一乙醇胺合成草甘膦的新工艺

研究了一种新的制备草甘膦的工艺：在合适的反应条件下，加入-乙醇胺、甲醛、亚磷酸三甲酯生成一种混合物，再在适当的条件下水解该混合物，生成N-(膦酰基甲基)乙醇胺及其盐，在同一浴中，N-(膦酰基甲基)乙醇胺及其盐用Raney Cu催化氧化，再水解得到草甘膦。草甘膦的平均收率可达80％。     

以锰系化合物为循环介质HCl制备Cl2的清洁工艺（英文）

A new process is developed by using compound Mn as intermediate to produce Cl2 from HCl, with the following steps. (1) HCl steam is decomposed by intermediate Mn2O3 to produce Cl2 and MnCl2 at 500 °C. (2) Produced MnCl2 is oxidized by water steam to produce MnO at 450 °C. (3) The MnO compound is oxidized by air to yield Mn2O3. The X-ray diffraction (XRD) crystallite characterization results indicate the high conversion in each step under the optimum experimental conditions. Long term experiments for continuous conversion of HCl to Cl2 by using Mn2O3 as intermediate in a fixed bed reactor indicate that over 90%of HCl could be converted to Cl2 on stream of 30 h. The production of Cl2 from HCl with Mn compound as an intermediate and atmospheric steam is a feasible and recyclable process.     

Semicontinuous emulsion copolymerization to obtain styrene–methyl acrylate copolymers with predetermined chemical composition distributions

Four types of emulsion copolymerization processes were applied to produce various styrene–methyl acrylate copolymer latices. (1) Batch emulsion copolymerization. (2) Monomer starved semicontinuous emulsion copolymerization, i.e., a monomer mixture of constant composition was fed to the reactor at a constant rate. Sufficiently low addition rates led to homogeneous copolymers. (3) Optimal addition rate profiles were used to produce homogeneous emulsion copolymers in relatively short times. The profiles were determined in a semiempirical way, and applied to three different copolymer compositions. (4) We made an attempt to determine an addition rate profile to produce a heterogeneous emulsion copolymer with predetermined heterogeneity, i.e., a copolymer of which the chemical composition distribution (CCD) did not consist of one narrow peak, as with homogeneous copolymers, but had a predetermined broadness profile. Strategies (2) and (3) were used to produce homogeneous emulsion copolymers with varying fractions of styrene. Strategy (3) was also used to demonstrate the influence of the monomer ratio on the kinetics. The advantage of this method is that the monomer ratio is constant over the whole conversion range in the latex particles. High performance liquid chromatography (HPLC) was used to determine the homogeneity/heterogeneity of the copolymers produced, and proved to be invaluable in determining the optimal addition rate profile. The final goal will be to study the influence of the chemical composition distribution (CCD) on mechanical properties of these copolymers, as both homopolymers used in this study have quite differentglass transition temperatures; the results will be published later. © 1993 John Wiley & Sons, Inc.     

甲氧基二氢香茅醛的合成研究

甲氧基香茅醛是国内未有工业化生产的新香原料 ,本文报导了由香茅醛合成甲氧基香茅醛工艺路线的改进。由香茅醛与二乙醇胺制备唑烷 ,再由唑烷与甲醇在硫酸存在下碳碳双键反应再脱胺得产品 ,反应过程加入抑制剂BH -YZJ(属BHT一类的抗氧剂 ) ,抑制缩甲醛生成从而提高产品纯度与得率。纯度可达 96 %以上 ,收率可达 6 3%。     

Synthesis of Trimethylolpropane Esters by Base‐Catalyzed Transesterification

Trimethylolpropane (TMP) esters are synthesized from fatty acid methyl esters (FAMEs) and TMP to produce a fluid with properties suitable for use as a lubricant base oil, exhibiting good stability, and low‐temperature performances. In this study, triacylglyceride (TAG) molecules are modified to produce FAME and then linked to TMP. Initially, vegetable oil is transesterified with excess methanol, and potassium hydroxide to produce crude FAME. The FAMEs are then refined and further transesterified with TMP and heating, under vacuum, using potassium carbonate catalyst. The conversion of TMP is successfully achieved by adding an excess of FAME to a reaction mixture of base and polyol in the second step. All reactions are monitored and confirmed using ¹H‐NMR. The reactions proceed quickly as an efficient production of FAME and TMP to TMP triesters is successfully achieved by adding an excess of FAME slowly to a mixture of TMP and catalyst. Practical Applications: The major objective is to develop and optimize a reverse addition reaction method for TMP‐based biolubricant production. The highly enriched TMP biolubricant is prepared by reverse phase chromatography and these biolubricant products are characterized for oxidative stability index and low‐temperature performance. The optimum conditions are applied to different vegetable oils.     

