An analysis method of thermodynamic cycle for Stirling engine

The second-order analysis approach for the cycle of Stirling engine is amended on the basis of mechanical loss and the temperature check of heater and radiator. Stirling engine is taken as the object, the alternating flow and heat exchange process of GPU-3 Stirling engine is simulated, and the changing rules of its internal pressure, temperature, velocity, power and efficiency are obtained. The simulation results are identical to the test results of NASA. The amended second-order analysis approach is used to analyze the effect of engine’s rotating speed, working substance and average pressure on the engine’s output performance. The error of the amended approach is less than 20%. The approach may be useful for the optimization design and the characteristic analysis of Stirling engine.     

The application to simplify the complicated power grid through adjacent two-node equivalent method

Most real power systems are not radial networks and evaluation of the stability often needs to establish electromagnetic transient simulation models. So the network equivalent is required first and foremost. The adjacent two-node equivalent method, which considers the coupling impedance between equivalent nodes, is used to realize the simplification and modeling to complex power grid. The analysis and simulation on both the HVDC system from Deyang to Baoji and a real extra-high voltage AC transmission system in South China shows that the static performance of the simulated system by using the adjacent two-node equivalent method is completely equivalent to the original one, as well as the performance of dynamic equivalent is in a satisfied level. Thus the transient system model simplified can be well established to support research of power grid’s security and stability.     

烟支重量、圆周与硬度关系的二元回归分析

卷烟的单支重量、圆周和硬度是构成卷烟质量的几个重要指标,通过统计学原理初步建立了烟支硬度与单支重量和圆周之间的二元回归方程,并对它们之间的相关关系进行了分析,结果表明：单支重量、圆周（circle）与烟支硬度间具有极显著的线性相关关系,且单支重量与烟支硬度呈正相关,相关程度较强;烟支圆周与烟支硬度呈负相关,相关程度较弱。在给定重量指标和圆周指标的基础上,对烟支硬度指标取值范围进行预测,预测的置信区间为（70.5,72.6）,与一元回归方程置信区间（69.1,73.3）相比,得到的结果更准确。     

Effects of Chilling Stress on Photosynthetic Rate and Chlorophyll Fluorescence Parameter in Seedlings of Two Rice Cultivars Differing in Cold Tolerance

It has been reported that rice showed damage from chilling when the temperature was lower than 10–12℃ [1]. The injury to metabolism and physiological process in rice upon chilling is irreversible, including the increased membrane permeability, inhibition of chlorophyll synthesis [2], the broken chloroplast [3], and eventually the decreased photosynthetic ability. Moreover, it was investigated that the photo-inhibition more easily occurred under low temperatures both in cold-tolerant and cold…     

Free Amino Acid Profiles of Fermented Soybean Products Prepared by Bacillus subtilis and Rhizopus oligosporus

Fermented soybean is one of the traditional foods widely consumed in many Asian countries. Most products(i.e., Natto, Jang, Kinema and Thua nao) are produced mainly by the bacterial activity. This study was performed as a part of the program to improve the soybean fermentation, and a use of the co-culture between the bacterium Bacillus subtilis and the fungus Rhizopus oligosporus was selected. For fermentation, the raw soybeans were washed, sterilized by autoclaving, and inoculated with a mixed microbial starter culture of B. subtilis(102 CFU · g~(-1)) and R. oligosporus(102 conidia · g~(-1)). The Free Amino Acid(FAA) contents were then investigated by using High Performance Liquid Chromatography(HPLC). The results showed that the amounts of FAAs and essential amino acids in the fermented soybean samples were found at significantly higher concentration when compared to those of the cooked, non-fermented soybean samples(p0.05). These data indicated that an involvement of microbial fermentation helped to accelerate an increase of FAA. The food compositional data were useful as a reference(and/or guidance) for the nutritional value, when compared to other fermented soybeans and related products.     

Preference and Willingness of Consumers to Pay for Value-added Poultry Products in Niger Delta Region of Nigeria

There has been a steady growth in demand for convenience and ready-cooked food has influenced the interest of poultry processors in developing value-added chicken products that meet consumers' demand/choice. A conjoint analysis was done in this study on the survey of 975 chicken consumers in the Niger Delta Region of Nigeria, between March and September, 2014 to valuate consumers, preferences and willingness to pay (WTP) for various chicken attributed parts, production method, processing method, storage method, the presence of flavor and cooking method. The estimates of consumers, WTP premium prices for various mixtures of value-added characteristics were ascertained. The consumers preferred chicken products refrigerated, from chicken produced under free-range management, chicken breast, chicken product that was addictive and flavor free, which could be oven-heated or pan heated. One half of the entire respondents were willing to pay about 25% more for value-added chicken product over the price for conventional products. On the whole, a premium for value-added chicken products was more likely to be paid for by young consumers, consumers who patronized farmers' markets and preferred free-range or organic chicken products. WTP by consumers was negatively affected by price of products. The poultry industry could utilize combined knowledge of consumers' WTP for value-added chicken product price as a guide of develop innovative value-added chicken products.     

1961~2010年云南省≥10℃活动积温时空变化格局

活动积温与植被演替、农作物生长关系密切,对区域生态状况和粮食安全具有决定性作用。基于GIS平台,研究了云南省31个气象站50 a的≥10℃活动积温时空分布格局及其变化特征。结果表明：（1）1961~2010年云南省≥10℃活动积温呈增长趋势,增幅为9.080℃/a,其中,1961~1978年≥10℃活动积温为负距平,1998~2010年为正距平,1979~1997年≥10℃活动积温距平以振荡为主;（2）5个代际≥10℃活动积温代际内最高值和均值随时间推移逐渐增大;（3）基本以景洪-思茅-元江-元谋为线,≥10℃活动积温向西、东2个方向逐渐减少;同时,空间差异程度随着时间推移有减小趋势。     

管式原油加热炉设计应注意的几个问题

阐述了管式原油加热炉的工作原理,指出提高管式加热炉热效率的最有效的办法是合理降低过量空气系数和排烟温度,降低排烟温度的最佳途径是增加原油的对流受热面,而不是增设空气预热器。认为以预先设定加热炉辐射室热负荷的办法来设计加热炉,可以大幅度降低设计工作量。分析结果表明,采用小管径翅片管是对流受热面设计的最佳选择。