用∑WESH图评价某涂料化工厂的可持续性

介绍了在清洁生产过程中用∑WESH图评价涂料化工厂的可持续发展的原理及方法,并进行了一个实例的评价.从该厂的∑WESH图得出该厂的水及能源的利用率高,所用的原材料的稀缺性都不大,唯一较严重的问题是二甲苯的通过量大,危害性较严重.因此建议该厂在配方上尽量减少二甲苯的使用,开发新产品.     

喷涂前处理污染源的分析及其处理措施

随着我国国民经济的快速发展和国家"节能减排"重点项目的深入开展,各种污染源的分析及其处理措施的研究备受关注.本文在充分研究若干家电企业的钢铁喷涂制件的前处理工艺(如:预脱脂、脱脂、清洗、表调、磷化等)的基础上,分析喷涂前处理过程中的污染源,研究污染源的处理措施.     

一代宗师何朝宗瓷塑艺术的文化解读

明代德化瓷塑大师、瓷圣何朝宗的瓷塑艺术具有独特和永恒的艺术魅力,它达到了中国古代瓷塑艺术成就的高峰。何朝宗鬼斧神工的瓷塑艺术将宗教精神、人生哲学、审美情趣融入德化的白瓷,创造出了一件件不朽的瓷塑艺术品,他的艺术风格一直影响到数百年后的今天。现存福建泉州海交馆的何朝宗瓷塑艺术代表作品《渡海观音》,就是一尊何氏精湛的雕塑艺术语言和艺术家心目中的“世上独一无二的艺术珍品”。何朝宗的瓷塑艺术凝铸着一个时代的智慧,它将永恒的闪耀着灿烂的光辉。     

酿酒酵母细胞表达异源萜类化合物的研究进展

萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。     

香叶油的研究进展

为了全面了解香叶油的研究现状,为我国香叶油的开发利用提供思路, 综述了香叶的栽培、组培技术研究、香叶油的应用、香叶油的提取及化学成分研究、香叶油调配研究等方面的现状,并对香叶品种的遗传改良提出一些有益的建议.     

胶原纤维的性能特点和作用

1胶原纤维巴西Novaprom胶原纤维是以精选的牛皮内剖层(真皮)组织提取的,它不同于明胶或明胶的衍生物。它的生产是在严格控制的时间和温度范围内进行的,从而确保其主要成分──胶原蛋白的活性不变,并以天然纤维的形式存在。它在肉制品中的结构呈纤维状而不是一般的胶冻,因而这种结构是非常稳定的,是不可逆的。它是很好的功能性动物纤维蛋白,在肉制品及鱼糜制品等相关的食品中得到广泛的应用。2胶原纤维的性能及相关指标(1)蛋白质含量:胶原纤维中的动物蛋白质(M×6.25)高达98%,含有人体必需的氨基酸。(2)吸水、持水性:胶原纤维结构良好,呈矩…     

鲜为人知的科学珍闻

有言在先,珍闻的挑选奉行以下原则:科学应该是有趣的,科学之所以好玩,部分原因在于你了解、知道这些奇谈怪论的存在。科学的伟大之处在于,它不必是教条的、有价值的实验,也不要求对所有理论进行最准确的过滤以得     

玻璃纤维拉丝池窑配合料设备研制的进展

玻璃纤维池窑拉丝生产线配合料的制备中,原料是形成优质玻璃液的基础,因此可以说配合料的稳定性、均匀性和准确性对玻璃纤维的质量起着决定的作用.生产实践证明:组分和粒度均匀的配合料,不但能强化玻璃液的熔化和澄清过程,而且还能减少或消除影响玻璃质量的各种弊病.所以认真拟定玻璃纤维原料的成分和选择玻璃纤维的种类和化学性质:严格控制进厂原料化学成分、粒度和水份;做好原料的分堆、存放、加工、称量、混合、输送是优质配合料制备不可缺少的手段,这也是做好玻璃纤维池窑配合料的基本任务.     

氢氧化镁阻燃剂的研究进展

主要论述了国内外阻燃剂的种类和发展,指出由于环境和健康的原因,无机阻燃剂是最有发展前途的,其中的氢氧化镁因其特有的性质,在无机阻燃剂中尤为突出.考虑到氢氧化镁的广泛应用的前景和其本身的缺点,对其改性成为业界的研究重点,其中主要介绍了钛酸酯、硬脂酸(盐)、镁盐晶须和胶囊化等技术,指出以后的发展方向是在改性基础上的协同作用.     

