浅析扶绥县秋季降水的气候特征及甘蔗种植秋旱防御对策

以国家标准中的农业气象干旱等级为灾害指标,利用扶绥县1960～2019年国家地面观测站的全年逐日降水量资料进行趋势分析、累积距平分析、Morlet小波分析,分析了扶绥县秋季降水的特征和干旱发生频率。结果表明:秋季降水量具有向上增加的趋势而降水日数则相反呈向下减少趋势,秋季降水的量级增加趋势明显。在秋季年平均降水日数中,主要降水类型以小雨为主,小雨和暴雨及以上量级呈上升趋势,中雨和大雨略呈下降趋势,暴雨及以上量级对秋季降水量的贡献才是主要的,其次是中雨再次是大雨。秋季降水序列存在4个较明显的周期特征时间尺度,分别是2、6、14和30 a,其中,2、6a的振荡周期偏弱;14、30a的振荡周期偏强,未来一到两年(2020～2021年)扶绥县秋季干旱的可能性仍较大且处于14a的周期等值线范围内振荡。扶绥县秋季发生干旱频率达31.7%,其发生秋旱的可能性较大。     

丽江烟区烤烟大田期的降水变化趋势分析

为进一步明确丽江烟区烤烟大田生育期降水资源的时空分布特征,采用线性趋势拟合和“逐步回归的趋势面模拟+残差内插”法对丽江主产烟区4个气候观测站1959-2009年的降水量数据进行了分析。结果表明,丽江烟区降雨充沛,烤烟全生育期平均降水量760.61 mm,降水量时间变化为移栽至团棵期少、旺长期和成熟期较多,适宜优质烟叶的生产,但各年份及各生育期间降水变率较大,空间分布呈现出由东北向西南逐级递减的趋势。烤烟各生育期降水大约10年为1个周期,呈倒S型曲线变化,预测2010-2020年丽江烟区烤烟移栽至团棵期降水呈下降趋势,旺长期和成熟期降水呈增加趋势。     

湖南桂阳和桑植烟区烤烟生育期气温及降水特征

采用湖南桂阳和桑植烟区1981-2010 年气温和降水量观测资料,以线性趋势函数和Mann-Kendall 突变检测方法分析不同烟区烤烟生育期气温和降水变化特征。结果表明:(1)桂阳烟区各生育期平均气温呈上升趋势,尤其是苗期和伸根期上升速率最为明显,分别为0.863℃/10a 和0.596℃/10a,并且在烤烟苗期、伸根期和旺长期气温都出现了突变,突变均发生在20 世纪90 年代和21 世纪初期,均是由寒转暖的趋势;桑植烟区各生育期平均气温总体高于桂阳烟区,其中苗期上升速率最快,为0.547℃/10a,并且20 世纪90 年代苗期出现了突变,表明桂阳烟区烤烟苗期低温是影响烟苗培育的主要气候障碍因素。(2)桂阳烟区各生育期降水量变化趋势呈现伸根期下降、成熟期上升趋势,并且在20 世纪90 年代伸根期和成熟期出现突变点。桑植烟区各生育期平均年降水量比桂阳低,年度间变化小,并且不存在突变点,表明桑植烟区烤烟大田生长期的降水量是影响其烟叶产质量的主要气候障碍因素。      

江苏盐场近50年的气候变化特征分析

分析了江苏盐场近50年的平均气温、降水量、蒸发量、雨日等气象要素的变化情况，利用突变分析及一元线性回归统计分析等工具对各气象要素的突变及年、季节和年代际的变化规律进行了研究，结果发现江苏盐场近50年来年平均气温总体上呈上升趋势，年蒸发量、降水量、雨日总体上呈下降趋势，其中年平均气温、蒸发量、降水量的阶段性变化明显，平均气温、蒸发量、降水量及雨日等气象要素都存在明显的突变现象。     

