超高交联树脂吸附处理2,4-D含酚废水的研究

采取超高交联树脂NDA-150吸附处理2,4-二氯苯氧乙酸含酚生产废水,取得了良好的效果。通过静态吸附比较和动态吸附-脱附研究,确定了最佳工艺参数。原废水呈深红褐色,总酚质量浓度>16000mg/L,树脂吸附后出水无色透明,总酚质量浓度<0.5mg/L,达到国家排放标准。原废水酸化和高浓脱附液酸化处理,能回收大量的2,4-二氯酚和2,4-二氯苯氧乙酸。该工艺简单,操作方便,是一项具有环境效益和经济效益,值得推广的技术。     

面向客户体验的移动数据网络的测量分析系统及其应用

随着数据业务的丰富,现有的移动数据网络指标无法直接反映用户感知,必须建立面向客户体验的网络测量分析系统,从而有效刻画用户的业务感知.以流媒体业务为例,利用面向客户体验的网络测量分析系统,通过建立网络测试指标和客户感知指标之间的对应关系,探讨了基于客户体验的移动数据业务的的评测及进一步的优化.     

3-甲硫基-1-丙醇的合成研究

研究了以 3 氯 1 丙醇和甲硫醇钠为原料 ,在相转移催化剂四甲基溴化铵的作用下 ,在 0℃下反应 1h ,然后升温至 30℃ ,并在此温度下反应 0 .5h ,合成了 3 甲硫基 1 丙醇 ,并用气相色谱、红外光谱和气质联用对其结构进行了确定。该方法工艺简单 ,条件温和 ,反应时间短 ,易于工业化 ,环境污染少 ,也适应于合成其他甲硫基化合物。     

选择性螯合滴定法测定电镀液和镀层中铜的含量

本法先用ＥＤＴＡ螯合Ｃｕ＾２＋和其他金属阳离子，然后加入ＤＬ－半胱氨酸作为释放剂分解Ｃｕ－ＥＤＴＡ释放出的ＥＤＴＡ用Ｐｂ＾２＋标准溶液返滴定，以ＸＯ－ＭＴＢ－ＣＰＢ为混合指示剂，滴定终点颜色变化敏锐，测定结果准确，并对多种金属离子的干扰进行了研究。     

First-Principles Study of the High-Temperature Behaviors of the Willemite-Ⅱ and Post-Phenacite Phases of Silicon Nitride

The structural and elastic properties of the recently-discovered wⅡ- and δ-Si_3N_4 are investigated through the plane-wave pseudo-potential method within ultrasoft pseudopotentials.The elastic constants show that wⅡ- and δ-Si_3N_4 are mechanically stable in the pressure ranges of 0-50 GPa and 40-50 GPa,respectively.The α→wⅡ phase transition can be observed at 18.6 GPa and 300 K.The β→δ phase transformation occurs at pressures of 29.6,32.1,35.9,39.6,41.8,and 44.1 GPa when the temperatures are100,200,300,400,500,and 600 K,respectively.The results show that the interactions among the N-2s,Si-3s,3p bands(lower valence band) and the Si-3p,N-2p bands(upper valence band) play an important role in the stabilities of the wⅡ and S phases.Moreover,several thermodynamic parameters(thermal expansion,free energy,bulk modulus and heat capacity) of δ-Si_3N_4 are also obtained.Some interesting features are found in these properties.δ-Si_3N_4 is predicted to be a negative thermal expansion material.The adiabatic bulk modulus decreases with applied pressure,but a majority of materials show the opposite trend.Further experimental investigations with higher precisions may be required to determine the fundamental properties of wⅡ- andδ-Si_3N_4.     