木块填料对高浓度乙醇连续发酵过程中振荡行为的弱化机制

前期研究发现，添加木块填料可有效弱化管式反应器中的振荡行为，并推测其机理可能与酵母细胞的固定化、酵母细胞生长微环境的改变和管式反应器中稀释速率的改变三方面因素有关。本文实验证明了木块填料反应器的稀释率的改变不是导致振荡弱化的主要原因。进一步研究表明：一方面，与其他填料体系相比，木块填料体系不仅维持了较高的生物量浓度，而且维持了较高的细胞活性，从而具备了弱化振荡的前提条件；另一方面，与无填料体系培养出的酵母细胞相比，木块填料体系培养的酵母细胞具有较高的乙醇耐受性，从而弱化了乙醇浓度变化导致的发酵参数的大幅度波动。     

Effectiveness in the Removal of Organic Compounds from Municipal Landfill Leachate in Integrated Membrane Systems: Coagulation – NF/RO

The article presents the results of studies concerning the hydraulic permeability of integrated membrane systems during the treatment of municipal landfill leachate. The laboratory-scale experiments were conducted to determine the effectiveness of coagulation as a pretreatment option for treating stabilized landfill leachate and effectiveness of nanofiltration (NF) and reverse osmosis (RO) processes. The municipal landfill leachates were analyzed for the concentration of the following: polycyclic aromatic hydrocarbons (PAHs), nitrate nitrogen, ammonium nitrogen, chemical oxygen demand (COD), total organic carbon (TOC), total carbon (TC), suspended soils (SS), turbidity, pH. The commercially available coagulant – aluminum sulfate Al₂(SO₄)₃·18H₂O (alum) was used as a coagulant. The NF process was carried out at the transmembrane pressure of 1.5 MPa. The membrane separation process was based on a thin film membrane (DK). The transmembrane pressure of the RO stood at 2 MPa and for this process one polyamide membrane (AG) was used. The level of leachate treatment was defined for raw and cleaned wastewater indicators. Both NF and RO membranes allowed obtaining the high level of pollutants removal. In the coagulation–NF system, the removal efficiency was equal to 77% for PAHs, 88% for COD, 72% for ammonium nitrogen, 80% for nitrate nitrogen, 67% for TOC, 80% for TC, 96% for SS and during the RO – 86% for PAHs, 98% for COD, 93% for ammonium nitrogen, 87% for nitrate nitrogen, 89% for TOC, 100% for TC, 98% for SS. The calculations based on the assumptions of the mathematical filtration model (relaxation) made it possible to predict the efficiency of commercial filtration membranes used for leachate treatment.     

丙型肝炎病毒核心总抗原检测试剂的评价

目的评价国外丙型肝类病毒核心抗原检测试剂盒的质量以及窗口期检测核心总抗原(HCVcAgTrak-C)的意义。方法用该试剂检测8649份自然献血员及566份HCV可疑感染者血清的核心总抗原,并与抗体试剂(Anti-HCV)、游离抗原(HCVfreeAg)试剂、核酸(HCVRNA)试剂进行比较。结果筛出核心总抗原和抗体同时阳性血清152份,抗体阴性而总抗原阳性血清5份。利用RNA试剂检测这5份血清,结果HCVRNA阳性。利用HCVfreeAg试剂检测这9215份血清,发现2份阳性,其中1份为抗原和抗体同时阳性,RIBA检测确证这份血清产生的是核心区抗体。另1份为单独抗原阳性。结论在应用HCV抗体试剂对血液进行筛查的同时使用HCVcAg试剂检测,可以减少因窗口期造成的漏检。     

国内甲醇消费市场状况

我国甲醇主要用于甲醛、对苯二甲酸二甲酯、农药、甲基叔丁基醚、醋酸的生产,我国甲醇消费量增长最快的领域将是燃料甲醇、醋酸和甲醛。预计 2005年甲醛对甲醇的需求量为 175万t左右,聚甲醛对甲醇的需求量为 40万t,醋酸需求甲醇为 62万t,甲基叔丁基醚为 46万t左右,甲胺为 30万t,碳酸二甲酯为 11万t,甲烷氯化物为 10万t,甲醇燃料为 80万t,农药为 22万t,对苯二甲酸二甲酯 3 0万t,其他衍生物 27万t。     

Mathematical Modeling and Simulation of Drying Using Two Industrial Concurrent and Countercurrent Rotary Dryers for Ammonium Nitrate

Drying of ammonium nitrate (AN) is accomplished in the Shiraz Petrochemical Complex (SPC) using a concurrent rotary dryer following a countercurrent rotary dryer. A mathematical model for these rotary dryers including heat and mass transfer was developed. The model was checked against industrial-scale data, which showed a good agreement. The average absolute deviation of the simulation results compared to the industrial data for the concurrent dryer was 4.0% for solids moisture, 1.3% for solids temperature, and 1.8% for air temperature and for the countercurrent dryer it was 9.0% for the solids moisture, 2.0% for solids temperature, and 4.6% for air temperature. These simulation results reveal that for outlet solid moisture, inlet AN moisture, and air temperature as well as the outlet temperature of product, the inlet solid and air temperature have major effects for both concurrent and countercurrent flow.     

