Se(Ⅳ)对钝顶和极大螺旋藻生长的影响

采用藻类生长动力学函数和藻类测试化学品毒性的标准方法,分别研究了高、低质量浓度Se（Ⅳ）对钝顶（S．platensis）和极大（S．maxima）螺旋藻生长的影响,结果表明：低质量浓度组中,Se（Ⅳ）的质量浓度低于16mg／L时对钝顶螺旋藻前4d的生长影响差异无显著性意义,但当质量浓度为32mg／L时出现明显的抑制作用;而低质量浓度范围内,即质量浓度低于32mg／L的Se（Ⅳ）在前4d对极大螺旋藻的生长的影响不明显．高质量浓度组中,当质量浓度高于560mg／L时,钝顶螺旋藻的生长被完全抑制;硒对极大螺旋藻的最低完全抑制质量浓度为600mg/L.     

香樟与地被植物配植对其生长和富集Cd的影响

以草本植物肾蕨、麦冬和头花蓼的幼苗为材料,分别与香樟幼苗组合配植并进行Cd胁迫(0.1, 0.3, 1, 5 mg/L)溶液培养(CK:香樟单种), 4周后测定香樟幼苗生物量、幼苗和培养液Cd质量浓度,研究地被植物对香樟生长和富集Cd的影响.结果表明,香樟—肾蕨(CN)、香樟—麦冬(CO)组合可显著增加香樟生物量.当Cd的质量浓度为5.0 mg/L时,香樟全株生物量比CK分别提高46.77%和42.47%; CN组合能显著提高香樟Cd富集量.当Cd的质量浓度为0.1 mg/L时,其地上部分和全株富集量分别为(1.639±0.133)μg/株和(7.351±0.575)μg/株,比CK分别提高137.88%和77.86%; CN、香樟—头花蓼(CP)组合可显著提高香樟对Cd的转运能力.当Cd的质量浓度为5.0 mg/L时,其转移系数分别为0.161和0.138,比CK分别提高76.92%和106.41%; CO组合能显著提高培养液Cd去除率.当Cd质量浓度为0.1 mg/L时, Cd去除率达68.67%,比CK提高50.01%.结果显示,香樟与地被植物肾蕨、麦冬和头花蓼配植可显著促进其生...     

两种抗生素对褶皱臂尾轮虫种群增长的影响

采用种群累积培养法,研究了两种抗生素,即氯霉素(Chloromycetin)和烟酸氟哌酸(Nicotinic Norfloxacinum)对褶皱臂尾轮虫(Brachionus plicatilis)种群增长的影响.结果表明,不同剂量的氯霉素对轮虫种群的增长有明显的影响(P<0.01),浓度为0.012 5 mg/mL时可促进种群增长,当浓度增加到0.025 0～0.050 0 mg/mL时,则有不同程度的抑制作用,0.050 0 mg/mL的浓度抑制作用明显;不同剂量的烟酸氟哌酸对轮虫种群的增长亦有明显的影响(P<0.01),低剂量组(0.250 0和0.500 0 mg/mL)可促进种群增长,而高剂量组(0.75和1.00 mg/mL)则为抑制作用.     

低剂量臭氧处理污泥减量的研究

对低剂量臭氧在剩余活性污泥减量中的应用进行了探讨.结果表明,当活性污泥进行低剂量臭氧(≤0.010 mgO3/mgMLSS)处理时,可取得较好的减量化效果.当臭氧投加剂量为0.010 mgO3/mgMLSS时,反应60 min活性污泥的总去除率达到77.73%.臭氧处理会同时导致溶解性化学需氧量(SCOD)的增加.臭氧投加剂量为0.005 mgO3/mgMLSS时污泥中的SCOD增加至20.28 mg/gMLSS·L.污泥沉降比(SV%)减少率随臭氧投加剂量的增大呈线性增加趋势.低剂量处理后的污泥容积指数(SVI)值在58～62 mg/L之间,污泥的沉降性能良好,并未产生污泥膨胀现象.     

γ-亚麻酸产生菌的低能离子束诱变选育

为了得到γ-亚麻酸(GLA)高产菌株,以深黄被孢霉As3.3410为出发菌株,利用氮离子(N+)注入诱变,并采用马来酰肼抗性筛选和红四氮唑(TTC)法相结合对突变株进行筛选。试验结果表明:当能量为10 ke V时,最佳氮离子诱变剂量为1.56×1015cm-2;当马来酰肼的添加量为40 mg/L时,出发菌株的抑制率为100%;TTC法酶活测定的最佳条件为:温度35℃、p H为8.4、TTC浓度为8 g/L、反应时间为1 h,以此作为摇瓶初筛的条件。经过反复诱变筛选获得一株遗传稳定的高产突变株F312,其γ-亚麻酸产量为1 236 mg/L,比出发菌株(480 mg/L)提高了157.5%。     

