《本草纲目》在中药剂型学方面的成就

《本草纲目》对祖国医药学的巨大贡献已为世人所公认,有关研究论文很多,但《本草纲目》在中药剂型学方面的成就尚未引起人们的注意,许多文献均记《本草纲目》收载中药剂型40余种,至今一直未见有确切的研究报告,笔者依照经典药剂学剂型的综合分类法对《本草纲目》收载的剂型进行汇综整理,确认有约60种,多数剂型现在仍在广泛使用,部分剂型被改进,对现代药物剂型的设计影响极为深远。

《临床中药剂型学》课程体系的构建及教学方法的改革探讨

根据临床上剂型的选择及应用以及在《临床中药剂型学》教学过程中存在的问题与不足,教学团队重新构建了《临床中药剂型学》的教学内容和课程体系,使其教学内容由原来的重视生产工艺和质量控制向临床应用转变,并对其教学方法和手段进行了改革与探索。实践表明,新构建的教学内容及课程体系对学生临床剂型的选择和合理用药能力的培养更加符合临床需求;采用多种教学模式和教学方法能有效地调动学生的积极性和主动性,提高了学生的学习兴趣及课堂教学质量。

Kinetics of cerium(Ⅳ) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant(Bif-ILE)[A336][P204]

The extraction kinetics of Ce（Ⅳ） and Ce（Ⅳ）-F^- mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE[A336][P204]（[trialkylmethylammonium][di-2-ethylhewanxylphosphinate]） with a constant interfacial area cell with laminar flow were studied,just to elucidate the extraction mechanism and the mass transfer models.The data were analyzed in terms of pseudo-first-order constants.The effects of stirring speed,specific interfacial area and temperature on the extraction rate in both systems were discussed,suggesting that the extractions were mixed bulk phases-interfacial control process.Supported by the experimental data,the corresponding rate equations for Ce（Ⅳ） extraction system and Ce（Ⅳ）-F^- mixture extraction system were obtained.The experimental results indicated the rate-controlling step.The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.

Leaching characteristics of ion-adsorption type rare earths ore with magnesium sulfate

Magnesium sulfate was proposed to be leaching agent to deal with the ion-adsorption type rare earths ore to reduce or even eliminate ammonia?nitrogen emissions. The effects of temperature, particle size and stirring speed on rare earth leaching process and the leaching behaviors of the single rare earth element were investigated in order to reveal the rare earth leaching characteristics. Besides, the comparison of leaching effects between magnesium sulfate and ammonium sulfate was also studied. The results showed that the rare earth leaching process could be well described with inner diffusion control model and the apparent activation energy was 9.48 kJ/mol. The leaching behaviors of the single rare earth element were brought into correspondence with rare earths. Moreover, when the concentration of leaching agent was 0.20 mol/L, the rare earth leaching efficiency could all reach above 95% and the leaching efficiency of aluminum impurities could be restrained by 10% using magnesium sulfate compared with ammonium sulfate.

Synthesis of Li^+ adsorbent(H_2TiO_3) and its adsorption properties

H2TiO3 was obtained from the acid-modified adsorbent precursor Li2TiO3,which was synthesized by a solid-phase reaction between TiO2 and Li2CO3.The extraction ratio of Li＋ from Li2TiO3 was 98.86%,almost with no Ti4＋ extracted.The effects of lithium titanium ratio,calcining temperature and time were investigated on the synthesis of Li2TiO3.Li2TiO3,H2TiO3 and the adsorbed Li＋ adsorbent were characterized by XRD and SEM.The lithium adsorption properties were investigated by the adsorption kinetics and adsorption isotherm.The results indicate that H2TiO3 has an excellent adsorptive capacity for Li＋.Two simplified kinetic models including the pseudo-first-order and pseudo-second-order equations were selected to follow the adsorption processes.The rate constants of adsorption for these kinetic models were calculated.The results show that the adsorption process can be described by the pseudo-second-order equation,and the process is proved to be a chemical adsorption.The adsorption process that H2TiO3 adsorbs Li＋ in LiCl solution well fits the Langmuir equation with monolayer adsorption.

