A study on the impedance responses of inhibitor desorption

INTRODUCTIONInhibit0rdesorptionfrequenhyresultSininstabilityandtheninvalidationoftheads0boiIiliibitorincertainanodicp0tenhalrangePraricV.J.andDradeD.M.,l99O,WangJiaetal.,l99l).InrenzandMansfeld(l98l)rePortedthattheinhibitordesorpti0ncouldproduceonthetheedancediagramaninductivelo0p,whichdePends0nthenabeoftheadd,theadditives,tirneandpotential.Sineeproonessuchasndldiss0lution,adsorph0nanddesorptionofinhibitorandotherreevantionsinteraCtwithcachother,theinhibitordesorpti0nbehaviorrnayprov…     

Corrosion behavior of anodic oxidized TiO<Subscript>2</Subscript> film in seawater

TiO₂ films were formed on metallic titanium substrates by the anodic oxidation method in H₂SO₄ solution under the 80V D.C.. Phase component and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Water contact angles on titanium oxide film surface were measured under both dark and sunlight illumination conditions. Corrosion tests were carried out in seawater under different illumination conditions by electrochemistry impedance spectrum (EIS) and polarization curves. The result showed that the TiO₂ film prepared by the anodic oxidation method was anatase with a uniform structure and without obvious pores or cracks on its surface. The average water contact angle of the film was 116.4° in dark, in contrast to an angle of 42.7° under the UV illumination for 2 hours, which demonstrates good hydrophobic property. The anti-corrosion behavior of the TiO₂ film was declining with the extended immersion time. Under dark conditions, however, the hydrophobic TiO₂ film retarded the water infiltrating into the substrate. The impedance changed slowly and the corrosion current density was 2 orders of magnitude lower than that with the film illuminated by sunlight. All of those mentioned above indicate that the TiO₂ film possesses much better performance under dark condition, and it can be applied as an engineering material under dark seawater environment.     

Freeze-thaw effects on sorption/desorption of dissolved organic carbon in wetland soils

The effects of freeze-thaw cycles on sorption/desorption of dissolved organic carbon (DOC) in two wetland soils and one reclaimed wetland soil were investigated. DOC concentrations added were 0-600 mg/L. Laboratory incubations of sorption/desorption of DOC had been carried out at -15℃ for 10 h, and then at +5℃ for 13 h. Soil samples were refrozen and thawed subsequently for 5 cycles. Initial Mass model was used to describe sorption behavior of DOC. The results indicate that freeze-thaw cycles can significantly increase the sorption capacity of DOC and reduce the desorption capacity of DOC in the three soils. The freeze-thaw effects on desorption of DOC in soils increase with the increasing freeze-thaw cycles. The conversion of natural wetlands to soybean farmland can decrease the sorption capacity and increase the desorption capacity of DOC in soils. Global warming and reclamation may increase DOC release, and subsequently increase the loss of carbon and the emission of greenhouse gas.     

合浦珠母贝丝氨酸蛋白酶抑制因子基因pfser1克隆与表达

【目的】克隆合浦珠母贝(Pinctada fucata)丝氨酸蛋白酶抑制因子pfser1基因,探讨该基因的组织表达及其在天然免疫过程中的作用,以及与生物矿化过程的关系。【方法】通过RACE技术获得pfser1基因的全长,通过生物信息学分析其序列结构特征,利用实时荧光定量PCR方法检测pfser1基因在不同组织中的表达,检测健康合浦珠母贝在被大肠杆菌(Escherichia coli)MG1655刺激后和在贝壳损伤修复实验中pfser1基因表达量的变化。【结果】合浦珠母贝pfser1基因cDNA全长为1240 bp,包含1035 bp的开放阅读框(ORF),编码344个氨基酸,氨基酸序列的功能结构域含有丝氨酸蛋白酶抑制因子Serpin家族保守结构域。pfser1基因在合浦珠母贝各个组织中均有表达,在外套膜边缘膜中表达量最高;大肠杆菌MG1655刺激后,该基因表达量显著升高;在贝壳损伤修复过程中,pfser1基因表达先升高后受到抑制。【结论】pfser1基因所表达的蛋白参与了合浦珠母贝的天然免疫应答过程,并与生物矿化过程有一定关系。     

