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1.
探讨了壳寡糖及全乙酰壳寡糖的制备方法,通过正交实验考察了原料、温度、时间对降解产物的影响.制备了八种寡糖(八乙酰壳二糖、十一乙酰壳三糖、十四乙酰壳四糖和十七乙酰壳五糖,以及N,N′-二乙酰壳二糖、N,N′,N″-三乙酰壳三糖、N,N′,N″,N′′′四乙酰壳四糖和N,N′,N″,N′′′,N′′′′-五乙酰壳五糖),并通过IR、NMR及MS等确定了其化学结构.  相似文献   

2.
I~crIONThestudiesofseaalgageneticengineeringstartedintheearly1950s.HOwever,itSdevelopmentishinderedgreatlybecauseitisdifficulttogetisolatedlivecellsandprotoplasts.TheenZymeswhicharesuitabletohigherplantsarenotsuitabletoisolatetheseaalgaecellsandproto...  相似文献   

3.
中国湖泊与环境演变研究的回顾与展望   总被引:1,自引:0,他引:1  
通过大量文献资料,总结了近30年来中国湖泊与环境演变研究的状况。20世纪70—80年代中期,湖泊沉积研究受油田开发的带动而得以兴起;80年代中期以后,研究的内容侧重气候变化,研究区域不断扩大,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表现为:注重研究云贵高原和青藏高原湖泊,加强短时间尺度研究,注重人为因素对湖泊沉积环境的影响。今后研究方向为:①加强环境指标与环境要素间的定量关系研究;②加强分析人为因素对环境演变的影响。③加强高分辨率湖泊沉积与环境演变的整体、长序列研究,建立湖泊数据库。  相似文献   

4.
高畦深沟种植水稻、有机蔬菜,沟中施投化粪池污水、生活废水、腐烂瓜果蔬菜、各类粪便、田间杂草、藤蔓秸秆等培养水蚯蚓、福寿螺、小球藻、水蚤等饵料生物,构成良性循环的人工生态系统,通过水生生物和农作物的作用使有机污染物在田间得到衰减和清除。这种立体生产、综合利用集约生产模式,有利于降低饵料生物生产成本,有助于解决自然耕种收获量较少、成本较高的问题,能使有机垃圾、污水处理工艺简单、费用少,并能变废为宝生产出大量的动物蛋白和植物蛋白。  相似文献   

5.
三种绿藻多糖的提取及理化性质和活性比较   总被引:3,自引:0,他引:3  
采用80℃水浴8h、乙醇沉淀、Sevage法去除蛋白质的方法提取湛江裂片石莼、肠浒苔和总状蕨藻多糖,并用Molish反应、Fehling反应鉴定多糖的化学性质,用苯酚-硫酸法测定多糖的总糖含量,用Dodgson法测定多糖的硫酸基含量,用Folin-酚法测定多糖的蛋白质含量.结果表明:3种绿藻的多糖提取率和多糖总糖含量以裂片石莼最高,分别为3.0%和72.6%,总状蕨藻最低分别为1.65%和38.6%;3种绿藻的硫酸基含量相差不大.总状蕨藻的蛋白质含量最高,为14.5%.3种多糖溶液作用于体外白血病细胞结果以总状蕨藻的抑制效果最明显,浓度为12mg/dm^3的总状蕨藻多糖溶液作用72h的抑瘤率达66%.  相似文献   

6.
选取在台湾岛附近发生异常北折的台风“洛坦”和异常西折的台风“奥玛”, 对其环流形势进行对比分析, 之后将全风场分解为气候场和瞬时扰动风场, 应用扩展的β-平流模型对“洛坦”和“奥玛”的异常偏折路径进行预报尝试。结果表明: 1)两个台风的500hPa全风场分析表明, 副高及槽前西南气流为“奥玛”异常北折的主要影响系统; 而“洛坦”北侧的大陆高压与副高合并加强有利于其西折。2)扰动风场的分布表明, 北折“洛坦”南侧的西南风逐渐增大, 东侧的东南风逐渐转变为南风, 在异常偏折时刻形成一条向北的“输送带”利于其北折; 西折“奥玛”在其异常偏折过程中其北侧一直维持着一个反气旋性环流, 向西输送分量逐渐增加, 利于其西折。3)利用扩展的β-平流模型对两个台风路径进行预报, 发现在综合考虑气候态和扰动场时, “洛坦”的路径预报效果最好, 而考虑瞬时扰动场时“奥玛”的西折预报效果最好。  相似文献   

7.
肌肽的提取分离与生物活性的研究进展   总被引:1,自引:0,他引:1  
肌肽(carnosine)是一种水溶性二肽,天然存在于多种脊椎动物的骨骼肌以及新陈代谢旺盛的脑中。1900年,俄国学者Gulewitsch最早发现了肌肽。他  相似文献   

