Effect of calcium ion on the adsorption of dissolved humic acid onto TiO2 particles in water

In order to clarify the role of HA (humic acid)-TiO2 adsorption in the photocatalytic process, a series of experiments were performed to investigate the adsorption mechanisms in the absence or presence of calcium according to the intermolecular interaction force theory. Based on the experimental results, the models of adsorption mechanism were designed, which were useful in explaining the phenomena that happened during adsorption processes. The adsorption of humic acid onto the TiO2 particles was desperately pH-dependent; however, calcium could increase the amount of adsorption, which was mainly attributed to the calcium ion bridging. The effects of calcium concentration and TiO2 dosage on the adsorption process are also discussed.     

Effect of groove rolling on the microstructure and properties of Cu–Nb microcomposite wires

Cu–Nb microcomposite wire was successfully prepared by a groove rolling process. The effects of groove rolling on the diffraction peaks, microstructure, and properties of the Cu–Nb microcomposite were investigated and the microstructure evolutions and strengthening mechanism were discussed. The tensile strength of the Cu–Nb microcomposite wire with a diameter of 2.02 mm was greater than 1 GPa, and its conductivity reached 68% of the International Annealed Copper Standard, demonstrating the Cu–Nb microcomposite wire with high tensile strength and high conductivity after groove rolling. The results show that an appropriate groove rolling method can improve the performance of the Cu–Nb microcomposite wire.     

Effect of pre-annealing treatment on the microstructure and mechanical properties of extruded Al-Zn-Mg-Cu alloy bars

Taking extruded Al-Zn-Mg-Cu alloy (7A04 alloy) bars as the research object, the effect and mechanism of pre-annealing treatments on the microstructure and mechanical properties of the aged alloy bars were investigated. The results show that a pre-annealing treatment at 350℃ for 15 h before a T6 treatment substantially reduced the sensitivity of the microstructure and mechanical properties of the extruded 7A04 aluminum alloy specimens toward the extrusion temperature. The average grain sizes of the specimens extruded at 390 and 430℃ after T6 treatment were 3.4 and 8.1 μm, respectively, and their elongations to failure were 7.0% and 9.2%, respectively. However, after pre-annealing + T6 treatment, the differences in both the grain sizes and the elongations of the specimens became small, i.e., their average grain sizes were 3.2 and 3.8 μm and their elongations were 12.0% and 13.3%, respectively. For the specimens extruded at the same temperature, pre-annealing treatment obviously improved the plasticity of the alloy, which is attributed to an increase in soft texture or to grain refinement in the specimens as a result of the pre-annealing + T6 treatment.     

Effect of Thrombin on the Apoptosis of Hippocampal Neurons in vitro

Hippocampal neurons were treated by thrombin and thrombin receptor activating peptides (TRAP). Cell survival rate was decreased in a dose-dependent manner by MTT assay. The numbers of apoptotic cell and apoptotic rate of hippocampal neurons treated by different concentrations of thrombin were increased in a dose-dependent manner by terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick end-labeling (TUNEL) method and Flow Cytometry. When the concentration of thrombin is 40 U/mL, TUNEL positive cells and apoptotic rate of hippocampal neurons reached peak value, were 27. 3 4.0 and (29.333 4.633 ) %, respectively. Immunocytochemistry assay show that Bcl-2 protein expression was down- regulated and Bax protein expression was up-regulated with the concentration of thrombin increased. TRAP can mimic the effect of thrombin to induce apoptosis on hippocampal neurons. These data demonstrated that thrombin induced hippocampal neuron apoptosis in a dose-dependent manner through activating protease-activated protein-1 (PAR-1). The change in expression of Bcl-2 and Bax was related with the effect of high concentration thrombin induced apoptosis on hippocampal neurons.     

Effects of dissolved organic matter on the growth and pigments synthesis of Spirulina platensis (Arthrospira)

Excessive accumulation of dissolved organic matter (DOM) in the culture ponds of Spirulina platensis is usually considered to be one of the potential factors affecting the production of S. platensis, however, we are not quite aware of effects of DOM on the growth and pigments synthesis of S. platensis. In the present study, S. platensis was grown in batch or semi?continuous cultures using the filtrate in the culture ponds that had not been renewed for years. It was found that disssolved organic carbon up to 60 mg/L did not bring about an inhibitory effect on the growth of S. platensis, but increased the contents of chlorophyll a and phycocyanin instead. However, further accumulation of dissolved organic matter could decrease the content of chlorophyll a.     

