Sterilization Effect of Cooking Process for Guilin Rice Noodles Based on Heat Conduction Model

Guilin rice noodles, a unique cuisine from Guilin, Guangxi, is renowned both domestically and internationally as one of the top ten “Guilin Classics”. Utilizing a heat conduction model, this study explores the effectiveness of the cooking process in sterilizing Guilin rice noodles before consumption. The model assumes that a large pot is filled with boiling water which is maintained at a constant high temperature heat resource through continuous gentle heating. And the room temperature is set as the initial temperature for the preheating process and the final temperature for the cooling process. The objective is to assess whether the cooking process achieves satisfactory sterilization results. The temperature distribution function of rice noodle with time is analytically obtained using the separation of variables method in the three-dimensional cylindrical coordinate system. Meanwhile, the thermal diffusion coefficient of Guilin rice noodles is obtained in terms of Riedel’ theory. By analyzing the elimination characteristics of Pseudomonas cocovenenans subsp. farinofermentans, this study obtains the optimal time required for effective sterilization at the core of Guilin rice noodles. The results show that the potential Pseudomonas cocovenenans subsp. farinofermentans will be completely eliminated through continuously preheating more than 31 seconds during the cooking process before consumption. This study provides a valuable reference of food safety standards in the cooking process of Guilin rice noodles, particularly in ensuring the complete inactivation of potentially harmful strains such as Pseudomonas cocovenenans subsp. farinofermentans.

Research on Influence of Guilin Topography on Haze

This paper analyzed space-time distribution features of haze at different topographical representative stations using haze days observation data of 50 years in different meteorological observatories of Guilin to study the topography influence on haze. Different topographical representative stations were classified into four types of mountain,hill,river and city. Mountain stations were classified into two types,surrounded by mountains and faced with mountains on two sides. Under parallel comparison method,change features of wind direction,wind speed,temperature and haze days at different meteorological observatories were analyzed to investigate the topography influence on haze with pollution increase factors excluded. The study found that the city station had the biggest haze occurrence rate,followed by the mountain station surrounded by the mountains,and the river station had the smallest haze occurrence rate. Urban heat island wind can easily cause urban pollutants concentration around the city center,and the terrain blocking to the wind is not conducive to the spread of pollutants,but the water vapor over the river can reduce the haze.

Analysis on the Variation of Rainfall Data from Guilin Weather Station during 1957-2007

[Objective] The research aimed to study the variation of rainfall data from Guilin Weather Station during 1957-2007.[Method] Based on the daily rainfall data in Guilin during 1957-2007,the trend,period and mutation of precipitation in Guilin in 51 years were analyzed by using the trend analysis,wavelet analysis and Mann-Kendall non-parameter statistics test method.[Result] The rainfall in Guilin in 51 years presented the rising trend.The rainfall variation was same in the first,second and third quarters of most years,except in the individual year.The rainfall in the fourth quarter had the decrease trend,and the variation was obvious in each year.It illustrated that the rainfall variation in winter was very unstable and had the decrease trend in recent years.But as a whole,the variation of total rainfall in Guilin wasn’t obvious and had the rise trend.It illustrated that the climate variation in Guilin in 51 years wasn’t obvious.The wavelet analysis showed that the rainfall variation in Guilin had 15-year big period and the small period of 2-3 years.Mann-Kendall non-parameter statistics test showed that the mutation situation of total rainfall in Guilin in 51 years wasn’t obvious.But the mutation situations in the second and third quarters were more.The variation in recent 10 years was the most obvious.Maybe it was affected by the global climate variation.[Conclusion] The research provided the theory basis for analyzing the climate variation in Guilin.

