纳米银粒子在高岭石层间的合成与表征

以高岭石-二甲基亚砜作为前驱体,用硝酸银层间取代,以高岭石的层间作为反应器来控制银粒子的大小,采用还原剂水合肼还原出单质银,制备高岭石-纳米银复合物。由红外光谱研究可知,插层作用破坏了层间氢键,二甲基亚砜与高岭石的外羟基形成了氢键,银的插入使得高岭石在2θ=38.1108～38.3942°之间出现了一个陡峭Ag(111)的衍射峰。TEM研究表明,Ag已进入层间,但粒度分布不均匀。     

On-column coaxial flow chemiluminescence detection for underivatized amino acids by pressurized capillary electrochromatography using a monolithic column

A new method for pressurized capillary electrochromatography (pCEC) coupling with chemiluminescence (CL) detection using a modified on-column coaxial flow detection interface was developed. To evaluate the feasibility and reliability of the experimental setup, the typical CL compounds luminol and isoluminol were separated and detected by using this pCEC-CL system. A detailed investigation of CL detection interface and postcolumn CL reagent flow rate parameters was described. The excellent resolution and detection sensitivity was achieved by using 3-microm ODS-C18 packed column with 30% ACN (v/v), 5 mmol/L phosphate buffer (pH 8.0). Moreover, with the presence of Co(II) (1.0 x 10(-4) mol/L) in the mobile phase, the linear range of the concentration for luminol was 2.0 x 10(-9)-2.0 x 10(-6) mol/L with a detection limit (S/N = 3) of 2.0 x 10(-10) mol/L, and 2.5 x 10(4) theoretical plates was achieved. In addition, separation and detection of the underivatized amino acids (l-threonine and l-tyrosine) were accomplished by using a polymerized monolithic column based on the principle of the luminol-H2O2-Cu(II)-amino acid CL system. Under the optimum conditions, the mixture of amino acids was efficiently separated with satisfactory results.     

模糊控制器在中央空调控制系统中的应用

分析了中央空调系统的特性，并对其各个部件建立数学模型，基于MATLAB环境下，利用simulink和fuzzy工具箱，对空调系统采用PID控制与模糊控制器的仿真比较，通过仿真结果显示，空调系统采用模糊控制具有较强的鲁棒性，波动小等优点。     

连续混炼过程比能耗分析

将连续混炼过程的有效比能耗分为升温、混炼、脱挥和建压比能耗,并提出了计算各项的一种方法。用该方法对不同机型、不同规格、不同加工对象的连续混炼机的比能耗进行了分析。结果表明,在多数连续混炼过程中,升温比能耗在总有效比能耗中所占比例都较大,建压比能耗所占比例都很小;原料热物性是影响有效比能耗及其构成的根本因素;当原料和混炼产物质量确定时,连续混炼机的螺杆与机筒结构、螺杆直径、产量、混炼工艺等都会影响有效比能耗及其构成。     

Shape‐Controlled Synthesis of High‐Quality Cu7S4 Nanocrystals for Efficient Light‐Induced Water Evaporation

Copper sulfides (Cu_2–xS), are a novel kind of photothermal material exhibiting significant photothermal conversion efficiency, making them very attractive in various energy conversion related devices. Preparing high quality uniform Cu_2‐xS nanocrystals (NCs) is a top priority for further energy‐and sustainability relevant nanodevices. Here, a shape‐controlled high quality Cu₇S₄ NCs synthesis strategy is reported using sulfur in 1‐octadecene as precursor by varying the heating temperature, as well as its forming mechanism. The performance of the Cu₇S₄ NCs is further explored for light‐driven water evaporation without the need of heating the bulk liquid to the boiling point, and the results suggest that as‐synthesized highly monodisperse NCs perform higher evaporation rate than polydisperse NCs under the identical morphology. Furthermore, disk‐like NCs exhibit higher water evaporation rate than spherical NCs. The water evaporation rate can be further enhanced by assembling the organic phase Cu₇S₄ NCs into a dense film on the aqueous solution surface. The maximum photothermal conversion efficiency is as high as 77.1%.     

