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Semi-solid materials for controlled release drug formulation: current status and future prospects

Michelle TRAN,Chun WANG

《化学科学与工程前沿（英文）》 2014年第8卷第2期页码 225-232 doi: 10.1007/s11705-014-1429-7

摘要： Semi-solid materials represent an important category of inactive ingredients (excipients) of pharmaceutical products. Here we review several common semi-solid polymers currently used in the controlled release formulations of many drugs. These polymers are selected based on their importance and broad scope of application in FDA-approved drug products and include several polysaccharides (cellulose, starch, chitosan, alginate) and carbomers, a group of mucoadhesive synthetic polymers. Glyceride-based polymers used in self-emulsifying drug delivery systems (SEDDS) will also be discussed for its importance in formulating poorly water-soluble drugs. Unique features and advantages of each type of semi-solid materials are discussed and examples of their use in oral delivery of drugs are provided. Finally, future prospects of developing new and better semi-solid excipients are discussed with the objective of facilitating clinical translation.

关键词： controlled release drug delivery semi-solids polymer excipient

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A concise review about fracture assessments of brittle solids with V-notches

Hsien-Yang YEH, Bin YANG

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 478-485 doi: 10.1007/s11709-019-0520-z

摘要：

A concise review of recent studies about the fracture assessments of elastic brittle solid materials containing V-notches is presented. In this preliminary and brief survey, elastic stress distributions in V-notched solids are discussed first. The concept of notch stress intensity factor is introduced. Combine the digital image correlation method with numerical computation techniques to analyze the stress distribution near the notches. Fracture criteria such as strain energy density, J-integral, theory of critical distance are used.

关键词： fracture assessment brittle solids V-notches review

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High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion with high solids

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

《化学科学与工程前沿（英文）》 2020年第14卷第6期页码 1087-1099 doi: 10.1007/s11705-019-1895-z

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Modeling of solids segregation in circulating fluidized bed boilers

Xuan YAO, Tao WANG, Jia ZHAO, Hairui YANG, Hai ZHANG

《能源前沿（英文）》 2011年第5卷第1期页码 115-119 doi: 10.1007/s11708-010-0103-0

摘要： Segregation always occurs in a circulating fluidized bed (CFB) because of the wide distribution of particle size and density of the bed material. Terminal velocity has a significant influence on solids segregation; thus, it is convenient to describe the segregation tendency using single particle terminal velocity . This paper proposes a segregation model in CFB boilers based on the Cell Model. In each cell along the riser, varied-sized particles have different tendencies toward segregation; finer particles are carried out more easily, while coarser ones tend to sink into the cell. It is assumed that the average terminal velocity , corresponding to the mean particle size in the cell, has a segregation index of = 1.0 as the reference point. The segregation index of particles with higher terminal velocity is lower than 1.0, while that for finer particles is larger than 1.0. The empirical formulae of segregation parameters, namely and , are derived by optimizing experimental data in published literature. The test result of ash size distribution in a 220 t/h CFB boiler validates the reasonableness of the model.

关键词： segregation model terminal velocity circulating fluidized bed (CFB)

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Micromixing performance of the teethed high shear mixer under semi-batch operation

《化学科学与工程前沿（英文）》 2022年第16卷第4期页码 546-559 doi: 10.1007/s11705-021-2069-3

摘要： Semi-batch operated reaction processes are necessary for some competitive reaction systems to achieve a desirable process selectivity and productivity of fine chemical products. Herein the structural and operating parameters of the teethed high shear mixers were adjusted to study the micromixing performance in the semi-batch operated system, using the Villermaux/Dushman reaction system. The results indicate that the rising of the rotor speed and the number of rotor teeth, the decrease of the width of the shear gap and the radial distance between the feed position and the inner wall of stator can enhance the micromixing level and lead to the decrease of the segregation index. Additionally, computational fluid dynamics calculations were carried out to disclose the evolution of the flow pattern and turbulent energy dissipation rate of the semi-batch operated high shear mixer. Furthermore, the correlation was established with a mean relative error of 8.05% and R² of 0.955 to fit the segregation index and the parameters studied in this work, which can provide valuable guidance on the design and optimization of the semi-batch operated high shear mixers in practical applications.

