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排序方式: 共有522条查询结果,搜索用时 15 毫秒
1.
Yiping Zhang Shuqi Zhang Zirun Zhao Zhiheng Xu Songyang Wang Yuhang Zhang Maike Yang Xuanlin Yu Yaxian Zhu 《大学化学》2020,35(6):25-30
2018年和2019年小学期,厦门大学本科生"绿行之踪"社会实践队赴重庆、上海等长江流域主要城市进行社会实践活动,采集了当地的水样,测定了水样中的磷酸根含量和高锰酸盐指数,同时进行了水资源保护的宣传活动和网络问卷调查。 相似文献
2.
以某低渗透油藏为对象,首先在数据挖掘的基础上制定了低渗透油藏注CO_2驱筛选标准.基于模糊综合评价法,建立了适用于低渗透油藏CO_2驱适宜度评价的模糊综合评价模型,并运用该模型对目标油藏注CO_2的适宜度进行了评价.计算结果表明目标油藏注气驱开发适应性较好.评价过程有效地降低了直接进行注气开发的风险,为之后低渗透油藏注气开发提供了技术和经济上的指导. 相似文献
3.
Daniela Nunes da Silva Hanna Leijoto de Oliveira Keyller Bastos Borges Arnaldo César Pereira 《Electroanalysis》2021,33(2):506-514
The analysis of 17β-estradiol with high sensitivity and selectivity is extremely relevant to control the impacts that this compound can cause on health and the environment. Thus, we describe the development and application of a magneto carbon paste electrode based on magnetic molecularly imprinted polymer (MCPE-MMIP) for determination of 17β-estradiol. The analyte adsorbed on the MMIP was immobilized on the electrode surface by magnetic capture. The morphological and structural characterization of the obtained MMIP suggests that the material was effectively synthesized. MCPE-MMIP showed an improvement in the sensitivity for 17β-estradiol detection when compared to electrode configurations in the absence of this material. The optimum conditions (0.10 mol L−1 phosphate buffer pH 7.0) were reached by differential pulse adsorptive stripping voltammetry (DPAdSV), in which the method presented linearity ranged from 0.06 to 175 μmol L−1 with limits of detection and quantification of 0.02 and 0.06 μmol L−1, respectively. The proposed sensor was applied effectively in the analysis of 17β-estradiol in river water and raw milk samples, exhibiting excellent recovery values (between 96.20 and 104 %), which were confirmed by HPLC analysis. 相似文献
4.
Synthesis and performances for treating oily wastewater produced from polymer flooding of new demulsifiers based on polyoxyalkylated N,N‐dimethylethanolamine 下载免费PDF全文
Usually, oily wastewater produced from polymer flooding (OWPF) was treated by cationic polymer in oilfield. In this paper, six block copolymers of ethylene oxide and propylene oxide were prepared by using N,N‐dimethylethanolamine (DMEA) as the acceptor (DMEA‐mnp and DMEA‐mnpq, n:m:p:q represented the weight ratio of different blocks). Most of DMEA products could perform well for treating OWPF, especially DMEA1231. Their performances were mainly affected by temperature. The reason of increasing oil removal performance of DMEA1231 with temperature was the decrease of interfacial dilational modulus (ε) with increasing temperature. When temperature raised up to 55°C, the ε of DMEA1231 had the minimum (1.5 l mN/m). Therefore, the OiW had the minimum (90 mg/l). Because DMEA1231 had the best performance, its flocculation kinetics was studied systemically. The results showed that the optimum condition for DMEA1231 was as follows: dosage was 300 mg/l, temperature was 55°C, stirring speed was 200 rpm and stirring time was 5 min. At last, the offshore oil field test was carried out to check the DMEA1231 performance. The result showed that at the optimum condition, DMEA1231 could perform as well as the cationic polymer. The most important thing was that flocs of DMEA1231 were not viscous and floated on the surface of the water. The results obtained by this paper provide a good choice for the treatment of OWPF in offshore oilfield to avoid the formation of viscous flocs. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
5.
SPATIAL AND SEASONAL DISTRIBUTIONS OF ATMOSPHERIC CARBONACEOUS AEROSOLS IN PEARL RIVER DELTA REGION, CHINA 总被引:11,自引:0,他引:11
Concentrations and spatial distributions of organic carbon (OC) and elemental carbon (EC) in atmospheric particles were measured at 8 sites in four cities (Hong Kong, Guangzhou, Shenzhen and Zhuhai) of Pearl River Delta Region (PRDR), China during 2001 winter period and 2002 summer period. PM2.5 (particie diameter smaller than 2.5 um) and PM10 (particie diameter smaller than 10 um) samples were collected on pre-fired quartz filters with mini-volume samplers and analyzed using thermal optical reflectance (TOR) method. The average PM2.5and PM10 Ievel were 60.1 and 93.1 μg·m-3, respectively, with PM2.5 constituting 65.3% of the PM10 mass. The average OC and EC concentrations in PM2.5 were 12.0 and 5.1 μg·m-3, respectively, while those in PM10 were 16.0 and 6.5 μg·m-3, respectively. The carbo-naceous aerosol accounted for 37.2% of the PM2.5 and 32.8% of the PM10. The highest concentrations of OC and EC were observed at Guangzhou city in both vvinter and summer seasons. The average OC/EC ratios were 2. 相似文献
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7.
A chemical flood model for a three-component (petroleum, water, injected chemical) two-phase (aqueous, oleic) system is presented. It is ruled by a system of nonlinear partial differential equations: the continuity equation for the transport of each of its components and Darcy's equation for the two-phase flow. The transport mechanisms considered are ultralow interfacial tension, capillary pressure, dispersion, adsorption, and partition of the components between the fluid phases (including solubilization and swelling).The mathematical model is numerically solved in the one-dimensional case by finite differences using an explicit and direct iterative procedure for the discretization of the conservation equations. Numerical results are compared with Yortsos and Fokas' exact solution for the linear waterflood case including capillary pressure effects and with Larson's model for surfactant flooding. The effects of the above-mentioned transport mechanisms on concentration profiles and on oil recovery are also analyzed. 相似文献
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9.
西气东输工程中卫黄河穿越隧道长1197.77m,高4.3m,宽5.6m。隧道入口高于黄河水位28m,出口高于黄河水位45m。隧道顶板高程为1130m。位于黄河水下100m。隧道场地围岩为寒武系磨盘井组灰绿色、银灰色浅变质中厚层细粒长石石英砂岩、千枚状板岩、绢云母化千枚岩。围岩为弱风化Ⅲ~Ⅳ类岩石。透水率为4~67Lu,纵波波速为500~3300m.s-1。BQ为300~400。变形模量为6.11~9.22GPa。泊松比(μ)0.14~0.24。内摩擦角(ψ)为42.1°~44.7°。地下水为基岩裂隙水。含水层为寒武系浅变质岩,受大气降水渗入补给,单井涌水量为1.0~50m3.d-1。隧道轴线穿越区岩体较完整—较破碎,未有全新活动断层。隧道位置选择和开挖深度设计是可行的。施工和长期运营是安全的。 相似文献
10.
由地质作用影响形成的易出险堤段称为地质险段 ,主要包括活断层作用影响形成的堤基易渗漏段、强地震高发区段和地基稳定性差段等。构造节点是识别地质险段的重要的河流地貌标志之一。根据成因 ,本文将黄河下游的地质险段分为三类 ,即新构造险段、沉降险段、断裂复活险段。针对黄河下游堤防地质特征 ,圈定出东坝头、大刘屯—董口黄河南岸和路那里—十里堡黄河南岸地质险段 ,提出了治理的有关措施 相似文献