新型含羟基磷酸酯季铵盐两性表面活性剂的合成工艺

研究了含羟基磷酸酯季铵盐两性表面活性剂合成过程中反应液酸碱度和反应温度对酯化反应和季铵化反应的影响,提出当磷酸钠水溶液pH为4,酯化温度为75～87℃,磷酸二酯pH为5.5～8,季铵化温度为80～90℃时,可制得优良的两性表面活性剂。     

Control of nitrification rate by increasing ammonium concentration

Lysimeter experiments with maize and incubation experiments showed that increased ammonium concentrations in soil reduced nitrification rates. A modified Lees and Quastel kinetic model was proposed for predicting the relation between initial ammonium concentration in soil and nitrification rate. A term Mi strongly dependent on initial ammonium concentration ([NH4₀]) was introduced into the model which took the form: dy/dt = R(A – y)(Mi + y), where R is a rate constant, y represents the concentration of formed nitrate and A is an asymptotic value of initial ammonium concentration. Mi was obtained by a curve fitting procedure applied to experimental data. An exponential decay of Mi with [NH4]₀ was formulated. The modified model thus obtained provides an effective tool for predicting nitrification rates related to a wide range of ammonium concentrations.     

Photoluminescence enhancement of porous silicon prepared with ammonium sulfide pre-treated silicon

As-grown porous silicon prepared with ammonium sulfide pre-treated silicon show stable photoluminescence characteristics due to high Si–N/PS interface quality and less damage PS with Si–N passivation. After aging in air for 6 months, it shows much stronger photoluminescence intensity and stable wavelength due to higher Si–ON/PS interface quality and less damage of PS with Si–O–N passivation from the oxidation of Si–N.     

季铵型淀粉上浆性能的研究

用3-氯-2羟丙基三甲基氯化铵作为淀粉醚化试剂,采用半干法合成工艺制备了一系列不同取代度的季铵型阳离子淀粉,在取代度DS小于0.2的范围内,对其退浆性能、与PVA浆料的混溶性能及上浆性能进行了试验.低取代度的季铵型淀粉容易退浆;与PVA有较好的混溶性;取代度为0.030时对纯棉纱上浆性能优越,对涤棉纱上浆性能可行.     

糖蜜淀粉发酵味精处理废母液生产硫酸铵工艺研究

味精发酵液经冷冻等电点法提取谷氨酸后排放的母液具有COD高、BOD高、硫酸根含量高以及pH值低的特点,每生产1t味精,大约要排出5t提取谷氨酸后的母液。通过浓缩,采用连续结晶方法,严格控制pH、真空、密度、液位、温度,通过两级调控、两级结晶而制造出高产量高质量的硫酸铵肥料,含氮量≥19％（干基计）,回收率达到50％～5...     

Luminescence properties of Ammonium Silicon Fluoride films prepared by vapour etching technique

Photoluminescence (PL) properties of Ammonium Silicon Fluoride samples prepared by vapour etching technique are investigated with respect to excitation energy, excitation intensity and temperature. Ageing effect at ambient conditions is also examined by Fourier Transform Infrared Spectroscopy. PL peak maximum blue shifts as the excitation intensity increases and saturates at 2.106 eV. Temperature-dependent variations in PL peak energies and intensities cannot be thoroughly elucidated via Quantum Confinement model alone and require consideration of recombination rates at Si–SiO_x interface. Temperature dependence of integrated PL intensity is treated by a three-component functional form.Infrared absorption bands at 1060 cm^− 1, 1113 cm^− 1 and 1230 cm^− 1 attain saturation with time. Agreement between the saturation time of SiO_x longitudinal optic mode at 1230 cm^− 1 and that deduced from PL measurements in literature is noted. It is shown that PL emissions are intrinsic in nature and have a significant excitonic contribution.     

硫铵料仓斗堵料的处理方法

目前有几种处理硫铵料仓斗堵料的方法,但效果均不理想。建议采用热电厂原煤内部疏松装置,通过内部扰动使硫铵松动,并且对硫铵料仓斗的改动量小,能自动工作,比较适合硫铵料仓斗的技术改造。     

A physico-chemical study of an NH3BH3-based reactive composition for hydrogen generation

In order to reduce the use of fossil energies, the development of new technologies, such as those concerning fuel cells, is required. However, fuel cells currently involve issues of storing and generating hydrogen. Borohydride materials, like ammonia borane (NH₃BH₃), seem to present an interesting solution to these problems. In fact, NH₃BH₃ contains 19.6 wt.% of hydrogen, of which a high percentage can easily be released by moderate heating. Understanding and controlling the behaviour of ammonia borane would allow the development of a safe, lightweight and compact hydrogen storage system. The final purpose would consist in having a device that is able to be integrated in nomad applications such as GSM, PDA; or in thermal accumulators. The present study reports on thermal decompositions of ammonia borane doped with various percentages of NH₄NO₃. Differential scanning calorimetry (DSC) permitted an understanding of the thermal behaviour of the material, and the detection of released hydrogen was examined by evolved gas analysis on a thermo-gravimetric analyser (TGA) coupled to a mass spectrometer (MS). Finally, in order to avoid fuel cell malfunctioning due to pollutant gases, an identification of the decomposition products was carried out.     

硫氰酸盐法从工业废渣中浸取金银的实验研究

对硫氰酸盐法浸取工业废渣中金银进行了工艺试验研究,实验结果表明:硫氰酸铵浓度为6%,pH为1,软锰矿用量为矿粉量的7.5%,液固比为2,搅拌浸出5h,金银的浸出率可分别达到81%和40%。     

聚磷酸铵基复合膨胀型阻燃剂的制备及其对聚甲醛的阻燃作用

针对聚甲醛(POM)阻燃的难点,在传统简单共混膨胀阻燃体系聚磷酸铵(APP)/三聚氰胺(ME)/季戊四醇(PER)的基础上,采用高温热反应处理技术将APP(酸源)、ME(气源)和PER(炭源)集成在一个大分子膨胀阻燃体系(RMAPP)中,并将所得大分子一体化产物RMAPP阻燃POM,解决了简单共混膨胀体系中各组分混合不均匀、难分散以及与基体树脂相容性差的难题。研究结果表明:高温热反应产物RMAPP比传统的未经热处理简单共混阻燃体系具有较好的阻燃效果,当阻燃剂RMAPP的添加量为45%时,在垂直燃烧测试实验中,其3.2mm厚试样可达到UL94V—1级别。