Oxidation of formic acid on stepped Au(997) surface

The adsorption and reaction of formic acid （HCOOH） on clean and atomic oxygen‐covered Au（997） surfaces were studied by temperature‐programmed desorption/reaction spectroscopy （TPRS） and X‐ray photoelectron spectroscopy （XPS）. At 105 K, HCOOH molecularly adsorbs on clean Au（997） and interacts more strongly with low‐coordinated Au atoms at （111） step sites than with those at （111） terrace sites. On an atomic oxygen‐covered Au（997） surface, HCOOH reacts with oxygen at‐oms to form HCOO and OH at 105 K. Upon subsequent heating, surface reactions occur among ad‐sorbed HCOO, OH, and atomic oxygen and produce CO2, H2O, and HCOOH between 250 and 400 K. The Au（111） steps bind surface adsorbates more strongly than the Au（111） terraces and exhibit larger barriers for HCOO（a） oxidation reactions. The surface reactions also depend on the relative coverages of co‐existing surface species. Our results elucidate the elementary surface reactions between formic acid and oxygen adatoms on Au surfaces and highlight the effects of the coordina‐tion number of the Au atoms on the Au catalysis.

Research Progress of Palladium Catalysts for Methane Combustion

Recent research progress and development of the palladium catalysts for methane combustion are described in this study.The influence of active species,precursor,solvent,preparation methodologies,support and dopant on the catalytic activity and thermal stability of the palladium catalysts was discussed.Results of deactivation and poisoning of palladium catalysts were analyzed.Furthermore,possible kinetic models and reaction mechanism were indicated for Pd catalysts.

Simulation of gas-solid fluidized bed reactor for F-T synthesis

Using the lumping method, CH_4, C_3H_8, C_10H_22, and C_22H_44 were chosen as themodel products, and CO as the key component. The mathematical model of a gas-solidfluidized bed reactor was established based on some hypotheses. The consumption kinetic model of CO was investigated, and the parameters were estimated by UniversalGlobal Optimization with the Marquardt method. Residual error distribution and a statisticaltest show that the intrinsic kinetic models are reliable and acceptable. A model of carbonchain growth probability was established in terms of experiments. Coupled with the Ander-son- Schulz-Flory (ASF) distribution, the amount of specific product could be obtained.Large- scale cold model experiments were conducted to investigate the distribution of thegas (solid) phase and determine the function of the voidage with the location of the catalytic bed. The change tendencies of the components in the catalytic bed at different temperatures were computed and figured out. The calculated value computed by the modelestablished for the Fe-based F-T synthesis catalyst fit the experimental value very wellunder the same operating conditions, and all the absolute values of the relative deviationsare less than 5%.

Mathematical models for properties of mortars with admixtures and recycled fine aggregates from demolished concretes

In order to expand the engineering application of recycle aggregate mortars （RAM） with aggregates from demolished concretes, the models for the properties of RAM and the replacement rate of these recycled fine aggregates were proposed. First, different kinds of mathematical models for the basic properties （compressive strength, water retention rate, and consistency loss） of RAM with two kinds of admixtures, thickening powders （TP） and self-made powdery admixtures （SSCT） designed for RAM, and the replacement rates were established, while the average relative errors and relative standard errors of these models were calculated. Additionally, the models and their error analyses for the curves of drying shrinkage and curing time of RAM ＋ SSCT at different replacement rates were put forward. The results show that polynomial functions should be used to calculate the basic properties of RAM ＋ TP and RAM ＋ SSCT at different replacement rates. In addition, polynonfial functions are the most optimal models for the sharp shrinkage sections in the curves of drying shrinkage-curing time of RAM ＋ SSCT, while exponential functions should be used as the models for the slow shrinkage sections and steady shrinkage sections.

