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Estimation of thermodynamic properties of the ternary molten salt system, LiF-NaF-BeF2, by the modifiedPeng-Robinson equation

ZHANG Dalin, QIU Suizheng, SU Guanghui, JIA Dounan

《能源前沿（英文）》 2007年第1卷第2期页码 174-180 doi: 10.1007/s11708-007-0022-x

摘要： The molten salt reactor (MSR), which is one of the generation IV reactors, can meet the demand of transmutation and breeding. The thermodynamic properties of the molten salt system like LiF-NaF-BeF2 influence the design and construction of the fuel salt and coolant in the MSR for the new generation. In this paper, the equation of state of the ternary system 15%LiF-58%NaF-27%BeF, over the temperature range from 873.15 to 1 073.15 K at one atmosphere pressure, is described using a modified Peng-Robinson (PR) equation. The densities of the ternary system and its components are estimated by this equation directly, and compared with the experimental data. Based on the equation of state, the other thermodynamic properties such as the enthalpy, entropy and heat capacity at constant pressure are estimated by the residual function method and the fugacity coefficient method respectively. The densities calculated by PR equation are highly in agreement with the experimental data, and the enthalpy, entropy and heat capacity evaluated by the two different methods are consistent with each other. It can be concluded that the modified PR equation can be applied to evaluate the density of the molten salt system, and it is recommended that it be used as the basis to estimate the enthalpy, entropy and heat capacity of the molten salt system.

关键词： modified Peng-Robinson coolant consistent MSR entropy

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First law-based thermodynamic analysis on Kalina cycle

ZHANG Ying, HE Maogang, JIA Zhen, LIU Xun

《能源前沿（英文）》 2008年第2卷第2期页码 145-151 doi: 10.1007/s11708-008-0021-6

摘要： Based on the first law of thermodynamics, and adopting the Peng-Robinson equation (P-R equation) as the basic equation for the properties of ammonia-water mixtures, a thermodynamic analysis on a single-stage distillation Kalina cycle is presented. A program to calculate the thermodynamic properties of ammonia-water mixtures, and that for calculating the performance of Kalina cycles, were developed, with which the heat-work conversion particulars of Kalina cycles were theoretically calculated. The influences on the cycle performance of key parameters, such as the pressure and temperature at the inlet of the turbine, the back pressure of the turbine, the concentration of the working solution, the concentration of the basic solution and the cycle multiplication ratio, were analyzed.

关键词： ammonia-water P-R single-stage distillation Peng-Robinson pressure

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Comprehensive evaluation of heavy metal contamination of sediment in Lake Dianchi by using modified AHP

ZHANG Yan, GAO Xiang, ZHONG Zhenyu, PENG Buzhuo, DENG Xihai

《环境科学与工程前沿（英文）》 2008年第2卷第3期页码 370-379 doi: 10.1007/s11783-008-0054-4

摘要： Through the use of general sampling and measurement by Cs dating, problems regarding the absence of monitoring data can easily be resolved. Further, weighted values need to be determined while Environment Quality Comprehensive Index (EQCI) is commonly used as applied in environmental quality comprehensive evaluation. In order to overcome the subjectivity in determining weights, the modified Analytical Hierarchy Process (AHP) method was designed. The modified AHP method involved the following key procedures: First, the parameters and were calculated based on the monitoring data; second, the factors were put in order according to the symbol and value of and ; third, the continuous odd integers, which represented the importance of factors, were given to factors according to their seating order; and, fourth, the factor weights were determined from the pair-wise comparison matrix calculated by the ratio of the given odd integers. Therefore, the weights were completely based on the monitoring data. In the present study, the comprehensive quality of sediments in five sections of Lake Dianchi were evaluated and the results indicated that the current contamination of sediments in each lake section is much more serious than at any other time in history.

关键词： Dianchi Analytical Hierarchy monitoring modified Analytical importance

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Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns and gravel lenses

ROBINSON, Janis BOETTINGER, Scott B. JONES

《农业科学与工程前沿（英文）》 2017年第4卷第2期页码 135-145 doi: 10.15302/J-FASE-2017143

摘要： Knowledge of the spatial distribution of soil textural properties is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Our objective was to employ electromagnetic induction (EMI) mapping in low apparent electrical conductivity (EC ) soils at varying soil water contents to capture time invariant properties such as soil texture. Georeferenced EC measurements were taken using a ground conductivity meter on six different days where volumetric water content ( ) varied from 0.11 to 0.23. The 50 m × 50 m field included a subsurface gravelly patch in an otherwise homogeneous silt-loam alluvial soil. Ordinary block kriging predicted EC at unsampled areas to produce 1-m resolution maps. Temporal stability analysis was used to divide the field into three distinct EC regions. Subsequent ground-truthing confirmed the lowest conductivity region correlated with coarse textured soil parent materials associated with a former high-energy alluvial depositional area. Combining maps using temporal stability analysis gives the clearest image of the textural difference. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications.

