裸露型岩溶区人类活动输入对地下河水化学的影响

地下河是西南岩溶水的重要赋存形式,在区域人畜供水中发挥重要作用,裸露型岩溶区因其特殊水文地质结构,地下河易受到人类活动输入的影响。利用水文地球化学分析、水化学演化图(Hydrochemical Facies Evolution Diagram,HFE-D)、环境同位素辨析等多手段研究人类活动输入对开阳地下河水化学的影响。结果表明:阴阳主要离子分别是HCO_(3)^(-)、SO_(4)^(2-)和Ca^(2+)、Mg^(2+),水化学类型为HCO_(3)-Ca·Mg,主要受控于岩石风化控制,但地下河系统中SO_(4)^(2-)、NO_(3)^(-)及Cl^(-)受到南部县城、垃圾填埋场和渣场输入的影响。HFE-D发现地下河下游始终处于受影响状态,δ^(34) S-SO_(4)^(2-)同位素表明SO_(4)^(2-)主要来源生活污水输入(71%),其次是大气降雨(22%)。δ^(15) N-NO_(3)^(-)-δ^(18) O-NO_(3)^(-)同位素计算显示NO_(3)^(-)主要来源于污水排放(42%)、大气降雨(37%)和农业输入(21%),地下河系统的开放性不利于氮素的反硝化降解。

煤层气群井排采地层水来源判识及其意义

为指导煤层气生产区煤层气井排采,以沁水盆地南部樊庄区块生产监测区为例,通过系统采样测试分析了不同时间节点煤层气井产出地层水样的离子浓度变化特征、溶解性总固体、电导率和总硬度的变化特征,判识了产出地层水的水质类型和水化学相。研究表明:产出地层水的离子浓度、溶解性总固体、电导率和总硬度呈现出波动性变化的特征,具有明显的一致性,地层水中离子浓度除受地层水来源、矿物和离子性质影响外,还受区域井间干扰形成条件下煤层气井产出地层水的流体场影响。产出地层水质类型主要为HCO3—Na型,部分为Cl—Na型,产出地层水水化学相主要为煤层水,部分煤层气井产出地层水水化学相为顶底板围岩水(砂岩或泥岩水)或混有顶底板围岩水的煤层水。生产监测区煤层气群井排采地层水来源的判识有利于指导煤层气生产区排采控制。

Correlation Analysis of Two Hydrochemical Factors Affecting the Distribution of Ceratopteris thalictroides in China

[ Objective] This study was to analyze the two hydrochemical factors affecting the distribution of Ceratopteris thalictroides, further to provide basis for its habitat protection and population restoration. [ Method ] Twenty two hydrochemical parameters of 22 sampling sites in China＇s tropical and subtropical zones were respectively averaged for calculating their variation coefficients, of which the two showing significant differences were used for multiple comparisons and correlation analyses via least significant difference and correlation coefficient. E Result ] The correlation coefficients of all the 22 tested hydrochemical parameters varied hugely, but only pH value and conductivity showed significantly differences in two water body （type A and type B）. Analysis of correlation presented that pH value were positively correlated with conductivity; further the multiple comparisons showed that the significant difference of pH value was higher than that of conductivity. [Conclusion] With regard to the two hydrochemical parameters showing significant differences, pH value influences the distribution of C. thalictroides more.

Kinetics of Formic Acid-autocatalyzed Preparation of Performic Acid in Aqueous Phase

Performic acid （PFA） is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed reaction. It was found that the intrinsic activation energies of PFA synthesis and hydrolysis were 75.2 kJ·mol^-1 and 40.4 kJ·mol^-1 respectively. The observed activation energy of PFA decomposition was 95.4 kJ·mol^-1. The experi-mental results indicated that the decomposition of PFA was liable to occur even at the ambient temperature. Both the spontaneous decomposition and the radical-introduced decomposition contributed to the decomposition of PFA.

Research on the relation between the geologic environment and the trace elements of underground water in Huaibei Coalfield

Based on testing the trace elements of the four main aquifers of underground water in Huaibei Coalfield by using the ICP-MS in the University of Science and Tech- nology of China(USTC), the relation of trace elements of the four main aquifers was analyzed by using maximum correlation coefficient method. The study indicates that the different aquifers posses respective microelement distributional characteristics, which caused with average contents of trace elements in the different aquifers are related to the pH of the underground water and the contents of trace elements of the wall rock source in the research area, so researching on the distribution of geographic space and the change trend of hydro-geochemical character of different aquifers and the relation of the geologic environment and the trace elements conduce to establish the disciminand model of water inrush source.