Thymoquinone and Poloxin are slow-irreversible inhibitors to human Polo-like kinase 1 Polo-box domain

Objective： To provide a kinetic model（s） and reveal the mechanism of thymoquinone and Poloxin blocking an emerging anti-cancer target, human Polo-like kinase 1 （hPlkl） Polo-box domain （PBD）. Methods： The binding kinetics was determined by using a fluorescence polarization based assay. The putative mechanism was examined with a competition test. Results： Thymoquinone follows a one-step binding with an association rate constant （k1） of 6.635× 10^3 L.mol^-1 min^-1.Poloxin fit a two-step binding with a dissociation constant （Ki） of 118 μmol/L for the intermediate complex and its isomerization rate （k4） of 0.131 5 minJ to form an irreversible adduct. No significant dissociation was observed for either ligand up to 13 h. The inhibitors responded insignificantly to the presence of Michael donors as hPIkl-PBD competitors. Conclusion： Thymoquinone and Poloxin are slow-tight ligands to the hPlkl-PBD with kinetic models distinct from each other. Michael addition as the mechanism is excluded.

Experimental and Kinetic Study of Selective Catalytic Reduction of NO with NH_3 over CuO/Al_2O_3/Cordierite Catalyst

The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy Eá of 94.01 kJ·mol-1 and the corresponding p re-exponential factor A′ of 3.39×108 cm3·g-1·s-1 when NH3 is excessive. However, when NH3 is not enough, an E ley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ·mol-1, the corresponding A of 2 .94×109 cm3·g-1·s-1, heat of adsorption-Hads of 87.90 kJ·mol-1 and the corresponding Aads of 9.24 cm3·mol-1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reac-tor design and engineering scale-up.

A Unified Model for the Degradation Kinetics of Pesticides Applied Continually to Soils

This paper deduces a kinetic model for microbial degradation of pesticides in soils:where x is the concentration of pesticide at time t, so the initial concentration of the pesticide, me the initial number of pesticide-degrading microorganisms, M the carrying capacity for the microorganisms, μ the specific growth rate of the microorganisms, and k the rate constant for the pesticide degradation.In periodic applications of pesticides, this model can be used to continuously describe every degradation curve. Whether a lag phase occurs or not, we can obtain the minimum residue of the pesticide (xe):xe=xdexp(-kMr)/[1-exp(-ker) ]where r is the regular time internals between applications, and xd the dosage of the pesticide.

Study on methanol synthesis from coal-based syngas

The intrinsic kinetic models of the Langmuir-Hinshelwood type were investigated in terms of the reaction rates of CO hydrogenation and CO_2 hydrogenation in theform of reactant fugacity. The parameters were estimated by the Universal Global Optimization using the Marquardt method. Residual error distribution and statistic tests show thatthe intrinsic kinetic models are reliable and acceptable. The mathematic model of a combined converter formed by gas-cooled and water-cooled reactor was developed and thegas-cooled reactor and the water-cooled reactor were characterized with one-dimensionalmathematic model. The distributions of temperature and concentration in the catalytic bedof the gas-cooled reactor and the water-cooled reactor in a combined converter with ayield of 1.2 Mt/a were simulated. The parallel cross linking pore model was used to describe the transfer process of multi-component diffusion system in the catalyst. The calculated value computed by the internal diffusion efficiency factor calculation model established for methanol synthesis catalyst fit the experimental value very well.

