连续逆流流化床软化水系统在化工生产中的应用

多层流化床离子交换系统主要用于工业锅炉用水的软化以及无阳离子水和纯水的制备,并介绍了该系统的基本原理、工艺过程的设置等.     

多层流化床离子交换软化水系统在化工生产中的应用

多层流化床离子交换系统主要用于工业锅炉用水的软化以及无阳离子水和纯水的制备。本文介绍了该系统的基本原理、工艺过程的设置等。     

人工神经网络用于电除盐产水水质预测研究

为了实现化工行业高纯水全自动生产,本文利用电除盐（electrodeionization,EDI）技术替代传统的混床技术,并研究了人工神经网络对EDI产水过程模拟仿真的可行性,采用误差反向传播网络（BP网络）建立了进水流量、电导率、pH值以及工作电压与EDI透过水电阻率之间关系的动态模型,并对不同的训练样本归一化方法和训练方法进行比较。结果表明,在网络隐含层层数为1、节点数为13时,采用归一化方法三能够较好的预测EDI透过水电阻率,且该模型可用于EDI除盐过程的动态描述,为实现化工行业高纯水全自动生产奠定了基础。     

海上油田注水纳滤软化中试研究

针对海上油田回注驱油工艺中的海水软化问题,以胶州湾某海域海水为例,采用超滤-纳滤技术进行了中试规模的海水软化研究。考察了操作压力对两种型号（NF-A、NF-B）纳滤膜软化性能的影响,以及回收率为70%时的水质情况及其与地层水的配伍性,并对NF-A型纳滤膜进行了长期运行稳定性实验。结果表明NF-A型纳滤膜软化水能够与某海上油田地层水配伍,超滤-纳滤集成膜技术能长期、稳定地为海上油田提供软化水。     

UF-EDI集成膜过程制备初级纯水

以超滤-电去离子（UF-EDI）集成膜过程对城市自来水的初级除盐制备纯水进行了研究。通过对过程特征曲线的研究表明，UF-EDI的过程工况介于传统ED过程，以及低原水含盐量条件下用以深度除盐的EDI过程之间。原水电导率为580～700μS／cm，pH6．0时，膜对电压为2．5～3．0V，产品水电导率可达2．4～8．8μS／cm，脱盐率为99％，过程稳定。与反渗透（R0）技术相比，UF-EDI工艺在过程能耗、水利用率、投资费用方面具有优势，有望发展成为低成本低能耗的高效初级纯水制备技术。     

ICP—OES在二次盐水质量监测中的应用

介绍OPTIMA2100型电感耦合等离子体发射光谱仪（ICP—OES）,探讨采用ICP—OES在二次精盐水生产过程中监测α-纤维素中以及纯水中金属离子含量的方法,并指出监测过程中的注意事项。     

苯乙酸溶解度测定及6—氨基青霉烷酸在苯乙酸中萃取动力学的研究

测定了苯乙酸（PAA）在纯水和水－乙醇、水－丙醇混合溶剂中的溶解度以及6－氨基青霉烷酸（6－APA）在PAA溶剂中的萃取动力学。研究得出了PAA在纯水中、水－乙醇混合溶剂、水－丙酮混合溶剂中的溶解度方程。6－APA在PAA中被萃取剂萃取了95％以上所需的时间为60s。     

液－固色谱中二元流动相组成对保留值影响的讨论

在二元（甲醇－水）流动相体系中，假定固定相对溶质的吸附量（ηｓ）与甲醇、水的体积分数（φＢ、φＷ）和在纯甲醇、纯水中固定相对溶质的吸附量（ηＢ、ηＷ）的关系为： 从该假定式出发推导得到二元流动相体系中溶质保留值（ｋ＇）与纯甲醇、纯水中的溶质保留值（ｋＢ＇ｋＷ＇）和在纯甲醇、纯水中固定相对溶质吸附量之乘积（ηＢ·Ｗ）的关系式为：　经误差对比分析，此关系式比已发表的一些关系式有较广泛的通用性。     

木糖生产净化工艺的改进

介绍了禹城福田药业有限公司木糖生产装置中净化工序改造前后的工艺流程,针对原工艺流程存在的单柱交换量小、消耗碱液多、消耗纯水多、单位成本高等问题,提出了串联运行的交换工艺和回收色碱、色水、正洗水的改造方案以及顶替、再生操作由泵提供动力改为由压缩空气提供动力的新的净化工艺流程,克服了原工艺流程存在的缺点,并且使单柱交换量提高了46 7%,耗碱量降低了34%,耗纯水量降低了44%,单柱处理周期由每天 8 次降至 5 次,大大降低了生产成本和工人的劳动强度。处理1 t木糖液可节约成本21 46元,年增经济效益321 9万元。     

