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1.
从广饶盐田藻垫提取多糖,分析盐田表土中多糖的含量,再把多糖按比例(4%,85)加入干净土样,在布氏漏斗中进行渗透对照实验,测定结果和计算数据表明:多糖显著地降低了土壤的孔隙度(14—265);增加了土壤的含水量降低了土壤对水的渗透率(60-98%),并具有一定的离子选择透性(Ca,Mg,Zn等减少,K增加).在土层上加一薄层(2mm)藻垫进行类似的对照实验,也证明了藻垫明显的防渗作用.  相似文献   

2.
讨论藻垫的组成及其在不同纬度、盐度的分布,对各种类型的藻垫随纬度、盐度的季节性变化规律进行初步分析,并从生态学角度讨论了这种变化的原因,及其对生产工艺的要求和在盐田生态管理上的意义。  相似文献   

3.
滇池微囊藻“水华”藻胆蛋白资源化研究   总被引:4,自引:0,他引:4  
对从滇池采集的惠氏微囊藻(Microcystiswesenbergii(惠氏微囊藻的多率达90%以上)和人工养殖螺旋藻的藻胆蛋白和粗蛋白进行了比较研究,结果显示,滇池微囊藻水华中藻胆蛋白的含量占干藻的15.07%晒干后的螺旋藻其藻胆蛋白含量8.05%,喷雾干燥的3.68%,此外,超滤前破细胞的溶液含小白鼠致死的毒素,超滤提取得到的藻胆蛋白结果为阴性,藻胆蛋白的安全性好。  相似文献   

4.
针对标准的人工藻算法(AAA)会由于参数选取不当等原因导致过早收敛和易陷入局部最优解等问题,本文提出一种自适应动态惯性权重(SW)加压缩因子(CF)的人工藻算法(CFSWAAA).为了平衡算法的全局探索和局部改良能力,自适应动态惯性权重被引入到人工藻算法中:为了控制和约束人工藻位置的移动距离,压缩因子被引入到人工藻算法的位置更新中,从而提高算法的收敛速度.最后文章利用4个标准测试函数对改进的算法进行了仿真测试.仿真结果表明,基于自适应动态惯性权重加压缩因子的人工藻算法相比现有的其他四种算法具有较高的优化性能.  相似文献   

5.
盐生杜氏藻新品系的选育   总被引:3,自引:0,他引:3  
盐生杜氏藻SY-1品系是通过单细胞分离培养方法从江苏盐田采得的天然盐藻种群中选育出来的新品系.该品系可在NaCl含量5%~20%人工培养液或浓缩海水中正常生长,也可用制盐后的废卤水稀释后培养.在实验室培养时,其平均日增长率可达25%,表现出生长速度快、产量高、耐低温、抗浓度骤变的能力较强等优良性状.可望代替国外藻种,在我国各地广泛使用  相似文献   

6.
用包埋脱水法冰冻保存绿色巴夫藻(Pavlova viridis)、湛江等鞭藻(Isochrysis zhanjiangensis)和球等鞭金藻(Isochrysis galbana 3011)3种海洋饵料金藻,探讨了胶球含水量和预培养对冰冻保存存活率的影响.结果表明:3种藻冰冻前胶球的最佳含水量不同,绿色巴夫藻为35%。湛江等鞭藻和球等鞭金藻都为30%;预培养后3种藻都在20%含水量获得最高存活率,其中绿色巴夫藻经2%PEG预培养后存活率提高了6%,效果好于5%PVP预培养.预培养对其他两种藻的存活率没有提高.  相似文献   

7.
微藻是一种广泛存在的自养型微生物,同时能够降解水体中的营养物质和积累油脂,光照强度是影响藻类生长的重要条件之一;利用原始市政污水来培养栅藻,通过调节光强的不同,分别研究了栅藻在1000lux和3000lux光照强度下对污水水质的影响,结果表明:栅藻的藻密度在3000lux条件下要高于1000lux,其中栅藻在3000lux下培养时最大藻密度为268×10^5个/mL,明显高于其他3组;不同光强下,栅藻在光照为1000lux和3000lux条件下TN去除率分别为90%和94%;TP去除率分别为98%和99%,高于相应污水组的67%和94%,在一定范围内,光照强度的提高能够促进藻类的生长,提高藻细胞的活性,从而提高栅藻对水体中污染物质的去除率。  相似文献   

8.
利用固定化藻类的生物富积作用净化污水中的氮和磷,将栅藻包埋固定在褐藻酸钙凝胶胶球中,对人工污水进行深度净化.研究藻细胞年龄和饥饿处理时间对污水中NH4^+-N和PO4^3--P的净化效率以及净化过程中藻类叶绿索a含量变化.结果表明:静止初期藻细胞对NH4^+-N和PO4^3--P去除率比指数末期高,处理5d后,静止初期细胞对NH4^+-N和PO4^3--P的去除率分别为76.7%及91.7%,指数末期细胞氮、磷的去除率分别为75.4%和88.7%;饥饿处理可明显提高藻细胞对NH4^+-N和PO4^3--P的去除效率,藻细胞饥饿时间对NH4^+-N和PO4^3--P去除率的影响大小依次为48h,72h,24h,0h.  相似文献   

9.
几种环境因子对太平洋哲镖水蚤清滤率和摄食率的影响   总被引:7,自引:1,他引:6  
本文用放射性同位素~(32)P和~(35)S标志饵料生物——中肋骨条藻(Skeletonema costatum)来研究几种环境因子(饵料密度、饵料‘年龄’(藻龄)、温度、光度)对太平洋哲镖水蚤(Calanus paci-ficus)清滤率和摄食率的影响.研究结果表明:(1)清滤率在高密度(>3.O×10~4个细胞/毫升)饵料溶液中,几乎随饵料密度的增高而按比例地下降;但在低密度饵料溶液中,清滤率虽有所提高,但绝对摄食量却是下降的.(2)哲镖水蚤对骨条藻的吸收率是很高的,通常为50—90%(平均80%左右),吸收率与藻龄有密切关系:当以生长良好的骨条藻(培养3—4天的藻液)为饵料,吸收率达80%以上;但以‘衰老’的藻液(培养6—7天)为饵料时,吸收率仅50%左右.(3)在10—20℃范围内,摄食率随温度上升而增加.超过20℃以后,摄食率即下降.(4)摄食率在黑暗中最高.在室内人工光照下,摄食率随光照强度的增加而下降.  相似文献   

10.
为了明确柴达木盆地新生代湖相碳酸盐岩类型特征及发育规律,利用野外露头、钻井取芯、显微结构特征等资料,按照碳酸盐岩成因分类法,对碳酸盐岩类型进行划分。结果表明,柴达木盆地新生代发育两种成因类型碳酸盐岩储层,即生物成因和机械-化学复合成因。生物成因碳酸盐岩为藻灰/云岩类;机械-化学复合成因碳酸盐岩为颗粒灰/云岩类和泥晶灰/云岩。柴达木盆地碳酸盐岩发育颗粒滩-灰/云坪、颗粒滩(鲕粒滩)-藻丘、藻席-灰/云坪、颗粒滩-藻丘(席)-灰/云坪4种类型组合样式;灰/云坪储层在柴达木盆地西部地区大面积分布,颗粒滩储层分布于水体较浅、水动力条件相对较强的滨浅湖亚相带中,藻丘(席)分布在滨浅湖亚相内的清水、富氧环境中。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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