中国造纸用精细化学品的现状和发展(摘选)

造纸工业是以纤维为原料的化学加工工业。在制浆、漂白、打浆、抄造及成纸后加工这一工艺全过程中，均离不开各种化学品的应用。造纸用精细化学品就是指那些加入量虽不大，但往往起关键作用的各种化学添加剂，它不包括通常大宗用的苛性纳、硫化物、液氯、滑石粉、高岭土等。这些精细化学品添加量约占纸张总量的1％～3％，但对纸张生产的经济性起决定性的作用。它使生产过程优化、纸张运行速度提高，能使较差的纤维原料生产出更薄、更白、更强的纸张，不但有很高的经济效益，而且具有大幅度改善环境污染的优点。世界各国都十分重视造纸用精细化学品的研究与开发。

Effect of Additive EDTA on Crystallization Process of Magnesium Hydroxide Precipitation

The effects of additive ethylenediaminetetraacetic acid (EDTA) on crystallization process were investigated by the induction time of MgSO 4-NaOH system. Nucleation and growth rates, growth mechanism and particle size distribution of magnesium hydroxide precipitation were involved with. The induction time in unseeded and seeded precipitation of magnesium hydroxide with and without additive EDTA was measured. The conductivity method was used to determine the induction period. Theoretical relations of the induction time and supersaturation ratio for different growth mechanisms and a combined analysis on the induction time were applied to determine nucleation and growth rates. The growth mechanism of magnesium hydroxide precipitation was disclosed by analyzing the experimental data with and without additive. The analysis on induction time indicated that additive EDTA had a significant influence on both nucleation and growth of magnesium hydroxide precipitation. The mechanism underlying the effect of EDTA on crystal growth was 2-dimension nucleation-mediated growth model.

Exploiting Additive Manufacturing Infill in Topology Optimization for Improved Buckling Load

Additive manufacturing （AM） permits the fabrication of functionally optimized components with high geometrical complexity. The opportunity of using porous infill as an integrated part of the manufactur- ing process is an example of a unique AM feature. Automated design methods are still incapable of fully exploiting this design freedom. In this work, we show how the so-called coating approach to topology optimization provides a means for designing infill-based components that possess a strongly improved buckling load and, as a result, improved structural stability. The suggested approach thereby addresses an important inadequacy of the standard minimum compliance topology optimization approach, in which buckling is rarely accounted for; rather, a satisfactory buckling load is usually assured through a post-processing step that may lead to sub-optimal components. The present work compares the stan- dard and coating approaches to topology optimization for the MBB beam benchmark case. The opti- mized structures are additively manufactured using a filamentary technique. This experimental study validates the numerical model used in the coating approach. Depending on the properties of the infill material, the buckling load may be more than four times higher than that of solid structures optimized under the same conditions.

Additive Manufacturing： Is It a New Era for Furniture Production？

The purpose of this study is to make a review and or definition of AM （additive manufacturing）, and an evaluation of its use in furniture production within a few projects to provide industry-specific awareness. AM can be considered as one of the latest innovative processes, as a state-of-the-art development, in manufacturing industries. AM is expressed as the future of the products and localization of the manufacturing processes in some studies. Innovation is a key factor both for firms and consumer products or service output. And, in today＇s competitive environment, it compels all the partners for R ＆ D activities to provide technological development. But, all the partners come to a parting of the ways of disruptive or sustainable innovation. It can be said that furniture manufacturing by AM method is relatively new. Non-industrial use of the AM in furniture production can be stated as one of the latest innovative development. Thereby, this study reviews how AM is used to produce furniture within applied projects, which materials and methods are used for production and suggests its future impact.

Lubrication performance of rapeseed oil-based nano-lubricants in parallel tubular channel angular pressing process

Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.

Stability of [BMIM]HSO_4 for using as additive during zinc electrowinning from acidic sulfate solution

The stability of ionic liquid additive 1-butyl-3-methylimidazolium hydrogen sulfate （[BMIM]HSO4） during zinc electrowinning from acidic sulfate solution was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. Compared with the traditional industrial additives, gelatine and gum arabic, [BMIM]HSO4 has more excellent chemical and thermal stabilities. The inhibition effects of gelatine and gum arabic on the zinc electrocrystallization are observed to markedly weaken due to their part degradation after 12 h longtime successive electrolysis and high temperature （90 ℃） treatments. In contrast, the activity of [BMIM]HSO4 is practically unaffected after 24 h longtime successive electrolysis and high temperature treatments. These results are corroborated with the corresponding morphological analysis of the cathodic deposits.