Mechanical behavior of electrospun polyurethane

Electrospinning is a method to produce polymer fibers from solution (or melt) with diameters ranging from 100 to 500 nm. A thermoplastic polyurethane was electrospun from solution to produce an isotropic fiber mat. The mechanical behavior of the mat was characterized by uniaxial tensile tests. The electrospun polyurethane produces a stress-strain response characteristically different to that of the material from which the mat is spun. Scanning electron microscopy and infrared spectroscopy were also used to characterize the electrospun material and determine the source of the differing mechanical responses.     

Template-assisted assembly of electrospun fibers

Ordinarily, the electrospinning process generates one-dimensional fibers which assemble into non-woven membrane structures due to instabilities in the fluid jet. In this paper, an electrospinning procedure is developed that utilizes patterned collectors to produce aligned membranes with designed topological structures. The template-assisted electrospinning approach is demonstrated using polycaprolactone (PCL) fibers to produce patterns including alphanumeric characters and a printed electronic circuit chip, with feature sizes on the order of several hundred microns. The process has a significant impact on micro-manufacturing, and provides the capability for incorporation of oriented fiber materials in patterned micro-composites and electronic components.     

Controlling the growth morphology of carbon nanotubes: from suspended bridges to upright forests

We have developed two strategies to produce carbon nanotubes (CNTs) from low-density surface growth to high-density forest growth. We have demonstrated that by introducing a C(2)H(2) pulse at the beginning of the growth, where methane is still used as the main carbon feeding gas, the growth tendency of CNTs can be changed and the resulting growth morphology will vary from surface growth to forest growth. Similarly, the growth morphology can be changed when the growth temperature is raised. The further characterization via Raman spectroscopy indicates that an increasing C(2)H(2) pulse time will lead to a rise of the D peak for as-grown CNTs, due to the formation of more multi-walled CNTs and the amorphous carbon contamination introduced by extra C(2)H(2), while a high growth temperature tends to produce high-quality CNTs and to reduce the amorphous carbon contamination. Furthermore, by appropriately adjusting the growth temperature and controlling the C(2)H(2) pulse time, we have managed to produce both suspended CNT bridges and upright forests within a single growth procedure and to form suspended pristine CNT transistors with a relatively high yield. In addition, the electrical properties of these CNT nanostructures have been investigated by electrical transport and scanning photocurrent measurements.     

Enzymatic synthesis of trierucin from high-erucic acid rapeseed oil

The lipase fromCandida rugosa has been shown to discriminate against erucic acid. Advantage of this property has been taken to produce trierucin from high-erucic acid rapeseed (HEAR) oil. A method has been developed for extracting erucic acid from the oil as dierucin and subsequently enzymatically converting it to trierucin. Unrefined HEAR oil was hydrolyzed with lipase fromC. rugosa to produce a mixture of free fatty acids and dierucin. Precipitation and filtration from cold ethanol gave 73% pure dierucin, free of fatty acids. This dierucin was treated in two ways to produce trierucin. First, in the presence of an immobilized lipase and a known amount of water, some trierucin is produced by interesterification. Second, a more efficient route to trierucin utilizedRhizopus arrhizus lipase to completely hydrolyze dierucin to erucic acid, which was then combined with an appropriate amount of dierucin in the presence of an immobilized lipase to produce trierucin in a quantitative yield. Partly presented at the AOCS Annual Meeting held in Toronto, May 10–14, 1992.     