8.
海洋中蕴藏着丰富的微生物资源,其在海洋生态系统中起着重要的作用。综述海洋微生物微包埋培养技术的相关研究概况及应用进展。适于海洋微生物包埋的微球制备技术主要有:水油乳化法、膜乳化法、挤出法、微流体法等。在此基础上建立的培养技术可用于海洋微生物生物多样性研究;慢速生长菌株的培养和分离及微生物传感器的制备等。随着研究的深入,该技术将在海洋微生物的研究方面得到更广泛的应用。  相似文献   

9.
全球有效波高和风速的时空变化及相关关系研究   总被引:2,自引:1,他引:1  
The climatology of significant wave height(SWH) and sea surface wind speed are matters of concern in the fields of both meteorology and oceanography because they are very important parameters for planning offshore structures and ship routings. The TOPEX/Poseidon altimeter, which collected data for about 13 years from September 1992 to October 2005, has measured SWHs and surface wind speeds over most of the world's oceans. In this paper, a study of the global spatiotemporal distributions and variations of SWH and sea surface wind speed was conducted using the TOPEX/Poseidon altimeter data set. The range and characteristics of the variations were analyzed quantitatively for the Pacific, Atlantic, and Indian oceans. Areas of rough waves and strong sea surface winds were localized precisely, and the correlation between SWH and sea surface wind speed analyzed.  相似文献   

10.
在无菌条件下,单种培养具齿原甲藻以研究温度和盐度对其生长的影响。实验设计了5个温度梯度和6个盐度梯度,并计算了不同培养条件下藻细胞在指数生长期的比生长率。实验结果表明:具齿原甲藻生长的最适温、盐范围分别为22℃和25~31。温度对藻类生长的影响比盐度的要明显得多,而且藻生长的最适盐度有随着温度升高向低盐度偏移的趋势。同时,实验研究了同样条件下中肋骨条藻的生长情况,并与具齿原甲藻进行了比较,以试图探讨东海大规模爆发具齿原甲藻赤潮的原因。  相似文献   

11.
12.
辽东湾两侧砂质海岸侵蚀灾害与防治   总被引:9,自引:1,他引:9  
自20世纪60年代至90年代,由于多种原因,辽东湾东西两侧的初始沙质海岸侵蚀范围逐年扩大,侵蚀不断加剧,给当人民的生产和生活带来严重危害。由多年监测资料发现,侵蚀严重的熊岳岸线以2~4m/a的速率而大幅度后退,特别严重的地区最大后退达10km;辽西绥中某些岸段平均每年后退1~2m。20世纪90年代后期,由于一些海域管理措施的出台和相应的海岸防护工程的建设,海岸侵蚀逐渐减弱。通过现场调查和多年监测,分析了辽东湾东西两侧砂质海岸侵蚀的特点,认为海岸组成物质松散与海岸动力作用强烈是本区现代海岸侵蚀的基本条件,人为活动是关键因素,并提出了海岸侵蚀灾害的防治对策。  相似文献   

13.
分析了海洋测绘教育培训国际化和标准化的原因及进程,论述了海洋测绘国际化教育培训的指导性文件及内容,针对国际化海洋测绘教育培训的特点与发展趋势,提出了发展我国海洋测绘教育培训的对策与建议。  相似文献   

14.
聚多巴胺(polydopamine, PDA)含有大量的酚羟基和氨基官能团, 可以在玻璃、不锈钢、塑料、橡胶、聚四氟乙烯等材料表面黏附, 具有优异的粘附性能, 是重要的功能材料之一。本文对近年来国内外围绕聚多巴胺展开的研究进行了综述, 从聚多巴胺的合成方法、聚合机理和性能出发, 分析总结了当前合成的特点、机理研究的方案和存在的问题, 并对聚多巴胺在海洋防腐领域的应用进行了总结和展望, 旨在为研究者较全面了解聚多巴胺的研究现状提供参考。  相似文献   

