特色食物“冷蒸”及其原料种植·制作工艺优化

介绍了长江下游沿江沿海地区利用裸大麦青麦粒制作的特色食物"冷蒸",及其食用方法、开发前景。从产地环境、品种选用、播种、沟系配套、肥料施用和病虫草害综合防治等方面,明确了"冷蒸"制作原料裸大麦优质高产栽培技术关键。提出了制作"冷蒸"的麦穗3个方面形态指标特征,以及最适宜的采收时期。简述了"冷蒸"制作的加工流程,提出能够较好地保持其传统风味与品质、显著地提高效率的两段式制作加工模式,研制出基于该模式基础上的半机械化作业的"冷蒸"制作优化工艺。

“冷蒸”热处理工艺的研究

为探讨加热温度和加热时间对"冷蒸"品质的影响,获取"冷蒸"灭菌的最佳工艺,采用响应面法中的中心组合设计对加热处理后"冷蒸"的色泽、葡萄糖含量、感官品质进行研究。结果表明,当加热温度为79℃、加热时间为20 min时,"冷蒸"的a*值为0.928,葡萄糖含量为50.80μg/m L,感官品质为优,与模型预测值基本符合。说明利用响应面法优化加热灭菌工艺是可行的,加热时间(20 min)与温度(79℃)组合方案具有实际应用价值,可为加热灭菌在"冷蒸"贮藏加工中的应用提供理论依据。

不同灭菌处理对“冷蒸”微生物指标及感官品质的影响

为研究不同灭菌处理对"冷蒸"的微生物指标及感官品质的影响,采用臭氧、巴氏灭菌以及两者组合对样品进行处理。试验结果表明:臭氧与巴氏灭菌的结合(10 min+80℃/20 min)处理的感官品质评分较高,该处理在温度为4℃下贮藏30 d后,其细菌总数、大肠菌群、酵母菌总数分别为20 cfu/g、<3 cfu/g、<10 cfu/g以及无霉菌生长。结论:经臭氧灭菌10 min与巴氏灭菌(80℃/20 min)相结合对样品处理后,其产品感官品质得分较高,且将其贮藏时间从10 d延长至30 d。

有机化学品不同温度下(过冷)液体蒸气压预测模型的建立与评价

（过冷）液体蒸气压（PL）是评价化学品在环境中分配、迁移和归趋行为的重要参数。PL具有较强的温度依附性。发展一种能够精确预测不同环境温度下化学品PL的方法,有助于填补化学品生态风险评估的大量数据缺失。本研究收集整理了661种有机化合物在不同温度下（200~830 K）共计10 478个log PL值。在此基础上,采用偏最小二乘（PLS）回归和支持向量机（SVM）方法,构建了PL的线性和非线性预测模型。结果表明：2种模型均具有良好的拟合度、稳健性及预测能力,SVM模型的预测性能略高于PLS模型（PLS：R2adj.tra=0.912,RMSEtra=0.477,Q2ext=0.910;SVM：R2adj.tra=0.997,RMSEtra=0.092,Q2ext=0.967）。机理分析表明,温度是影响PL的主要因素,温度越高,蒸气压越大;其次,X1sol也影响PL大小,X1sol用来描述分子间的色散作用,分子间色散力越小,蒸气压越大;此外,化合物的氢键个数、极性和分子构型等因素也影响PL大小。采用Wiliams plot方法表征了PLS模型应用域。所建立的模型可用来预测烷烃、烯烃、醇、酮、羧酸、苯、酚、联苯、卤代芳香烃、含N化合物及含S化合物在不同温度下的PL数据。

凝汽器冷却面积的优化选择

大型汽轮机组凝汽器冷却面积的选择应通过技术和经济性的比较后确定，以满足电厂长期安全、经济运行的要求。本文介绍凝汽器设计工况的确定，冷却面积的计算及其选择的经济性分析和变工况运行等。

大气中多环芳烃气固相分配与颗粒物粒径的关系

聚集了2005年5月16日-6月3日上海市桃浦地区气相样品、TSP样品及不同粒径的颗粒物样品．用GC—MS对各样品中美国EPA规定优先控制的16种多环芳烃（PAHs）做了定量分析．结果表明，大气中PAHs的气固相分配系数（Kp）和各物质的过冷饱和蒸气压（P1^0）呈良好的线性相关．多元线性回归分析表明，PAHs的气固相分配受颗粒物粒径大小的影响，粒径越大，对PAHs的气固相分配影响越大；过冷饱和蒸气压越高，气固相分配越易受到粒径大小的影响．

