高掺量粉煤灰矿渣水泥胶凝材料水化物相的研究

采用工业废渣粉煤灰和矿渣为主要原料 ,通过掺加适当比例的自制复合活性激发剂 ,配制和研究高掺量粉煤灰矿渣水泥胶凝材料。运用扫描电子显微镜 (SEM )、X射线衍射 (XRD)和差热分析 (DTA)等手段研究了胶凝材料的水化物相。结果表明 。

水灰比对热环境中混凝土早期水化物相组成与强度发展的影响

大体积混凝土内部水化热以及制品的外部热源养护使得胶凝材料早期水化反应处在一定的温度场中,其物相组成与强度发展不同于常温养护。通过试验研究不同水灰比混凝土在不同环境温度下的早期水化物相组成和强度发展历程,采用劈裂抗拉强度与抗压强度的比值评价其脆性。试验结果表明,随着环境温度的提高,不同水灰比混凝土抗压强度呈现增长趋势。不同水灰比混凝土的劈裂抗拉强度在50℃环境温度下最高,温度继续升高,劈裂抗拉强度呈现降低趋势,且低水灰比混凝土劈裂抗拉强度降低明显。在较低温环境下,水灰比对水泥石物相组成几乎没有影响;而在较高温环境中,水灰比不同,水泥石物相组成也不相同。

基于纳米压痕技术的蒸养高强水泥浆体微观力学性能试验研究

为从微观尺度上理解铁路预制构件蒸养混凝土力学特性,论文采用纳米压痕试验及其统计分析技术,以铁路预制构件常用的C60混凝土为基础,研究了相同水灰比蒸养高强水泥浆体主要水化物相的力学性能,比较分析了蒸养和标养条件对浆体各物相的力学性能的影响。研究表明,养护条件对水泥浆体中各主要水化物相的力学性能及体积含量有较大影响;相较于标养条件,蒸养条件下高强水泥浆体的低密度和高密度CSH凝胶的压痕模量稍大,且高密度CSH凝胶数量明显增多,而Ca(OH)2晶体的压痕模量则偏低。

Aromatic Compounds Production from Sorbitol by Aqueous Catalytic Reforming

The rules on regulating aromatic compounds production was investigated by aqueous cat- alytic reforming of sorbitol. It was found that aromatics, ketones, furans, organic acids were main compounds in organic phase. The obvious effect of metal content showed that the highest carbon selectivity of aromatics was 34.36% when 3wt% Ni content was loaded on HZSM-5 zeolite modified by MCM-41. However, it was decreased only to 4.82% when Ni content was improved to 20wt%. Meanwhile, different reaction parameters also displayed important impacts on carbon selectivity. It was improved with the increase of temperature, while it was decreased as liquid hourly space velocity and hydrogen pressure was increased. The results showed that appropriate higher temperature, longer contact time and lower hy- drogen pressure were in favor of aromatics information, which suggested a feasible process to solve energy crisis.

Density Functional Study on Structures and Relative Stability of Gd（H2O）n^3＋ （n=8,9）

Density functional theory calculations were performed to study the structures and relative stability of the gadolinium complexes, Gd（H2O）n^3＋ （n=8,9）, in vacuo and in aqueous solution. The polarizable continuum model with various radii for the solute cavity was used to study the relative stability in aqueous solution. The calculated molecular geometries for n=8 and 9 obtained in vacuo are consistent with those observed in experiments. It was found that while the nona-aqua complex is favored in the gas phase, in aqueous solution the octa-aqua conformation is preferred. This result, independent of the types of cavities employed, is in agreement with the experimental observation. The reliability of the present calculation was also addressed by comparing the calculated and experimental free energy of hydration, which revealed that the UA0, UAHF, and UAKS cavities are most appropriate when only the first solvation shell is treated explicitly.

Measurements of Hydrate Equilibrium Conditions for CH4, CO2, and CH4＋C2H6＋C3H8 in Various Systems by Step-heating Method

Phase equilibrium conditions of gas hydrate in several systems were measured by the step-heating method using the cylindrical transparent sapphire cell device.The experimental data for pure CH4 or CO2+deionized water systems showed good agreement with those in the literatures.This kind of method was then applied to CH4/CO2+sodium dodecyl sulfate(SDS)aqueous solution,CH4/CO2+SDS aqueous solution+silica sand,and(CH4+C2H6+C3H8)gas mixture+SDS aqueous solution systems,where SDS was added to increase the hydrate formation rate without evident influence on the equilibrium conditions.The feasibility and reliability of the step-heating method,especially for porous media systems and gas mixtures systems were determined.The experimental data for CO2+silica sand data shows that the equilibrium pressure will change significantly when the particle size of silica sand is less than 96μm.The formation equilibrium pressure was also measured by the reformation of hydrate.

