聚丙烯酸钠为结合相的梯度扩散薄膜技术预测甘蔗田土壤中镉的生物有效性

DGT技术一直以固态结合相原位采集和测量水体、土壤或沉积物中有效态重金属,液态结合相的DGT主要应用于现场水体中金属离子的检测.本研究分别采用固态结合相梯度扩散薄膜(chelex100-DGT)装置和改进的液态结合相梯度薄膜扩散(CDM-PAAS-DGT)装置,对广西甘蔗田土壤中有效态Cd进行了测定.结果表明,2种装置提取的土壤有效态Cd含量与甘蔗(根、茎、叶)体内Cd含量都呈极显著正相关,改进的CDM-PAAS-DGT装置对土壤中有效态Cd的提取能力更强;融合土壤pH、阳离子交换量(CEC)、有机质(OM%)和土壤颗粒组成等理化指标影响,运用多元统计分析,提取出2种主成分因子,建立了多元回归模型.液态结合相DGT技术能较好地预测甘蔗田土壤中Cd的生物有效性,拓展了其应用范围.     

Phosphorus removal from sediments by Potamogeton crispus: New high-resolution in-situ evidence for rhizosphere assimilation and oxidization-induced retention

Macrophytes are usually chosen for phytoremediation tools to remove P in eutrophic aquatic ecosystems, but the lack of test methods hinders the understanding of removal mechanism and application. In this study, we used the novel technologies combined of Diffusive gradients in thin films (DGT), Planar optode (PO), and Non-invasive micro-test technology (NMT) to explore P dynamics in water-sediment continuum and rhizosphere of Potamogeton crispus over time. Results of the high-resolution in situ measurement showed that labile P(LP_DGT) fluxes at the surficial sediment significantly decreased from approximate 120, 140, and 200 pg/ (cm²?sec) via 30 days incubation period to 17, 40, and 56 pg/(cm²?sec) via that of 15 days. Obvious synchronous increase of LP_DGT was not detected in overlying water, suggesting the intense assimilation of dissolve reactive P via root over time. PO measurement indicated that O₂ concentration around the rhizosphere remarkably increased and radially diffused into deeper sediment until 100% saturation along with the root stretch downwards. NMT detection of roots showed the obvious O₂ inflow into root tissue with the uppermost flux of 30 pmol/(cm²?sec) from surroundings via aerenchyma on different treatment conditions. Different from previous reports, gradually saturating O₂ concentrations around the rhizosphere was principally driven by O₂ penetration through interspace attributing to root stretch downward rather than root O₂ leakage. Increased O₂ concentrations in deep sediment over time finally induced the oxidization of labile Fe(II) into Fe(III) bound P and local P immobilization.     

Diffusive gradients in thin films (DGT) probe for effectively sampling of per- and polyfluoroalkyl substances in waters and sediments

The passive sampling technique, diffusive gradients in thin films (DGT) has attracted increasing interests as an in-situ sampler for organic contaminants including per- and polyfluoroalkyl substances (PFAS). However, its effectiveness has been questioned because of the small effective sampling area (3.1 cm²). In this study, we developed a DGT probe for rapid sampling of eight PFAS in waters and applied it to a water-sediment system. It has a much larger sampling area (27 cm²) and as a result lower method quantification limits (0.15 – 0.21 ng/L for one-day deployment and 0.02 – 0.03 ng/L for one-week deployment) and much higher (by > 10 factors) sampling rate (100 mL/day) compared to the standard DGT (piston configuration). The sampler could linearly accumulate PFAS from wastewater, was sensitive enough even for a 24 hr deployment with performance comparable to grab sampling (500 mL). The DGT probe provided homogeneous sampling performance along the large exposure area. The use of the probe to investigate distributions of dissolved PFAS around the sediment-water interface was demonstrated. This work, for the first time, demonstrated that the DGT probe is a promising monitoring tool for trace levels of PFAS and a research tool for studying their distribution, migration, and fate in aquatic environments including the sediment-water interface.     

水力冲孔技术在大倾角薄煤层中的应用

针对矿井现有防突措施的不足,介绍了水力冲孔技术的设备、工艺流程及现场试验情况.研究表明,在大倾角薄煤层应用水力冲孔技术,可有效地消除激发突出的应力,大幅度地释放煤体中的瓦斯,能明显提高瓦斯的抽采效果,很好地起到了综合防突的作用,且石门揭煤周期缩短为2个月.     