关键词： soil electrical conductivity soil texture mapping temporal stability analysis

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Enhanced disinfection of Escherichia coli and bacteriophage MS2 in water using a copper and silver loaded titanium dioxide nanowire membrane

BRASTAD, Qianyi ZHANG, Rebecca ROBINSON, Zhen HE, Ying LI

《环境科学与工程前沿（英文）》 2016年第10卷第4期 doi: 10.1007/s11783-016-0854-x

摘要： A novel photocatalytic Ag-Cu-TiO nanowire membrane was fabricated. Bacteria and virus disinfection was improved by co-depositing Ag and Cu onto membrane. Synergetic photocatalytic effects and free metal ions of Ag and Cu contribute to disinfection. 7.68 log removal of and 4.02 log removal of bacteriophage MS2 were achieved. Titanium dioxide (TiO ) is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO nanowire membrane (Cu-Ag-TiO ) was prepared and evaluated for its efficiency to inactivate and bacteriophage MS2. Enhanced photo-activated bactericidal and virucidal activities were obtained by the Cu-Ag-TiO membrane than by the TiO , Ag-TiO and Cu-TiO membranes under both dark and UV light illumination. The better performance was attributed to the synergies of enhanced membrane photoactivity by loading silver and copper on the membrane and the synergistic effect between the free silver and copper ions in water. At the end of a 30 min test of dead-end filtration under 254 nm UV irradiation, the Cu-Ag-TiO membrane was able to obtain an removal of 7.68 log and bacteriophage MS2 removal of 4.02 log, which have met the US EPA standard. The free metal ions coming off the membrane have concentrations of less than 10 ppb in the water effluent, far below the US EPA maximum contaminant level for silver and copper ions in drinking water. Therefore, the photo-activated disinfection by the Cu-Ag-TiO membrane is a viable technique for meeting drinking water treatment standards of microbiological water purifiers.

关键词： Photo-activated disinfection Titanium dioxide Nanowire membrane Silver Copper

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Regulatory issues for genetically modified animals

Perry Bradbury HACKETT

《农业科学与工程前沿（英文）》 2020年第7卷第2期页码 188-203 doi: 10.15302/J-FASE-2019307

摘要：

Precision genetics and breeding have the potential to meet the agricultural needs and goals of the world in the 21st century. These needs include increasing the efficiency of production of animals and improving their products with minimal impact on the environment. The USA is the major innovator in genomic science and the acknowledged leader in formulating policies to regulate genetic applications in medicine and agriculture. However, governments worldwide have been exceedingly reluctant to support the introduction of genetically modified (GM) animals into agriculture. Regulatory policies have stagnated due to legal guidelines that could not anticipate the needs and solutions that are evident today. This must change if we are to maintain planetary integrity. I propose a new, market-based regulatory model for GM livestock that has both a strong scientific foundation and has worked for 10000 years. The model is similar to that for information technology in which specific algorithms drive computer and cell phone applications. Genome engineers write genetic algorithms that drive the traits in biological organisms. Accordingly, GM products should be viewed in terms of their use and public benefit rather than by limitations to the genetic programing coming from a few highly vocal groups. Genetic algorithms (Genapps) of the 21st century will include not only introduction of synthetic genes, but also complete natural and synthetic biochemical pathways to produce agricultural products that are maximally efficient, healthy to humans and animals, and sustainable in an era of changing climates while avoiding environmental degradation.

