Very large scale droplet microfluidic integration (VLDMI) using genetic algorithm

Droplet microfluidics is likely to play a central role in the development of lab-on-a-chip technologies and as a result, significant research is directed toward this field. Understanding the spatiotemporal dynamics of discrete droplets inside microfluidic devices and the design of microfluidic devices for specific tasks are some of the dominant research topics. These works have since resulted in the development of microfluidic devices with functionalities, such as sorting, merging, synchronization, storing etc. However, the anticipated application of microfluidic devices to more complex problems will require more integrated devices that can incorporate the above functionalities on a single chip. In the current work, we present a genetic algorithm optimization-based design tool for discovering very large-scale integration of discrete microfluidic networks for a given objective function. The application of the algorithm is demonstrated through a combinatorial sequencing problem, where the objective is to achieve three different droplet combinatorial sequences for three different droplet types. Multiple fascinating, but nonobvious designs were discovered for this application. It is difficult to imagine such devices being designed using trial and error experimental procedure, which has been the main route for obtaining microfluidic device designs. With advances in technologies for fabrication of microfluidic devices, the current tool can be a significant step toward drastically cutting down on the laborious trial-and-error design process and help in developing droplet microfluidics-based lab-on-a-chip platforms cheaper and faster.     

EXTRACTION OF Ni(It) BY DI-(2-ETHYLHEXlfL)PHUSPHOKIC ACID DISSOLVED IN TOLUENE

ABSTRACT

The extraction of Ni(II) from 1.0 mol-dm^-3aqueous NaNO₃medium by di-(2-ethylhexyl) phosphoric acid (HDEHP) dissolved in toluene has been studieo as a function of the total extractant concentration, the equilibrium pH and the total raetal concentration in the aqueous phase. Nickel distribution data have been interpreted in terms of the formation of NiR₂(HR)₂, and NiR₂species in the organic phase in the low pH range anc by the formation of Na-HUEHP micelles, due to the neutralization of the reagent in the organic phase, and the further exchange of Na⁺by Ni²⁺in these micelles in the high pH range for each of the total extractant concentrations used.     

开车过程中中压吸收塔液位的判断和控制

我公司尿素装置采用意大利斯那姆氨汽提工艺,自1990年5月投料试车以来,因开车过程中控制不当造成中压吸收塔（C101）漫液、抽空、CO2上窜而导致装置停车的事故多次重复发生,可见C101液位控制的难度和重要性。     

制造玻璃器皿的H28机组(续)

(6)协调运转的控制--在固定的机器支承筒体上安置着为实现下列控制程序的诸凸轮扇形件:初型模气缸向上,压制气缸往下,压制气缸向上,初型模气缸往下[得凸轮片装在一公用的可活动的托架上,它们当机器运转(即"头"公转)时会通过相应的杠杆去驱去并调整各运动,压制时间便得到变更],预吹制,终吹制,颈环离合器,供水阀,吹气头往下,成型模打开.     

Apparent and Real Distribution in GPC (Experiments with PMMA Samples)

Abstract

Molecular weight distribution curves obtained by GPC are broadened if concentration and flow rate are fixed in the usual range. Therefore, the apparent nonuniformity U _app of the samples is larger than the real non-uniformity U = (M_w/M_n) ?1. For a number of fractionated and unfractionated samples of polymethyl methacrylate we determined M _n and M _w by osmotic, light-scattering, and viscosity measurements. Thus, the real value of U can be compared to U _app obtained by GPC at different concentrations and flow rates, υ. The excess nonuniformity U _exc is evaluated as function of concentration c, polydispersity, molecular weight, and flow rate. For c = 0 and υ = 0, U _exc is not far from zero. For standard conditions one certain value of the excess standard deviation of the elution volume allow calculation of U _exc for narrow and broader distributions and the obtaining of nearly correct values for the real nonuniformity U.     