Antithrombotic effects of bromophenol,an alga-derived thrombin inhibitor

Thrombin,the ultimate proteinase of the coagulation cascade,is an attractive target for the treatment of a variety of cardiovascular diseases.A bromophenol derivative named (+)-3-(2,3-dibromo-4,5-dihydroxy-phenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroiso-benzofuran 1,isolated from the brown alga Leathesia nana exhibited significant thrombin inhibitory activity.In this study,we investigated the inhibition of human thrombin in vitro with this bromophenol derivative,and its antithrombotic efficacy in vivo using th...     

Comparative study on the protease inhibitors from fish eggs

The protease inhibitor was purified from five different fish eggs. The molecular weights of Pacific herring, chum salmon, pond smelt, glassfish, and Alaska pollock egg protease inhibitors were 120, 89, 84.5, 17, and 16.8kDa, respectively. The specific inhibitory activity of glassfish egg protease inhibitor was the highest followed by those of Pacific herring and Alaska pollock in order. The specific inhibitory activity and purity of glassfish egg protease inhibitor were 19.70 U mg^- 1 protein and 164.70 folds of purification, respectively. Glassfish egg protease inhibitor was reasonably stable at 50 - 65℃ and pH 8, which was more stable at high temperature and pH than protease inhibitors from the other fish species. Glassfish egg protease inhibitor was noncompetitive with inhibitor constant （Ki） of 4.44 nmol L^-1     

Effect of high iron concentration enrichment on the phytoplankton in the Prydz Bay

1　IntroductionForthepast 1 5years,muchattentionofoceanographershasbeenfocusedontheroleofironinlimiting phytoplankton productivityinthehigh nutrient ,low chlorophyll(HNLC)regions.OnboardshipironenrichmentincubationshavebeencarriedoutinthethreewellknownHNLCregions :notablyequatorialPacificOcean ,subarcticPacificO ceanandSouthernOcean (seereferencesinTable 1 ) .Theinsituironenrichmentexper imentshavebeenaccomplishedintheequatorialPacific (IronEx1in 1 993 (Wells 1 994)andIronEx2in 1 996(…     

针铁矿和蒙脱石对菲的吸附解吸行为与热力学研究

采用批量振荡吸附平衡法设计针铁矿和蒙脱石对菲的吸附解吸试验,对比研究了针铁矿和蒙脱石对菲的吸附解吸行为,并考察了不同K+浓度的溶液对蒙脱石吸附菲的影响,比较分析了线性吸附模型和Freundlich吸附模型描述矿物吸附等温线的准确性,并从吸附热力学角度探讨了矿物的吸附机理。结果表明:针铁矿和蒙脱石对菲的吸附解吸均表现出明显的非线性和解吸滞后现象;相对于线性吸附模型来说,针铁矿和蒙脱石对菲的吸附解吸更符合Freundlich吸附模型;与蒙脱石相比,针铁矿对菲的吸附更为显著,且具有更好的稳定性;溶液中软阳离子K+的存在使蒙脱石对菲的吸附能力得到显著提高;菲在蒙脱石和针铁矿上的吸附过程是一个自发放热,同时伴随着熵值减小的过程;随着温度的升高,蒙脱石和针铁矿对菲的吸附能力均减弱。     

A theoretical analysis of interactive coercing effects between urbanization and eco-environment