雅鲁藏布江流域枯水期化学风化及 CO2 消耗

基于雅鲁藏布江流域枯水期干支流地表径流、泉水、地下水以及降水样品,对主要离子、pH、TDS和CO_2消耗进行分析,研究枯水期水化学特征及成因,并分析流域化学风化速率及CO_2消耗通量。结果表明:流域水体总体呈现弱碱性,地表径流TDS均值约为世界河流的2.3倍,和长江流域相似,但远低于黄河流域。岩石风化是地表径流离子来源的主要影响因素。碳酸盐风化、硅酸盐风化和蒸发盐风化分别占离子来源的46.3%、28.6%和21.3%,碳酸盐风化速率和硅酸盐风化速率分别为1.43t/(km~2·a)和1.11t/(km~2·a),对应的CO_2消耗速率为0.80×10~5mol/(km~2·a)和0.55×10~5 mol/(km~2·a),枯水期化学风化速率和CO_2消耗速率较小。     

Improved NSGA-Ⅱ algorithm based on the uniformly crowding distance

With the wide application and further study of the genetic algorithm in multi-objective optimization problems, the NSGA-Ⅱ has been one of the representative evolutionary algorithms for multi-objective optimization problems. Crowding distance in the NSGA-Ⅱ plays an important role in convergence and uniform distribution of the solutions, but the NSGA-Ⅱ does not fully take the effect of each individual and the whole population into consideration. To estimate the region density more reasonably so as to make the solution set more uniformly converge to the Pareto optimal front, we design a uniformly crowding distance operator based on the uniformly crowding range and Gini weight, and propose an improved NSGA-Ⅱ algorithm. Finally, the effectiveness of the proposed algorithm is verified by experiments on six multi-objective optimization test functions.     

高效液相色谱测定J酸及其在废水处理过程中的中控分析

建立了废水中J酸的高效液相色谱检测方法,并利用所建方法对J酸废水的处理进行控制分析.采用Krornasil-C18色谱柱分离,流动相为甲醇和水(含4 g/L的四丁基溴化铵)(体积比为35∶65),紫外检测波长为230 nm.结果表明,J酸的浓度在1.06~17.10 mg/L时线性关系良好(r=0.999 6),相对标准偏差为1.03%.该方法简便快速,结果准确,重现性好,可为J酸废水的处理提供较好的中控分析.     

三维电极／电Fenton法处理苯酚废水机理研究

目的确定三维电杉电Fenton法处理苯酚废水的最佳反应条件并探讨反应机理．方法设计正交试验确定最佳反应条件,对处理结果进行紫外光谱分析;采用叔丁醇验证·OH的存在．结果在最佳反应条件pH值3,电解电压为12V,极板间距为10．5cm,电解质投加质量浓度为1．2g/L,Fe^2＋投加浓度为0．9mmol／L条件下,苯酚最大去除率为97．38％．苯酚去除率影响因素大小为pH值〉电解电压〉Fe^2＋投加浓度〉极板间距〉电解质投加质量浓度．反应过程中,苯酚首先被降解为醌类化合物并进一步降解为其他中间产物,最终被氧化为小分子化合物．结论苯酚的去除主要是电极的直接氧化,·OH以及其他活性氧化物共同作用的结果,其中·OH对苯酚的降解起到主要作用．     

Dual-responsive shape memory hydrogels with self-healing and dual-responsive swelling behaviors

Shape memory hydrogels (SMHs) can fix the hydrogels in a provisional shape and restore the initial shape under external stimulation. Herein, a dual-responsive shape memory hydrogel with dual-responsive swelling and self-healing properties is presented in this work. The SMHs were fabricated by one-step emulsion copolymerization of acrylic acid (AAc), acrylamide (AAm) and stearyl methacrylate (SMA). Sodium alginate (SA) was introduced as an interpenetrating polymer in the network. With ionic cross-linking between -COO⁻ and Fe³⁺ or saline-reinforced hydrophobic association, the hydrogels can be fixed in a provisional shape, which can be restored by immersing the hydrogels in vitamin C solution or pure water, respectively. When the as-prepared hydrogels were immersed in FeCl₃ solutions, additional ionic cross-linking between Fe³⁺ and -COO⁻ could be formed, thus constructing the dual physically cross-linked (DPC) network, which endows the hydrogels with excellent fracture stress (2.6 MPa) and toughness (5.47 MJ/m³). Besides, the reversible physical cross-linkings endowed the hydrogel with outstanding self-healing capability. Furthermore, the pH and saline responsive swelling properties of the SMHs are additional fantastic properties. Therefore, we believe that this simple strategy provides a great opportunity for the preparation of SMHs with multiple intellectual performances.