Fabricating blazing grating on NGD by photochemical etching

This paper tries to introduce the reader to the method of using photochemical re-action to copy holographic optical elements(HOEs)in relief.The holographic blazing gratingso copied is groove depth adjustable phase modulability enlarged through copying and 3.3times the diffraction efficiency(DE)of the original grating.It is expected that the newmethod will lead to the mass production of the light-weight HOEs at low cost.     

Polymer-Nanoparticle Composites Composed of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Coated Silver Nanoparticles

The effects of addition of synthesized organic-suspension silver nanoparticles on the crystallization and thermal stability of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were studied by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD), UV-Vis absorption spectroscopy, polarized optical microscopy (POM), and thermal gravimetric analysis (TGA). The TEM images showed the average primary size of the as-synthesized silver nanoparticles, coated with a monolayer of the surfactants consisting of oleic acid and an alkylamine, was about 5 nm with narrow distribution, and that they were uniformly dispersed in n-heptane. PHBV/silver nanocomposites were prepared by melt mixing in an internal mixer and then injection molded into rectangle-shaped specimens by a labscale injection molding device. The coated silver nanoparticles showed a homogenuous dispersion in the PHBV matrix when the content of coated silver nanoparticles was about 1%. Both the DSC and POM data showed the efficient heterogeneous nucleation by the coated silver nanoparticles for facilitating PHBV crystallization. The thermal stability of the PHBV/silver nanocomposites improved with the increase in the content of the coated silver nanoparticles.     

关于广义三项指数和的四次幂均值

The main purpose of this paper is using estimates for trigonometric sums and properties of congruence to study the computation of one kind of fourth power mean of a generalized three-term exponential sum, and give an interesting identity for it.     

DNA aggregation and cleavage in CGE induced by high electric field in aqueous solution accompanying electrokinetic sample injection

The phenomenon of peak area decrease due to high injection voltage (V_inj, e.g. 10–30 kV, 200–600 V/cm in the 50 cm capillary) was found in the analysis of very dilute DNA fragments (<0.2 mg/L) by using high‐sensitive electrokinetic supercharging‐CGE. The possibility of DNA cleavage in aqueous solution was suggested, in addition to the aggregation phenomenon that is already known. The analysis of intentionally voltage‐affected fragments (at 200 V/cm) also showed decreased peak areas depending on the time of the voltage being applied. Computer simulation suggested that a high electric field (a few kV/cm or more) could be generated partly between the electrode and the capillary end during electrokinetic injection (EKI) process. After thorough experimental verification, it was found that the factors affecting the damage during EKI were the magnitude of electric field, the distance between tips of electrode and capillary (D_e/c), sample concentration and traveling time during EKI in sample vials. Furthermore, these factors are correlating with each other. A low conductivity of diluted sample would cause a high electric field (over a few hundred volts per centimeter), while the longer D_e/c results in a longer traveling time during EKI, which may cause a larger degree of damage (aggregation and cleavage) on the DNA fragments. As an important practical implication of this study, when the dilute DNA fragments (sub mg/L) are to be analyzed by CGE using EKI, injection voltage should be kept as low as possible.     

Cooling crystallization of aluminum sulfate in pure water modulated by sodium dodecylbenzenesulfonate

This study investigated the cooling crystallization of aluminum sulfate to explore the basic data for the recovery of aluminum resources from coal spoil. Cooling crystallization process of aluminum sulfate with sodium dodecylbenzenesulfonate (SDBS) was investigated experimentally. The effects of operating conditions, namely rotate speed and cooling rate on the crystal size (Median diameter, D_0.5) were studied. Based on single factor experimental results, the response surface method (RSM) with a Box–Behnken design (BBD) was used to determine the key operating conditions, from which a predictive equation was established to quantitatively describe the relationships of D_0.5 and there relative parameters. The optimum operating conditions for cooling crystallization of aluminum sulfate were as follows: rotate speed of 200–300 rpm, cooling rate of 4–5 °C /min and n (SDBS)/n (Al₂(SO₄)₃) of around 5E‐4. Molecular dynamics (MD) results reveal that SDBS decreases the diffusion coefficient (D) of Al³⁺ molecules, which inhibits nucleation and promotes crystal growth.     