关键词： high shear mixer semi-batch operation micromixing performance Villermaux/Dushman system segregation index

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Bending and rotational behaviour of semi-continuous composite beams

WANG Jingfeng, LI Guoqiang

《结构与土木工程前沿（英文）》 2008年第2卷第2期页码 116-122 doi: 10.1007/s11709-008-0015-9

摘要： Stresses and deflections were measured in various semi-continuous composite beams. The bending and rotational capacities of the composite connections were measured in terms of beam curvatures and deflections by using two full-scale semi-rigid composite frames with monotonic loadings. The effect of semi-rigid connections on the performance of composite beams with various loadings was compared with predictions and codes. The tests show that the semi-continuous composite beams are more economic and effective than the simple or continuous composite beams. The semi-rigid connections affect the bending capacities and beam deflections, so the connection behavior should be considered in the design of composite beams. Yielding analysis of the steel beam bottom flange has some influence on the deflection calculation of composite beams.

关键词： rotational effective deflection calculation semi-continuous composite full-scale semi-rigid

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Impact of solids on biphasic biodegradation of phenanthrene in the presence of hydroxypropyl- β

Zhenyi ZHANG, Chihiro INOUE, Guanghe LI,

《环境科学与工程前沿（英文）》 2010年第4卷第3期页码 329-333 doi: 10.1007/s11783-010-0232-z

摘要： The consequence of polycyclic aromatic hydrocarbons (PAHs) in the environment is of great concern. The hydrophobic properties of PAHs significantly impact phase distribution causing limited bioavailability. Enhanced biodegradation has been extensively carried out by surfactants and the redeployment effect was recognized. However, the quantitative relationship concerning the impact of solids was rarely reported. A batch of biphasic tests were carried out by introducing PYR-1 and hydroxypropyl--cyclodextrin (HPCD) into a mixture of phenanthrene solution and various glass beads (GB37-63, GB105-125, and GB350-500). The comparative results demonstrated that HPCD had little effect on microbial growth and was not degradable by bacterium. A model was proposed to describe the biodegradation process. The regression results indicated that the partition coefficient (1.234, 0.726 and 0.448 L·g) and the degradation rate (0 mmol·L: 0.055, 0.094, and 0.112; 20 mmol·L: 0.126, 0.141, and 0.156; 40 mmol·L: 0.141, 0.156 and 0.184 d) were positively and negatively correlated with the calculated total surface area (TSA) of solids, respectively. Degradation enhanced in the presence of HPCD, and the enhancing factor was calculated (20 mmol·L: 15.16, 40.01, and 145.5; 40 mmol·L: 13.29, 37.97, and 138.4), indicating that the impact of solids was significant for the enhancement of biodegradation.

关键词： biphasic biodegradation hydroxypropyl-β -cyclodextrin (HPCD) polycyclic aromatic hydrocarbons (PAHs)

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Gas-solids separation model of a novel FCC riser terminator device: super short quick separator (SSQS

LU Chunxi, LI Ruxin, SHI Mingxian, LIU Xiancheng

《化学科学与工程前沿（英文）》 2008年第2卷第4期页码 462-467 doi: 10.1007/s11705-008-0068-2

摘要： The gas flow field and the separation efficiency of a novel fluid catalytic cracking (FCC) riser terminal device, named as Super Short Quick Separator (SSQS), were studied. On the basis of above investigations, a section-lateral-mixing separation model was proposed, which included both the effect of inertia and structure of gas outlet on particles capture. After final modification, the results predicted with this model could be in good agreement with the cold experimental data. According to this model, the separation efficiency of SSQS is mainly influenced by the difference between the arc radius and the center pipe radius as well as the magnitude of particle tangential velocity.