FULLY DEVELOPED LAMINAR CONVECTION FROM A HELICAL COIL

A general correlating equation has been developed for all Prandtl and Dean numbers. This expression was constructed by joining the theoretical Nusselt number for a straight tube, a theoretical asymptote for the regime of creeping secondary flow, a semi-theoretical expression for the boundary layer regime and an asymptotic value of Nu for the intervening regime of flow.The arbitrary coefficients and exponents in the model were evaluated using experimental and numerically computed values. Slightly differing sets of coefficients are required for uniform wall temperature and longitudinally uniform heating with uniform peripheral wall temperature.

All prior theoretical results were for toroidal flow (zero pitch). A numerical solution was developed for helical flow (finite pitch). These results confirm the validity of neglecting pitch for tightly wound coils but suggest a generalization of the correlating equation for large pitch.     

Reactive separation of dilute ethylene by hydroformylation using slurried rhodium catalysts on phosphinated resins and silica

A series of slurried rhodium catalysts on phosphinated resins and silica were tested for the reactive separation of dilute ethylene by hydroformylation to propanal. The amount of rhodium leaching was determined for most of the systems investigated. Leaching ranged from <2 to 11% for catalytic runs for resin supported systems, but was found to be much more significant for the phosphinated silica system studied, 19%. The level of rhodium leaching correlated well with the loss in rate of propanal formation between repeated experiments using recycled catalysts for the resin based systems, but the loss in rate was much more significant for the silica based system. This level of leaching is very high for a commercial process for basic chemical synthesis, for which leaching is typically at the ppb level. Rates of propanal formation for resin supported catalyst systems correlated well with the cone angle of the free phosphine, with rates as high as 0.35 mol/l/h. However, while smaller cone angles were found to be directly proportional to rate, supported systems were less active than homogeneous counterparts.     

汽车工业用粘接材料的现状与展望

本文按照汽车制造工序介绍国外汽车工业折边用胶粘剂、点焊胶接用胶粘剂、车身密封胶、车身底涂料、窗玻璃用单组份湿气固化型聚氨酯胶粘剂以及纤维增强树脂用结构胶粘剂等主要胶种的最新技术发展动向。讨论了我国汽车工业用胶粘剂的现状和差距，提出几点建议。     

Peculiarities of Adhesion Interaction of Ag,Cu and Au with Diamond

Wettability tests were performed for Cu, Ag, Au liquid drops on diamond substrates as well as measurements of mechanical contact strength (MCS) between solidified metal drops and diamond. The work of adhesion was calculated using data for metal surface tension and observed contact angles. Cu, Ag, Au (metals of the group I_B of the Periodic Table) show non-monotonic changes of wettability and work of adhesion within their group in the sequence Au → Cu → Ag. The work of adhesion was found to be almost two times higher for Ag than for Cu and almost five times higher for Ag than for Au. Measured mechanical contact strength (MCS) was ～4 times higher, on average, for Ag/diamond samples than for Cu/diamond or Au/diamond samples. Maximum value of the MCS reached ～70 MPa for Ag/diamond samples. Non-monotonic changes of the wettability and work of adhesion observed for the group I_B metals (Cu, Ag, Au) are discussed on the basis of classical London equation for the energy of van der Waals (vdW) bond for two atoms.     

Computation of asymmetric signal extraction filters and mean squared error for ARIMA component models

Abstract.  Standard signal extraction results for both stationary and nonstationary time series are expressed as linear filters applied to the observed series. Computation of the filter weights, and of the corresponding frequency response function, is relevant for studying properties of the filter and of the resulting signal extraction estimates. Methods for doing such computations for symmetric, doubly infinite filters are well established. This study develops an algorithm for computing filter weights for asymmetric, semi-infinite signal extraction filters, including the important case of the concurrent filter (for signal extraction at the current time point). The setting is where the time series components being estimated follow autoregressive integrated moving-average (ARIMA) models. The algorithm provides expressions for the asymmetric signal extraction filters as rational polynomial functions of the backshift operator. The filter weights are then readily generated by simple expansion of these expressions, and the corresponding frequency response function is directly evaluated. Recursive expressions are also developed that relate the weights for filters that use successively increasing amounts of data. The results for the filter weights are then used to develop methods for computing mean squared error results for the asymmetric signal extraction estimates.     

少烟三元乙丙橡胶材料研制

以三元乙丙橡胶(EPDM)为基体材料，三氧化二锑、十溴苯醚为阻燃剂制备了材料配方，试验了三氧化二锑(Sb22O3)、十溴苯醚(DBDPO))配比对材料烟雾和力学性能的影响，测试了材料的氧指数，可见光的透过率，自熄性等。结果表明，DBDPO与EPDM的相容性比较好，Sb2O3的相容性则相对比较差，两者都可以提高材料的阻燃性能。以4045EPDM橡胶为基体材料，当EPDM100g，白炭黑10g，二硫化四甲基秋兰姆(TMTD)2g，ZnO5g，促进剂M1g，硬脂酸2g，硫磺3g，Sb2O3和DBDPO质量比为20．0／40．0，可以获得具有较好力学性能的少烟EPDM橡胶材料。