螺旋藻(Spirulina maxima)对降低高血脂大鼠血清甘油三酯浓度的量效分析

以高脂饲料造型高血脂大鼠 ,饲喂不同剂量的螺旋藻饲料 ,建立血清甘油三酯值(TG)随时间 (t)变化的函数 ,通过求解其降脂极限临界值 ,推算出使高血脂大鼠达到健康标准的剂量组区间为 4 5 0mg/kg≤TG≤ 810mg/kg ,相应的理论服用期为 13.6周≤t≤ 195 5周 ;利用求得的理论值与对应的剂量建立量效函数关系 ,精确求解出最低有效剂量临界值为 377.4mg/kg .并应用该函数模型对螺旋藻降血脂量效与时效的互逆运算进行了探讨     

亚致死浓度的吡虫啉对萼花臂尾轮虫种群动态的影响

吡虫啉(Imidacloprid)是一种新烟碱类杀虫剂,但其对轮虫等水生无脊椎动物的毒性尚无从知晓.本文以萼花臂尾轮虫(Brachionus calyciflorus)为受试生物,应用种群增长、休眠卵产量和生命表实验等方法,研究了不同浓度的吡虫啉(0、1.56、3.12、6.25、12.5、25、50和100 mg/L)对其种群增长和生命表统计学等参数的影响.结果表明,吡虫啉浓度对轮虫存活(以生命期望为指标)、发育(世代时间)、生殖(净生殖率)和种群增长(内禀增长率和种群增长率)等参数均有显著性影响(P<0.01),但对有性生殖(后代混交率、种群混交率和休眠卵产量)等参数都无显著性影响(P>0.05).与对照组相比,12.5 mg/L吡虫啉处理组中轮虫种群增长率显著升高(P<0.05),而50和100 mg/L吡虫啉处理组中轮虫种群增长率则显著降低(P<0.05).3.12～12.5 mg/L吡虫啉处理组中轮虫的生命期望显著延长(P<0.05),而25～100 mg/L吡虫啉处理组中轮虫的生命期望则显著缩短(P<0.01).1.56～12.5 mg/L吡虫啉处理组中轮虫的世代时间显著延长(P<0.05),净生殖率显著升高(P<0.01),而50～100 mg/L吡虫啉处理组中轮虫的世代时间显著缩短(P<0.01),25～100 mg/L吡虫啉处理组中轮虫的净生殖率显著降低(P<0.01).50～100 mg/L吡虫啉处理组中种群内禀增长率显著降低(P<0.05).吡虫啉浓度与轮虫存活、发育、生殖和种群增长等参数之间均具有显著的剂量-效应关系.在监测吡虫啉的慢性毒性时,净生殖率是较敏感的指标.     

臭灵丹杀蝗虫活性成分的提取与分离研究

为了从有毒植物中发现新的农药活性化合物进行植物源农药的研究与开发,采用浸叶法测定了6种有毒植物乙醇提取物对蚜虫的触杀活性,结果表明臭灵丹乙醇提取物在2000 mg/L、5000 mg/L和10000 mg/L浓度时,对蚜虫的校正死亡率分别为76.83%、92.85%和100%;采用浸虫浸草法测定了6种有毒植物乙醇提取物对东亚飞蝗的触杀活性,结果表明臭灵丹乙醇提取物在10000 mg/L、作用120 h时,对东亚飞蝗的校正死亡率达到72.00%;采用活性跟踪法对臭灵丹杀蝗虫活性成分进行分离、纯化,最终得到活性较好的化合物1,在1000 mg/L、作用72 h时,对东亚飞蝗的校正死亡率为67.86%,为进一步研究臭灵丹的杀虫活性成分提供了一定理论研究基础.     

不同浓度血红蛋白对小鼠骨髓瘤细胞体外培养的影响

用含不同浓度的牛源性血红蛋白细胞培养液培养小鼠骨髓瘤细胞,通过细胞计数绘制生长曲线,计算最大增殖浓度和倍增时间,并进行比较分析.结果表明:当培养液的血红蛋白浓度在1~5 mg/dL时小鼠骨髓瘤细胞生长较好,细胞最大增殖浓度在1.2×106个/mL以上,倍增时间小于20 h,当培养液的血红蛋白浓度为6 mg/dL时细胞生长抑制,细胞最大增殖浓度和倍增时间为6.7×105个/mL和21.6 h.由此可见,培养液中血红蛋白浓度≤5 mg/dL时不影响细胞生长,达到6 mg/dL时抑制细胞生长.     

谷氨酸钠对钝顶螺旋藻生长及色素的影响

在Zarrouk培养液中添加不同质量浓度的谷氨酸钠,研究其对钝顶螺旋藻生长和色素质量比的影响。结果表明,低质量浓度的谷氨酸钠能促进螺旋藻的生长,提高螺旋藻中叶绿素a、类胡萝卜素和藻蓝蛋白的质量比,而当谷氨酸钠质量浓度超过1g/L后,钝顶螺旋藻的生长和色素质量比都受到明显抑制,藻蓝蛋白也受到破坏。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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