关键词： catalytic cracking separation efficiency tangential velocity agreement magnitude

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Prediction of the theoretical and semi-empirical model of ambient temperature

Foued CHABANE,Noureddine MOUMMI,Abdelhafid BRIMA,Abdelhafid MOUMMI

《能源前沿（英文）》 2016年第10卷第3期页码 268-276 doi: 10.1007/s11708-016-0413-y

摘要： It is well known that the ambient temperature is a sensitive parameter which has a great effect on biology, technology, geology and even on human behavior. A prediction is a statement about an uncertain event. It is often, but not always, based upon experience or knowledge. Although guaranteed accurate information about the future is in many cases impossible, prediction can be useful to assist in making plans about possible developments. As a result, temperature profiles can be developed which accurately represent the expected ambient temperature exposure that this environment experiences during measurement. The ambient temperature over time is modeled based on the previous and data and using a Lagrange interpolation. To observe the comprehensive variation of ambient temperature the profile must be determined numerically. The model proposed in this paper can provide an acceptable way to measure the change in ambient temperature.

关键词： ambient temperature environment correlation theoretical model semi-empirical

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Cavitation in semi-open centrifugal impellers for a miniature pump

LUO Xianwu, LIU Shuhong, ZHANG Yao, XU Hongyuan

《能源前沿（英文）》 2008年第2卷第1期页码 31-35 doi: 10.1007/s11708-008-0011-8

摘要： Cavitation in miniature pumps was investigated experimentally for two semi-open centrifugal impellers. Although both impellers had the same blade cross-section, one impeller had a two-dimensional blade, while the other had a leaned blade. The flows were also analyzed using a numerical model of the three-dimensional turbulent flow in the pumps near the peak efficiency point using the -? turbulence model and the VOF cavitation model. The average cavitation performance of each impeller was satisfactorily predicted by the numerical simulations. The results show that the miniature pumps have similar cavitation performances as an ordinary-size pump, with the cavitation performance of the semi-open impeller reduced by increased axial tip clearances. Also, both the hydraulic and cavitation performance of the semi-open impeller were improved by the leaned blade. The results also show that uniform flow upstream of the impeller inlet will improve the cavitation performance of a miniature pump.

关键词： cavitation performance semi-open impeller increased two-dimensional efficiency

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Removal of dyes from wastewater by growing fungal pellets in a semi-continuous mode

Tao Lu, Qilei Zhang, Shanjing Yao

《化学科学与工程前沿（英文）》 2017年第11卷第3期页码 338-345 doi: 10.1007/s11705-017-1644-0

摘要： To increase the efficiency of dye removal from wastewater using mycelial pellets, a bubble column reactor with a simple structure was designed and efficiently used to remove dyes from solution containing dyes. The mycelial pellets were prepared by marine fungus ZJUBE-1. Eight dyes were tested as dye targets for the adsorption capacity of mycelial pellets and good removal results were obtained. Eriochrome black T was selected as a model dye for characterizing the adsorption processes in detail. The measurement results of Zeta potential and FT-IR analysis indicate that the electrostatic attraction may play a key role in the biosorption process. The bubble column reactor was utilized to study the batch dye-removal efficiency of mycelial pellets. A re-culture process between every two batches, which was under non-sterile condition, successfully enhanced the utilization of mycelium biomass. The dye removal rate is 96.4% after 12 h in the first batch and then decreases slowly in the following batches. This semi-continuous mode, which consists of commutative processes of dye-removal and re-culture, has some outstanding advantages, such as low power consumption, easy operation, high dye removal rate, and efficient biomass utilization.

