Cr^3＋在改善三元复合驱中的作用实验研究     

任艳滨  卢祥国  赵兰兰  张运来 《海洋地质译丛》2008,(4):50-54

在三元复合驱矿场应用实践中,由于三元复合体系自身流度控制能力的局限性,必须通过聚合物凝胶前置段塞来改善吸液剖面,这就涉及到聚合物凝胶与三元复合体系的配伍性。通过向三元复合体系中加入有机铬,考察Cr^3＋对三元复合体系黏度、界面张力和阻力系数等性能影响,进而对Cr^3＋聚合物凝胶与三元复合体系配伍性以及Cr^3＋在改善三元复合体系性能方面的作用做出评价。结果表明,Cr^3＋的加入对三元复合体系黏度和界面张力影响不大,但阻力系数和残余阻力系数却明显增加。当采用Cr^3＋聚合物凝胶作为前置段塞或采用添加Cr^3＋的三元复合体系进行复合驱油实验时,其采收率增加幅度都要高于普通三元复合驱。这不仅显示出Cr^3＋聚合物凝胶与三元复合体系间良好的配伍性,而且为改善三元复合驱增油效果提供了新的途径。  相似文献   

Synthesis,algal inhibition activities and QSAR studies of novel gramine compounds containing ester functional groups     

李霞  于良民  姜晓辉  夏树伟  赵海洲 《中国海洋湖沼学报》2009,27(2):309-316

  相似文献   

Paleoenvironmental implications of the guano phosphatic cementation on Dongdao Island in the South China Sea     

Xiao-Dong Liu  Li-Guang Sun  Zhong-Qi Cheng  San-Ping Zhao  Ke-Xin Liu  Xiao-Hong Wu  Zhou-Qing Xie  Xue-Bin Yin  Hong-Hao Luo  Xing-Fang Ding  Dong-Bo Fu  Yu-Hong Wang 《Marine Geology》2008,247(1-2):1-16

The phosphatic cement in the bioclastic sediment sequence on the northeastern shore of Dongdao Island in the South China Sea was studied and its paleoenvironmental implications discussed. Petrological characteristics and major, trace, REE element data unequivocally supported the notion that phosphatization was closely associated with avian guano decomposition and leaching, whereas carbon and oxygen isotope results further revealed that meteoric water were involved in these processes. AMS ¹⁴C dates on the brown phosphate cements indicate that they were formed around 5700, 5000–5100 and 2900 yr BP, respectively. The multi-episodes of phosphatization very likely correspond to intermittent seabird occupation on this island — possibly reflecting Holocene sea-level oscillation and/or long term climate changes in the South China Sea that have controlled seabird habitat. The phosphate cementation, which occurs widely in tropical islands, may be another useful monitor for sea-level and/or paleoclimate changes.  相似文献   

Screening of extraction methods for glycoproteins from jellyfish (Rhopilema esculentum) oral-arms by high performance liquid chromatography     

Guoyan Ren  Bafang Li  Xue Zhao  Yongliang Zhuang  Mingyan Yan  Hu Hou  Xiukun Zhang  Li Chen 《中国海洋大学学报(英文版)》2009,8(1):83-88

In order to select an optimum extraction method for the target glycoprotein (TGP) from jellyfish (Rhopilema esculentum) oral-arms, a high performance liquid chromatography (HPLC)-assay for the determination of the TGP was developed. Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear (r = 0.9984, y = 4.5895x+47.601) over concentrations ranging from 50 to 400 mgL-1. The mean extraction recovery was 97.84% (CV2.60%). The fractions containing TGP were isolated from jellyfish (R. esculentum) oral-arms by four extraction methods: 1) water extraction (WE), 2) phosphate buffer solution (PBS) extraction (PE), 3) ultrasound-assisted water extraction (UA-WE), 4) ultrasound-assisted PBS extraction (UA-PE). The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL (7.8 mm×300 mm) column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.  相似文献   

Fuzzy comprehensive evaluation model for water resources carrying capacity in Tarim River Basin, Xinjiang, China   总被引：12，自引：0，他引：12  

