6-APA溶液物理化学特性的测定

6-氨基青霉烷酸(6-APA)是青霉素的母核,是半合成β-内酞胺抗生素生产的重要中间体。本文对于6-APA的溶液物理化学特性进行了分析与测定,其中包括溶解度、密度、粘度数据等,为6-APA工业化设计提供了依据。

Effect of Salt Solution on Characteristics of Soil Infiltration

[Objective] The aim was to study the effect of salt solution on characteristics of soil infiltration, and to provide references for the further studies on the effect of water quality on soil infiltration characteristics and its mechanism. [Method] With the NaCl, CaCl2 solutions as the main test materials, the effect of different water quality and salt solution concentration on soil infiltration was studied under one-dimensional vertical ponded water infiltration at laboratory. [Result] The solution concentration could affect the infiltration performance. The trends of the infiltration rates, cumulative infiltrations and wetting front migration distances were all 50 mg/L 100 mg/L 10 mg/L. At the same concentration, the effect of NaCl solution on soil infiltration characteristics was more significant than CaCl2 solution： in the same time, cumulative infiltration and wetting front migration distance of NaCl solution were greater than CaCl2 solution; compared with NaCl solution, CaCl2 solution took longer time to infiltrate the same amount of water. The dynamic changes of infiltration rate, wetting front and cumulative infiltration were well fitted to the Philip model. [Conclusion] This study only conducted indoor experiment to the infiltration of salt solutions, involving in low concentration and small range. Although it provided some references for the study on the effect of water quality on soil infiltration characteristics and its mechanism, studies in larger areas and with bigger concentrations are demanding.

Numerical Study on Interaction Between Two Bubbles Rising Side by Side in CMC Solution

A numerical simulation was performed to investigate the interaction of two bubbles rising side by side in shear-thinning fluid using volume of fluid （VOF） method coupled with continuous surface force （CSF） method. By considering rheological characteristics of fluid, this approach was able to accurately capture the deformation of bubble interface, and validated by comparing with the experimental results. The rising of bubble pairs with different configurations, including horizontal alignment and oblique alignment, was simulated by the method. The influences of the bubble initial distance and the bubble alignment were studied by analyzing the bubble deformation, rising paths and flow fields surrounding bubbles. The results indicate that within certam mltlal bubble spacing of S = 3.3 （S＊ = SI/D, SI initial distance between bubbles, and D bubble diameter）, the dynamic interaction between two bub- bles aligned horizontally shows repulsive effect that decreases with the increase of initial bubble spacing, but weakens to certain degree by the shear-thinning properties of fluid. However, the interaction between two bubbles aligned obliquely presents a repulsive effect for the small angle involved but an attractive impact for the large one, which is vet strengthened by the rheological characteristics of fluid.

Rheological Properties of Soy Protein Isolate and Polyurethane in the PAN/DMSO Solution

The rheological properties of soy protein isolate （SPI） and polyurethane （PU） in the PAN/DMSO solution were investigated in this study. The results showed that all these solutions possessed pseudo-plastic solution properties. There are opposite effects of SPI and PU in the PAN/DMSO solution. Their apparent viscosity, degree of non-Newtonian fluid, and extent of structuralization of blend system increase with the addition of SPI, whereas, all of these decrease with the addition of PU. Moreover, the theological properties of PAN/DMSO solution were affected when SPI and PU were added equally, and SPI presented more effect when the proportion of ingredient was less, and PU presented more effect when the proportion of ingredient was more.

Study on Absorption and Regeneration Performance of Novel Hybrid Solutions for CO_2 Capture

Recently, a kind of hybrid solution MEA-methanol shows a better CO_2 capture performance over aqueous MEA solution. However, the vaporization of methanol is the biggest disadvantage that hinders its application, so it is necessary to minimize the vaporization of methanol during both the absorption and regeneration processes. In this work, two kinds of hybrid solutions were studied and compared with aqueous MEA solution and MEA-methanol solution, including MEA/TEA/methanol solution and MEA/glycerol/methanol solution. The absorption property of MEA/glycerol/methanol solution is better than aqueous MEA solution within a certain period of time and the absorption property of MEA/TEA/methanol solution is too poor to be used in CO_2 capture. By increasing the concentration of TEA and decreasing the concentration of MEA, the absorption rate, CO_2 capture efficiency and absorption capacity all decreased. Upon adding glycerol, the cyclic capacity decreased and the generation temperature increased, and moreover, the density and viscosity also increased considerably. So after adding TEA and glycerol, the CO_2 capture performance of MEAmethanol solvent cannot be improved.