关键词： algorithms editing FDA GMO recombinant DNA USDA

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改性亚麻屑纤维素对活性翠蓝染料的吸附性能研究

王鹏,王立娟

《中国工程科学》 2014年第16卷第4期页码 60-63

摘要：

采用环氧氯丙烷和三乙胺对分离出来的亚麻屑纤维素进行改性，制备了一种新型吸附剂。采用扫描电子显微镜和傅里叶变换红外光谱仪分别观察了所制备的吸附剂的表面形貌并分析了主要官能团，研究了其对活性翠蓝染料的吸附性能，探讨了吸附时间、吸附剂用量、染料初始浓度及pH等对吸附的影响。结果表明，随时间延长吸附容量逐渐增加，180 min 后吸附即可达到平衡，升高温度有利于吸附反应的进行，40 ℃时最大吸附容量为198.45 mg/g；染料初始浓度较高时，吸附容量较大，吸附受pH的影响较为明显。

关键词：亚麻屑纤维素改性活性翠蓝吸附

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Tuned reactive power dispatch through modified differential evolution technique

S. BISWAS (RAHA), N. CHAKRABORTY

《能源前沿（英文）》 2012年第6卷第2期页码 138-147 doi: 10.1007/s11708-012-0188-8

摘要： This paper explores the capability of modified differential evolution (MDE) technique for solving the reactive power dispatch (RPD) problem. The proposed method is based on the basic differential evolution (DE) technique with a few modifications made into it. DE is one of the strongest optimization techniques though it suffers from the problem of slow convergence while global minima appear. The proposed modifications are tried to resolve the problem. The RPD problem mainly defines loss minimization with stable voltage profile. To solve the RPD problem, the generator bus voltage, transformer tap setting and shunt capacitor placements are controlled by the MDE approach. In this paper, IEEE 14-bus and IEEE 30-bus systems are chosen for MDE implementation. The applied modification show much improved result in comparison to normal DE technique. Comparative study with other soft-computing technique including DE validates the effectiveness of the proposed method.

关键词： reactive power dispatch (RPD) modified differential evolution (MDE) differential evolution algorithm with localizations around the best vector (DELB)

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Approaching the binding between Cu(II) and aerobic granules by a modified titration and µ-XRF

Hongwei LUO,Longfei WANG,Zhonghua TONG,Hanqing YU,Guoping SHENG

《环境科学与工程前沿（英文）》 2016年第10卷第2期页码 362-367 doi: 10.1007/s11783-015-0803-0

摘要： Interactions between metals and activated sludge can substantially affect the fate and transport of heavy metals in wastewater treatment plants. Therefore, it is important to develop a simple, fast and efficient method to elucidate the interaction. In this study, a modified titration method with a dynamic mode was developed to investigate the binding of Cu(II), a typical heavy metal, onto aerobic granules. The titration results indicated that pH and ionic strength both had a positive effect on the biosorption capacity of the granular sludge. The -XRF results demonstrated that the distribution of metals on the granular surface was heterogeneous, and Cu showed strong correlations and had the same “hot spots” positions with other metal ions (e.g., Ca, Mg, Fe etc.). Ion exchange and complexing were the main mechanisms for the biosorption of Cu(II) by aerobic granules. These results would be beneficial for better understanding of Cu(II) migration and its fate in wastewater treatment plants.

关键词： aerobic granules Cu(II) modified titration µ-XRF analysis

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Kinetics and thermodynamics of the phosphine adsorption on the modified activated carbon

Bingnan REN

《化学科学与工程前沿（英文）》 2011年第5卷第2期页码 203-208 doi: 10.1007/s11705-010-0571-0

摘要： The kinetics and the thermodynamics of phosphine (PH ) adsorption on the modified activated carbon have been explained for the adsorption process of PH . This study investigated the kinetic and thermodynamic properties of PH adsorption on the activated carbon impregnated with 5% HCl solution. The thermodynamic properties including PH adsorption isotherm and adsorption heat were separately investigated at 20°C, 70°C, 90°C. The results showed that the Freundlich-type isotherm equation described the isotherms well. The adsorption capacity increased with increasing temperature between 20°C and 70°C. Between 70°C and 90°C, the adsorption capacity decreased obviously with increasing temperature. The adsorption capacity reached the maximum at 70°C. By analyzing the results of the kinetics and the thermodynamics, we found that the adsorption of PH was dominated by physical adsorption at the lower temperature (20°C). Then with increasing temperature, chemical adsorption gradually dominated in the adsorption process. The adsorption capacity decreased at above 70°C is due to the exothermic effects in the process of adsorption.