昌黎县降水天气特征及对鲜食葡萄生产的影响

本文基于对河北昌黎县2017-2021年降水资料的研究,统计了该地区近5年来的降水量、降水日数、暴雨日数等,采用趋势分析等方法分析了昌黎县降水天气特征。重点探讨降水对鲜食葡萄生产的影响以及科学有效的管理措施。     

烟草马铃薯Y病毒病与气象因子的相关性

为了明确烟草马铃薯Y病毒病发生的适宜气候条件,依据云南昭通市昭阳区2009—2011年的病情观测数据及其同步气候观测资料,分析了气象因子对烟草马铃薯Y病毒病发生的影响。结果表明:气温、降水、日照时数与烟草马铃薯Y病毒病发生初期、盛期及其发病株率、病情指数密切相关,其发病株率、病情指数与气温、降水量均呈正相关,与日照呈负相关,在气温高、降水多、日照少的气候条件下,容易导致烟草马铃薯Y病毒病的发生蔓延。     

降水与烤烟感官评吸质量的关系

对山东22个植烟县169个乡镇的2001年、2002年和2004年共计464个烤烟初烤烟叶C3F样品的评吸指标得分与同期5～8月降水进行了相关和逐步回归分析,结果表明,(1) 降水与烟叶评吸质量的相关和逐步回归分析结果基本一致;（2）香气质、余味、杂气、刺激性、燃烧性、总得分与降水的回归方程达极显著水平,劲头和灰色与降水的回归方程达显著水平,浓度和香气量与降水量在0.05显著水平下没有得到逐步回归方程。（3）评吸总得分与5月和8月降水量呈正相关;燃烧性与5月和8月降水量呈负相关;劲头与6月降水量,呈正相关;香气质与5月降水量呈负相关,与6月降水量呈正相关;余味和杂气与5月和5～8月降水量呈正相关;刺激性与5～8月总降水量呈正相关。     

服装流行色变化趋势及突变分析

为探析服装流行色的变化趋势及突变情况,基于中国纺织信息中心发布的2000—2019年春夏流行色定案,采用线性趋势分析、滑动平均法和Mann-Kendall检验,探讨了流行色系统的分布规律及其作用机制。结果表明:1)近20年来服装流行色呈非周期振荡现象,色相数据变化没有明显的总体上升或下降趋势,整体上是以暖色调为主、冷色为辅的春夏季节特色; 2)服装流行色系统存在大量的不连续及突变现象,但不同色相的突变点数量具有显著差异; 3)服装流行色系统并非是平稳渐变的,当内部和外部影响因素满足一定条件时,会发生色彩突变现象。该研究为认识服装流行色突变规律提供了理论支撑。     

醇甜型白酒不同馏分中主要微量成分的检测及变化规律研究

对醇甜型白酒不同馏分进行微量成分变化差异分析发现,醇甜型白酒中乙醛、乙酸乙酯、正丙醇、仲丁醇、异丁醇随着蒸馏过程呈下降趋势;乳酸乙酯及乙酸随着蒸馏过程呈上升趋势;甲醇含量随着蒸馏过程略呈下降趋势,但下降趋势不明显。其中酯类中乙酸乙酯含量最高,其中丁酸乙酯以及己酸乙酯只有极少量或者未检出。微量成分中含量由高到低分别是：醇类、酯类、酸类以及醛类。     

气候变暖对阿勒泰地区春玉米播种期和种植布局的影响--测试文章

采用阿勒泰地区7个气象站1961—2010年逐日平均气温资料,使用线性趋势分析、累积距平、t检验并基于Kriging插值法,分析近50年日平均气温稳定通过≥10℃的初日、终日、持续日数和积温的时空变化特征,揭示春玉米播种期及种植布局的变化规律。结果表明,阿勒泰地区近50年≥10℃积温呈现初日提前、终日推迟、持续日数延长、积温增加的现象,其倾向率分别为0.3、1.3、1.6 d·10a^-1和57.1℃·10a^-1,且突变年份均发生在20世纪90年代中期。各县市春玉米播种期提前3～8 d,生长季延长6～11 d。突变前青河东部不能种植春玉米,晚熟品种不能种植或种植风险较大。随着气候不断变暖,春玉米不同熟性品种可种植区逐渐东扩,各县市春玉米在品种熟性上均发生了改变,表现为由不能种植到种植早熟、早熟向中（晚）熟、中晚熟向晚熟品种的变化。     