Effect of Residue Mutation on the Electrostatic Potential in EcCIC

The effect of mutation of strongly conserved porelining residues in the chloride channel EcClC on the electrostatic potential and binding free energy of the chloride ion was studied using explicit protein-membrane structures. Electrostatic potential distribution and binding free energy of the chloride ion at different binding sites in the wild-type and mutated EcClC were calculated with APBS. The potential data reveal that the electrostatic potential around the selectivity filter, especially around the site Sext and Scen becomes more negative as the residue R147 was mutated to C147. The electrostatic binding free energy shows that the binding free energy of the chloride ion at all binding sites becomes more positive as R147 was mutated. It follows that mutation of R147 decreases ion stabilization at binding sites and affects channel＇s gating.     

Effect of changes in flow runoff on the elevation of Tongguan in Sanmenxia Reservoir

This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the elevation of Tongguan, which is defined as the stage corresponding to a discharge of I000 m^3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream energy that integrates the current and the preceding years‘ flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a relatively large range of variations, then the elevation of Tongguan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primarily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.     

Activities of the Deriviatives of Chitin on the Osbeoblast Proliferation and the Effect on Bone Strength in Ovariectomized Rats

This study intends to examine the effects of different concentrations of four kinds of degradations of chitin： glucosamine （GLC）, N-acetyl-D-glucosamine （NAG）, chitooligosaccharide（COS）, CM-chitooligosaccharide （CM-COS）—on the proliferation of MC3T3-E1 cell line cultured in vitro. Results suggest that all of the glucoses mentioned above promoted the proliferation of osteoblast, and various concentrations have different effects： the proliferation was remarkable when the concentration of GLC, NAG, COS, CM-COS was 100 , 100, 500, 500 μg/mL ,respectively. Furthermore we choose the glucosamine as the material and study the effect on the bone strength in ovariectomized rats. The results showed that the middle does of glucosamine can significantly increase the hone strength of femur in ovariectomized rats.     

Effect of Calcining Temperature on the Structure of Li_4Ti_5O_(12)

1 Introduction Recently there had considerable interest in Li4Ti5O12 as a potential anode for use in Li-ion batteries. Usually, it was used as an anode combined with a high voltage cathode[1-5]. It has many advantages compared to the currently used graphite. For example, it presents virtually unlimited cycle life due to zero strain or volume change when lithium intercalates into and de-intercalates from[6]. Generally, Li4Ti5O12 was prepared by a solid-state reaction from stoichiometric amounts of Li2CO3 and TiO2. However, the different calcining temperature has strong influence on the structure and electrochemical properties of Li4Ti5O12.     

Effect of Sr on microstructure and aging behavior of Mg–14Li alloys

The as-cast and as-extruded Mg–14 wt%Li–x Sr ( x=0.14, 0.19, 0.39 wt%) alloys were,respectively, prepared through a simple alloying process and hot extrusion. The effects of Sr addition on microstructure and aging behavior of the Mg–14 wt%Li–xSr alloys were studied. The results indicated that β(Li) and Mg2Sr were the two primary phases in the microstructures of both as-cast and as-extruded Mg–14 wt%Li–xSr alloys. Interestingly, with the increase of Sr content from 0.14 wt% to 0.39 wt%, the grain sizes of the as-cast and as-extruded Mg–14 wt%Li–xSr alloys markedly decreased from 5000mm and 38mm to 330 mm and 22mm respectively, while no obvious changes of the micro-hardness and microstructure of the as-extruded alloys were observed during the aging treatment.     