Analysis on the Flood Rainstorm in the Lijiang River of Guilin

[Objective] The research aimed to study the flood rainstorm in the Lijiang River of Guilin. [Method] By using the observation data of flood rainstorm and water level in the Lijiang River, the flood rainstorm standard in the Lijiang River was delimited. Via the analysis on the spatial and temporal distribution, weather situation of flood rainstorm in South China, the flood rainstorm in the Lijiang River was systematically studied. [Result] The flood in the Lijiang River closely related to the duration and intensity of torrential rain in the upstream. When the daily rainfall in the upstream ≥100 mm, or the daily rainfall in above continuous 2 d ≥ 50 mm, the flood was easy to happen in the Lijiang River. During April-July in every year, the flood was possible to happen in the flood season in the Lijiang River but mainly happened during May-June. The period of flood water level variation in the Lijiang River was ten-year. When the highest water level was lower than the warning stage (145.00 m) in the year, most of highest water level in the next year surpassed the warning stage and reached above 146.00 m. The weather type which caused the flood rainstorm could be divided into the frontal zone type (frontal zone southward movement type, stationary front northward movement type) and the low pressure vortex type. The upstream in the Lijiang River was the rainstorm center in Guilin area and the key zone of flood rainstorm in the Lijiang River. The special terrain provided the favorable condition for the multi-occurrence of rainstorm. [Conclusion] The research provided the basis for the forecast of flood rainstorm in the Lijiang River.

Analysis on Meteorological Conditions of Winter Cold Injury of Sugar Orange Industry in Guilin

Yield and quality of sugar orange are closely related to meteorological conditions,especially the low temperature and cold injury in mature period of fruit. To study the influence of winter cold injury on sugar orange industry of Guilin,the chilling injury weather in each county of Guilin planting sugar orange is analyzed,and the disastrous cold weather and its defense measures are studied. Frost,freezing and cold wave happen in Guilin winter sometimes,and the disastrous weather could seriously harm maturing sugar orange or that in the tree,causing peel coke,dehiscent fruit,fruit drop and quality decline. It can effectively reduce the loss by chilling injury and guarantee excellent quantity and high yield of sugar orange by timely understanding weather change information,scientifically managing water and fertilizer,and doing film cover well.

Analysis on Hot Weather in Guilin in 2013

Based on observation data of temperature from automatic meteorological stations in all towns and the national weather station in Guilin City,annual and monthly variations of average temperature,distribution of high-temperature days in Guilin in 2013,and weather situations causing high temperature in Guilin were analyzed.The results showed that in 2013,annual average temperature in Guilin was 1.4℃higher than the multiyear average.The hottest weather occurred in Wenqiao Township,Quanzhou County in the northeast,followed by the urban district and suburbs of Guilin,Lianhua Town of Gongcheng County in the south,Tongan,Zhangjia and Dafa towns of Pingle County,Dongchang and Datang towns of Lipu County.Terrain had distinct effects on regional high temperature,that is,there was no hot weather with daily maximum temperature of≥35.0℃in mountainous areas with an altitude of≥1 200 m;temperature was abnormally high in low-lying areas surrounded by mountains.In addition,the Western Pacific subtropical high pressure was the main weather system leading to hot weather in Guilin.

Study on the Features and Risk Assessment of Drought in Guilin

Based on the precipitation data of all counties in Guilin from 1957 to 2010, the analysis has been made on the features of spatial and temporal distribution, the probability of occurrence and the periodic change of drought in Guilin. Afterwards, by using the method of disaster risk assessment, the disaster-causing factors, breed disasters environment and fragility of hazard-bearing body of Guilin drought have been analyzed, and the comprehensive evaluation on drought disaster has been made. The results show that above medium drought in Guilin mainly appeared in au- tumn, followed by winter, while Guilin only suffered from slight drought in spring; the principal period of drought occurrence in Guilin was six years, while its secondary period was two years; on the whole, drought risk was high in the southeast and low in the northwest.