Temporal variations and controlling factors of nitrogen export from an artificially drained coastal forest

Nitrogen losses in drainage water from coastal forest plantations can constrain the long term sustainability of the system and could negatively affect adjacent nutrient sensitive coastal waters. Based on long-term (21 years) field measurements of hydrology and water quality, we investigated the temporal variations and controlling factors of nitrate and dissolved organic nitrogen (DON) export from an artificially drained coastal forest over various time scales (interannual, seasonal, and storm events). According to results of stepwise multiple linear regression analyses, the observed large interannual variations of nitrate flux and concentration from the drained forest were significantly (p < 0.004) controlled by annual mean water table depth, and annual drainage or precipitation. Annual precipitation and drainage were found to be dominant factors controlling variations of annual DON fluxes. Temporal trends of annual mean DON concentration could not be explained explicitly by climate or hydrologic factors. No significant difference was observed between nitrogen (both nitrate and DON) export during growing and nongrowing seasons. Nitrate exhibited distinguished export patterns during six selected storm events. Peak nitrate concentrations during storm events were significantly (p < 0.003) related to 30-day antecedent precipitation index and the minimum water table depth during individual events. The temporal variations of DON export within storm events did not follow a clear trend and its peak concentration during the storm events was found to be significantly (p < 0.006) controlled by the short-term drying and rewetting cycles.     

Behavioral changes in dairy cows with metritis in seasonal calving pasture-based dairy system

The aims of this study were to determine changes in lying and rumination behavior of transition dairy cows that were healthy or affected by metritis during the autumn and spring calving season in a temperate climate and determine the effect of some weather variables (precipitation and heat stress) on these behaviors. A total of 103 multiparous cows were monitored during the autumn (February to April) and spring calving season (July to October) from 10 d before to 10 d after calving. Cows were chosen retrospectively by diagnosis of metritis [autumn season, (n = 11); spring season, (n = 13)] or as healthy [autumn season, (n = 25); spring season, (n = 25)] based on vaginal discharge characteristics evaluated during the first 10 days in milk. In all animals, electronic data loggers recorded lying (Hobo Pendant G Acceleration, Onset Computer Corp.) and rumination behavior (Hi-Tag rumination monitoring system, SCR Engineers Ltd.) during the study period. We included precipitation level (>1 mm/d = with rain, and ≤1 mm/d = without rain) and heat stress [no heat stress = temperature-humidity index (THI) < 68 vs. heat stress = THI ≥ 68] as weather factors that may have affected lying and rumination behavior during the spring and autumn season in a temperate climate, respectively. Metritis during the spring calving season was associated only with longer lying times (≥1.3 h/d) after calving. During the autumn calving season cows with metritis lay down longer the day of calving (~2.1 h/d) and had fewer lying bouts of longer duration during the prepartum period compared with healthy cows. Rumination time did not differ by health status during the spring calving season, whereas cows with metritis during autumn ruminated 30, 21, and 24 min/d less than healthy cows during the prepartum, calving, and postpartum period, respectively. Precipitation and heat stress were associated with decreased daily lying and rumination time in sick cows. Our results indicate that differences in lying and rumination behavior depended on the metritis status, and support the idea that weather factors such as rainfall or heat stress requires to be considered in analyses of transition cow behavior in seasonal calving pasture-based dairy systems.     

