湖南镇水电站左坝肩地下水质酸性化的成因机理分析

文章在论述地下水主要水化学特征的基础上,分析了地下水质酸性化的形成机理。认为研究区地下水质的酸性化主要发生于地下水位季节变化带内,与岩体中黄铁矿的氧化作用密切相关;不同部位岩体中硫化物含量的高低造成了产酸作用的差异,而后者则导致不同部位间地下水质的差异。所建的化学热力学模型模拟结果表明,在地下水质呈强酸化的部位,水-岩系列间的相互作用具有较大的反应动力。对如何防治酸性水提出了建议。

二循水质酸性原因分析及对策

对二循循环水水质出现酸性的原因进行了理论分析。在排除系统漏酸的可能后 ,指出氨及硫化物等碱性介质的泄漏是导致水质出现酸性的主要原因 。

某电站地下厂房地下水质酸性化成因机理分析

地下厂房的开挖改变地下水的赋存条件,使地下水状态发生改变。地下水酸性化主要与岩体中黄铁矿的氧化作用密切相关,不同部位岩体中硫化物含量的高低造成产酸作用的差异,也造成地下水质的差异。

沙陇水库酸性水质的影响因素分析

沙陇水库酸性水质已经影响到当地的工农业生产和居民生活,为了查清该水库酸性水质的影响因素以指明下一步的防治方向,受瑞金市环境保护局委托,本文通过现场调查及采集土壤和水体样品、实验室分析化验等手段,在初步了解沙陇水库及周边土壤、水体环境状况的基础上,采用定性-半定量的评价方法,得出沙陇水库水质酸化的根本影响因素为高含硫的区域地质环境背景条件和主要诱发因素为未采取有效保护措施的露天采矿活动的结论,并针对水库水质现状提出了相应的防治建议。

如何改造酸性鱼塘

在渔业生产实践中，发现有些新开挖的鱼塘，施放绿肥沤不烂，塘水透明见底，养的鱼长得慢而且瘦，有时还会死鱼。究其原因，主要是由于鱼塘水质酸性大而引起的。对这些酸性鱼塘。要进行改造，才能夺取渔业丰收。

如何改造酸性渔塘

在渔业生产实践中,发现有些新开挖的渔塘,施放绿肥沤不烂,塘水透明见底,养的鱼长得慢而且瘦,有时还会死鱼。究其原因,主要是由于渔塘水质酸性大而引起的。对这些酸性渔塘,要进行改造,才能夺取渔业丰收。

巧改酸性鱼塘

在渔业生产实践中，发现有些新开挖的鱼塘，施放绿肥沤不烂，塘水透明见底，鱼长得慢而且瘦，有时还会死鱼。究其原因，主要是由于鱼塘水质酸性大而引起的。对这些酸性鱼塘，要进行改造，才能夺取渔业丰收。

水质酸度对甜菜苗期几项生理指标的影响

用不同酸度的水质喷洒甜莱苗期植株,结果表明,甜菜的细胞透性增加,细胞 pH 值、原生质等电点、细胞的缓冲客量、耐酸力、抗坏血酸氧化酶和多酚氧化酶的活性均降低。对各项生理指标变化的原因进行了一定的分析和讨论。

柔性脂质体的促渗作用研究(英文)

In this article different types of ultradeformable liposomes were designed and the properties of transdermal delivery were studied with sodium salicylate as model drug. These results showed that liposomes with strong hydrophilic surfactant added is a new type of penetration enhancer.

125TSW型离心水泵轴套的维护

叙述了 1 2 5 TSW型离心水泵的工作条件及其结构 ,对其轴套损坏的原因进行了分析 。

Effects of Composted and Thermally Dried Sewage Sludges on Soil and Soil Humic Acid Properties

