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 共查询到19条相似文献,搜索用时 204 毫秒
1.
田野  刘鹰 《海洋科学》2018,42(2):167-176
水体中的重金属污染物不能被微生物降解,并且环境中只要存在微量的重金属即可产生毒性效应。因此,研发新材料去除水体中重金属离子受到了广泛的关注。利用绿色、经济、产量丰富的壳聚糖为原料,以物理和化学改性方法为手段制备移除水体中重金属离子的壳聚糖基吸附材料是当今研究热点。本文以壳聚糖基材料的制备方法为主线,概括总结了壳聚糖的改性方法及其衍生物对重金属离子吸附行为的研究进展,展望了壳聚糖基材料在重金属废水处理方面的未来研究方向及前景。  相似文献   

2.
鞠豪  张全斌 《海洋科学》2020,44(9):139-145
琼脂糖是一种具有高凝胶特性的天然高分子红藻多糖,具有良好的物理、化学和热稳定性,在医学和科研方面具有广泛的用途。在琼脂糖制备工业中,传统生产技术的局限性造成了国内琼脂糖尚未规模化生产。因此,有必要开发新的成本可控的琼脂糖制备方法。本文采用一种聚丙烯酰胺和弱碱性苯丙烯系阴离子交换树脂联用的方法来分离制备琼脂糖,以江蓠琼胶为原料,通过单因素试验优化琼脂糖的制备参数并对琼脂糖的理化指标进行测定。所得琼脂糖硫酸根含量为0.22%、凝胶强度为1 524 g/cm2、透明度为58.9%,凝固温度为39.7℃、融化温度为87.6℃,表明其具有相对较高的质量。该工艺简单经济,对发展琼脂糖工业具有一定的参考价值。  相似文献   

3.
本研究以CaO、煅烧后的牡蛎壳、蛤蜊壳、扇贝壳和脉红螺壳为原料, 分别采用反相微乳液法和聚乙二醇(PEG)辅助微波加热法制备了纳米羟基磷灰石(HA), 并从产物的物理化学特性以及形态学参数方面进行比较。利用傅里叶变换红外光谱、X射线衍射对各组产物进行了化学表征, 扫描电子显微镜观察样品的表面形貌, Zeta电位仪测定样品表面的电势差。结果表明, 反相微乳液法制备的HA尺寸在(104.10±1.95) nm至(207.90±3.75) nm范围内, 为近球形颗粒; 而PEG辅助微波加热法制备得到的HA尺寸在(61.17±3.11) nm与(182.70±1.05) nm范围内, 倾向于形成椭圆及棒状的颗粒, 稳定性更高, 且各组样品均表现出完全的亲水性。此外, 对比于CaO制备的HA, 以贝壳为原料制备的HA具有更好的纳米结构, 其中利用脉红螺壳制备的HA在粒径大小、稳定性以及亲水性等方面均具有优势, 并且具有更接近天然骨的钙磷比。因此脉红螺壳可以作为PEG辅助微波加热法制备羟基磷灰石的主要原料。  相似文献   

4.
近年来,作为生物活性物质理想的"储库",微纳米药物控释载体的研究已得到快速发展。其中,以海带、龙虾壳为原料的壳聚糖和以海藻酸钠为代表的海洋多糖基微胶囊由于价廉易得、安全无毒、理化性质稳定好而受到推崇,但海洋多糖基微纳米药物控  相似文献   

5.
壳聚糖基水凝胶对肿瘤在体内外生长的影响研究   总被引:1,自引:0,他引:1  
本文介绍壳聚糖基水凝胶(CH)对肿瘤生长的影响。用MTT法检测水凝胶对Hela及SGC-7901两种肿瘤细胞体外生长增殖的影响。建立小鼠移植性肿瘤S180实体瘤模型,通过腹腔注射给药研究水凝胶的体内抑瘤效果。结果表明水凝胶能轻微抑制肿瘤细胞的体外生长,提高荷瘤小鼠免疫器官指数和细胞因子水平,显著抑制荷瘤小鼠体内肿瘤组织的生长。说明壳聚糖基水凝胶对肿瘤在体内外的生长具有一定抑制作用。  相似文献   