Exploration of the active phase of the hydrotalcite-derived cobalt catalyst for HCHO oxidation

A series of Co-based oxide catalysts were prepared by calcining hydrotalcite precursors in different atmospheres and studied for HCHO catalytic oxidation. The N2-calcined catalyst exhibits enhanced HCHO oxidation and superior stability. On the basis of H2-TPR, X-ray photoelectron spectroscopy, and Raman characterizations, this can be ascribed to better redox ability, octahedrally coordinated Co2+ ions derived from the CoO phase, and other surface oxygen species, such as O2– or O–. The extra octahedrally coordinated Co2+ ions may reside in a more open framework site than the inactive tetrahedrally coordinated Co2+ ions. This species of Co2+ can easily make contact with oxygen and oxidize. The surface oxygen species, along with the octahedrally coordinated Co2+ ions, and a part of the Co3+ species constitute the Co2+-oxygen species-Co3+ sites, which enhance the catalytic activities. According to DRIFTS, Co2+-oxygen species-Co3+ makes oxidation of HCHO and conversion of DOM to formate easier.

First and Second Laws Analyses of a Closed Latent Heat Thermal Energy Storage System

First and Second Law analyses were conducted to evaluate the performance of a closed latent heat thermal energy storage (LHTES) system employing calcium chloride hexahydrate (CaCl2·6H2O). The First and the Second Laws of thermodynamics were applied to the system from viewpoint of energy and exergy analyses, respectively. The energy storage tank in the system is neither fully mixed nor fully stratified. It may be considered as semithermal stratified. Experimente that include both charging and discharging periods were performed on sunny winter days in 1996. The energy and exergy variations and the overall energy and exergy efficiencies of the closed LHTES system were calculated for the complete charging and discharging cycle of the selected fifteen clear-sky winter days. Mean energy and exergy efficiencies were found to be 55.20% and 34.83%, respectively.

DFT Study of the Interaction of Cu（II）, Zn（II）, Sn（II） with Carbohydrates in Aqueous Solution

In the present work, authors studied the interaction between carbohydrates as ligands such as L1： fructose, L2： glucose and L3： sucrose with metal（II） halides such as CuCl2, ZnCl2, SnCl2. Also authors compare the stability of the metal-ligand bond strength. DFT （density functional theory） was utilized using the B3LYP functional and the 6-31G（d） basis set. This level of calculation was used for optimization of geometry of ligands and exploring electronic properties such as ionization potential （I）, electron affinity （A）, chemical potential （μ）, hardness （η）, band gap （HOMO （highest occupied molecular orbital）-LUMO （lowest unoccupied molecular orbital））. The local reactivity was analyzed by the fukui function indices and the indices local of nucleophilicity in order to predict the sites of attack of carbohydrates. In addition, the strength of interaction has been evaluated by energy lowering and charge transfer using DFT at the B3LYP level employing the basis set Lan2DZ. As a result, the sequence of high stability of metal-ligand bond for ligands is in the following order; sucrose 〉 glucose 〉 fructose. Furthermore, the sequence of high stability for metal halides is in the following order, CuCl2 〉 SnCl2 〉 ZnCl2. We advise person who carries a dental amalgam do not exceed the consommation of monosaccharides, because their complexes are not sufficiently stable and hence these ions are not ejected easily outside the human body.

Significance of serum tumor markers CA50 and CEA in gastric cancer

AIMS The CAS0 and CEA are well-described human tumor-as- sociated antigens most useful clinically in gastrointestinal cancer. In this study we compared these markers in sera from patients with malignant and benign digestive tract diseases. METHODS Using a side-phase radioimmunoassay,CA50 and CEA serum levels were measured in 33 control subjects and 86 patients with gastric cancer(n=34),gastric ulcer(n=27)and chronic atrophic gastritis(n=25).Carcinoma of the stomach was found in the antrum(n=22),in the body(n=3),and the fundus(n=9),and histopathologically,was divided into adeno- carcinoma(n=21),squamous cancer(n=4)and not divided (n=9).Gastric ulcer,when present,appeared in the antrun(18 patients),the body(3)and the fundus(9)and chronic atrophic gastritis was all associated with intestinal metaplasia(IM). RESULTS The normal ranges established for CA50 and CEA in the control group were 16.26+6.14 kU/L and 3.12±1.03/μg/L respectively.In the patients with gastric cancer,serum levels of CA50(112.67±38.36 kU/L)and CEA(10.28±3.76μg/L) were elevated significantly(P<0.01,respectively),the former being>22 kU/L in 18 of 34 patients(53%;range,5-1 550 kU/ L),and the latter>5 μg/L in 19 of 34 patients(55.8%,range, 0.5-17.4 μg/L).A statistically significant correlation was found between the levels of CA50 and GEA(r=0.648,P<0.01). The serum levels of CA50(46.4±25.9 kU/L,P<0.01 )and CEA(6.85±2.43 μg/L,P<0.01)were much lower in patients with gastric ulcer or chronic atrophic gastritis(P>0.05). CONCLUSIONS Based on these results,it is concluded that CA50 and CEA are indicators for advanced gastric cancer,and af- ter surgery,their serum levels may decrease considerably. Overall,there is such a close correlation between them that in clinical practice they might be of great value to the diagnosis of gastric cancer.