Effects of Different Farming Methods and Their Effects on Soil Physicochemical Properties of Guilin Maojian Tea Gardens

In order to further optimize the cultivation and agronomic technology of Guilin Maojian tea gardens, the effects, efficiencies and costs of different farming methods and their effects on the physiochemical properties of tea garden soil were studied through the modification of the test sites with the non-farming land as the control. The results showed that human farming, mini-tiller farming and crawler tractor farming could improve the physical and chemical properties of soil. After farming, the soil had good water retention but low moisture content compared to the control group, while the soil bulk density and hardness value were significantly lower than those of the control, and the porosity of soil was significantly higher than that of contrast. With the passage of time, soil bulk density and hardness value gradually increased after farming, while the porosity of soil decreased gradually. There were great differences in the effects, efficiencies and costs of different farming methods. Crawler tractor had the best and most stable farming effect, and the operation efficiency was 10 times that of human farming while the cost was only 0.39 times of human farming. Therefore, it was feasible to adopt mini-tiller or crawler tractor to carry out mechanical farming of Guilin Maojian tea garden, which provided theoretical references for the soil property improvement using mechanical farming and was favorable for promoting the popularization of farming machines and the acceleration of mechanization of tea gardens. But for tea plantations that are intended to be mechanized, apart from the mechanical and technical personnel to be configured in place, the site conditions, planting modes and mechanical way reservation of tea garden should be planned accordingly. It is recommended to select flat or gentle slope for reclamation, and preference is given to non-sexual tea tree varieties with big line spacing over 180 cm long. Moreover, the main road construction should be more than 3.0 m, and trunk road 2.0 m or above. And isolation ditch and drain should be set between the tea garden and the surrounding mountain forests and farmland.

A Middle-Upper Devonian Boundary Section in the Open Platform,Platform Margin Facies of Guilin,South China

The Caiziyan Middle and Upper Devonian boundary section is located approximately 30 km northeast of Guilin. It hosts relatively abundant benthic and common-rare pelagic fossils, including brachiopods, corals, tentaculites, and conodonts, which may serve as a better suitable section for pelagic and neritic stratigraphic correlation. In this section, 10 ＂standard＂ conodont zones are recognized across the Givetian-Frasnian boundary, including, in descending order, the Lower hassi Zone, punctata Zone, transitans Zone, the Upperfalsiovalis Zone, the Lowerfalsiovalis Zone, disparilis Zone, the Upper hermanni-cristatus Zone, the Lower hermanni-cristatus Zone, the Upper varcus Zone, and the Middle varcus Zone, all of which are defined by the first occurrence of their defining conodont species. The Middle-Upper Devonian （Givetian-Frasnian） boundary is defined by the first occurrence of Ancyrodella pristina in accordance with the Global Stratotype Section and Point （GSSP）, which is assigned at 6.2m above the base of bed 19 in the Caiziyan section.

Study on Hail Weather Analysis and Forecast in Guilin

[Objective] The hail weather and forecast storm in Guilin were studied. [Method] In allusion to the occurrence of hailstorm in Guilin and considering the observation data of a new generation of Doppler weather radar in Guilin, the weather situation and radar echo characteristics in Guilin was summarized so as to explore the short time forecast method. [Result] There were one or two icy storms every year in Guilin. The occurrence of icy storm was distinctly influenced by terrain. A new generation of Doppler weather radar detection ice storm was very effective. The singular intensity of echo of icy storm in Guilin was above or equal to 50 dBz and the height of echo was above or equal to 10 km. The vertical liquid content was above or equal to 40 kg/m2, accompanied by mild cyclone. When there was strong icy storm, there were three flux characteristics. The forecast of icy storm was mainly short time forecast. [Conclusion] The study offered reference for the forecast of icy storm, artificial storm and disaster prevention and mitigation work.

Pool Sizes and Turnover of Soil Organic Carbon of Farmland Soil in Karst Area of Guilin

The three-pool and first-order model separates the mineralizable organic carbon into active,slow,and passive carbon pools.This paper used the model and decomposition curves of the soil organic carbon to fit the active pool and its decomposition rate,slow pool and its decomposition rate.The results showed that the size of the active pool from different profiles accounted for 2.09%-3.08% of the total soil organic carbon and the mean residue time was 3.57-17.21 days.And the size of the slow pool accounted for 3.19%-43.55% and the mean residue time was 1.12-4.94 years.Acid hydrolysis（6M HCl） was used to fractionate the passive organic carbon,which accounted for 50.83%-94.44% of the total soil organic carbon.