关键词： adsorption PH₃ activated carbon kinetics thermodynamics

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Removing phosphorus from aqueous solutions by using iron-modified corn straw biochar

Fenglin LIU,Jiane ZUO,Tong CHI,Pei WANG,Bo YANG

《环境科学与工程前沿（英文）》 2015年第9卷第6期页码 1066-1075 doi: 10.1007/s11783-015-0769-y

摘要： Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus (TP) concentration of 1.86 mg·L to 2.47 mg·L were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02 mg·L were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe O . The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe-O-P and P-C were found, which suggested that the new iron oxides tend to be Fe (PO ) (OH) . Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.

关键词： iron-modified biochar phosphorus removal agricultural waste agricultural runoff

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Immobilization of penicillin G acylase onto amino-modified silica hydrogel

Weibing Dong, Huining HE, Junbo Gong, Victor C. YANG,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 87-90 doi: 10.1007/s11705-009-0298-y

摘要： Amino-modified silica hydrogel (N-MSHG) was prepared by a simple sol-gel processing via the co-condensation of commercial silica sol with 3-aminopropyltrie-oxysilane. Penicillin G acylase (PGA), a model enzyme, was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin. The samples were characterized by Nitrogen sorption analysis, FT-IR and thermal gravimetric analysis (TGA). The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17nm. The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency. The yield of the synthesis of amoxicillin in aqueous media was 38% for 2.5h. This sol-gel preparation is simple and shows prominent potential value in industrial processing.

关键词： gravimetric amino-modified efficient Amino-modified amoxicillin

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一款基于改进的步进式译码算法实现的流水线架构RS码译码器 Article

Xing-ru PENG,Wei ZHANG,Yan-yan LIU

《信息与电子工程前沿（英文）》 2016年第17卷第9期页码 954-961 doi: 10.1631/FITEE.1500303

摘要：因此，对于RS（23,17）码，我们所设计的译码器面积比ME（modified Euclidean）架构和pDCME（pipelined degree-computationless modified

关键词： Reed-Solomon码；步进式译码算法；超宽带；流水线架构

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Phosphorous removal from wastewater by lanthanum modified Y zeolites

Weikang ZHANG, Ye TIAN

《化学科学与工程前沿（英文）》 2015年第9卷第2期页码 209-215 doi: 10.1007/s11705-014-1448-4

摘要： The adsorption capacities of Y zeolite and La (III)-modified Y zeolite were studied. A series of La(III)-modified Y zeolites with different La/Y zeolite mass ratios were characterized by X-ray diffraction, X-ray fluorescence and Brunauer-Emmett-Teller surface area analysis. Batch experiments were conducted to evaluate the effects of various experimental parameters, such as pH, ionic strength, coexisting anions ( , Cl , and ) and temperature, on the phosphate adsorption. The capacity of the La (III)-modified Y zeolite to remove phosphate increased as the La/Y zeolite mass ratio increased and after 4 h, a phosphate removal efficiency of 95% was achieved for a La/Y zeolite mass ratio of 0.10. The equilibrium adsorption isotherm data correlated better to the Langmuir model than the Freundlich model and the data followed a pseudo-second-order kinetic equation.

关键词： phosphate removal wastewater lanthanum impregnation Y zeolites

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Outdoor aging of road asphalt and SBS modified asphalt

Li XIANG, Juan TU, Jian CHENG, Guohe QUE

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 35-42 doi: 10.1007/s11705-010-0551-4

摘要： The process of performance degradation of road asphalt (RA) is regarded as aging. At present, better understanding of the thermal-oxidative aging of asphalt is achieved and the corresponding method to evaluate this process is developed; meanwhile, photo-oxidative aging (aging in an atmospheric environment, which is referred to as “outdoor aging” in this paper) of asphalt remains at the initial stages of scientific exploration. The outdoor natural ultraviolet (UV) aging of RA and SBS modified asphalt (SBSMA) are investigated in this study. The experimental results show that the basic performances of RA and SBSMA present similar change tendencies. The softening point increased, while the penetration and ductility decreased as the outdoor aging time passed by, and the 5°C ductility (ductility measured at 5°C) of SBSMA decreased very quickly. The group components of RA and SBSMA also change during UV aging. The content of asphaltene rose and that of aromatics and saturates decreased, while the content of resins changed insignificantly. Moreover, the Fourier transform infrared (FTIR) graphs show that the content of sulfoxide and carbonyl groups in RA and SBSMA increased significantly during the outdoor aging process.

关键词： asphalt SBS modified road asphalt outdoor aging ultraviolet