An identification method of mechanical properties of materials based on the full‐field measurement method based on the fringe pattern

With the development of image processing technology, optical methods based on fringe patterns, for example, the grid method, electronic speckle pattern interferometry, moiré techniques (including moiré interferometry and digital moiré), and coherent gradient sensing, have become useful techniques for measuring the full‐field deformation of materials and structures. An important application of these techniques is to offer deformation fields for extracting constitutive parameters in the inverse methods. In this paper, we proposed a novel inversion method based on fringe patterns (IMFP), which can be used to identify constitutive model parameters by comparing simulated fringe patterns obtained using the finite element method with experimentally measured fringe patterns. The feasibility and identification accuracy of IMFP were evaluated through numerical experiments, and an additional series of numerical tests were conducted to analyse the noise immunity of IMFP and its sensitivity to the number of constitutive model parameters. Finally, IMFP was applied in the identification of the mechanical parameters of selective laser melting three‐dimensional printed stainless steel.     

Cause and pre-alarm control of bulking and foaming by Microthrix parvicella--a case study in triple oxidation ditch at a wastewater treatment plant

The cause and control of foaming and bulking in triple oxidation ditch at a wastewater treatment plant (WWTP) were investigated. The results showed that the foaming and bulking was mainly caused by the excessive propagation of Microthrix parvicella, and mostly occurred in the cold winter and spring. Batch and continuous flow experiments indicated that biological techniques such as reducing sludge retention time (SRT) and increasing F/M ratio, chemical methods such as addition of chlorine (NaOCl), quaternary ammonium salt (QAS), or cationic polyacrylamide flocculants (PAM), polyaluminum salt (PAC) could decrease Sludge Volume Index (SVI) and control foaming and bulking at different levels. In practical application, the shorter SRT was effective to control foaming and bulking in initial stage, although it took longer time. Addition of 10gClkgMLSSd(-1) could gradually change the activated sludge with serious foaming and bulking to normal state within a week. Pre-alert control strategies should be established for the control of filamentous foaming and bulking.     

机械活化淀粉反相乳液五元体系的接枝共聚反应动力学

以机械活化淀粉为接枝母体,研究了在机械活化淀粉/单体(AM)/乳化剂/油/水五元反相乳液体系中引发机械活化淀粉接枝丙烯酰胺共聚反应的动力学。分别考察了引发剂浓度、单体浓度、淀粉乳浓度和乳化剂浓度等对接枝量和接枝共聚速率(R g)的影响。结果表明,在本实验考察范围内的动力学关系式为R g∞[mSt]1.24[I]0.76[M]1.54[E]0.33,淀粉与丙烯酰胺的接枝共聚速率随体系温度升高而加快,淀粉乳浓度和单体浓度对接枝共聚速率影响显著,在45℃～60℃范围内,接枝共聚反应链增长步骤的活化能为34.85 kJ/mol。     

Direct measurement of the Raman enhancement factor of rhodamine 6G on graphene under resonant excitation

Graphene substrates have recently been found to generate Raman enhancement. Systematic studies using different Raman probes have been implemented, but one of the most commonly used Raman probes, rhodamine 6G （R6G）, has yielded controversial results for the enhancement effect on graphene. Indeed, the Raman enhancement factor of R6G induced by graphene has never been measured directly under resonant excitation because of the presence of intense fluorescence backgrounds. In this study, a polarization-difference technique is used to suppress the fluorescence background by subtracting two spectra collected using different excitation laser polarizations. As a result, enhancement factors are obtained ranging between 1.7 and 5.6 for the four Raman modes of R6G at 611, 1,183, 1,361, and 1,647 cm-~ under resonant excitation by a 514.5 nm laser. By comparing these results with the results obtained under non-resonant excitation （632.8 nm） and pre-resonant excitation （593 nm）, the enhancement can be attributed to static chemical enhancement （CHEM） and tuning of the molecular resonance. Density functional theory simulations reveal that the orbital energies and densities for R6G are modified bv ~raphene dots.     

结构性岩体的爆破破碎分形

讨论了结构性岩体内部结构和岩石破碎的分形特性，建立了岩体结构体的分布函数；用概率统计的方法证明了结构性岩体破碎的实质是一个分维数逐渐增加的分形过程，破碎体块度分布的分形特性是岩体结构性分形和破碎分形的必然结果。同时给出了结构体分形和破碎块度分形之间的关系。通过分析结构性岩体爆破破碎的模拟试验结果，进一步验证了文中的结论。