15.
Abstract

Given sufficient light and heat, the growth of aquatic macrophytes and algae associated with eutrophication is generally controlled by the concentration, form and ratio between nitrogen (N) and phosphorus (P). Data from 1100 freshwater sites monitored for the last 10 years by New Zealand's regional councils and unitary authorities were assessed for streams and rivers with mean nitrate/ nitrite‐N (NNN), dissolved reactive P (DRP), total N (TN) and total P (TP) concentrations in excess of New Zealand guidelines, and to generate a data set of N:P ratios to predict potential periphyton response according to the concentration of the limiting nutrient. The frequency of sites exceeding the guidelines varied from 0 to 100% depending on the parameter and region, but South Island regions were generally more compliant. The dissolved inorganic N (DIN) to dissolved reactive P (DRP) ratio was used to group data into three nutrient limitation classes: <7:1 (N‐limited), between 7:1 and 15:1 (co‐limited), and>15:l (P‐limited), by mass. P‐limitation was the most frequent scenario in New Zealand streams (overall, 76% of sites were P‐limited, 12% N‐limited, and 12% co‐limited). The mean concentration of the limiting nutrient for each site was combined with empirical relationships to predict periphyton densities (the average of N‐and P‐limited growth was used for sites with co‐limitation). This assessment predicted that 22 sites were likely to exceed the periphyton guideline for protecting benthic biodiversity (50 mg chlorophyll a m?2), but this assessment is likely to be highly changeable in response to climatic conditions and present and future land use. As an example, we modelled N and P losses from an average sheep and a dairy farm in Southland (South Island, New Zealand) in 1958, 1988, 2008 and 2028. We predicted that with time, as farm systems have and continue to intensify, N losses increase at a greater rate than P losses. Since the pathway for N to reach fresh waters may be more tortuous and take longer than P to reach a stream or river, focusing mitigation on P losses may have a quicker effect on potential algal growth. In addition, with time, it is expected that P‐limitation in New Zealand's rivers and streams will be more widespread as N‐losses are unabated. Hence, although strategies to decrease N losses should be practised, mitigating P losses is also central to preventing eutrophication.  相似文献   

16.
Long-period oscillations of moored ships whose periods are about 1 or 2 min cause many troubles in many ports and harbours. It is necessary to investigate these phenomena and verify their causes and countermeasures in each case because they are strongly dependent on the environment of each port and harbour. From this point of view, long-period oscillations of moored ships in the Port of Shibushi in Japan were investigated by means of wave observations, the image processing of moored ship motions using the video camera and motion-capture software and numerical simulations. From observation results, the relationship between offshore long-period waves and long-period oscillations of moored ships was recognized and surge and heave amplitudes were quantified by using wave data in order to forecast moored ship motions. Furthermore, from observation and numerical results, it was revealed that long-period waves with the peak period of 120 s from the offshore typhoon kept or exaggerated the local harbour oscillation of 60–70 s and it caused long-period oscillations of moored ships. Numerical results in case of reducing the reflection coefficient of the target berth implied that it ceased the local harbour oscillation and it would give an effective countermeasure to reduce long-period oscillations of moored ships in the Port of Shibushi.  相似文献   

17.
李健  何海波  孙悦 《海洋测绘》2004,24(6):52-55
在分析河道测量导航技术现状和应用背景的基础上,讨论了河道导航与测量系统的设计原则、设计方案和运作流程,对某些设计细节作了较为详尽的介绍,对某些关键问题提出了相应的解决方法。  相似文献   

18.
为了研究海洋生物污损对船体和海洋工程的影响,作者将热喷涂镀钴基、镍基及含铜氧化钛基膜的船用厚钢板试样片放置在海水中,利用振荡培养箱模拟海洋环境,进行晃片培养。分离纯化镀膜钢片表面上的细菌,研究早期污损细菌的生长规律,通过革兰氏染色、生理生化实验对细菌进行鉴定,伯杰氏系统细菌学手册查证。采用纸片法测定抑菌圈,研究铜、钴、镍3种金属离子对污损细菌的影响,观察不同离子浓度的抑菌圈。研究结果表明:早期海洋污损细菌有G~+芽孢杆菌属(Bacillus)、G~+芽孢乳杆菌属(Sporolactobacillus)、G~+无芽孢杆菌(Bacilli)、葡萄球菌属(Staphylococcus)、G~+无芽孢丝状菌、假单胞菌属(Pseudomonas)6类;其中G~+细菌首先吸附; Cu~(2+)的最佳抑制质量浓度为30 g/L, Co~(2+)的最佳抑制质量浓度为80 g/L, Ni~(2+)的最佳抑制质量浓度为110 g/L。  相似文献   

19.
-A joint probability density is derived for wavelengths and wave heights.It is asymmetric anddepends only on the spectral bandwidthεdefined by Cartwright and Longuet-Higgins(1956).After that atheoretical probability density for wave steepness is obtained.It tends to Rayleigh distribution asε→0.Acomparison between theorethal steepness distribution and laboratory experiment result shows good agree-ment.  相似文献   

20.
潮流与泥沙数值模拟回顾及进展   总被引:9,自引:0,他引:9  
回顾和总结了近年来国内外潮流与泥沙数值模拟的进展,评价分析了数学模型的多种数值解法,特别是有关二维、三维潮流数值模拟以及水沙数学模型近年来的进展,并根据目前潮流、泥沙数值模拟技术中存在的不足,讨论了进一步研究的方向和发展趋势。  相似文献   

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