Preliminary Investigation on the Causes of Odd Vibration of Buildings in Guilin City——a Study on the Resonance between Buildings and the Underlying Soil Layer

A residential building in Guilin City, China, underwent an up-and-down vibration with an amplitude of 2 cm. By eliminating several causes such as earthquake, wind and construction, in combination with the unique karst geological conditions of Guilin, it was inferred that the effect of turbulent karst water is the main contributor to the occurrence of this vibration. Therefore, a geophysical survey was undertaken on the vibration zone and its surroundings. The resutls suggest that the soil in the upper part of the karst grooves shows conspicuous traces of disturbance and the water content has low resistance. A comprehensive analysis indicates that there is a karst strong runoff zone beneath the area. According to the water level and water temperature data collected automatically by the instrument, it can be concluded that the groundwater level had changed significantly twice during this period, so it was determined that the denudation of groundwater strong runoff causes the overlying soil layer to collapse, forming a soil-water soft-flow material with mixed phase. Since the building in this area was supported by friction piles, the groundwater-soil soft-flow material with mixed phase has intense plasticity, and the up-and-down vibration resulted in the change of the friction piles, which caused the up-and-down vibration of the building structure.

A Comparative Study on That Design of Agricultural Canal in Ecological and Traditional Renovation of Agricultural Land—Take a Project Area in Lingchuan County, Guilin City, Guangxi, China as an Example

In the current context of vigorously promoting the construction of ecological civilization, land consolidation in the construction of the constant pursuit of ecological design, to achieve sustainable use of land resources, China has made great progress in ecological land consolidation. In this paper, through the comparison of flow design and cross section design of agricultural canal design in ecological land remediation and traditional land remediation, the characteristic design of some agricultural canals in ecological land remediation was introduced, and the ecological, social and economic benefits of two land remediation methods were systematically analyzed. The analysis shows that ecological agricultural canals play a great role in protecting biodiversity, alleviating the contradiction between people and land, saving energy, purifying water resources and improving land quality, the research result has provided the basis and the model for the land consolidation in carrying on the ecology type ditch design.

Potential Analysis of Inefficient Garden Land and Residual Forest Land Remediation in Comprehensive Land Remediation of the Whole Region—A Case Study of Zhemu Town, Guilin City, China

The remediation of inefficient garden land and defective forest land is one of the important sources and types of supplementary cultivated land in the comprehensive land remediation of the whole region. The remediation and development of inefficient garden land and defective forest land will effectively alleviate the multiple pressures faced by cultivated land at present. Taking Zhemu Town, Guilin City, China as an example, on that basis of the data of the third national land survey, using analytic hierarchy process, this paper selects six evaluation factors, including water source, traffic, slope, field concentration, farmland infrastructure and villagers’ will, to study the remediation potential of inefficient garden land and defective forest land in Zhemu Town, and delimits four potential divisions, in order to provide the basis for the arrangement of land remediation projects in Zhemu Town. The results show that the northern, central and western regions of Zhemu Town have great remediation potential.

Derivation of Rainstorm Intensity Formula in Guilin City

A total of 58 years self-recording rainfall records at Guilin National Weather Station from January 1957 to December 1957 were used. Using the annual maximum sampling method,11 short-duration maximum rainfall records in every year were selected,and statistical samples of rainstorm intensity formula were obtained. Fitting of statistical samples was conducted by using three kinds of frequency distribution curves: Pearson-Ⅲdistribution,Gumbel distribution and exponential distribution. The formula of rainstorm intensity was derived by the least square method and Gauss Newton method,and then the accuracy of results was inspected. The results showed that the fitting effect based on the Pearson-Ⅲdistribution and Gumbel distribution was better than that of the exponential distribution;the accuracy of rainstorm intensity formula based on Pearson-Ⅲdistribution was better than that of Gumbel distribution and exponential distribution;the accuracy of rainstorm intensity formula derived by the least square method was better than that of Gauss Newton method;the accuracy of interval parameter formula of rainstorm intensity was better than that of rainstorm intensity formula.