Measurement and Correlation of Partition Coefficients of Baicalin in EOPO/Salt Aqueous Two-Phase Systems

The partition coefficients of baicalin were measured in ethylene oxide and propylene oxide (EOPO)/salt aqueous two-phase systems at 298.15K. It was found that most of baicalin partitioned into EOPO-rich phase. The partition coefficients of baicalin varied from 10 to 120. The effect of various factors, including tie-line length, salt composition, molecular weight of EOPO, and solution pH, on the partition behavior was investigated in EOPO/salt systems. Furthermore the partition coefficients of baicalin were correlated using the modified Diamond-Hsu model. Good agreement with experimental data is obtained. The average relative deviations are less than 5.0%.

Fibrous TiO_2 prepared by chemical vapor deposition using activated carbon fibers as template via adsorption,hydrolysis and calcinations

TiO2 fibers were prepared via alternatively introducing water vapor and Ti precursor carried by N2 to an APCVD （chemical vapor deposition under atmospheric pressure） reactor at ≤200 ℃. Activated carbon fibers （ACFs） were used as templates for deposition and later removed by calcinations. The obtained catalysts were characterized by scanning electron micros- copy （SEM）, transmission electron microscopy （TEM）, Brunauer, Emmett and Teller （BET） and X-ray diffraction （XRD） analysis The pores within TiO2 fibers included micro-range and meso-range, e.g., 7 nm, and the specific surface areas for TiO2 fibers were 141 m^2/g and 148 m^2/g for samples deposited at 100 ℃ and 200℃ （using ACFI700 as template）, respectively. The deposition temperature significantly influenced TiO2 morphology. The special advantages of this technique for preparing porous nano-material include no consumption of organic solvent in the process and easy control of deposition conditions and speeds.

Kinetic and Phase Behaviors of Catalytic Cracking Dry Gas Hydrate in Water-in-Oil Emulsion

The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion. The effect of temperature, pressure and initial gas-liquid ratio on the hydrate formation was studied, respectively. The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatur.es from 274.15 to 277.15 K. The results showed that hydrogen and methane can be separated Irom the （~2＋ ti＇action by tOrming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method, and the hydrate formation rate can be enhanced in the wa- ter-in-oil emulsion compared to pure water. The experiments provided the basic data for designing the industrial process, and setting the suitable operational conditions. The measured data ot gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.

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.

Water wettability in nanoconfined environment

Water confined in nanoscale space behaves quite differently from that in the bulk.For example,in biological aquaporins and in carbon nanotubes,the traversing water molecules form a single file configuration.Water would stay in vapor state in extremely hydrophobic narrow nanopores owing to the physicochemical interactions between the water molecules and the surface of the nanopore.A spontaneous wet-dry transition has been identified in both biological and artificial nanopores.The nanopore is either fulfilled with liquid water or completely empty.Based on this mechanism,the wetting and dewetting processes inside nanopores have been further developed into highly efficient nanofluidic gates that can be switched by external stimuli,such as light irradiation,electric potential,temperature,and mechanical pressure.This review briefly covers the recent progress in the special wettability in nanoconfined environment,water transportation through biological or artificial nanochannels,as well as the smart nanofluidic gating system controlled by the water wettability.

The use of graphene oxide membranes for the softening of hard water

Strong chemical interactions between the oxygen-containing functional groups on graphene oxide(GO)sheets and the ions of divalent metals were exploited for the softening of hard water.GO membranes were prepared and evaluated for their ability to absorb Ca2+and Mg2+ions.These GO membranes can effectively absorb Ca2+ions from hard water;a 1 mg GO membrane can remove as much as 0.05 mg Ca2+ions.These GO membranes can be regenerated and used repeatedly.

Electrochemically sensitive supra-crosslink and its corresponding hydrogel

In this work, through inclusion complexation between cyclodextrin (CD) host and ferrocene (Fc) guest, a monomer with double bond was incorporated to the surface of CdS quantum dot (QD). The obtained supra-structure could act as a supra-crosslink (Fc-SCL) in its copolymerizing with N,N-dimethylacrylamide (DMA) leading to a hybrid supramolecular hydrogel (Fc-Gel). Fc-SCL inherited satisfactory electrochemical activity from Fc. When the weight percentage of Fc-SCL in Fc-Gel was increased, an apparent increase of elastic modulus (G ′) was observed. Furthermore, Fc-Gel also exhibited good fluorescent properties. It was also demonstrated that the inclusion complexation of CD and Fc played a crucial role in constructing the hydrogel; therefore, this Fc-Gel was an organic-inorganic hybrid hydrogel induced by supramolecular interaction.