关键词： dye mycelial pellets marine fungus bubble column reactor semi-continuous biosorption

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Utilization of waste vanadium-bearing resources in the preparation of rare-earth vanadate catalysts for semi-hydrogenation

《化学科学与工程前沿（英文）》 2022年第16卷第12期页码 1793-1806 doi: 10.1007/s11705-022-2191-x

摘要： Recycling industrial solid waste not only saves resources but also eliminates environmental concerns of toxic threats. Herein, we proposed a new strategy for the utilization of petrochemical-derived carbon black waste, a waste vanadium-bearing resource (V > 30000 ppm (10 ⁻⁶)). Chemical leaching was employed to extract metallic vanadium from the waste and the leachate containing V was used as an alternative raw material for the fabrication of vanadate nanomaterials. Through the screening of various metal cations, it was found that the contaminated Na⁺ during the leaching process showed strong competitive coordination with the vanadium ions. However, by adding foreign Ce³⁺ and Y³⁺ cations, two rare-earth vanadates, viz., flower-like CeVO₄ and spherical YVO₄ nanomaterials, were successfully synthesized. Characterization techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier-transform infrared, and N₂ physisorption were applied to analyze the physicochemical properties of the waste-derived nanomaterials. Importantly, we found that rare-earth vanadate catalysts exhibited good activities toward the semi-hydrogenation of α,β-unsaturated aldehydes. The conversion of cinnamaldehyde and cinnamic alcohol selectivity were even higher than those of the common CeVO₄ prepared using pure chemicals (67.2% vs. 27.7% and 88.4% vs. 53.5%). Our work provides a valuable new reference for preparing vanadate catalysts by the use of abundant vanadium-bearing waste resources.

关键词： petrochemical solid wastes vanadium recovery resource utilization nanomaterials semi-hydrogenation

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北方缺水地区半旱地农业有限补灌模式探讨

李英能

《中国工程科学》 2012年第14卷第3期页码 41-45

摘要：

以降水利用和灌溉程度为依据，对半旱地农业进行了研究，着重讨论了与半旱地农业涵义有关的问题，论述了在北方缺水地区发展半旱地农业的意义，给出了半旱地农业有限补灌技术模式。针对北方缺水地区的特点，提出了不同类型区半旱地农业有限补灌发展模式，并探讨了北方缺水地区半旱地农业发展有限补灌的策略。

关键词：半旱地农业有限补灌模式

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6G移动网络架构SOLIDS——驱动力、特征及功能拓扑 Review

刘光毅, 李娜, 邓娟, 王莹莹, 孙军帅, 黄宇红

《工程（英文）》 2022年第8卷第1期页码 42-59 doi: 10.1016/j.eng.2021.07.013

摘要：所提6G网络架构称为SOLIDS，由其六大基本网络特征构成，即柔性（soft）、按需服务（on-demand fulfillment）、至简（lite）、内生智慧（native intelligence

关键词：第六代网络特征网络架构

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Uncertainty propagation in dynamics of composite plates: A semi-analytical non-sampling-based approach

Mahdi FAKOOR, Hadi PARVIZ

《结构与土木工程前沿（英文）》 2020年第14卷第6期页码 1359-1371 doi: 10.1007/s11709-020-0658-8

摘要： In this study, the influences of spatially varying stochastic properties on free vibration analysis of composite plates were investigated via development of a new approach named the deterministic-stochastic Galerkin-based semi-analytical method. The material properties including tensile modulus, shear modulus, and density of the plate were assumed to be spatially varying and uncertain. Gaussian fields with first-order Markov kernels were utilized to define the aforementioned material properties. The stochastic fields were decomposed via application of the Karhunen-Loeve theorem. A first-order shear deformation theory was assumed, following which the displacement field was defined using admissible trigonometric modes to derive the potential and kinetic energies. The stochastic equations of motion of the plate were obtained using the variational principle. The deterministic-stochastic Galerkin-based method was utilized to find the probability space of natural frequencies, and the corresponding mode shapes of the plate were determined using a polynomial chaos approach. The proposed method significantly reduced the size of the mathematical models of the structure, which is very useful for enhancing the computational efficiency of stochastic simulations. The methodology was verified using a stochastic finite element method and the available results in literature. The sensitivity of natural frequencies and corresponding mode shapes due to the uncertainty of material properties was investigated, and the results indicated that the higher-order modes are more sensitive to uncertainty propagation in spatially varying properties.

关键词： composite plate spatially varying stochastic properties Galerkin method polynomial chaos approach semi-analytical approach