霍山石斛多糖理化性质与生物活性的年动态变化研究

为分析霍山石斛多糖理化性质与生物活性的年动态变化规律来确定霍山石斛的适宜采收期,本文利用高效凝胶渗透色谱(HPGPC)、红外光谱、乌氏黏度计、分光光度法等方法分析霍山石斛多糖的理化性质,并通过体外细胞实验检测了霍山石斛多糖的肠黏膜免疫调节活性和抗食管癌活性。结果表明,霍山石斛多糖主要由甘露糖和葡萄糖组成的两组分子量不同的组分构成,多糖含量和高分子量组分的分子量在全年呈现降-升-降-升的变化,多糖黏度、乙酰基含量和单糖摩尔比呈现降-升-降的变化,低分子量组分则在5~9月期间消失。霍山石斛多糖具有一定的肠黏膜免疫调节活性和抗食管癌活性,其免疫调节活性在9月至翌年4月优于5~8月,而多糖抑制食管癌细胞生长的作用在秋冬季好于春夏季。由霍山石斛多糖理化性质与生物活性变化之间的关系,可初步确定霍山石斛的最佳采收期为秋冬季。     

普洱生茶贮藏过程中品质指标的规律变化分析

该研究选用贮藏时间在3～20年的18个普洱生茶茶样,通过感官审评和理化成分分析,探究贮藏过程中普洱生茶品质指标的规律变化。结果表明,随着贮藏时间增加,普洱生茶的汤色色泽逐渐加深,香气由清香转为陈香,滋味由醇厚转为醇和,叶底颜色变深变暗,贮藏10年及以上感官品质有所提升,但贮藏18年后,感官品质开始下降;水浸出物、咖啡碱、GC、C、CG的含量呈不规则变化,没食子酸含量逐渐增加,游离氨基酸、EGC、EC、EGCG、GCG、ECG的含量随着贮藏时间的增加呈下降趋势。对17个品质指标标准化后进行相关性分析、主成分分析和聚类分析,发现品质指标间存在显著相关性,通过系统聚类可将茶样分为5类,每间隔3～4年聚为一类,其中,A类综合得分最高,D类次之,E类最低,说明品质指标随着贮藏年份的增加呈现下降趋势,且在3～4年贮藏时间内保持稳定。该结果为深入研究普洱生茶贮藏过程中的品质变化提供依据。     

Impacts of climate change and inter-annual variability on cereal crops in China from 1980 to 2008

BACKGROUND: Negative climate impacts on crop yield increase pressures on food security in China. In this study, climatic impacts on cereal yields (rice, wheat and maize) were investigated by analyzing climate‐yield relationships from 1980 to 2008. RESULTS: Results indicated that warming was significant, but trends in precipitation and solar radiation were not statistically significant in most of China. In general, maize is particularly sensitive to warming. However, increase in temperature was correlated with both lower and higher yield of rice and wheat, which is inconsistent with the current view that warming results in decline in yields. Of the three cereal crops, further analysis suggested that reduction in yields with higher temperature is accompanied by lower precipitation, which mainly occurred in northern parts of China, suggesting droughts reduced yield due to lack of water resources. Similarly, a positive correlation between temperature and yield can be alternatively explained by the effect of solar radiation, mainly in the southern part of China where water resources are abundant. CONCLUSION: Overall, our study suggests that it is inter‐annual variations in precipitation and solar radiation that have driven change in cereal yields in China over the last three decades. Copyright © 2011 Society of Chemical Industry     