Electrodeposition behavior and characteristics of Ni-carbon nanotube composite coatings

Ni-CNT (carbon nanotube) composite coatings were processed by electrodeposition and their hardness and corrosion characteristics were investigated with variations of CNT concentration in an electrolyte solution and electrodeposition current density. With increasing the CNT concentration in the electrodeposition bath and the current density, more CNTs are incorporated into Ni matrix. Hardness values of the Ni-CNT coatings are irrelevant to the CNT concentration in the solution, the current density, and current mode, implying poor adhesion of CNTs to Ni matrix. With increasing the CNT content in the coating, the corrosion resistance of the Ni-CNT composite coating becomes inferior due to the porous microstructure.

The Flow Behavior of Poly(m-Phenyleneisophthalamide) Concentrated Solution

By means of HAAKE RS105L cone and plate rheometer the concentrated solution, including viscous flow activation energy, non-Newtonian index, structural viscosity index and relaxation time of the PMIA solution were studied. The effect of concentration and temperature of the solution and molecular weight of the polymer on its non-Newtonian behavior was investigated. The results showed that PMIA concentrated solution prepared via low temperature condensation was of non-Newtonian fluid. With the decrease of temperature, increase of solution concentration and PMIA molecular weight, the deviation of the solution from Newtonian behavior decreased. The molecular weight of the polymer and the concentration of the solution affected the non- Newtonian behavior mete intensively.

Alkaline extraction characteristics of steelmaking slag batch in NH_4Cl solution under environmental pressure

In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH4CI concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH4C1 solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38-75 μm slag batch is more obvious than 75 150 μm slag and slag with larger particle size when leaching in 0.4 mol/L NH4Cl solution for 90 rain at 60 ℃.

Experimental study on SO_2 recovery using a sodium-zinc sorbent based flue gas desulfurization technology

A sodium–zinc sorbent based flue gas desulfurization technology(Na–Zn-FGD) was proposed based on the experiments and analyses of the thermal decomposition characteristics of Ca SO3 and Zn SO3·2.5H2 O, the waste products of calcium-based semi-dry and zinc-based flue gas desulfurization(Ca–SD-FGD and Zn–SD-FGD) technologies, respectively. It was found that Zn SO3·2.5H2 O first lost crystal H2 O at 100 °C and then decomposed into SO2 and solid Zn O at 260 °C in the air, while Ca SO3 is oxidized at 450 °C before it decomposed in the air. The experimental results confirm that Zn–SD-FGD technology is good for SO2 removal and recycling, but with problem in clogging and high operational cost. The proposed Na–Zn-FGD is clogging proof, and more cost-effective. In the new process, Na2CO3 is used to generate Na2SO3 for SO2absorption, and the intermediate product Na HSO3 reacts with Zn O powders, producing Zn SO3·2.5H2 O precipitate and Na2SO3 solution. The Na2SO3 solution is clogging proof, which is re-used for SO2 absorption. By thermal decomposition of Zn SO3·2.5H2 O, Zn O is re-generated and SO2 with high purity is co-produced as well. The cycle consumes some amount of raw material Na2CO3 and a small amount of Zn O only. The newly proposed FGD technology could be a substitute of the traditional semi-dry FGD technologies.

SYNTHESIS OF BOWL-LIKE PARTICLES BY EMULSION POLYMERIZATION AND RELEASE BEHAVIOR OF SOLVENT FROM THE PARTICLES

Poly(styrene-glycidyl methacrylate) particles having bowl-shaped hollow structures were synthesized by swollen seed emulsion polymerization. The PS emulsion synthesized through soap-free emulsion polymerization was swollen by toluene, and then the mixture of second monomers was added under polymerization condition. So a thin shell of poly(styrene-glycidyl methacrylate) cross-linked by triethylene glycol diacrylate was formed around the swollen PS particle. The bowl-shaped particles were obtained after the collapsing of the thin shell when the toluene emanated from the particles, but the shapes were effected by the degrees of cross-linking. The shape of the particles was observed by SEM. The release behavior of solvent from the particles was examined by TG.

Effect of Injection Parameters on Evaporation and Thermolysis Characteristics of UWS （Urea-Water-Solution） in SCR （Selective Catalytic Reduction） Systems

UWS （optimized Urea-Water Solution） injection system is required to increase the NH3 conversion efficiency of urea-based SCR （Selective Catalytic Reduction） system of modem automobiles. The focus of the current study is to do parametric studies by simulation in a three-dimensional model using CFD （Computational Fluid Dynamics） code AVL FIRE. Simulations were carried out to study the characteristics of evaporation and thermolysis UWS considering the effect of injection velocity, duration of injection, injection angle and for different types of injection. In the case of the injection velocities up to 20-50 m/sec, the ammonia concentration continues to increase. It is found that as the duration injection decreases, the concentration of ammonia increases. In case of continuous injection, the flow rate is less which results in lower velocity of injection, lesser atomization and slower evaporation resulting lesser conversion of UWS into NH3. Shorter duration of injection leads better atomization with increased velocity of injection which results in faster evaporation and thermolysis.