Magnesium vapor nucleation in phase transitions and condensation under vacuum conditions

Recent findings related to coagulable magnesium vapor nucleation and growth in vacuum were assessed critically, with emphasis on understanding these processes at a fundamental molecular level. The effects of magnesium vapor pressure, condensation temperature, and condensation zone temperature gradient on magnesium vapor nucleation in phase transitions and condensation from atomic collision and coacervation with collision under vacuum conditions were discussed. Magnesium powder and magnesium lump condensates were produced under different conditions and characterized by scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDS）. The right condensation zone temperature approach to the liquid transition primarily improved the magnesium vapor concentration rate. The gas-solid phase transition was primarily inhibited by setting a small condenser temperature gradient. Under the right condensation temperature and temperature gradients, increasing magnesium vapor partial pressure improved crystallization and reduced the oxidation rate.

Design calculation of porous ceramics tube type dew point indirect evaporative cooler

To improve the wall surface hydrophilicity of a tube type indirect evaporative cooler,a new method adopting porous ceramics is proposed.This method realizes the combination of porous ceramics and the evaporative cooling technique.The design calculation of the porous ceramics tube type dew point indirect evaporative cooler are carried out from such aspects as the volumes and status parameters of the primary and secondary air,the cooler structure,the heat transfer of the solid porous ceramic tubes and the resistance of the cooler.The calculation results show that the design is reasonable.Finally,based on the design calculation,the porous ceramics tube type dew point indirect evaporative cooler is successfully manufactured.

Influence Factors on Particle Growth for On-line Aerosol Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry

An evaporation/condensation flow cell was developed and interfaced with the matrix-assisted laser desorption/ionization （MALDI） time-of-flight mass spectrometer for on-line bioaerosol detection and characterization, which allows matrix addition by condensation onto the laboratory-generated bioaerosol particles. The final coated particle exiting from the con- denser is then introduced into the aerodynamic particle sizer spectrometer or home-built aerosol laser time-of-flight mass spectrometer, and its aerodynamic size directly effects on the matrix-to-analyte molar ratio, which is very important for MALDI technique. In order to observe the protonated analyte molecular ion, and then determine the classification of bi- ological aerosols, the matrix-to-analyte molar ratio must be appropriate. Four experimental parameters, including the temperature of the heated reservoir, the initial particle size, its number concentration, and the matrix material, were tested experimentally to analyze their influences on the final particle size. This technique represents an on-line system of detection that has the potential to provide rapid and reliable identification of airborne biological aerosols.

Modelling and Solution of a Ablation-Transpiration Cooling Control Systems

A controlled model of thermal shield of ablation with trapspiration cooling is develoed. The existence and uniqueness of the classical solution can be obtained by Friedman and Jiang's methods. The positivity of the solution is proved and the conditions for the coolant flux under which the abladtion process will complete in finite time are also determined. Finally, we show the existence of critical coolant flux beyond which the ablation material begin melting.

APPLICATION POSSIBILITY OF BINARY NONAZEOTROPIC REFRIGERANT IN JET REFRIGERATION *

This paper analyzes the possibility of applying binary nonazeotropic refrigerants in the jet refrigeration cycle. The thermodynamic cycle performance of two kinds of working pairs (R30/R142b, R30/R124) are calculated using the EOS of PR equation of state, and the results are discussed. The theoretical calculations indicate that refrigerating quality can be improved if the binary mixtures evaporate just in the low temperature region. The character of the rejecter to compress two phase medium supports the possibility of this kind of cycle.

Genesis of underground brine along south coast of Laizhou Bay:hydrochemical characteristics

Hydrochemistry of underground brines along south coast of Laizhou Bay, Shandong, China has been analyzed. Brine samples were collected from 43 wells in this area. It was considered that the brines were originated from seawater. However, whether they were formed by seawater evaporation or seawater freezing was not fully sure. We created a simple method by plotting Na/Cl vs. seawater concen-tration factor (SCF) and Ca/Mg vs. SCF to determine the brine formation geochemically. Comparison of our results to previous seawater freezing and evaporation experiments indicated that the brines were formed by seawater evaporation. The ratios of HCO3/Cl of some low salinity brines in the study area were relatively higher, indicating that the brines may have mixed with other waters after the generation. The Br/Cl ratios of the brines decreased annually in the past 20 to 30 years of exploitation, indicating down-ward permeation of the brine from which bromine was extracted.