Effect of Y_2O_3 content in the pack mixtures on microstructure and oxidation resistance of B–Y modified silicide coating

B–Y modified silicide coatings were prepared on Nb–Si based alloy by pack cementation at 1300 ℃ for 10 h. The effect of Y_2O_3 content in the pack mixtures on microstructure and oxidation resistance of the coatings was investigated. The results show that the four coatings have similar structures, which possess a(Nb,X)Si_2 outer layer and a(Nb,X)_5Si_3 transitional layer. Y_2O_3 content in the pack mixtures has an obvious effect on the Si content in the coating. The mass gains of the coatings prepared with 0.5, 1, 2 and 3 wt% Y_2O_3 in pack mixtures are 2.33, 1.96, 2.05 and 2.86 mg/cm~2 after oxidation at 1250 ℃ for 100 h, respectively. The coating prepared with 1 wt% Y_2O_3 exhibits the best oxidation resistance due to the formation of a dense glass-like borosilicate scale.     

Effect of Mn content on the microstructure and mechanical properties of Mg–6Li–4Zn-xMn alloys

The as-cast Mg–6Li–4Zn-x Mn alloys were prepared and extruded at 280℃ with an extrusion ratio of 25:1. The effects of Mn content on the microstructure and mechanical properties of Mg–6Li–4Zn-x Mn alloys were investigated in this study. The XRD results show that Mg–6Li–4Zn–x Mn alloys consisted of α-Mg(hcp) + β-Li(bcc)duplex structured matrix, Mg Li₂Zn and Mn phases. The grains of the extruded Mg–6Li–4Zn–x Mn alloys were refined by dynamic recrystallization during the extrusion process...     

Effect of bromization on the properties of a series of sub-stituted 1,8,15,22-tetra(2,4-ditertbutylphenoxy) phthalocyanines

As a novel kind of functional dyes, phthalocyanines and metallophthalocyanines have been attracting the at-tention of many scientists for many years. Recently, the chemistry of Pcs has been undergoing a renaissance because Pcs and many of their derivatives exhibit theirproperties for potential application in materials science[1,2 One of the main questions in the field of phthalocya-nines research is to modify the molecular structure re-placing the benzene-spherical hydrogen atoms by various s…     

Effect of Phosphatidylcholine on the Steady State Fluorescence of Chlorophyll in Photosystem Ⅱ Particles

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｐｈｏｔｏｓｙｎｔｈｅｓｉｓｌｉｇｈｔｒｅａｃｔｉｏｎｉｎ ｐｌａｎｔｓｏｃｃｕｒｓｉｎｔｈｅｔｈｙｌａｋｏｉｄｍｅｍｂｒａｎｅｏｆｔｈｅｃｈｌｏｒｏｐｌａｓｔｓ .Ｔｈｅｐｒｏｔｅｉｎｃｏｍｐｌｅｘｅｓｉｎｔｈｅｔｈｙｌａｋｏｉｄｍｅｍｂｒａｎｅｓａｒｅｓｕｐｅｒｍｏｌｅｃｕｌａｒｓｙｓｔｅｍｓｃｏｎｓｉｓｔｉｎｇｏｆ ｐｒｏｔｅｉｎｓ ,ｌｉｐｉｄｓａｎｄ ｐｉｇｍｅｎｔｓｗｈｉｃｈｒｅｇｕｌａｔｅａｎｄｃｏｎｔｒｏｌｔｈｅｌｉｇｈｔｅｎｅｒｇｙａｂｓｏｒｐｔｉｏｎ ,…     

Effect of Mn cluster on the formation of superoxide radicals in photoinhibition of photosystem Ⅱ

To further realize the action of superoxide radicals (O₂^{− .}) in photoinhibition of photosystem Ⅱ (PSⅡ), we employed 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap, associated with EPR spectroscopy, to study the effect of illumination time on O₂^{− .} formation during high light photoinhibition in PSⅡ membranes and Mn-depleted PSⅡ membranes. Results indicated that the removal of Mn cluster from PS
membranes has a strong influence on the dynamics of superoxide formation. The relative mechanism was also discussed. These novel findings may further promote the studies of the structure and function of PSⅡ and the mechanism of photoinhibition.     

Effect of flapping trajectories on the dragonfly aerodynamics

Insects cannot provide enough lift force to keep them afloat according to the conventional aerodynamics. But in fact they can not only perform the free flight, but also perform the maneuver activities such as fast take-off, suspending, back flight, etc. D…