Lihong Meng  Yaning Chen  Weihong Li  Ruifeng Zhao 《中国地理科学(英文版)》2009,19(1):89-95

This paper explores the method of comprehensive evaluation of water resources carrying capacity and sets up an evaluation model applying the fuzzy comprehensive evaluation method. Based on the data of nature, society, economics and water resources of the Tarim River Basin in 2002, we evaluated the water resources carrying capacity of the basin by means of the model. The results show that the comprehensive grades are 0.438 and 0.454 for Aksu and Kashi prefectures respectively, where the current water resources exploitation and utilization has reached a relative high degree and there is only a very limited water carrying capacity, 0.620 for Kizilsu Kirgiz Autonomous Prefecture, where water resources carrying capacity is much higher, and in between for Hotan Prefecture and Bayingolin Mongolian Autonomous Prefecture. As a whole, the comprehensive grade of the Tarim River Basin is 0.508 and the current water resources exploitation and utilization has reached a relative high degree. Thus, we suggest that the integrated management of the water resources in the basin should be strengthened in order to utilize water resources scientifically and sustainably.  相似文献   

The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock (Theragra chalcogramma) skin     

Yongliang Zhuang  Bafang Li  Xue Zhao 《中国海洋大学学报(英文版)》2009,8(2):171-176

Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.  相似文献   

中国铁路客运流联结的城市时间可达性     

张莉  赵英杰  陆玉麒  滕野 《地理科学》2020,40(3):354-363

基于中国铁路客户服务中心提供的客运流数据,采集全国地级以上行政单元（未含港澳台数据）间铁路客运运行的最短历时,基于GIS网络分析和空间分析等方法,选取时间可达性和一日交流圈2个指标对城市可达性进行测度和分析。研究发现： ① 城市时间可达性水平划分为7个级别,在空间上呈现中心-外围式圈层结构,中心区域沿铁路干线和高速铁路线轴向扩展,廊道效应明显,东部、中部地区的城市时间可达性优于西部地区。② 城市之间的时间可达性小于2.0 h的城市对在空间上构成了由京广、京沪、京哈、京福、杭深、青太、徐兰、沪汉蓉、沪昆、广昆等高速铁路连接的“五纵五横”带状分布格局。时间可达性小于10.0 h的城市对覆盖了“胡焕庸线”东南部的大部分区域,城市带转为城市网络。③ 直辖市、省会/首府城市一日交流圈以31个城市为中心,按照时间可达性由小到大呈现轴向扩展,廊道效应明显。基于城市一日交流圈划分了19个城市群和拉萨城市圈,为城市群的划分提供方法借鉴。  相似文献   

面向应用的高校GIS教学探索与实践   总被引：8，自引：2，他引：6  

党安荣  刘钊  贾海峰 《地理信息世界》2007,5(2):9-14

高校GIS教学是近年来国内探讨的热点教学问题之一,涉及到GIS专业课程体系设置、教学内容设置、实践环节设置、教学体制改革等多个方面;但这些探讨主要是针对GIS专业学士学位与硕士学位教学而引发的,较少关注非GIS专业学位的GIS教学问题.本文通过分析清华大学GIS教学发展与现状,结合作者在GIS教学中的探索与实践,从教学平台、教学内容、授课形式、考试方式、教学效果等几个方面,讨论如何开展针对非GIS专业、面向应用的高校GIS教学模式,与全国高校GIS教育工作者共勉.  相似文献   

东营市东营区实施城区村居改造集约利用城市土地          下载免费PDF全文

刘建强  赵云秀  商述珍 《山东国土资源》2007,23(2):20-21

近年来,在市委、市政府的正确领导下,东营区按照“统一规划、合理布局、综合开发、配套建设”的原则,积极推进城区村居改造建设,促进了城市土地的节约集约利用。1加强组织领导强力保证村居改造工作东营市是在石油矿区基础上发展起来的新兴城市,受过去“随矿建镇”模式的影响,中心城建设布局分散,土地利用粗放,特别是有18个村居散落在城区之内,环境质量差,基础设施不配套,浪费了土地资源,影响了城市化进程。为充分发挥土地资源效益,促进城市和谐发展,该区把城区村居改造工作摆上了重要议事日程,明确目标责任,实行重点调度,在人力、物力、财力…  相似文献   

数字抽取滤波器的DSP优化设计     

谭耀银  廖成旺  邓涛  赵凤花  丁炜  陈卫明 《大地测量与地球动力学》2007,27(Z1):87-90

为了降低地震数据采集系统的成本和功耗，采用数字信号处理器（DSP）实现∑-△模数转换器中的数字抽取滤波器算法。通过采取查表法、倒序循环遍历法以及模拟循环寻址法等优化方法，以较低工作频率实现了四通道四级抽取滤波运算，达到了系统设计的要求。  相似文献