Intrinsic viscosity of polymer solutions: fresh ideas to an old problem

Intrinsic viscosity is one of the most fundamental properties of dilute polymer solutions; its study forms an integral part of the cornerstone of the modern macromolecular theory. However, a general theory applicable to any chain architectures and solvent conditions has remained elusive, due to the formidable challenges in the theoretical treatment of the long-range, many-body and accumulative hydrodynamic effects. Recently, Lijia An and coworkers at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, has developed a new approach that largely overcomes these challenges. Their new theory provides a simple and unified theoretical framework for describing the intrinsic viscosity of polymers with arbitrary architectures under any solvent conditions and forms the theoretical basis for inferring the polymer chain structure from intrinsic viscosity measurements. Comparisons with existing experimental data yield extensive, quantitative agreement.

Drag-reduction of a nonionic surfactant aqueous solution and its rheological characteristics

In order to develop turbulent drag-reducing technology by using an environmentally friendly additive in a water-transporting system,the drag reducing characteristics in a non-ionic surfactant(Oleyldimethylamineoxide,ODMAO) dilute aqueous solution flowing in a circular pipe of 5 mm diameter have been experimentally investigated with an air-driven fluid resistance test device.The rheological characteristics of the solution have also been examined by a rheometer with a cone-plate flow cell.The results show that the ODMAO solutions are drag-reducing when concentration is 400 ppm or higher,that the critical Reynolds number corresponding to the maximum drag reduction rate increases with both concentration and temperature,and that the maximum drag reduction rate can reach up to 70% in the straight pipe.At low shear rates,the shear viscosity of ODMAO solutions with a relatively high drag-reduction behaves similarly to Newtonian fluids;at above a certain critical shear rate,it is firstly shear-thickening,then shear-thinning.Such shear-rate-dependent characteristics of the shear viscosity are attributed to the different transitions of micellar network structure induced by different shear rates.Relaxation of shear stress after removing an applied constant shear rate at which the solution is in the SIS(shear-induced structure) state is found to be well expressed by a 2-step Maxwell model with a tail relaxation time much shorter than that for a drag-reducing cationic surfactant,which indicates that for the ODMAO solution,a viscoelasticity as strong as a drag-reducing cationic surfactant is not needed to realize turbulent drag-reduction.

Nickel-doped CoN nanowire bundles as efficient electrocatalysts for oxygen evolution reaction

Cost-efficient electrocatalysts composed of earth-abundant elements are highly desired for enhanced oxygen evolution reaction (OER).As a promising candidate,metallic Co4N already demonstrated electrocatalytic performance relying on specific nanostructures and electronic configurations.Herein,nickel was introduced as the dopant into one-dimensional (1D) hierarchical Co4N structures,achieving effective electronic regulation of Co4N toward high OER performance.The amount of Co3+increased after Ni-doping,and the in-situ formed surface oxyhydroxide during OER enhanced the electrocatalytic kinetics.Meanwhile,the 1D hierarchical structure further promoted the performances of Co4N owing to the high electrical conductivity and abundant activesites on the rough surface.As expected,the optimal Ni-doped Co4N with a Ni/Co molar ratio of 0.25 provides a small overpotential of 233 mV at a current density of 10 mA cm^(-2),with a low Tafel slope of 61 mV dec^(-1),and high long-term stability in 1.0 mol L^(-1)KOH.Following these results,the enhancement by doping the Co4N nanowire bundles with Fe and Cu was further evidenced for the OER.

Facile synthesis of nickel cobalt selenide hollow nanospheres as efficient bifunctional electrocatalyst for rechargeable Zn-air battery

Designing high active,low cost and bifunctional electrocatalysts is urgent for developing clean energy storage and conversion systems.Transition metal selenides exhibit optimal electronic conductivity and tunable physicochemical properties,which endow them with potential for efficient electrocatalysts to facilitate the oxygen reduction and oxygen evolution reactions(ORR and OER).Herein,hollow NixCo0.85-xSe nanospheres were synthesized using a facile polyol based solution chemical method.The NixCo0.85-xSe exhibits an onset overpotential of 0.89 V for ORR,and an overpotential of 305 mV to achieve 10 mA cm^-2 for OER.Moreover,the NixCo0.85-xSe based Zn-air battery displays remarkable specific capacity and durability.Such superior catalytic performances can be attributed to the synergistic effect,large specific surface area and enhanced electron transfer rate.This approach provides a new way to design highly efficient bifunctional electrocatalysts for electrochemical energy storage and utilization.