Evaluation of solvent-mediated phase transformation of glycine using oleic acid: Morphology and characterization study

The polymorphic phase transformation of β-glycine to α-glycine was carried out both in the absence and presence of various concentrations of oleic acid used as additive at 25 ℃ in a water/ethanol medium. The effects of oleic acid and its concentration on phase transformation time were determined by continuously measuring the ultrasonic velocity. The crystals obtained by the completion of the phase transformation were characterized by XRD, SEM, and TG/DTG. The XRD and SEM results indicated that oleic acid significantly impacted phase transformation time and the morphological characteristics of the crystals. In addition to SEM analysis, detailed crystal shape analysis was performed and the circularity, elongation, and convexity parameters were determined quantitatively. TG/DTG analyses were performed to investigate thermal decomposition behavior and to calculate the activation energies based on different kinetic models such as FWO, KAS, Starink, and Tang kinetic models. With the addition of oleic acid to the medium, the calculated activation energy values increased from 89.63–90.63 to153.8–155.4 kJ·mol^（-1）. The activation energy values showed that oleic acid was adsorbed on the crystal surface;this result was supported by FTIR, elemental, and Kjeldahl analyses.

Synthesis of a novel functional group-bridged magnetized bentonite adsorbent:Characterization,kinetics,isotherm,thermodynamics and regeneration

A novel magnetic adsorbent was synthesized by magnetizing bentonite by APTES-Fe_3O_4 via a functional groupbridged interaction. The characterization of APTES-Fe_3O_4/bentonite was conducted via transmission electron microscope(TEM), X-ray diffraction(XRD), Fourier transform infrared spectrophotometer(FT-IR), thermal gravimetric analysis(TGA), vibrating sample magnetometer(VSM), zeta potential analysis and Brunner–Emmet–Teller(BET). The APTES-Fe_3O_4/bentonite was assessed as adsorbents for methylene blue(MB) with a high adsorption capacity(91.83 mg·g^(-1)). Factors affecting the adsorption of MB(such as p H, equilibrium time, temperature and initial concentration) were investigated. The adsorption process completely reaches equilibrium after 120 min and the maximum sorption is achieved at p H 8.0. The adsorption trend follows the pseudosecond order kinetics model. The adsorption data gives good fits with Langmuir isotherm model. The parameter factor RLfalls between 0 and 1, indicating the adsorption of MB is favorable. The adsorption process is endothermic with positive ΔH^0 values. The positive values of ΔG^0 confirm the affinity of the adsorbent towards MB, and suggest an increased randomness at the solid–liquid interface during the adsorption process. Regeneration of the saturated adsorbent was easily carried out via gamma-irradiation.

Nanoscale architecture of ceria-based model catalysts: Pt-Co nanostructures on well-ordered CeO_(2)(111) thin films

We have prepared and characterized atomically well-defined model systems for ceria-supported Pt-Co core-shell catalysts. Pt@Co and Co@Pt core-shell nanostructures were grown on well-ordered CeO2(111) films on Cu(111) by physical vapour deposition of Pt and Co metals in ultrahigh vacuum and investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The deposition of Co onto CeO2(111) yields CoCeO2(111) solid solution at low Co coverage(0.5 ML), followed by the growth of metallic Co nanoparticles at higher Co coverages. Both Pt@Co and Co@Pt model structures are stable against sintering in the temperature range between 300 and 500 K. After annealing at 500 K, the Pt@Co nanostructure contains nearly pure Co-shell while the Pt-shell in the Co@Pt is partially covered by metallic Co. Above 550 K, the re-ordering in the near surface regions yields a subsurface Pt-Co alloy and Pt-rich shells in both Pt@Co and Co@Pt nanostructures. In the case of Co@Pt nanoparticles, the chemical ordering in the near surface region depends on the initial thickness of the deposited Pt-shell. Annealing of the Co@Pt nanostructures in the presence of O2 triggers the decomposition of Pt-Co alloy along with the oxidation of Co, regardless of the thickness of the initial Pt-shell. Progressive oxidation of Co coupled with adsorbate-induced Co segregation leads to the formation of thick CoO layers on the surfaces of the supported Co@Pt nanostructures. This process is accompanied by the disintegration of the CeO2(111) film and encapsulation of oxidized Co@Pt nanostructures by CeO2 upon annealing in O2 above 550 K. Notably, during oxidation and reduction cycles with O2 and H2 at different temperatures, the changes in the structure and chemical composition of supported Co@Pt nanostructures were driven mainly by oxidation while reduction treatments had little effect regardless of the initial thickness of the Pt-shell.

