鄂尔多斯湖盆西南部晚三叠世深水坡折特征 及其对砂体的控制

该文对鄂尔多斯盆地晚三叠世发育的坳陷型湖盆坡折带进行研究,通过岩石类型及相组合分析法、地震反射特征识 别法在湖盆西南缘、东北缘识别出了深水坡折,分别是西南坡折和东北坡折。通过地层厚度变化率计算坡降对坡折点进行 定位,确定长7-长6沉积期坡折带的展布特征。西南坡折规模大,东北坡折规模小。坡折带具有明显的控砂作用,主要体 现在对砂体成因类型、砂体厚度变化以及砂体展布形态三方面。深水坡折之上发育三角洲前缘成因砂体,坡折之下以重力 流为主,多发育湖底扇、滑塌体体等重力流砂体,同时由于坡度的不同,西南坡折与东北坡折也发育不同类型重力流砂 体。同一物源形成的砂体厚度由坡折带上方至坡脚形成“厚-薄-厚”的变化趋势。坡折带上方砂体呈条带状及席状展布, 坡折带下方根据坡度陡缓以及距坡脚的距离不同而砂体形态有所不同。     

A reliable traffic prediction approach for bike‐sharing system by exploiting rich information with temporal link prediction strategy

Bike‐sharing systems have been widely used in major cities across the world. As bike borrowing and return at different stations in different periods are not balanced, the bikes in a bike‐sharing system need to be redistributed frequently to rebalance the system. Therefore, traffic flow forecasting of the bike‐sharing system is an important issue, as this is conducive to achieving rebalancing of the bike system. In this article, we present a new traffic flow prediction approach based on the temporal links in dynamic traffic flow networks. A station clustering algorithm is first introduced to cluster stations into groups. A temporal link prediction method based on the dynamic traffic flow network method (STW+M) is then proposed to predict the traffic flow between stations. In our method, the non‐negative tensor decomposition and time‐series analysis model capture the rich information (temporal variabilities, spatial characteristics, and weather information) of the across‐clusters transition. Then, a temporal link prediction strategy is used to forecast potential links and weights in the traffic flow network by investigating both the network structure and the results of tensor computations. In order to assess the methods proposed in this article, we have used the data of bike‐sharing systems in New York and Washington, DC to conduct bike traffic prediction and the experimental results have shown that our method produces the lowest root mean square error (RMSE) and mean square error (MSE). Compared to four prediction methods from the literature, our RMSE and MSE of the two datasets have been lowered by an average of 2.55 (Washington, DC) and 2.41 (New York) and 3.35 (Washington, DC) and 2.96 (New York), respectively. The results show that the proposed approach improves predictions of traffic flow.     

Payments for Watershed Services and Practices in China: Achievements and Challenges

Implementation of payments for watershed services (PWS) has been regarded as a promising approach to coordinating the interests of upstream and downstream ecosystem services stakeholders. There is growing concern about whether PWS programs have achieved their original environmental goals of improving water quality and quantity, as well as the ancillary objective of increasing the welfare of local people. We start with an overview of PWS schemes and focus on their particularity and implementation mechanisms in China. We proceed to review 62 active PWS cases and examine their environmental performance in detail. The resulting findings show that PWS schemes have been able to reduce water pollution to some extent by establishing collaborative upstream/downstream watershed management policies, thereby improving water quality and quantity, as well as by making government officials more responsible for water resource management. In addition, their continued effectiveness in light of present challenges such as water-quality data availability is discussed. Chinese PWS schemes and their implementation mechanisms also provide information useful in monitoring environmental outcomes and guiding future designs of PWS programs in other regions.     

泉州市砂质海岸侵蚀特征及原因分析

基于泉州市沿岸岸滩侵蚀状况调查,结合海岸动力地貌学知识研究,分析泉州市沿岸岸滩侵蚀状况.调查岸段有32个,对其进行采样拍照及侵蚀现状描述,对7个岸段进行了剖面调查及沉积物分析.研究表明泉州市沙质海岸以岬控岸和沙坝--泻湖为主,岬控岸的沉积物和剖面表现为中细粒沉积和岸坡由近岸向海变平缓,而沙坝--泻湖岸则以粗粒沉积和岸坡起伏不平为特征,沉积物特征、沿岸输沙、平衡剖面及动力地貌均反映了泉州砂质海岸的侵蚀状况.在全球海平面上升的大背景下,除特大自然灾害影响,泉州近海域的人为活动恶化了海岸侵蚀的程度,其中以海砂开采最为严重.     