Effect of sample treatment on determination of arsenic （Ⅲ） and arsenic （Ⅴ） in aqueous and tissue samples by hydride generation atomic absorption spectrometry

The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic （Ⅲ） and arsenic （Ⅴ） in biological and environmental samples. The method is based on hydride generation and atomic absorption spectrometry. For both As （Ⅲ） and As （Ⅴ） the parameters such as NaBH4, HCI concentration, and pH were optimized. Absorption signal of As （Ⅴ） was approximately 17% of As （Ⅲ） signal. Therefore, for estimation of As （Ⅲ） and As （Ⅴ） concentrations in various samples the difference between the absorbance obtained for arsenic, without and with previous treatment of samples with potassium iodide （KI）, can be applied. The calibration graphs were linear （r〉0.99）, and the detection limits of the method based on three times the standard deviation of the blank were 0.14 and 0.64 μL^-1 for As （Ⅲ） and As （Ⅴ）, respectively. The relative standard deviation （R.S.D.） of measurements was less than 10%. As a means of checking performance method, water samples were spiked with known concentrations of both As （Ⅲ） and As （Ⅴ）, and recovery above 94% was obtained. The proposed method was applied successfully to determine inorganic As （Ⅲ） and As （Ⅴ） in various environmental and total As in biological samples.

Lewis base-assisted Lewis acid-catalyzed selective alkene formation via alcohol dehydration and synthesis of 2-cinnamyl-1,3-dicarbonyl compounds from 2-aryl-3,4-dihydropyrans

Acid-catalyzed dehydration of alcohols has been widely employed for the synthesis of alkenes. However, activated alcohols when employed as substrates in dehydration reactions are often pla-gued by the lack of alkene selectivity. In this work, the reaction system can be significantly improved through enhancing the performance of Lewis acid catalysts in the dehydration of activated alcohols by combining with a Lewis base. Observations of the reaction mechanism revealed that the Lewis base component might have changed the reaction rate order. Although both the principal and side reaction rates decreased, the effect was markedly more observed on the latter reaction. Therefore, the selectivity of the dehydration reaction was improved. On the basis of this observation, a new route to synthesize 2-cinnamyl-1,3-dicarbonyl compounds was developed by using 2-aryl-3,4- di-hydropyran as a starting substrate in the presence of a Lewis acid/Lewis base combined catalyst system.

Probing Molecular Interactions in 1-Butyl-3-methylimidazolium Chloride-Water and 2,6-Dimethoxyphenol Mixtures Using Attenuated Total Reflection Infrared Spectroscopy

Molecular interactions of the ternary mixtures of 1-butyl-3-methylimidazolium chloride （[C4C1im]Cl）-water-2,6-dimethoxyphenol （2,6-DMP, a phenolic monomer lignin model compound） were investigated in comparison with the [C4C1im]Cl-water binary systems through attenuated total reflection infrared spectroscopy. Results indicated that the microstructures of water and [C4C1im]Cl changed with varying mole fraction of [C4C1im]Cl （xIL） from 0.01 to 1.0. This change was mainly attributed to the interactions of [C4C1im]Cl-water and the self-aggregation of [C4C1im]Cl through hydrogen bonding. The band shifts of C-H on imidazolium ring and the functional groups in 2,6-DMP indicated that the occurrence of intermolecular interactions by different mechanisms （i.e., hydrogen bonding or π-π stacking） resulted in 2,6-DMP dissolution. In the case of xIL=0.12, the slightly hydrogen-bonded water was fully destroyed and [C4C1im]Cl existed in the form of hydrated ion pairs. Interestingly, the maximum 2,6-DMP solubility （238.5 g/100 g） was achieved in this case. The interactions and microstructures of [C4C1im]Cl-water mixtures influenced the dissolution behavior of 2,6-DMP.