Objectively, a complex interactive coercing relationship exists between urbanization and eco-environment, and the research of this relationship is primarily divided into three schools, i.e., interactive coercion theory, interactive promotion theory and coupling symbiosis theory. Harmonizing the relationship between urbanization and eco-environment is not only an important proposition for the national development plan but also the only way to promote healthy urbanization. Based on an analysis of urbanization process and its relationship with the eco-environment, this article analyzes interactive coercing effects between urbanization and eco-environment from three perspectives of population urbanization, economic urbanization and spatial urbanization, respectively, and analyzes risk effects of the interactive coercion. Further, it shows six basic laws followed by interactive coercion between urbanization and eco-environment, namely, coupling fission law, dynamic hierarchy law, stochastic fluctuation law, non-linear synergetic law, threshold value law and forewarning law, and divides the interactive coercing process into five stages, namely, low-level coordinate, antagonistic, break-in, ameliorative and high-grade coordinate. Based on the geometric derivation, the interactive coercing relationship between urbanization and eco-environment is judged to be non-linear and it can be explained by a double-exponential function formed by the combination of power and exponential functions. Then, the evolutionary types of the interactive coercing relationship are divided into nine ones: rudimentary coordinating, ecology-dominated, synchronal coordinating, urbanization lagging, stepwise break-in, exorbitant urbanization, fragile ecology, rudimentary break-in and unsustainable types. Finally, based on an interactive coercion model, the degree of interactive coercion can be examined, and then, an evolutionary cycle can be divided into four phases, namely rudimentary symbiosis, harmonious development, utmost increasing and spiral type rising. The study results offer a scientific decision-making of healthy urbanization for achieving the goal of eco-environment protection and promoting urbanization.     

The effects of temperature and substrate on ontogenetic behavior of bastard halibut, Paralichthys olivaceus （T.et S.）

The effects of temperature and substrate on ontogenetic patterns and settlement behavior of bastard halibut, Paralichthys olivaceus （T. et S.） were studied in a series of laboratory experiments. Analysis on stage-based data revealed that except for settlement, and compared to the substrate, the ambient temperature dominantly controlled the hatch success and subsequent development of the species. The oosperm optimum survival rate of 60% during hatching occurred at 20℃, and survival rate of 29%, at 18℃ for larval rearing. The survival rate of larvae reared under variable temperature of 3.5-4.5℃ was higher than that of those reared under stable temperature. The maximum survival rate of 29%, corresponded to variation at temperature of 4℃. With increase in age newly settled juveniles preferred to lie on the fine substrate and gradually moved on the coarse substrate. GLM （general linear model） analysis showed that the combination of temperature and substrate had no significant impact on the survival of settling larvae, but definitely affected the duration of settlement.     

The effects of temperature and substrate on ontogenetic behavior of bastard halibut, Paralichthys olivaceus (T. et S.)

1 INTRODUCTION Scientific management of aquacultural andnatural populations studies on the early life historyof flatfishes in the aspects of their metamorphosisand benthic settlement accompanying pronouncedtransitions in morphology, behavior and habitatecology have received much attention (Youson,1988). Accumulated data showed that temperatureand substrate played a main role in the recruitmentsuccess of flatfish during their early development(Rijnsdorp et al., 1995, Gibson and Robb, 2000…     

Sorption behavior of o-nitrophenol on marine sediment

Systematic study on sorption behavior of o-nitrophenol on marine sediments was conducted.Isotherms of sorption of o-nitrophenol on marine sediments could be described by Freundlich model; and the isotherm of sorption of o-nitrophenol on HCl-treated sediment could be described by Langmuir model. The sorption behavior was affected by various factors including organic carbon content, aqueous solution salinity,temperature, and acidity. The sorption amount of o-nitrophenol increased when salinity and acidity of the aqueous solution increase, but decreased with increasing temperature. Organic carbon content in sediments had apparent effect on the behavior except for HCl-treated sediments.     