用废PET醇解制墨粉树脂的研究

本实验主要研究了回收PET瓶片在催化剂和二元醇存在下,进行醇解和酯交换转化为各种不同组成具有端羟基低分子链段和二醇,进而醇解产物与反丁烯二酸酯化缩聚为用于墨粉树脂的聚酯。探索了从原料配比到反应工艺条件等多方面因素合成聚酯树脂的条件。利用聚酯回收料为原料醇解后直接合成墨粉用聚酯树脂的工艺简单、产品质量稳定、具有良好的经济效益和环保效应。     

稀土在搪瓷与玻璃中的应用(三)

4　玻璃的稀土澄清脱色4.1　氧化铈澄清剂在玻璃的熔制过程中,为了排除玻璃液中残留的微小气泡,在配合料中需要添加澄清剂。其作用是在玻璃熔化的澄清阶段分解放出氧气,将玻璃液中的小气泡扩大,逸出液面。氧化剂本身则由高价的氧化物变成低价态。氧化铈为变价氧化物。二氧...     

Explosives Detection Using Direct Analysis in Real Time (DART) Mass Spectrometry

The growing use of explosives by terrorists and criminals creates a need for instrumentation which can rapidly analyze these energetic compounds, preferably on site. Direct analysis in real time (DART) is a promising technology for surface analysis with little or no sample preparation. Therefore, DART ionization is evaluated for use in detecting explosives on solid substrates and in liquid matrices. Fifteen explosives were chosen as a consequence of their common usage. Five surfaces were chosen to represent a wide range of physical properties such as composition, porosity, surface morphology, and thermal and electrical conductivity. Additionally these surfaces are commonly found in everyday surroundings. All 75 compound‐surface combinations produced a clear, easily identifiable, mass spectra characteristic of the targeted analyte. Simultaneous detection of five explosives is demonstrated on these same surfaces. Lastly, rapid detection of trace contamination in common fluids is also explored.     

2-(对硝基苯氧基)三乙胺及其类似物的合成及植物生长调节作用的研究

以对硝基苯酚为原料 ,与 1,2 二氯乙烷在pH >10的氢氧化钠水溶液 ,在四丁基溴化铵作相转移催化剂 ,温度约 80℃的条件下反应约 2 0h ,直至对硝基苯酚反应完全 ,收率 85 %。所合成的中间体 1 氯 2 对硝基苯氧基乙烷再与二乙胺继续在氢氧化钠、水、甲苯为反应介质 ,四丁基溴化铵作相转移催化剂 ,温度约 90℃的条件下反应约 12h ,得产品 2 (对硝基苯氧基 )三乙胺 ,收率 95 %。使用相同的方法合成了中间体和最终产物的类似物。所得产品对水稻作了生物活性实验 ,结果表明 ,对水稻的生长发育有一定的促进作用 ,并提高了水稻的产量     

Delivery of Nucleotide Sugars to the Mammalian Golgi: A Very Well (un)Explained Story

Nucleotide sugars (NSs) serve as substrates for glycosylation reactions. The majority of these compounds are synthesized in the cytoplasm, whereas glycosylation occurs in the endoplasmic reticulum (ER) and Golgi lumens, where catalytic domains of glycosyltransferases (GTs) are located. Therefore, translocation of NS across the organelle membranes is a prerequisite. This process is thought to be mediated by a group of multi-transmembrane proteins from the SLC35 family, i.e., nucleotide sugar transporters (NSTs). Despite many years of research, some uncertainties/inconsistencies related with the mechanisms of NS transport and the substrate specificities of NSTs remain. Here we present a comprehensive review of the NS import into the mammalian Golgi, which consists of three major parts. In the first part, we provide a historical view of the experimental approaches used to study NS transport and evaluate the most important achievements. The second part summarizes various aspects of knowledge concerning NSTs, ranging from subcellular localization up to the pathologies related with their defective function. In the third part, we present the outcomes of our research performed using mammalian cell-based models and discuss its relevance in relation to the general context.     

Click Functionalization of Gold Nanoparticles Using the Very Efficient Catalyst Copper(I) (Hexabenzyl)tris(2‐aminoethyl)‐ amine Bromide

Whereas previous “click” functionalization (Huisgen‐type copper‐catalyzed alkyne‐azide cycloaddition, CuAAC) of various gold nanoparticles (AuNP) had systematically proven to be very difficult, tedious, providing low yields with the use of high amounts of copper sulfate+sodium ascorbate – the classic Sharpless catalyst, the new catalyst copper(I) (hexabenzyl)tris(2‐aminoethyl)amine bromide, {[Cu(I)(Hexabenzyl)Tren]Br} is shown here to be very efficient for the introduction of a large variety of organic, organometallic, dendronic and polymeric molecular fragments of various sizes, topologies and hydrophilicities. Indeed, 0.1–0.15 equiv. of this catalyst in toluene was used in each reaction under ambient conditions for 8 to 48 h with good yields without AuNP aggregation. The new functional AuNP have been characterized by ¹H NMR, IR and UV‐vis. (plasmon band) spectroscopy, cyclic voltammetry (CV), dynamic light scattering (DLS) and transmission electron microscopy (TEM).     