6.
贝壳有机基质与生物矿化   总被引:8,自引:1,他引:8  
姜国良  陈丽  刘云 《海洋科学》2002,26(2):16-18
生物矿化是以少量有机大分子(蛋白质、糖蛋白或多糖)为模板 ,进行分子操作(Molecularmanip ulation),高度有序地组合成无机材料的过程。在生物矿化材料(如牙齿、骨骼、贝壳等)里 ,软体动物壳的形成又是受有机大分子控制最复杂、最有序的一个过程 ,且形成的高度有序的晶体复合体与一般碳酸钙晶体相比有很多特殊的性质 ,如其强度比单一矿物晶体高3000倍[1]。研究软体动物壳有机基质 ,对研究壳生物矿化机理有着重要意义。1软体动物壳的结构软体动物壳是在一个有机基质框架中的碳酸钙单位组成的高度有序的…  相似文献   

7.
海藻多糖空心胶囊是以海藻多糖与植物膳食纤维作为主要材料研制的一种植物空心胶囊。对海藻多糖植物空心胶囊(植物壳)、明胶空心胶囊的阿奇霉素、头孢氨苄和布洛芬3种药物模型的胶囊剂进行了药物溶出度和溶出速率的对比研究。结果显示海藻多糖空心胶囊在药物最终溶出量和加速稳定性试验上优于或同等于明胶空心胶囊,因此海藻多糖空心胶囊具有代替动物明胶空心胶囊的潜在可能性。  相似文献   

8.
以枪乌贼的骨骼组织羽状壳为原料 ,设计正交实验分析了碱液浓度、温度和时间对壳聚糖脱乙酰度和粘度的影响 ;对枪乌贼羽状壳制备的壳聚糖的性能进行了初步研究。结果表明 ,以羽状壳制备的壳聚糖特点是具有较高的粘度 (3890 m Pa· s) ,颜色为浅黄褐色 ,可免除脱钙脱色环节。在碱液浓度为 4 5 % ,温度为 90℃ ,反应时间为 4 h的条件下 ,可得到较好品质的壳聚糖产品  相似文献   

9.
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   

10.
海洋多糖具有来源丰富、生物相容性好、易生物降解、低毒性、低成本、稳定性和安全性高等特点。同时,海洋多糖易于化学改性能够制备满足各种需求的纳米粒(如用于药物递送、基因递送和生物传感等)。因此,海洋多糖是目前被认为用于制备药物递送系统的理想原料。本文综述了海洋多糖的性质、制备海洋多糖纳米粒的主要方法,并从海洋多糖纳米粒的物化性质和结构特征出发讨论几个重要的概念,为临床前和临床应用研究提供依据。然而,目前这类研究大多仍处于实验室阶段,需要进一步进行体内和临床应用研究来开发医用的商品化的纳米产品。  相似文献   

11.
杨贵兰  秦松  李文军  李亚 《海洋科学》2021,45(10):123-132
许多海洋生物活性肽具有降血压、抗炎、抗氧化、抗血栓等多种生物活性,在功能食品及医药领域有着广阔的应用前景。本文主要综述了海洋生物活性肽的制备方法、功能活性及其作用机制,为进一步开发和利用海洋生物活性肽提供参考。  相似文献   

12.
Studyonshort-rangenumericalforecastingofoceancurrentintheEastChinaSea-ⅢThree-dimensionalbaroclinicanomalyforecastingmodelandi...  相似文献   

13.
Acoustic wave fields in an ocean waveguide with a sediment layer having continuously varying density and sound speed overlying an elastic subbottom are considered in this analysis. The objective of this study is to investigate the effects of seabed acoustic properties, including the density and sound speed of the sediment layer and subbottom, on the characteristics of the wave fields. Examination of the reflection coefficient, wavenumber spectrum, and noise intensity of the sound field through numerical analysis has shown that the variation in the acoustic properties in the sediment layer is an important factor in determining the reflected or noise sound fields. In particular, the sediment thickness-to-wavelength ratio and the types of variation of acoustic properties inside the layer give rise to many characteristics that potentially allow for acoustic inversion of the seabed properties. With regard to the wave-field components in a shallow-water environment, the various types of waves existing in a seismo-acoustic waveguide have been illustrated. The results indicate that the effects of the sediment properties on the wavenumber spectrum are primarily on the continuous and evanescent regimes of the wave field. The noise intensity generated by distributive random monopoles at various depths, together with the effect of refractive sound-speed distribution in the water column, has been obtained and analyzed.  相似文献   