Influence of grain segregation on the behavior of sand in triaxial tests

As a common phenomenon in granular flow, grain segregation plays a great role in affecting the behavior of granular soil by causing a great change of grain-void distribution in granular soil. This paper presents an experimental study on the influence of grain segregation on the behavior of sand, by a number of triaxial tests to interpret the characteristic behavior, friction and dilatancy behavior, excess pore water pressure behavior and critical state behavior of sand incorporating grain segregation. An index-grain segregation index was proposed to quantify grain segregation. Grain segregation affected greatly the characteristic behavior of sand, causing the movement of void ratio-dilatancy relation of sand towards the increase of void ratio and dilatancy of sand. In the drained tests, the mobilized friction angle of sand showed a decrease followed by an increase but the mobilized dilatancy angle of sand increased, with increasing grain segregation index. An increase in grain segregation index impaired the basic friction of sand. In the undrained tests, the mobilized friction angle of sand showed an increase followed by a decrease with increasing grain segregation index. However, grain segregation caused an increase of the mobilized dilatancy of sand followed by a different development. An increase in grain segregation resulted in a higher summit of the dilatancy of sand but with a faster decrease along axial strain. In the q-p′ plane, grain segregation caused a reciprocating rotation of the dilatancy line and failure line of sand. Grain segregation resulted in enhancement of the peak-state dilatancy of sand, affecting greatly peakstate friction angle and peak-state basic friction angle of sand as well as the normalized excess pore water pressure. The excess friction angle of sand showed an increase followed by a decrease in the drained tests but increased linearly in the undrained tests, with increasing grain segregation index. The excess friction angle-over-maximum dilatancy angle of sand decreased in up convexity while increasing grain segregation index. Grain segregation resulted in rotation and translation of the critical state line of sand in the e-p′α=0.7 plane. However, in the q-p′ plane, the critical state line of sand showed an anticlockwise rotation followed by a clockwise rotation with increasing grain segregation index.     

基于遥感蚀变信息提取巴林格撞击坑周边铁陨石

目前地球上已经得到确认的撞击坑有190余个，其中直径小于1 km的简单撞击坑绝大部分是由铁质撞击体撞击形成的。由铁质撞击体撞击而成的撞击坑周边存在大量的铁陨石物质，这些铁陨石物质的空间分布特征对研究撞击坑的撞击过程和机理具有重要意义。铁元素的异常富集也可作为探寻地球表面疑似撞击坑的重要信息。为了获取撞击坑周围的铁陨石残片，早期主要通过人工方式进行实地调查，但这种方法效率低下且需要投入大量人力物力。基于铁陨石独特的光谱特征，利用遥感蚀变信息提取手段可以很方便地获取撞击坑周边的铁陨石物质。根据铁陨石矿物的波谱特征，以美国亚利桑那州巴林格撞击坑（Barringer Meteor Crater）为研究对象，基于Landsat 8 OLI数据，采用目前提取蚀变信息的常用方法:波段比值（BandMath）—主成分分析法进行撞击坑周边铁陨石信息的提取。提取结果与前人实地调查获取的铁陨石分布情况契合程度较好。撞击坑东侧、东南侧、西南侧等处的铁陨石聚集区在提取结果图上均有较好的反映。表明利用波段比值-主成分分析方法提取巴林格撞击坑周边铁陨石信息是可行的，实验结果准确地获得了该撞击坑周围的铁陨石空间分布信息，为探寻地球表面撞击成因的环形构造提供了可行方案，同时为未来同类撞击坑信息提取提供了重要的方法参考。      

Janus激酶3抑制剂对马氏珠母贝珍珠囊发育和免疫相关基因表达的影响

【目的】研究JAK3抑制剂对珍珠囊发育及移植免疫反应的影响。【方法】以马氏珠母贝(Pinctada fucata martensii)为材料,植核前用JAK3抑制剂处理细胞小片和珠核,植核后18 d和30 d取珍珠囊,用石蜡切片技术和H.E.染色法(Hematoxylin-eosin Staining)观察JAK3抑制剂对珍珠囊发育的影响,利用荧光定量技术检测植核后不同时间(6、12、24 h和3、6、12、18、30 d)免疫相关基因NF-kappaB(Nuclear factor kappa B)、IkappaK(I-kappaB kinase)和炎性诱导因子IL-17(Interleukin 17)的表达变化。【结果】植核后18 d和30 d,与对照组相比,JAK3抑制剂对珍珠囊的发育没有显著影响(P> 0.05)。荧光定量结果显示,植核后6 h和12 h,JAK3抑制剂可以显著性抑制IL-17的表达,植核后6、3、6、12 d,JAK3抑制剂可以显著性抑制NF-kappaB的表达,植核后3、6 d,JAK3抑制剂可以显著性抑制IkappaK的表达(P <0.05)。【结论】JAK3抑制剂对马氏珠母贝免疫基因表达有明显的抑制作用,可以有效调控珍珠贝植核后的移植免疫,而对珍珠囊发育的影响不明显。     