膜软化及其应用

膜软化为近十几年发展起来的一种新的水软化工艺,属发离技术中的纳滤分离过程,具有无污染、无需再生、工艺简单、操作方便、设备占地省、出水水质好等优点,在国际上已得到广泛应用。作者主要阐述了膜软化的原理、软化用膜及其性能、膜软化过程及膜软化器设计等方面的内容;详细论述了膜软化在常规水脱硬、高硬度海岛水软化、海水去除硫酸盐和预软化等方面的应用;对膜软化过程的经济性进行了评述,并将膜软化的制水成本与常规软化     

21世纪的"绿色燃料"--二甲醚

被称为 2 1世纪“绿色燃料”的二甲醚具有清洁、低毒性、低蒸气压和优良的燃烧性能 ,因而成为多种产品的替代品 ,如环境友好的民用燃料、柴油和制冷剂 ,而且具有较好的市场潜力。本文主要介绍了二甲醚的生产方法、用途和国内外的发展状况     

High temperature behaviour of self-consolidating concrete: Microstructure and physicochemical properties

This paper presents an experimental study on the properties of self-compacting concrete (SCC) subjected to high temperature. Two SCC mixtures and one vibrated concrete mixture were tested. These concrete mixtures come from the French National Project B@P. The specimens of each concrete mixture were heated at a rate of 1 °C/min up to different temperatures (150, 300, 450 and 600 °C). In order to ensure a uniform temperature throughout the specimens, the temperature was held constant at the maximum temperature for 1 h before cooling. Mechanical properties at ambient temperature and residual mechanical properties after heating have already been determined. In this paper, the physicochemical properties and the microstuctural characteristics are presented. Thermogravimetric analysis, thermodifferential analysis, X-ray diffraction and SEM observations were used. The aim of these studies was in particular to explain the observed residual compressive strength increase between 150 and 300 °C.     

Plasticization of semicrystalline poly(l-lactide) with poly(propylene glycol)

Plasticization of semicrystalline poly(l-lactide) (PLA) with a new plasticizer - poly(propylene glycol) (PPG) is described. PLA was plasticized with PPG with nominal M_w of 425 g/mol (PPG4) and 1000 g/mol (PPG1) and crystallized. The plasticization decreased T_g, which was reflected in a lower yield stress and improved elongation at break. The crystallization in the blends was accompanied by a phase separation facilitated by an increase of plasticizer concentration in the amorphous phase and by annealing of blends at crystallization temperature. The ultimate properties of the blends with high plasticizer contents correlated with the acceleration of spherulite growth rate that reflected accumulation of plasticizer in front of growing spherulites causing weakness of interspherulitic boundaries. In PLA/PPG1 blends the phase separation was the most intense leading to the formation of PPG1 droplets, which facilitated plastic deformation of the blends that enabled to achieve the elongation at break of about 90-100% for 10 and 12.5 wt% PPG1 content in spite of relatively high T_g of PLA rich phase of the respective blends, 46.1-47.6 °C. Poly(ethylene glycol) (PEG), long known as a plasticizer for PLA, with nominal M_w of 600 g/mol, was also used to plasticize PLA for comparison.     

Formation of banded and non-banded poly(l-lactic acid) spherulites during crystallization of films of poly(l-lactic acid)/poly(ethylene oxide) blends

In this study, a series of poly(l-lactic acid) (PLLA)/poly(ethylene oxide) (PEO) blends with different PLLA concentrations was prepared. Films of these blends crystallized with and without a coverslip were characterized by the presence and absence of banded structures, respectively. This difference in morphology was observed because the PEO component of the blends was oxidized at a high temperature (125 °C) in air without the protection of a coverslip. X-ray photoelectron spectroscopy (XPS) results showed that the surface of the blends crystallized in nitrogen without a coverslip contained mostly PLLA while the surfaces of the same blends crystallized under a coverslip contained only a moderately higher concentration of PLLA than their bulks. The migration of PLLA to the surface of the blends during crystallization in nitrogen when no coverslip was used was due to its low surface tension. Phase images obtained using atomic force microscopy (AFM) indicated that the banded structures consisted of valleys and ridges, which were in fact flat-on and edge-on lamellae, respectively. A detailed time-of-flight secondary ion mass spectrometry (ToF-SIMS) examination suggested that PLLA and PEO were located mainly on the surfaces of the ridges and valleys, respectively.     