14.
由空气-海水-海底3层模型求得了海水中水平电偶极子源的电磁场分布。与以往不考虑空气层的两层模型的电磁场分布相比,它更接近于实际分布情况。文章还对不同海底电导率时水平电偶极子源的电场水平分量进行了数值计算和分析。  相似文献   

15.
For more and more applications in coastal and offshore engineering, numerical simulations of waves and surges are required. An important input parameter for such simulations are wind fields. They represent one of the major sources for uncertainties in wave and surge simulations. Wind fields for such simulations are frequently obtained from numerical hindcasts with regional atmospheric models (RAMs). The skill of these atmospheric hindcasts depends, among others, on the quality of the forcing at the boundaries. Furthermore, results may vary due to uncertainties in the initial conditions. By comparing different existing approaches for forcing a regional atmospheric model, it is shown that the models' sensitivity to uncertainties in the initial conditions may be reduced when a more sophisticated approach is used that has been suggested recently. For a specific, although somewhat brief test period, it is demonstrated that an improved hindcast skill for near surface wind fields is obtained when this approach is adopted. Consequences of the reduced uncertainty in wield fields for the hindcast skill of subsequent wave modelling studies are demonstrated. Recently, this new approach has been used together with a regional atmosphere model to produce a 40-year wind hindcast for the Northeast Atlantic, the North Sea and the Baltic Sea. The hindcast is presently extended to other areas and the wind fields are used to produce 40-year high-resolution hindcasts of waves and surges for various European coastal areas.  相似文献   

16.
海洋来源的功能寡糖具有多种生物活性,如抗炎、抗氧化、抗病毒、抗肿瘤和免疫调节等,因此在医药、农业、化工及环境等领域有着广泛的应用.然而,不同聚合度、不同结构的寡糖所具有的活性差异很大,因此有必要深入研究和探讨不同种类的海洋功能寡糖的结构与功能的关系及其应用潜力.本文对几种研究较多的海藻功能寡糖的来源、制备、纯化及应用进...  相似文献   

17.
This paper is a short review of publications on the influence that solar activity and geomagnetic disturbances (cosmic weather) have on physical-chemical systems. The effects of cosmic weather may some-times be detected by the presence of an uncontrolled factor in these experiments. Direct reactions to cosmic weather are reliably identified in quantitative observations over various test systems, mainly water solutions. The effects of cosmic weather are also found from the data obtained by monitoring some simple physical systems, including semiconductors. All these effects are either cosmic physical rhythms or they are easily registered sporadic heliogeophysical events (e.g., magnetic storms). There are convincing data that demonstrate the influence that cosmic weather has on the accident rate in various engineering and physical systems. Researchers are at odds on the physical nature of the main physical agent, but the contribution of electromagnetic fields to these processes is considered important.  相似文献   

18.
- This paper describes coating protection of production facilities of offshore oil fields based on the practice of development of Bohai Offshore Oil Field, with focus laid on the selection of coating systems, surface preparation, coating application, as well as coating inspection for four types of major production facilities.  相似文献   

19.
We analyze the statistical structure of the data of remote sensing of the fields of surface temperature and the concentration of chlorophyll in the northwest part of the Black Sea with an aim to apply the method of optimal interpolation to the restoration of the maps of these fields according to the restricted amounts of data. We determine the scales of smoothing for the selection of the random components of the fields and estimate their difference from the statistical model uniform and isotropic over the space correlation coefficients. The functions of spectral densities are constructed along various sections and the best intervals of discretization of the fields required to perform the optimal interpolation with given accuracy are determined. It is shown that the construction of the maps of fields under the conditions of controlled accuracy of reconstruction of their values remains possible even if the amounts of the input satellite data are significantly decreased. We consider a procedure of evaluation of the best possible amounts of data required for the use of the method of optimal interpolation. Some examples of application of this procedure to the data of remote sensing of the fields of surface temperature and the concentration of chlorophyll are presented.  相似文献   

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