冶炼厂烟囱降尘农田土壤重金属含量及潜在生态风险评价

摘要：为了研究冶炼厂下风向烟囱降尘对农田土壤重金属污染影响程度,以济源市某一冶炼厂工业烟囱下风向降尘覆盖农田土壤为研究对象,依次对距离该厂烟囱大约为750m-3000m的7个农田研究区（P1-P7）土壤中重金属（Hg、As、Pb、Cd、Cu、Zn、Ni、Cr、）含量进行污染状况分析,采用了单项潜在生态风险指数法和综合潜在生态风险指数法对冶炼厂下风向烟囱降尘土壤中重金属的潜在生态风险进行评价。结果表明：在3 km2研究区域范围内,距离冶炼厂越近土壤重金属含量越高,Pb、Cd为重度污染,超过了《土壤环境质量农用地土壤污染风险管控标准》（GB15618-2018）农用地土壤污染风险管制值的1.2倍,距离冶炼厂烟囱下风向P1区土壤中重金属As、Pb、Cd、Cu、Zn超过土壤环境质量农用地土壤风险筛选值,Cd 在浓度值均超过农用土壤污染风险管制值1.8倍,As元素平均浓度值超农用土壤污染风险管制值1.7倍,Pb、Cu和Zn污染较严重,Cd、Hg对综合指数（RI）贡献值较大分别为68.63和22.4。单项潜在生态风险指数评价结果显示Cd存在极严重的潜在生态风险,Pb、Cu存在较严重潜在生态风险,冶炼厂下风向土壤中综合潜在生态风险指数评价显示,冶炼厂下风向降尘土壤重金属具有较强的生态风险。     

重量法测定土壤水溶性盐总量的优化

土壤水溶性盐是表征土壤盐碱化程度的重要指标,也是评价耕地地力的重要参数,被纳入第三次全国土壤普查（“三普”）监测指标体系中。重量法是测定土壤水溶性盐总量的最常用方法,其测定过程易受多种因素影响,导致其测定结果不准。鉴于此,本文设计试验分别验证了水溶性盐浸提和浸提液固液分离这两个过程对测定结果的影响,结果表明浸提液固液分离是影响土壤水溶性盐总量测定准确度和精密度的主要因素。基于此进一步探究4种不同固液分离方式（布氏漏斗过滤、滤膜真空抽滤、离心、滤纸组合过滤）对测定结果的影响,结果表明相较于其它方式,滤纸组合过滤测定结果准确度高,适用于土壤水溶性盐总量的测定。对改进后的重量法测定土壤水溶性盐总量进行方法学确认,结果表明其检出限为0.01 g/kg,测定下限为0.04 g/kg;方法的准确度和精密度、适用范围等均符合相关要求。本文推荐的土壤水溶性盐总量测定方法为：土壤样品采用1:5土水比浸提,180 r/min振荡3 min,浸提液采用滤纸组合自然过滤;其测定结果的准确度和精密度符合相关要求。本文旨在为“三普”内业检测提供参考和借鉴,为全面摸清不同区域土壤水溶性盐含量水平及土壤盐渍化程度提供技术支撑。     

Layer-by-layer assembly of microcapsules and their biomedical applications

Nanoengineered multifunctional capsules with tailored structures and properties are of particular interest due to their multifunctions and potential applications as new colloidal structures in diverse fields. Among the available fabrication methods, the layer-by-layer (LbL) assembly of multilayer films onto colloidal particles followed by selective template removal has attracted extensive attention due to its advantages of precise control over the size, shape, composition, wall thickness and functions of the obtained capsules. The past decade has witnessed a rapid increase of research concerning the new fabrication strategies, functionalization and applications of this kind of capsules, particularly in the biomedical fields such as drug delivery, biosensors and bioreactors. In this critical review, the very recent progress of the multilayer capsules is summarized. First, the advances in assembly of capsules by the LbL technique are introduced with focus on tailoring the properties of hydrogen-bonded multilayer capsules by cross-linking, and fabrication of capsules based on covalent bonding and bio-specific interactions. Then the fabrication strategies which can speed up capsule fabrication are reviewed. In the following sections, the multi-compartmental capsules and the capsules that can transform their shape under stimulus are presented. Finally, the biomedical applications of multilayer capsules with particular emphasis on drug carriers, biosensors and bioreactors are described (306 references).