The effect of annual additions of composted sewage sludge (CS) and thermally dried sewage sludge (TS) at 80 t ha-1 on soil chemical properties was investigated for three years in a field experiment under semiarid conditions. Humic acids (HAs) isolated by conventional procedures from CS, TS, and unamended (SO) and sludge amended soils were analysed for elemental (C, H, N, S and O) and acidic functional groups (carboxylic and phenolic) and by ultraviolet-visible, Fourier transform infrared and fluorescence spectroscopies. With respect to CS, TS had similar pH and total P and K contents, larger dry matter, total organic C, total N and C/N ratio and smaller ash content and electrical conductivity. Amendment with both CS and TS induced a number of modifications in soil properties, including an increase of pH, electrical conductivity, total organic C, total N, and available P. The CS-HA had greater O, total acidity, carboxyl, and phenolic OH group contents and smaller C and H contents than TS-HA. The CS-HA and TS-HA had larger N and S contents, smaller C, O and acidic functional group contents, and lower aromatic polycondensation and humification degrees than SO-HA. Amended soil-HAs showed C, H, N and S contents larger than SO-HA, suggesting that sludge HAs were partially incorporated into soil HAs. These effects were more evident with increasing number of sludge applications.

Modifying the acidity of H-MOR and its catalytic carbonylation of dimethyl ether

Among the reactions catalyzed by zeolites there are some that exhibit high selectivity due to the spatial confinement effect of the zeolite framework.Tailoring the acidity,particularly the distribution and location of the Bronsted acid sites in the zeolite is effective for making it a better catalyst for these reactions.We prepared a series of H-mordenite（H-MOR） samples by varying the composition of the sol-gel,using different structure directing agents and post-treatment.NH3-TPD and IR characterization of adsorbed pyridine were employed to determine the amount of Bronsted acid sites in the 8-membered ring and 12-membered ring channels.It was shown that controlled synthesis was a promising approach to improve the concentration of Bronsted acid sites in MOR,even with a low Al content.Using an appropriate composition of Si and Al in the sol-gel favored a higher proportion of Bronsted acid sites in the 8-membered ring channels.HMI as a structure-direct agent gave an obvious enrichment of Bronsted acid sites in the 8-membered ring.Carbonylation of dimethyl ether was used as a probe reaction to examine the modification of the acid properties,especially the Bronsted acid sites in the 8-membered ring channels.There was a linear relationship between methyl acetate formation and the number of Bronsted acid sites in the 8-membered ring channels,demonstrating the successful modification of acid properties.Our results provide information for the rational design and modification of zeolites with spatial constraints.

Effect of Electrochemical Treatment in Aqueous Ammonium Bicarbonate on Surface Properties of PAN-based Carbon Fibers

The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Dynamic Contact Angle Analysis (DCAA). The results of characterization indicated that the oxygen and nitrogen contents in carbon fiber surface were significantly increased by electrochemical treatment, and amide groups was introduced onto it, which was related with the electrolyte. The AFM photographs illustrated that the roughness of the fiber surface was also increased. The wettibality of the fibers was improved after treatment because the surface energy especially the polar part of it was increased.

Change of Ecological Characteristics Due to Decrease of COD/SO_4^(2-) Ratio During Sulfate-reduction

In order to investigate the change of ecological characteristics due to the decrease of COD/SO_4^(2-) ratio during sulfate reduction, continuous-flew tests were conducted in an acidogenic sulfate-reducing reactor with molasses wastewater as sole organic carbon source and sodium snlfate as electron acceptor, and the change of pH value, oxidation reduction potential (ORP), volatile fat acids (VFAs), alkalinity (ALK) and the predominant populations with COD/SO_4^(2-) ratio decreasing from 4.2 to 2.0 were investigated. The experimental results demonstrated that, with decreasing COD/SO_4^(2-) ratio, ORP and ALK increased, pH value decreased, and the proportion of acetic acid in terminal products decreased significantly, and a stable -type microbial community with high COD/SO_4^(2-) ratio was converted into a sub -stable -type one with low COD/SO_4^(2-) ratio.

Hydrothermal synthesis and dielectric properties of lanthanum titanate ceramics

Lanthanum titanate （La2/3 TiO3） powders were synthesized by hydrothermal method based on the reaction of TiO2, La（NO3）3 and KOH at 160℃ for 24 h followed by the treatment of acidification. The microstructure, morphology and dielectric properties were investigated by using X-ray diffraction, scanning electron microscope, transmission electron microscope and impedance method. The results show that the La2/3TiO3 particles consist of nearly homogenous and lamellar grains. The particles can be sintered into porous ceramics above 1150℃. The dielectric properties of La2/3 TiO3 show that both the dielectric constant and the dielectric loss tangent decrease with the increase of frequency.