Ammonia emissions from dairy production in Wisconsin

Ammonia gas is the only significant basic gas that neutralizes atmospheric acid gases produced from combustion of fossil fuels. This reaction produces an aerosol that is a component of atmospheric haze, is implicated in nitrogen (N) deposition, and may be a potential human health hazard. Because of the potential impact of NH₃ emissions, environmentally and economically, the objective of this study was to obtain representative and accurate NH₃ emissions data from large dairy farms (>800 cows) in Wisconsin. Ammonia concentrations and climatic measurements were made on 3 dairy farms during winter, summer, and autumn to calculate emissions using an inverse-dispersion analysis technique. These study farms were confinement systems utilizing freestall housing with nearby sand separators and lagoons for waste management. Emissions were calculated from the whole farm including the barns and any waste management components (lagoons and sand separators), and from these components alone when possible. During winter, the lagoons’ NH₃ emissions were very low and not measurable. During autumn and summer, whole-farm emissions were significantly larger than during winter, with about two-thirds of the total emissions originating from the waste management systems. The mean whole-farm NH₃ emissions in winter, autumn, and summer were 1.5, 7.5, and 13.7% of feed N inputs emitted as NH₃-N, respectively. Average annual emission comparisons on a unit basis between the 3 farms were similar at 7.0, 7.5, and 8.4% of input feed N emitted as NH₃-N, with an annual average for all 3 farms of 7.6 ± 1.5%. These winter, summer, autumn, and average annual NH₃ emissions are considerably smaller than currently used estimates for dairy farms, and smaller than emissions from other types of animal-feeding operations.     

黄酒陈酿过程中主要成分变化的研究

对不同陈酿时间的黄酒原酒进行了分析,结果表明,随黄酒酒龄的延长,黄酒主要理化指标酒精度、pH值、总酸、总糖等指标没有显著变化;总多酚在贮存期间呈下降趋势,尤其贮存前6年,降低率达到了27.6%,阿魏酸、槲皮素和原儿茶酸是引起多酚含量下降的主要原因.贮存期间,氨基酸尤其是苦味氨基酸也呈显著的下降趋势,这也是贮存期间黄酒苦涩味逐渐降低的主要原因.各种风味物质在贮存期间的变化规律不同,但总的趋势是醇和酸含量在降低,而酯类、醛类的含量在增加.5-甲基糠醛作为啤酒的老化指标,在该研究中含量从初始的3.06g/L上升到了113.34.g/L.     

Impacts of lindane usage in the Canadian Prairies on the Great Lakes ecosystem. 2. Modeled fluxes and loadings to the Great Lakes

Atmospheric loadings of gamma-hexachlorocyclohexane (gamma-HCH) from May 1, 1998, to April 30, 1999, to the Great Lakes simulated by a coupled soil-air and water-air atmospheric transport model are presented. Modeling results on an annual basis indicate that Lake Superior received the highest dry deposition load of 2.17 kg yr(-1). Dry deposition to the lower Great Lakes (Lakes Erie and Ontario) was 2-6 times lower as compared to the upper Great Lakes. Greater deposition in the upper Great Lakes is due mainly to their larger surface area and greater proximity to sources of gamma-HCH. Dry deposition fluxes (pg m(-2)) to lake surfaces were much lower than to land as a result of lower deposition velocities and lower air concentrations of gamma-HCH over the lakes. The highest gamma-HCH loading (kg yr(-1), in 1998-99) due to wet deposition occurred for Lake Ontario. This was mainly attributed to greater annual rainfall over Lake Ontario. An investigation of average seasonal fluxes predicted by the model shows that deposition fluxes to the Great Lakes are considerably higher in the summer than that in the autumn and winter seasons. The net direction of gas exchange also exhibits a seasonal dependence. Lakes Michigan, Huron, and Ontario show net absorption in the summer 1998 whereas at all other times net outgassing occurred at all of the lakes. Overall, gas exchange was the dominant process affecting loadings to the Great Lakes. Model-derived loadings and total deposition flows across the Great Lakes basin due to dry and wet depositions and net gas exchange agree reasonably well with the summer estimates compiled by the Integrated Atmospheric Deposition Network whereas autumn values show greater discrepancies. Better agreement was also observed for dry deposition as compared to wet deposition. Specifically, to improve short-term loading estimates (e.g., over days to months), the model results indicate the need for better spatially and temporally resolved information on concentrations in air and surface water and better estimates of precipitation and deposition velocities over the lakes.