白炭黑生产工艺的研究进展

介绍了白炭黑生产的基本方法,并就目前我国白炭黑的生产与科研进行了综述。重点讨论了氟化法,碳化法等几种白炭黑生产新工艺的应用与研究,指出了今后我国白炭黑生产与研究的方向。     

Hetero-stereocomplex formation between substituted poly(lactic acid)s with linear and branched side chains,poly(l-2-hydroxybutanoic acid) and poly(d-2-hydroxy-3-methylbutanoic acid)

Differential scanning calorimetry and wide-angle X-ray diffractometry first revealed the formation of hetero-stereocomplex (HTSC) between biodegradable, optically active, and isotactic poly(2-hydroxyalkanoic acid)s having different chemical structures and opposite configurations, i.e., l-configured substituted poly(lactic acid) (PLA) [poly(l-2-hydroxybutanoic acid), P(l-2HB)] with linear side chains (ethyl groups) and d-configured substituted PLA [poly(d-2-hydroxy-3-methylbutanoic acid), P(d-2H3MB)] with branched side chains (isopropyl groups) in solution and in bulk from the melt. The melting temperature of P(l-2HB)/P(d-2H3MB) HTSC crystallites was 197–204 °C, which is much higher those of P(l-2HB) and P(d-2H3MB) homo-crystallites (100–101 °C and 158–165 °C, respectively). The interplain distances and crystalline lattice sizes of P(l-2HB)/P(d-2H3MB) HTSC crystallites were respectively larger and smaller than those of P(l-2HB)/P(d-2HB) and P(l-2H3MB)/P(d-2H3MB) homo-stereocomplexes. The HTSC formation of substituted PLA with opposite configurations reported in the present study will provide a versatile way to prepare poly(2-hydroxyalkanoic acid)-based biodegradable materials having a wide variety of physical properties and biodegradability.     

High molecular weight methyl ester of microbial poly(β,l-malic acid): Synthesis and crystallization

High molecular weight poly(α-methyl β,l-malate) (M_n ∼ 25,000, PD ∼ 1.7) was prepared from microbial poly(β,l-malic acid) (M_n ∼ 29,000, PD ∼ 1.3) by methylation with diazomethane in dry acetone without substantial cleavage of the polyester main chain. The thermal properties of this poly(malate) were assessed and its crystal structure was preliminary examined. Two crystal forms were identified by X-ray diffraction, their occurrence being dependent on crystallization conditions. The kinetics of nonisothermal and isothermal crystallizations from the melt were studied and modelled using the Avrami approach. Results were compared to those recently reported by us for low molecular weight poly(α-methyl β,l-malate) (M_n ∼ 3000, PD ∼ 1.3).     

基于LOM原型的“金属树脂”模具材料的研究

研究了以快速造型中的ＬＯＭ原型为母模、以金属粉末和环氧树脂为基料的“金属树脂”模具材料性能及其影响因素,比较了各种配方材料的性能,获得了较理想的、适于快速造型ＬＯＭ原型转制工艺的“金属树脂”模具材料配方。     

Integration approach of the Couette inverse problem of powder type self-compacting concrete in a wide-gap concentric cylinder rheometer: Part II. Influence of mineral additions and chemical admixtures on the shear thickening flow behaviour

The influence of mineral additions and chemical admixtures on the shear thickening flow behaviour of powder type self-compacting concrete (SCC) is studied by means of a wide-gap concentric cylinder rheometer. The Couette inverse problem is treated by means of the integration method in order to derive the flow curve τ(γ?) from the torque measurements.According to the experimental results, the shear thickening effect is found to be strongly influenced by the addition of the chemical admixture (a polycarboxylate ether based superplasticizer), whereas mineral additions were found to modify the intensity of shear thickening. The limestone, quartzite and fly ash addition used in this research project, respectively increase, unalter and decrease the shear thickening intensity. The powder volume and the available amount of free water proved to have a major impact on the viscosity of the powder type SCC mixes. Increasing the powder volume or decreasing the amount of free water results in an increased viscosity of the SCC mix.     

两种料浆法粉状磷铵流程比较

介绍了目前国内生产粉状磷铵的主要工艺流程 ,并详细比较了用于“中和料浆浓缩法磷铵工艺”的两种粉状磷铵工艺流程的各项技术经济指标 ,推荐采用“流化床逆流喷雾干燥制粉状磷铵流程