碳黑改性TiO2薄膜光催化剂的研制

通过掺杂碳黑来提高TiO2薄膜光催化剂的吸附性能，消除固定膜反应体系中经常出现的传质限制问题，使催化剂的活性由未经改性的3.2mg/L提高到4.8mg/L，相当于浓度为0.2g/L DegussaP25TiO2悬浮体系的效果，同时研究了影响催化剂活性的主要制备条件，获得的适宜制备条件为浓硝酸添加量1.0mL，热处理温度500℃，热处理时间2h，最佳涂覆次数为8次。     

电沉积ZnO膜光电催化降解4-硝基酚研究

用硝酸锌水溶液作电解质,采用阴极电沉积法在玻碳电极上制备了具有光电化学活性的氧化锌(ZnO)薄膜。以ZnO膜电极为工作电极对4-硝基酚进行了光电催化降解处理,系统研究了外加偏压、4-硝基酚浓度、电解液浓度以及pH值对4-硝基酚在ZnO膜电极上的光电催化降解效果的影响。结果表明:在外加偏压为1.0V,电解液浓度为0.1mol/L,溶液为近中性条件(pH为6.3)时对0.05mmol/L的4-硝基酚2小时的降解效率达到了98.8%。     

Detonation flows in aluminium particle gas suspensions,inhomogeneous in concentrations

A physical and mathematical model of the reduced kinetics is presented describing heterogeneous detonation in suspensions non-uniform in particle concentration. The model is based on the heterogeneous media approaches, semi-empirical laws of ignition and combustion, and data on the dependence of the detonation velocity on particle concentration. Formation of suboxides and incomplete combustion of aluminum are taken into account integrally. The dependence of the heat release of chemical reactions and the fraction of unburnt particles on the initial composition is determined from the solution of the stationary problem of the structure of the detonation wave. In the calculations of unsteady detonation flows, it is supposed to solve an additional equation for the spatial distribution of initial concentrations. The problems of initiation and development of cellular detonation in flat channels in suspensions of micron-sized aluminum particles are studied. Dependences of the cell size on particle concentration in uniform suspensions are determined. The flow patterns of cellular structures, the forms of the leading front, and the propagation velocities in channels with longitudinal or transversal gradients of particle concentration are analyzed.     

近距离薄煤层群上保护层开采邻近层卸压瓦斯抽采模式探究*

为研究近距离薄煤层群上保护层开采期间邻近层卸压瓦斯对回采工作面瓦斯涌出的影响,进而有效杜绝保护层开采过程中工作面瓦斯积聚或超限等事故,结合煤岩体破碎前“应力-裂隙-渗透率”间关系,建立卸压瓦斯三维渗流模型。采用Flac3D软件,以新维煤矿煤层条件为工程背景,研究保护层开采过程采场渗透率沿纵向分布规律,确立下保护层C3煤层处于三维增渗区、C7与C8号煤层处于水平增渗区。基于此,提出“近场定向钻孔全覆盖抽采与远场穿层钻孔层间卸压抽采结合”的瓦斯治理技术模式,并开展现场试验,结果表明:试验工作面回风瓦斯浓度降低44.4%,绝对瓦斯涌出量降低52.3%,该模式可显著提高卸压瓦斯的治理效果,为类似工况下的保护层开采提出1种新的瓦斯抽采模式,具有一定的指导及借鉴意义。     

Effects of CdCl2 thermal annealing on CdZnTe thin films deposited by close-spaced sublimation

采用近空间升华法制备了CdZnTe薄膜,并对其进行CdCl2退火,采用扫描电镜（SEM）、能谱仪（EDS）、X射线衍射仪（XRD）、紫外光谱仪、I-V测试仪等研究了退火对薄膜表面形貌、成分、结构以及光电性能的影响。结果表明,经过CdCl2退火后薄膜的晶粒尺寸明显增大,晶粒分布更加均匀;XRD分析结果显示,退火后薄膜的最强峰（111）峰的半峰宽变窄,薄膜沿（111）方向的择优取向明显增强;退火后薄膜的光学透过率降低,截止边红移,光学禁带宽度减小;薄膜的电阻率在退火后下降了两个数量级。     

利用秸秆微生物产絮凝剂的提取及性质分析

文章对一株利用秸秆粉——无机氮源培养基的细菌所产生的微生物絮凝剂进行了粗提和性质分析。该絮凝剂对于高岭土——氯化钙悬浊液的絮凝率达93.96%,效果较好。将该细菌接种在液体培养基中,于恒温摇床发酵培养,经测定,主要絮凝成分位于发酵液上清液中,对发酵液上清液进行热稳定性和pH稳定性实验,结果表明,该絮凝剂在室温25℃、pH为7条件下絮凝效果最好。采用乙醇法对发酵液上清液进行提取,即可得该微生物絮凝剂粗品。经Molish反应及茚三酮反应显色可知,该絮凝剂含有糖类及蛋白成分,经苯酚硫酸法测定其中糖含量占湿重的11.666%,经考马斯亮蓝法测定其中蛋白含量占湿重的0.586 4%,经薄层层析分析得,该微生物絮凝剂含有的主要糖类成分为阿拉伯糖。