Kinetic studies on the dimerization of isobutene with Ni/Al_2O_3 as a catalyst for reactive distillation process

Isooctane is a promising gasoline additive that could be produced by dimerization of isobutene(IB) with subsequent hydrogenation.In this work,the dimerization of IB has been carried out in a batch reactor over a temperature range of 338-383 K in the presence of laboratory prepared Ni/Al_2O_3 as a catalyst and n-pentane as solvent.The influence of various parameters such as temperature,catalyst loading and initial concentration of IB was examined.A Langmuir-Hinshelwood kinetic model of IB dimerization was established and the parameters were estimated on the basis of the measured data.The feasibility of oligomerization of IB based on the reactive distillation was simulated in ASPEN PLUS using the kinetics developed.The simulation results showed that the catalyst of Ni/Al_2O_3 had higher selectivity to diisobutene(DIB) and slightly lower conversion of IB than ion exchange resin in the absence of polar substances.

Cadmium sorption from aqueous solutions onto Iranian sepiolite:Kinetics and isotherms

This work aims to investigate the efficiency of Fariman sepiolite from Iran as an adsorbent to remove Cd from aqueous solutions. The effects of different experimental factors such as the initial Cd concentration, contact time and the sorbent dose were investigated through a series of batch adsorption experiments. The results show that the adsorption capacity of sepiolite for Cd increases with the contact time, the initial concentration of Cd solutions and the sorbent dose. Sorption of Cd by Fariman sepiolite is rapid within the first hour of the experiment and then slowly increases until a pseudo equilibrium is approached at 8 h. The results also show that the time-dependent Cd sorption data are better described with pseudo second-order （7〉0.999） than that of pseudo first-order （r2〉0.971） kinetic model. Equilibrium isotherm studies show that the experimental data are better correlated by the Freundlich adsorption isotherm （7〉0.995） than the Langmuir （P〉0.825）. It is suggested that both adsorption and cation exchange reactions are responsible for the sorption of Cd by the sepiolite, and the mineral has a very good potential to remove Cd from aqueous solutions.

On the fracture resistance of adhesively jointing structures

The interface toughness of adhesively bonded structural members is one of the critical parameters for adhesive joint design. It is often assumed that the joint toughness is a material constant so that its value can be obtained from fracture tests of simple geometries such as DCB for Mode-Ⅰ, ENF for Mode-Ⅱ, using linear elastic fracture mechanics （LEFM）. However, the LEFM assumption of point-wise crack-tip fracture process is overly simplistic and may cause significant error in interpreting fracture test data. In this paper, the accuracy and applicability of various traditional beam-bending-theory based methods for fracture toughness evaluation, such as simple beam theory （SBT）, corrected beam theory （CBT） and experimental compliance method （ECM）, were assessed using the cohesive zone modelling （CZM） approach. It was demonstrated that the fracture process zone （FPZ） size has profound influence on toughness calculation and unfortunately, all the classic beam-bending theories based methods fail to include this important element and are erroneous especially when the ratio of crack length to FPZ size is relatively small （〈5.0）. It has also been demonstrated that after the FPZ size is incorporated into simple beam formulations, they provide much improved evaluation for fracture toughness. Formulation of first order estimate of FPZ size is aIso given in this paper.

Application of a Kinetic Multireaction Model for Studying Metolachlor Adsorption in Soil

Metolachlor retention on a Sharkey clay soil was quantified using a kinetic batch method for different initial solution concentrations. Time-dependent adsorption was carried out by monitoring solution concentration at different reaction times. Adsorption was found to be highly kinetic in nature. Attempts were made to describe metolachlor retention based on a kinetic multireaction model which includes reversible and irreversible retention processes of the equilibrium and kinetic types. The predictive capability of the model for the description of experimental results for metolachlor retention was examined and proved to be adequate.