Characterization of Thermal Barrier Coatings Produced by Various Thermal Spray Techniques Using Solid Powder,Suspension, and Solution Precursor Feedstock Material

Use of a liquid feedstock in thermal spraying (an alternative to the conventional solid powder feedstock) is receiving an increasing level of interest due to its capability to produce the advanced submicrometer/nanostructured coatings. Suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS) are those advanced thermal spraying techniques which help to feed this liquid feedstock. These techniques have shown to produce better performance thermal barrier coatings (TBCs) than conventional thermal spraying. In this work, a comparative study was performed between SPS‐ and SPPS‐sprayed TBCs which then were also compared with the conventional atmospheric plasma‐sprayed (APS) TBCs. Experimental characterization included SEM, porosity analysis using weight difference by water infiltration, thermal conductivity measurements using laser flash analysis, and lifetime assessment using thermo‐cyclic fatigue test. It was concluded that SPS coatings can produce a microstructure with columnar type features (intermediary between the columnar and vertically cracked microstructure), whereas SPPS can produce vertically cracked microstructure. It was also shown that SPS coatings with particle size in suspension (D₅₀) <3 μm were highly porous with lower thermal conductivity than SPPS and APS coatings. Furthermore, SPS coatings have also shown a relatively better thermal cyclic fatigue lifetime than SPPS.     

甲烷部分氧化制乙炔过程研究

The partial oxidation of hydrocarbons is an important technical route to produce acetylene for chemical industry.The partial oxidation reactor is the key to high acetylene yields.This work is an experimental and numerical study on the use of a methane flame to produce acetylene.A lab scale partial oxidation reactor was used to produce ultra fuel-rich premixed jet flames.The axial temperature and species concentration profiles were measured for different equivalence ratios and preheating temperatures,and these were compared to numerical results from Computational Fluid Dynamics(CFD)simulations that used the Reynolds Averaged Navier-Stokes Probability Density Function(RANS-PDF)approach coupled with detailed chemical mechanisms.The Leeds 1.5,GRI 3.0 and San Diego mechanisms were used to investigate the effect of the detailed chemical mechanisms.The effects of equivalence ratio and preheating temperature on acetylene production were experimentally and numerically studied.The experimental validations indicated that the present numerical simulation provided reliable prediction on the partial oxidation of methane.Using this simulation method the optimal equivalence ratio for acetylene production was determined to be 3.6.Increasing preheating temperature improved acetylene production and shortened greatly the ignition delay time.So the increase of preheating temperature had to be limited to avoid uncontrolled ignition in the mixing chamber and the pyrolysis of methane in the preheater.     

Effect of an industrial expander on the discharge process of a lead microelectrode in 4.5M sulphuric acid

The presence or absence of an industrial expander is shown to produce a difference in the discharge of a lead microelectrode in concentrated sulphuric acid. The expander acts both before and after passivation, and modifies the concentration and relaxation time of Pb(II) soluble reaction intermediates.     

Phenolic epoxidised polyurethane coating for petroleum tanks from available raw materials

Summary  Linseed oil was epoxidised by 60% per acetic acid to produce epoxidised linseed oil. By this process, two new groups entered the molecule (epoxy group and hydroxyl group). These groups were detected by using infrared (IR) analysis. Product (I) reacted with phenol in different ratios by weight percent to produce Phenolic epoxidised resin (II). Product (II) reacted with toluene diisocyanate to produce product (III), Phenolic epoxidised polyurethane, which had an excellent adhesion character. Product (III) was examined chemically and physically according to ASTM-API standard methods. The results provide encouragement for their use as a petroleum tank coating material. They can be used as a one-layer coating which combines the properties of more than coating of two layers because it combines more than one function group.     

Novel carbon fiber-carbon filament structures

In an attempt to address the problems associated with delamination and fiber pull-out in carbon-fiber reinforced composites, we have used a novel concept which involves the generation of vapor-grown carbon microfibers (carbon filaments) on the sides of parent carbon fibers (this step being accomplished by the use of a suitable catalyst). The mixed structures are produced by impregnation of the parent fiber with selected copper-nickel catalyst precursors, which are subsequently treated in an ethylene-hydrogen environment at 600°C. The function of the catalyst is to produce carbon filaments possessing well-defined structural characteristics that can form interlocking networks with adjacent carbon fiber-filament structures. In this paper we report on fundamental studies for the development of a process to produce these unique preforms.     

Desulfurization of coke by recycling COG in coking process

The technology of desulfurization of coke during coking is conceptually designed, in which the coking oven gas (COG) is blown into the coking chamber of the coke oven during the coking stage. Analysis based on laboratory experiments and computer simulation shows the possibility to reduce sulfur of coke by 0.2% by recycling 20% of COG. The technology may be an economic way to produce low sulfur coke or to produce metallurgical coke using high sulfur coal.     