Development,territorial difference and spatial evolution of towns in China—A discussion on the views of anti-urbanism in China

Growth of Chinese small towns is a continuing process of urbanization. By analyzing regional disparity and comprehensive development level of Chinese small towns, it is considered that town development depends mainly on the regional agriculture and social development level. Their spatial distribution is restricted by population distribution and regional economic development level. Chinese urbanization, just the same as urbanization in developed countries, is a sign of socio-economic vigour and prosperity, and is not related to social and political systems. Thus, it is worth to discuss China’s anti-urbanism with abroad scholars.     

Influence factors on the seismic behavior and deformation modes of gravity retaining walls

This study investigated the influence factors on the seismic response and deformation modes of retaining walls using large-scale model shaking table tests. Experimental results showed that the distribution of peak seismic earth pressures along the height of a wall was a single peak value curve. The seismic earth pressures on a gravel soil retaining wall were larger than the pressures on the weathered granite and quartz retaining walls. Also, the peak seismic earth pressure increased with increases in the peak ground acceleration and the wall height. The measured seismic active earth pressures on a rock foundation retaining wall were larger than the calculated values, and the action position of resultant seismic pressure was higher than 0.33 H. In the soil foundation retaining wall, the measured seismic earth pressures were much smaller than the calculated values, while the action position was slightly higher than 0.33 H. The soil foundation retaining wall suffered base sliding and overturning under earthquake conditions, while overturning was the main failure mode for the rock foundation retaining walls.     

Electrochemical properties of electrodes with different shapes and diffusion kinetic analysis of microbial fuel cells on ocean floor

Microbial fuel cell(MFC) on the ocean floor is a kind of novel energy-harvesting device that can be developed to drive small instruments to work continuously.The shape of electrode has a great effect on the performance of the MFC.In this paper,several shapes of electrode and cell structure were designed,and their performance in MFC were compared in pairs:Mesh(cell-1) vs.flat plate(cell-2),branch(cell-3) vs.cylinder(cell-4),and forest(cell-5) vs.disk(cell-6) FC.Our results showed that the maximum power densities were 16.50,14.20,19.30,15.00,14.64,and 9.95 mWm-2 for cell-1,2,3,4,5 and 6 respectively.And the corre-sponding diffusion-limited currents were 7.16,2.80,18.86,10.50,18.00,and 6.900 mA.The mesh and branch anodes showed higher power densities and much higher diffusion-limited currents than the flat plate and the cylinder anodes respectively due to the low diffusion hindrance with the former anodes.The forest cathode improved by 47% of the power density and by 161% of diffusion-limited current than the disk cathode due to the former’s extended solid/liquid/gas three-phase boundary.These results indicated that the shape of electrode is a major parameter that determining the diffusion-limited current of an MFC,and the differences in the elec-trode shape lead to the differences in cell performance.These results would be useful for MFC structure design in practical applica-tions.     

A quantification of the effects of erosion on the productivity of purple soils

Research on the effects of soil erosion on soil productivity has attracted increasing attention.Purple soil is one of the main soil types in China and plays an important role in the national economy.However,the relationship between erosion and the productivity of purple soils has not been well studied.The purpose of this research was to determine if soil depth,which is dependent on the rate of erosion,has an influence on crop yield and growth.Plot and pot experiments at different soil depths were performed.Results indicate that soils from different parental materials had different growth features and crop yields due to the differential fertility of the derived soils.The yield reduction rate increases exponentially with the depth of eroded soil(level of erosion).The yield reduction rate per unit eroded soil horizon(10 cm) is approximately 10.5% for maize and wheat.     

民族主义的“建构”“重构”“解构”与民族主义进程的不同步性

民族主义进程也可以看作是一个"建构"、"重构"与"解构"的过程。在这三步曲中,不同的民族表现出明显的不同步性。民族主义进程是一个客观的过程,人为地推进民族主义进程不仅难以如愿,甚至可能会引起严重的民族问题和民族冲突。