extensive and meantime comparatively concentrated,temporarily covering a long and relatively continuous time-span.The rice relics in the Central China double and single rice cropping regions are among the earliest and the most abundant ones,possessing continuity in time sequence.Combined with the discovery of ancient rice and paddy filed relics,soil micromorphology, pollen combination and element geochemistry,it is suggested that Central China was the origin center of rice cultivation in China.Rice had been spread to the rest part of China in three major waves,also to the East Asian part like Korea and Japan.The temporal and spatial distribution of ancient rice reflects the past environmental change,which is also meaningful to the current rice regionalization and plan- ning as well as food security in China.     

Study on Support Vector Machine Based on 1-Norm

The model of optimization problem for Support Vector Machine（SVM） is provided, which based on the definitions of the dual norm and the distance between a point and its projection onto a given plane. The model of improved Support Vector Machine based on 1-norm （1 - SVM） is provided from the optimization problem, yet it is a discrete programming. With the smoothing technique and optimality knowledge, the discrete programming is changed into a continuous programming. Experimental results show that the algorithm is easy to implement and this method can select and suppress the problem features more efficiently.Illustrative examples show that the 1 - SVM deal with the linear or nonlinear classification well.     

柴达木盆地北缘地区第三系碎屑岩储层沉积相特征

柴达木盆地北缘地区是青海油田三大产油气区之一。该区第三系碎屑岩储层主要分布于下干柴沟组(E3)到下油砂山组 (N12 )地层中 ,前人认为此地层主要以河流相和泛滥平原相为主。对该地区的地面、井下岩性和岩相进一步研究表明 ,自下干柴沟组至下油砂山组的储集砂体主要为滨—浅湖滩坝亚相和湖泊三角洲相。这一结论对正确估算柴北缘地区的第三系油气储量及促进青海油田的增储上产具有重要的意义     

近30年来我国湖泊沉积研究的进展

总结了近30年来中国湖泊沉积研究的状况。70～80年代中期，受油田开发的带动湖泊沉积研究得以兴起，且侧重研究地质过程；80年代中期之后，研究的范围不断扩大，方法不断完善，测年手段更趋精确．目前该领域研究的新特点为：云贵高原和青藏高原湖泊又成为新热点，强化短时间尺度研究，注重提取与人类活动相关的环境信息及与其他相关热点研究相结合．今后该领域研究应注意：(1)加强环境指标与环境要素间的定量关系研究；(2)强化研究人类活动对湖泊的影响机制；(3)建立中国第四纪湖泊数据库；(4)涉足极地地区研究。     

青海湖旅游区的开发研究

本文从青海湖区自然地理论件,自古以来,社会政治历史的变迁而现存的古文化遗迹,绚丽的民族风情,阐述了奇特、迷离、多采的旅游资源,探讨了青海湖区发展旅游业的有利条件及今后的发展设想,目前存在问题及对策.     

青海湖区的生态环境研究

本文依据青海湖区的自然地理条件,湖水特征,湖水位下降,探讨了青海湖区的治理措施。     

近百年来岱海湖面变化的特点及对自然环境变化的指示意义

利用1881～1986年间岱海的水位资料,分别对近100a和近30a时段内湖面变化特点进行了分析,并将湖泊水量收支平衡与中亚有代表性的山地冰川物质平衡进行了对比。指出:中国北方东,西部环境变化受控于不同的气候变化模式,西部以内陆性气候下冷湿、暖干配置为特点;东部则以季风气候下冷干、暖湿配置为特点。两者的差异可清楚地反映在近100a时段的变化中。2种模式间的界线则随全新世以来季风气候范围的波动性萎缩而逐渐波动东移,现代季风气候与内陆气候的过渡带处于岱海和青海湖之间,为一易灾多灾的地带。     

咸宁地区湖泊水资源与水量平衡初步分析

本文根据多次调查的实■资料与长期观测资料,分析研究了咸宁地区湖泊水量资源时空变化规律;计算了咸宁地区湖泊水量平衡:并就咸宁地区湖泊水量资源进行了综合评价。     

湖北省湖泊水资源生态经济学评价

湖北省湖泊水资源具有以下特点：水质呈弱碱性,具有较大的缓冲能力。１５％的湖泊属于贫营养型,５４％的湖泊属于中营养型,３０％的湖泊属于富营养型。湖泊水源较充足,水位变幅小,湖流不明显,风浪小,适用鱼类生长的水温期长。但目前利用水平较低,作者在分析和评价湖水质量和水情后,提出了利用对策。