THE ROLE OF COLD AIR AND CHARACTERISTICS OF WATER VAPOR IN BOTH TCS NANMADOL (0428) AND IRMA (7427) MAKING LANDFALL ON CHINA IN WINTERTIME

The NCEP/NCAR reanalysis data are used to investigate the role of cold air and moisture characteristics during the evolution of two cases of tropical cyclones (Nanmadol and Irma) which made landfall on China in wintertime. The results are shown as follows. (1) The East Asia trough steered the cold air into the tropical ocean in early winter. The tropical cyclones moved in opposite directions with a high moving out to sea and the enhancement of the pressure gradient at the periphery played a role in maintaining and strengthening the intensity of the storms. The intrusion of weak cold air into the low levels of the tropical cyclones strengthened them by improving the cyclonic disturbance when they were still over the warm sea surface. When the cold air was strong enough and intruded into the eyes, the warm cores were damaged and stuffed before dissipation. (2) The tropical cyclones were formed in a convergence zone of moisture flux and their development could enhance the disturbance of water vapor convergence, thus strengthening the moisture convergence zone. However, when they were outside the moisture zone, the storms could not gain sufficient water vapor and became weak. There were no belts of strong moisture transportation during the wintertime tropical cyclone processes.

Coupling effect of evaporation and condensation processes of organic Rankine cycle for geothermal power generation improvement

Organic Rankine cycle(ORC)is widely used for the low grade geothermal power generation.However,a large amount of irreversible loss results in poor technical and economic performance due to its poor matching between the heat source/sink and the working medium in the condenser and the evaporator.The condensing temperature,cooling water temperature difference and pinch point temperature difference are often fixed according to engineering experience.In order to optimize the ORC system comprehensively,the coupling effect of evaporation and condensation process was proposed in this paper.Based on the laws of thermodynamics,the energy analysis,exergy analysis and entropy analysis were adopted to investigate the ORC performance including net output power,thermal efficiency,exergy efficiency,thermal conductivity,irreversible loss,etc.,using geothermal water at a temperature of 120℃as the heat source and isobutane as the working fluid.The results show that there exists a pair of optimal evaporating temperature and condensing temperatures to maximize the system performance.The net power output and the system comprehensive performance achieve their highest values at the same evaporating temperature,but the system comprehensive performance corresponds to a lower condensing temperature than the net power output.

Recovery of copper sulfate after treating As-containing wastewater by precipitation method

The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2：1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4：1 and copper arsenite was reduced by SO2 at 60℃ for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air. The results show that red residue is Cu3（SO3）2·2H2O and the white powder is As2O3. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H2SO4 to Cu is 1.70, H2SO4 concentration is 24% and the leaching temperature is 80 ℃. The direct recovery rate of copper sulfate is 79.11% and the content of CuSOa·5H2O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.

A novel ice slurry producing system with vacuum freezing

A novel vacuum ice slurry producing system with jet-pumps was proposed to deal with the problems of high energy consumption and ice blockage.In this novel system,one steam driven by a jet-pump was used to create vacuum in a hermetic vessel where water was sprayed through a nozzle to produce ice slurry,while the other steam was used to provide enough cold energy to make the left vapor in the hermetic vessel condense.Mathematical models of this novel system were established and theoretical simulation on the performance characteristics was also implemented based on the MATLAB program.Results show that the novel system is feasible and practicable,and the system performance is affected by many factors,such as the temperature of the generators,condensing temperature,evaporation temperature,and the cooling load of the refrigerator sub-system.The findings are helpful to improve the performance of ice slurry producing system.

Heat Transfer Characteristics of Dropwise Condensation of Steam on Vertical Polymer Coated Plates

The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmospheric pressure occurred. The condensation heat transfer coefficients increased by approximately 3 and 5－7 times for the polytrimethylvinylsilane film and polytetrafluoroethylene film respectively, compared with the value for film condensation under the same experimental conditions. The temperatures on the condensing surface and inside the test block were found to be rapidly and randomly fluctuated. The properties of the coated films and advantages of the methods used in this investigation were discussed briefly.