Study on Drying Process of 3Al_2O_3·2SiO_2 Mullite Gel

Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure.

Dechlorination Behavior of Mixed Plastic Waste by Employing Hydrothermal Process and Limestone Additive

The usage of plastic-impregnated waste derived solid fuel in conventional combustor is hindered by many technical factors, especially its organic chlorine content. In this paper, experimental study of hydrothermal treatment on mixed plastic waste using the mixture of polypropylene, polystyrene, polyethylene and polyvinyl chloride （PVC） has been performed to observe the dechlorination effect of hydrothermal treatment on the waste. The system was generally applying saturated steam at around 2.4 MPa in a stirring reactor for about 90 minutes. After undergoing the process, the organic chlorine in treated plastic waste was reduced to 1,700 ppm level while the inorganic chlorine content was increased, suggesting an organic chlorine conversion phenomenon to inorganic chlorine, accompanied with low pH due to dehydrochlorination process. Additional limestone （Ca（OH）2） in subsequent experiment showed that the similar phenomenon was occurred but with higher pH and lower chlorine content in the condensed water, suggesting the production of inorganic salt rather than hydrochloric acid. Laboratory scale experiment was also performed to confirm the dechlorination phenomena especially for PVC, and the result showed that the main parameter which affected the dechlorination phenomena was the amount of water in hydrothermal process rather than limestone addition. It is suggested that a combination ofhydrothermal process and alkali addition would produce a low-chlorine solid product from plastic waste, promoting its usage as alternative solid fuel.

Stochastic calculus for Markov processes associated with non-symmetric Dirichlet forms

Nakao＇s stochastic integrals for continuous additive functionals of zero energy are extended from the symmetric Dirichlet forms setting to the non-symmetric Dirichlet forms setting. ItS＇s formula in terms of the extended stochastic integrals is obtained.

Synergistic improvement of perovskite film quality for efficient solar cells via multiple chloride salt additives

Perovskite crystal film quality is critical for obtaining efficient perovskite solar cells. Anti-solvent processing was used for fast crystallization of perovskite precursor film, which can form dense perovskite film. However, the crystals from this method are usually small due to the fast crystal growth process, which could lead to grain boundary recombination. Here, element chloride is introduced to enhance the perovskite layer crystallinity via slowing down the perovskite crystallization process by simultaneous introduction of methylammounium chloride （MACI） and cesium chloride （CsCl） into precursor solution. As a result, we achieve high quality of pin-hole free perovskite film with large crystal size. A power conversion efficiency of 21.55% with free of hysteresis of the device is obtained, which is among the highest efficiency of planar structure perovskite solar cells.

Formation of magnesium calcite mesocrystals in the inorganic environment only by using Ca^(2+)and Mg^(2+)and its biological implications

Magnesium calcite(Mg-calcite)mesocrystal is widespread in the biominerals with specific functions.Until now,it remains challenging to obtain Mg-calcite mesocrystals without organic additives and the formation mechanism of Mg-calcite mesocrystals in the ocean is not clear yet.We report here the synthesis of corn-like Mg-calcite mesocrystals from pure amorphous calcium carbonate(ACC)via a facile method only by using Ca^(2+)and Mg^(2+).The obtained Mg-calcite is composed of many nanocubes with common crystallographic orientation,which shows very good single crystal feature.In the crystallizing procedure,the ACC nanospheres rapidly agglomerate into Mg-calcite corn-like mesocrystal by oriented attachment(OA)in a certain direction,which belongs to the non-classical nucleation.By this method,the molar ratio of Ca^(2+)and Mg^(2+)plays a vital role in the whole crystallization procedure,which may shed a new light on disclosing the mechanism behind for the effect of seawater in the formation of biological Mg-calcite in nature.

Car capacity near bus stops with mixed traffic derived by additive-conflict-flows procedure

To determinate car capacity at bus stops with mixed traffic, a new theoretical approach was developed on the basis of additive-conflict-flows procedure. The procedure was extended from homogeneous traffic flow to mixed traffic flow. The conflicts among cars, buses and bicycles near the stop can be described by the extended procedure. The procedure can be understood more easily than the theory of gap acceptance. Car capacity near the stop is the function of both bus stream and bicycle stream. The proposed model can also analyze the cases of pedestrian effects and limited priority of bicyclists. Numerical results show that the car capacity decreases with the increasing flow rates of other streams. In addition, pedestrian effects and bicyclist's limited priority have negative effects on car capacity near bus stops with mixed traffic flow.