Study on Risk Prevention of Rainstorm Disaster in the Jinji River of Guilin

The research aimed to prevent and reduce rainstorm disaster in the Jinji River of Yongfu County,Guilin City.Distribution of population,cultivated land and GDP in the Jinji River were analyzed,and the influence of historical rainstorm process was studied.Moreover,high risk area of meteorological disasters and the region not suitable for constructing residential areas,development zones and projects were distinguished,and its influence on agriculture and forestry was analyzed.If it was necessary to build residential areas,development zones and projects or the human society has already been in the high-risk area of meteorological disasters and it was difficult to move,what engineering measures should be taken to prevent the occurrence of risks.The research could provide scientific basis for design standard of disaster prevention engineering,to prevent the occurrence of disaster risk.

山银花茎叶化学成分及其抗炎活性研究

目的对山银花茎叶化学成分进行分离和结构鉴定,并进行体外抗炎活性评价。方法山银花茎叶80%甲醇提取物采用Diaion HP20SS、Sephadex LH-20、高速逆流色谱、反相半制备液相色谱等进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。通过测定单体化合物抑制LPS诱导小鼠巨噬细胞RAW264.7释放NO水平评价其抗炎活性。结果从山银花茎叶中分离得到13个化合物,分别鉴定为苄醇-O-β-D-吡喃葡萄糖-(1→6)-β-D-吡喃葡萄糖苷(1)、獐牙菜苷(2)、表断马钱子苷半缩醛内酯(3)、马钱子苷半缩醛内酯(4)、裂环马钱苷(5)、断氧化马钱苷(6)、裂马钱素二甲基乙缩醛(7)、绿原酸甲酯(8)、芹菜素-7-O-β-D-葡萄糖苷(9)、木犀草素-7-O-β-D-葡萄糖苷(10)、野漆树苷(11)、木犀草素-7-O-α-L-吡喃阿拉伯糖(1→6)-β-D-吡喃葡萄糖苷(12)、忍冬苷(13);化合物2~8、11~13可抑制LPS诱导RAW264.7细胞释放NO。结论化合物1首次从忍冬属植物中分离得到,化合物3、5、7、9、11~12首次从山银花茎叶中发现。化合物2~8、11~13具有一定的抗炎活性。

中高压直流断路器的研究与应用

多端直流系统及直流电网是未来柔性直流输配电系统的发展方向,其安全可靠稳定运行需要有直流断路器作为保障。虽然国内外研究人员提出了各种直流断路器技术方案,但目前市场上能够满足实际工程应用的直流断路器产品仍十分缺乏。该文对直流断路器的研究工作进行了梳理。首先,分析了不同技术方案采取的换流方式及性能,并介绍了直流断路器中的核心组件及其驱动保护。其次,对各类型的直流断路器拓扑结构进行了总结,并归纳出改进优化的方向。最后,对直流断路器研制的关键技术与未来的发展趋势进行了讨论和总结,为中高压直流断路器研制与应用提供参考。

最小二乘算法优化及其在锂离子电池参数辨识中的应用

传统最小二乘法(LS)用于锂离子电池模型在线参数辨识精度低,通过带遗忘因子递推最小二乘算法能够有效地提高辨识精度,但固定的遗忘因子影响模型动态特性。遗忘因子的自适应处理能提高算法对动态系统的参数辨识能力,而目前的自适应方法容易忽略模型参数的稳定性,同时方法待定系数范围较大且难以确认。为了得到高精度且稳定性良好的模型参数,该文设计了一种精度和稳定性兼优且更简单的自适应遗忘因子递推最小二乘(AFFRLS)改进方法,并与其他AFFRLS、可变遗忘因子递推最小二乘(VFFRLS)进行仿真对比分析。结果表明,改进的AFFRLS能够在模型精度和参数稳定性取得更好的平衡,且对不同的在线工况具有良好的适用性。