Comparative study on photocatalytic properties of TiO_2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic properties of TiO2 samples prepared in different pH conditions, TiO2 nanopartieles were prepared in acidic medium and basic medium by a hydrothermal process, respectively. The samples were characterized using XRD, TEM, BET, XPS, surface photovoltage spectroscopy （SPS） and field-induced surface photovohage spectroscopy （FISPS）. Effects of temperature and pH in the hydrothermal process on particle sizes, specific surface areas, and photoeatalytic properties of the TiO2 nanoerystalline were investigated. The experimental results indicate that the photocatalysis activity of TiO2 nanoparticles prepared in basic medium （ B-TiO2 ） is superior to that in acidic medium （ A-TiO2 ）, which is ascribed to the difference of surface state between A-TiO2 and B-TiO2.

Antioxidant Activity of Peptides Obtained from Cotton Ground Oil-Cake Proteins

Antioxidant activity of the peptides derived from proteins of defatted cottonseed kernels and cotton ground oil-cake by their enzymatic hydrolysis with acidic （Asp. niger） and neutral proteinases （Bac. amyloliquefaciens） was studied. Antioxidant activity of the derived peptides depended on the used proteins and enzymes. The peptides derived by using of neutral proteinase possessed higher antioxidant activity, in comparison with the peptides derived by acidic proteinases.

All-trans Retinoic Acid Induced the Differentiation of Human Glioma Cells

OBJECTIVE To observe the effect of all-trans retinoic acid （ATRA） on inducing human glioma MO59K cells differentiation and further explore the underlying molecular mechanisms.METHODS The expression of glial fibrillary acidic protein （GFAP） was detected by immunocytochemistry staining. The mRNA levels of GFAP, retinoid X receptor α（RXRα）, p21 were examined by semi-quantitative RT-PCR analysis. Luciferase activity assay was performed in the COS-7, MO59K cells to measure p21 promoter transcription activity.RESULTS ATRA could significantly enhance the expression and mRNA level of GFAP by immunostaining and RT-PCR （P〈0.05）. Simultaneously, the mRNA levels of RXRα and p21 were remarkably increased in dose-dependent manner by RT-PCR （P〈0.05）. Furthermore, luciferase assay confirmed that ATRA and RXRα could transactivate p21 promoter in COS-7 and glioma cells （P〈0.05）.CONCLUSION ATRA can induce differentiation of human glioma cells. The RXRα and p21 were activated during ATRAinduced differentiation process. This effect may be caused by directly RXRα-induced p21 gene transactivation. Our findings provide novel evidence for the future studies to explore the molecular mechanism of transcriptional regulation for glioma cell differentiation and cellular therapeutic approaches for glioblastoma.

如何改造酸性鱼塘

在渔业生产实践中，发现有些新开挖的鱼塘，施放绿肥沤不烂，塘水透明见底，养的鱼长得慢而且瘦，有时还会死鱼。究其原因，主要是由于鱼塘水质酸性大而引起的。对这些酸性鱼塘，要进行改造，才能夺取渔业丰收。

Study of Changes in Physiochemical Properties of Soil by the Addition of Cement

The effect of cement on physiochemical properties of three types of soils i.e garden soil, agricultural soil and roadside soil was investigated. The ordinary Portland cement was used. The amount of cement added to soil samples, as dry mass percentage was 20%. The results of analysis showed that the addition of cement is capable of bringing about changes in physiochemical properties of soil. The electrical conductivity and organic matter content in three soils get decreased by the addition of cement. While the pH, bulk density and water holding capacity of soils after the addition of cement gets increased. The soil found most suitable to be treated with cement was roadside soil. It was concluded that cement can be used to change the physiochemical properties of soil and this technique has great utility in improving the quality of problematic soils.