FRP-混凝土-钢双壁空心构件及其在桥梁结构中的应用前景

FRP-混凝土-钢双壁空心构件(DSTM)是一种新型组合构件,由外部FRP管、内部钢管以及两者之间填充的混凝土三部分组成,三种材料的协同互补和共同工作使该组合柱具有许多优于现有组合构件的力学性能。该种新型构件中,外FRP管和内钢管可以同心放置以用作受压构件,也可以偏心放置以用作受弯构件。本文阐述了该种新型组合构件截面形式的合理性及优点,总结了针对其力学性能和设计方法的现有研究,并探讨了其在桥梁工程中应用的潜力。     

Dry reforming of coke oven gases over activated carbon to produce syngas for methanol synthesis

The dry reforming of coke oven gases (COG) over an activated carbon used as catalyst has been studied in order to produce a syngas suitable for methanol synthesis. The primary aim of this work was to study the influence of the high amount of hydrogen present in the COG on the process of dry reforming, as well as the influence of other operation conditions, such us temperature and volumetric hourly space velocity (VHSV). It was found that the reverse water gas shift (RWGS) reaction takes place due to the hydrogen present in the COG, and that its influence on the process increases as the temperature decreases. This situation may give rise to the consumption of the hydrogen present in the COG, and the consequent formation of a syngas which is inappropriate for the synthesis of methanol. This reaction can be avoided by working at high temperatures (about 1000 °C) in order to produce a syngas that is suitable for methanol synthesis. It was also found that the RWGS reaction is favoured by an increase in the VHSV. In addition, the active carbon FY5 was proven to be an adequate catalyst for the production of syngas from COG.     

Biomimetic studies on iodothyronine deiodinase intermediates: modeling the reduction of selenenyl iodide by thiols

Enzyme mimetic studies on the crucial intermediate (E-SeI) of the iodothyronine deiodinase cycle have been carried out by using an areneselenenyl iodide stabilized by intramolecular Se.N interactions. Treatment of this compound with aromatic thiols and thiobenzoxazole in the presence of NEt(3) affords areneselenenyl sulfides that are stable towards disproportionation reactions. The structures of three of the areneselenenyl sulfides were determined by X-ray crystallography. In one case, in the absence of NEt(3), a diselenide can be formed rather than the selenenyl sulfide. The areneselenenyl iodide also reacts with a related selenol to produce the corresponding diselenide, and this reaction is found to be much faster than that with thiols. The high reactivity of the selenenyl iodide with the selenol suggests that a reduced selenol group (R'-SeH) may react with the E-SeI intermediate to produce a diselenide (E-Se-Se-R') without any thiol cosubstrate. The intermediacy of selenenyl sulfides during the reduction of selenenyl iodide by thiols and its possible relevance to the iodothyronine deiodinase catalytic cycle is also described.     

Alumina-based nanocomposites obtained by doping with inorganic salt solutions: Application to immiscible and reactive systems

Doping of commercial alumina nanopowders by using aqueous solutions of metal salts was exploited to prepare alumina-based nanocomposites.The same procedure was applied to produce a composite made of immiscible phases, that is an alumina–zirconia material, by doping an α-alumina powder with a zirconium chloride solution, as well as to produce an alumina–YAG (yttrium aluminium garnet) system by doping alumina with a yttrium chloride solution and promoting YAG formation by solid-state reaction at high temperature.For this latter case, the difference in reactivity between two commercial powders, one made of transition alumina, the other of pure α-phase, was investigated in terms of phase evolution and purity.In all cases natural sintering was performed to develop dense bodies.     

Non-autoclave processing of advanced composite repairs

Historically, the repair of 180°C (350°F) curing carbon fiber reinforced plastic (CFRP) laminates has required the use of an autoclave during the cure process to produce acceptable void-free laminates. A common technique for repairing 180°C (350°F) CFRP laminates without an autoclave is to use a 121°C (250°F) CFRP material or a wet lay-up. These repair laminates produce comparable RT/dry test results, although under the hot/wet condition there is a reduction in the laminate strength. Current high-pressure autoclave cure techniques work by pushing most of the entrapped air out of the laminate while compressing the remaining pockets of air into very small sizes. Using vacuum and ambient atmospheric pressure there is not enough pressure differential to squeeze out the entrapped air or compress the remaining pockets to small acceptable sizes. The double vacuum bagging technique produces a temporary degassing chamber over the repair laminate. A research program was established to develop a repair process that produces an autoclave quality laminate without the use of an autoclave. When combined with the C-staging of the repair laminate, the repair adaptation of the double vacuum bagging process is very promising.