Curupira tefeensis (Olacaceae) — A Rich Source of Very Long Chain Fatty Acids

The fatty acid composition of the seed oil of Curupira tefeensis was analysed by capillary GC of their methyl esters. The gaschromatographic assignments were ensured by corresponding mass spectra. The oil is composed to more than 62% of very long chain fatty acids (>C18). Erucic acid is found to be the main component (35%). The position of the double bonds of the monounsaturated fatty acids (MUFAME) was verified after derivatization with dimethyl disulfide and subsequent GC/MS analysis. All identified MUFAME belong to the (n-9-)type. The UV-spectroscopical data show that approx. 1.2% conjugated acetylenic fatty acids occur in the oil. Furthermore IR- and NMR-spectroscopical investigations and the basic analyses of the seed were carried out.     

美轮美奂的玻璃性

把180份沙子、180分海藻灰和5份白垩土一起熔化,就形成了这种奇妙的液体——玻璃。玻璃是一种地位不高的材料,它不像塑料那么年轻,也不像木材那样有那么多舶来品。     

Very stable, highly electroactive polymers of zinc(II)-5,15-bisthienylphenyl porphyrin exhibiting charge-trapping effects

Two new thiophene-substituted porphyrins and their zinc complexes were synthesized and electropolymerized via thiophene units on different electrode surfaces. Electrochemical characterizations show that the resultant polythiophenemetalloporphyrin hybrid materials are highly electroactive and exhibit remarkable higher electrochemical stability. Interestingly, they exhibit a charge-trapping effect. A mechanism for the observed charge-trapping phenomenon was proposed and supported by using model compounds. The deposited polymer films on different electrode surfaces exhibit a homogeneous morphology and possess good processability (soluble in polar solvents such as DMSO or DMF). Besides electrochemical method, UV/vis, NMR, FTIR, TEM and SEM were employed to characterize the new hybrid material.     

浅谈玲珑瓷

玲珑,明彻的意思.玲珑瓷属于镂花的一种.许之衡:<饮流斋说瓷>记载:"素瓷甚薄,雕花纹而映出青色者谓之影青镂花,而两面洞透者谓之玲珑瓷."其制作方法是,先在生坯上按图案设计的花形,镂刻一个个小米孔,使之两壁洞透,有如扇扇小窗,然后糊上特制的透明釉,就像窗户糊纸一样,再通体施釉.     

Making lightweight SiC(rGO,xMoSi2) bulk ceramics via polymeric precursor route

Unique properties of MoSi₂ open new opportunities for preparing bulk polymer-derived ceramics (PDCs) displaying favorable structural-functional capabilities. Herein, an ingenious production route via re-pyrolysis process of ball-milling-induced rigid SiC(rGO, xMoSi₂)_p fillers/flexible polycarbosilane-vinyltriethoxysilane-graphene oxide (PCS-VTES-GO, PVG) precursors blends is proposed to obtain in situ formed SiC(rGO, xMoSi₂) bulk PDCs. Interestingly, the possible dense β-SiC/SiOxCy/C_free(rGO, xMoSi₂) framework suffers load and tiny microsized pores relaxes stress, which is beneficial to providing optimized hardness and fracture toughness, ceramic yield, and linear shrinkage. Attractively, MoSi₂ prominently enhances thermal and electrical conductivities of the products owing to increased continuity and compactness. To the best of our knowledge, lightweight SiC(rGO, 20%MoSi₂) bulk PDCs own brilliant ceramic yield (92.13%), liner shrinkage (6.69%), hardness (10.34 GPa), fracture toughness (4.35 Mpa·m^1/2), and thermal conductivity (8.57 W·m^–1·K^–1), opening potential emerging uses in aerospace fields.