Correlation of Critical Loci for Water-Hydrocarbon Binary Systems by EOS Based on the Multi-Fluid Nonrandom Lattice Theory

Quantitative representation of complicated behavior of fluid mixtures in the critical region by any of equation-of-state theories re-mains as a difficult thermodynamic topics to date. In the present work, a computational efforts were made for representing various types of critical loci of binary water with hydrocarbon systems showing Type II and Type III phase behavior by an elementary equation of state [called multi-fluid nonrandom lattice fluid EOS (MF-NLF EOS)] based on the lattice statistical mechanical theory. The model EOS requires two mo-lecular parameters which representing molecular size and interaction energy for a pure component and single adjustable interaction energy pa-rameter for binary mixtures. Critical temperature and pressure data were used to obtain molecular size parameter and vapor pressure data were used to obtain interaction energy parameter. The MF-NLF EOS model adapted in the present study correlated quantitatively well the critical loci of various binary water with hydrocarbon systems.

Numerical Simulation of Enhanced Oil-Water Separation in a Three-Stage Double-Stirring Extraction Tank

Numerical simulation of enhanced fluid flow characteristics in a three-stage double-stirring extraction tank was conducted with the coupling of an Eulerian multiphase flow model and a Morsi-Alexander interphase drag force model. Results show that the addition of a stirring device into the settler can efficiently reduce the volume fraction of out-of-phase impurity in the outlet, and accelerate the settling separation of oil-water mixture. Such addition can also effectively break down the oil-water-wrapped liquid droplets coming from the mixer, inhibit reflux from the outlet, and improve the oil-water separation. The addition of a stirring device induces ignorable power consumption compared with that by the mixer, and can thus facilitate the commercialized promotion of this novel equipment.

Physiological and Biochemical Changes Induced by PRD Irrigation in Four Olive Varieties

The present study was conducted to evaluate the effects of partial root-zone drying （PRD） irrigation technique on stomatal conductance （gs）, leaf water potential （qJpd）, leaf relative water content （RWC）, vegetative growth, fruit quality and enzymatic antioxidants of young plants of four Olea europaea L. varieties （Picholine Marocaine, Haouzia, Picholine Languedoc and Manzanilla） grown under arid conditions in Southern Morocco. In this irrigation strategy, a split-root technique was used to divide the root system of the plants in two parts. Two water regimes were used： （1） control, with both root compartments well watered; （2） PRD, with one compartment irrigated （50% of the control）, the other compartment was kept dry switching every 10 days. For all olive varieties studied, gs and the shoot length of the plants subjected to PRD decreased, whereas, Woo and RWC remained higher. The effect of PRD was similar among the four olive varieties, with their stomata closing in response to the water deficit before any significant changes in leaf water status were detectable. At the agronomic level, the benefits of PRD on olive were expressed by an earlier maturity and by higher values of olive fruit weight and dimensions, especially, in Manzanilla, which produced a fruit reaching 7.1 g and 2.6 cm, respectively. The enzymatic activities of soluble peroxidases （POX）, insoluble peroxidases （POXins）, polyphenoloxidase （PPO） and superoxide dismutase （SOD） were up-regulated under PRD. Picholine Marocaine and Haouzia showed higher enzymatic activities revealing that in these two varieties, PRD had possibly induced oxidative stress, which resulted in an up-regulation of the antioxidant activities of POXins, POX, PPO and SOD under water deficit.

The deubiquitinase UCHLS/UCH37 positively regulates Hedgehog signaling by deubiquitinating Smoothened

The Hedgehog （Hh） signaling pathway plays important roles in developmental processes including pattern formation and tissue homeostasis. The seven-pass transmembrane receptor Smoothened （Smo） is the pivotal transducer in the pathway; it, and thus the pathway overall, is regulated by ubiquitin-mediated degradation, which occurs in the absence of Hh. In the presence of Hh, the ubiquitination levels of Smo are decreased, but the molecular basis for this outcome is not well understood. Here, we identify the deubiquitinase UCHL5 as a positive regulator of the Hh pathway. We provide both genetic and biochemical evidence that UCHL5 interacts with and deubiquitinates Smo, increasing stability and promoting accumulation at the cell membrane. Strikingly, we find that Hh enhances the interaction between UCHL5 and Smo, thereby stabilizing Smo. We also find that proteasome subunit RPN13, an activator of UCHL5, could enhance the effect of UCHL5 on Smo protein level. More importantly, we find that the mammalian counterpart of UCHL5, UCH37, plays the same role in the regulation of Hh signaling by modulating hSmo ubiquitination and stability. Our findings thus identify UCHL5/UCH37 as a critical regulator of Hh signaling and potential therapeutic target for cancers.

A simple catalyst for aqueous phase Suzuki reactions based on palladium nanoparticles immobilized on an ionic polymer

Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show good catalytic activities for aryl iodides and aryl bromides and moderate activity with aryl chloride substrates. Coupling of sterically hindered substrates could also be achieved in reasonable yields. The heterogeneous catalyst is stable, can be stored without precautions to exclude air or moisture, and can be easily recycled and reused.