固井冲洗液室内模拟评价方法研究

针对现有固井冲洗液评价方法对于油基钻井液冲洗情况评价存在不足的问题,运用环空壁面与改进装置内筒壁面处剪切速率相等的原理,研究出了一种适用于油基和水基钻井液条件的固井冲洗液室内评价新方法。室内模拟实验分析表明,该方法能更好地反映冲洗液的冲洗效率,并能模拟评价冲洗效率对固井第一或第二界面处胶结的影响情况。该方法操作方便,适用于油基和水基钻井液固井条件。     

Fe3+ -SiO2-TiO2薄膜的制备及其光催化活性

Sol-gel法制备Fe3 掺杂TiO2催化剂的基础上,掺入SiO2纳米粉体,制备了一种改性Fe3 -SiO2-TiO2薄膜。以甲醛为降解对象,探讨金属掺杂和半导体复合量、活化温度、负载量等对该薄膜光催化活性的影响。结果表明,在500℃焙烧、质量比Fe3 ∶SiO2∶TiO2=1.0∶12∶100、镀膜5层时,Fe3 -SiO2-TiO2薄膜的光催化活性最高,150min后甲醛降解率达93%,是单纯TiO2薄膜的1.9倍。     

赣北张十八铅锌银矿床主要金属矿物特征研究

张十八铅锌银矿是近年发现的一处大型矿床,它以其矿化元素较为均匀,矿化面积大,矿石品位中贫及矿体明显受特定层位控制等特点受到业界的广泛关注。通过研究,本矿床矿石中已查明的矿物种属达63种。主要金属矿物简单、微量金属矿物繁多为该矿床矿物成分的组成特点,本文着重介绍了几种主要金属矿物的特征及其嵌布特点。     

中国岩溶碳汇过程与效应研究成果及展望

我国是世界能源消费和CO₂总排放量第一大国,碳减排任务艰巨,责任重大。据调查,我国岩溶碳汇与森林、土壤碳汇在同一数量级,但其要在国家层面发挥重大作用,其影响因素及机理需要进一步调查和阐释,估算精度还有待提高。系统总结了流域尺度岩溶碳循环过程,并重点揭示了生物作用对岩溶碳循环的影响;研究了水圈二氧化碳的再循环规律;评估了外源水对岩溶作用的影响程度和促进强度;利用数学回归模型估算区域岩溶碳汇通量,提高了由点到面岩溶碳汇通量估算精度,并提出增加岩溶碳汇潜力技术途径,为我国岩溶碳汇通量科学估算提供支撑。     

Carbon and Oxygen Isotopic Composition of Surface-Sediment Carbonate in Bosten Lake (Xinjiang, China) and its Controlling Factors

Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition (δ13C) values of the carbonate sediment (-1‰ to -2‰) have no relation to the oxygen isotope composition of the carbonate (δ18O) values (-7‰ to -8‰), with both isotopes showing a low variability. The carbonate content is low (<20%). Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ13C values between approximately +0.5‰ and +3‰, and δ18O values between -1‰ and -5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg-calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg-calcite. Evaporation and biological processes are the main reasons for the salinity and carbonate mineralogy influence of the surface-sediment carbonate in Bosten Lake. The lake water residence time and the CO2 exchange between the atmosphere and the water body control the carbon and oxygen isotope composition of the carbonate sediment. In addition, organic matter pollution and decomposition result in the abnormally low carbon isotope values of the lake surface-sediment carbonate.     

基于CA的小流域分布式降雨径流模拟

构建基于元胞自动机(CA)模型的分布式水文模型,模拟小流域内降雨径流过程。从元胞状态、转换规则与时间步长3个方面扩展普通CA模型,包括5个子状态、5个元胞系数及两条转换规则,并实现模型与GIS的集成。以黄土高原岔巴沟流域的降雨径流观测数据对模型进行了验证分析。试验结果表明,确定性系数、峰现时差与洪峰误差3个评价指数都达到一定精度,实现了流域内径流过程的可视化。结合CA模型与GIS技术可以较为有效地模拟流域次降雨径流过程,模型在该试验区是基本适用的。