HPLC测定川楝子不同采收期及不同部位中川楝素的含量

通过测定不同采收期和不同部位川楝子中川楝素的含量,为确定川楝子最佳采收期提供依据。采用高效液相色谱法,色谱柱Agilent Zorbax SB-C18（4.6mm×150mm,5μm）,流动相乙腈—水（28∶72）,流速1.0mL/min,检测波长210nm,柱温35℃。不同采收期川楝子中川楝素以1—2月间采收的含量最高;同一采收期的川楝子果核和果肉中川楝素含量最高,外果皮次之,种子中未检出川楝素。     

新疆旅游气候舒适性分析与旅游区划

以新疆维吾尔自治区为案例,对研究区1962—2011年气象数据进行系统分析,选取气温、相对湿度、风速三个气候要素构建温湿指数(THI)、风效指数(WEI)、舒适指数(C)和着衣指数(ICL),通过与不同指数分级表的对比分析,得出新疆不同地域的适宜旅游期:4—10月是新疆的旅游适宜季节,其中只有北疆阿尔泰山系、天山北坡部分县市4月、10月气候偏冷,不适宜旅游。北疆地区和东疆哈密地区11月至次年3月份气候舒适度较差,不适宜开展旅游活动;南疆大部分地区3月份和11月份是适宜旅游的过渡季节,12月至次年2月天气偏冷,除冬季滑雪外,全疆大部分地区不适宜旅游。     

芦苇根系对湿地沉积物Pb的吸收累积特征

以芦苇为研究对象,运用SPSS进行回归分析和显著性检验,探讨芦苇根系及环境因子对沉积物Pb的影响。结果表明:芦苇根系对沉积物Pb富集效应明显,4月—10月富集效应强,根系Pb含量较高,而11月—次年2月富集效应弱,根系Pb含量较低;沉积物中Pb含量呈现枯水期丰水期平水期的变化趋势;DO与芦苇根系Pb含量呈显著正相关,而土温与沉积物Pb含量呈显著负相关;芦苇根系Pb含量与沉积物Pb含量的相关性较强,显著性系数为0.043 3。     

西宁市区大气CO_2浓度变化特征及与气象要素的关系

文章对2010年2~10月在西宁市区获得的大气CO2浓度观测资料及气象观测资料进行了分析。结果表明,西宁地区大气CO2本底浓度具有明显的季节变化,且变化幅度较大,最高值大约出现在每年的12月至次年2月,最低值出现在夏季的5~6月份;日变化也比较明显,并在四季均有明显的双峰值特征,最高值一般出现在一天之中的07:00~10:00时和19:00~22:00时,而低值一般在14:00~17:00时和00:00~03:00时时间段内出现;与气象要素的变化也比较明显,尤其与地面风向、风速及温度的变化比较明显;与瓦里关全球大气本底站大气CO2浓度的季节变化和日变化有明显的差异。     

薄层扫描法分析黄芪中黄芪甲苷含量

研究不同产地、不同生长期野生与栽培黄芪中黄芪甲苷含量的变化,确定其最佳采收期,为更好地开发利用黄芪资源提供理论依据。建立其分析方法,为黄芪的现代质量评价体系提供参考数据,扩大黄芪药源。采用薄层扫描法,结果表明黄芪甲苷在1.1—5.5μg范围内具有良好的线性关系,R2=0.998,n=3;平均回收率(n=3)为100.50%,RSD=2.19%。吉林省临江种植基地10月20日采收的黄芪中黄芪甲苷含量最高为1.195%,10月15日采收的黄芪甲苷含量为1.164%。不同产地的黄芪中黄芪甲苷的含量为甘肃吉林临江内蒙古黑龙江吉林长春河北。黄芪药材在贮存6个月之后的黄芪甲苷含量有所下降。该方法简便、精密度高、结果准确可靠,并确立了黄芪药材的最佳采收期为3年生10月中下旬。种植基地黄芪药材可代替野生黄芪药材使用,为黄芪药材的药用资源和深入开发利用提供了基础依据。     

太湖流域上游典型水体中氮、磷动态变化特征研究

本研究在太湖流域上游的太湖与湖间的区域内，选择了25个监测点，对6种典型水体中TN、TP含量进行了为期1年的动态监测，分析了不同类型水体中氮、磷动态变化特征。其结果表明，畜禽养殖厂周围水体TN、TP含量在4～8月份相对较低；水产养殖场周围水体和居民区周围水体TN含量在1～6月份高于其他时间段，水产养殖场周围水体TP含较低的月份在5～8月，而居民区周围水体TP含量变化无明显规律；农田周围水体TN、TP含量较高的月份在12月至次年5月期间，最大值出现在3～4月；入湖河流与湖水TN含量变化趋势与农田周围水体基本一致，入湖河流TP含量在6～10月期间明显低于其他时间段，而湖水中TP含量变化则无明显规律。     

秦皇岛市近63年自然降水资源变化特征

利用秦皇岛市1954—2016年逐日降水资料,运用线性趋势法、累计距平、方差分析等数理统计方法,分析了近63 a来秦皇岛市年、季、月自然降水总量与雨日的气候变化特征。结果表明:秦皇岛市年降水量总体呈减少趋势,气候倾向率-15.5 mm/10 a;夏、秋季降水量呈减少趋势,春季呈增加趋势,冬季变化不明显;1月、2月降水变化趋势不明显,7月—10月呈减少趋势,2月—4月、11月—12月呈增多趋势。年雨日明显减少,平均每10 a减少3.05 d,雨日的减少主要表现为小雨日数的减少。年降水强度变化不大,夏、春季降水强度呈增加趋势,秋季呈减小趋势,冬季变化不大。由上可知,年降水量和雨日的同步减少是秦皇岛市近63 a降水变化的明显特征,因此,秦皇岛市自然降水资源呈减少趋势,夏、秋两季变干明显。     

红肉猕猴桃新品种适时采收指标研究

以红肉猕猴桃新品种"红实2号"为材料,分别在盛花期后152d、156d、161d、171d、181d这5个时期进行采摘,在常温(20±1℃)和低温(1±0.5℃)下检测其品质指标变化,研究四川绵竹地区红肉猕猴桃最佳采收指标。结果表明:"红实2号"最佳采收期为盛花后156—171d,此时果实干物质17.9%—20.2%,可溶性固形物7.4%—9.0%,果肉硬度5.0—6.0kgf,果肉红色等级得分3.5—5分。该期采收的果实常温下软熟后平均糖度15.3%—17.1%,果柄出水率显著降低,好果率高。低温(1±0.5℃)下贮藏期60d,果肉硬度0.9kgf,好果率大于95%。     

杨梅采摘后的管理

杨梅的结果母枝一般在7月上、中旬,即采收杨梅后由结果枝顶芽萌发抽生。由于杨梅在开花、结果过程中,消耗了大量的养分,所以在采摘后应加强肥水管理,以利新梢抽生、花芽分化,提高翌年的杨梅产量。一、及时施好采后肥:采收杨梅后,应立即追施一次肥料。一般株采50kg以上的杨梅树应施草木灰10—15kg,或焦泥灰15—20kg;或土杂肥50kg;     

HPLC分析刺五加叶中金丝桃苷与绿原酸含量

对刺五加叶中金丝桃苷与绿原酸进行含量测定,探讨其最佳采收期,并比较不同采收期仿生栽培品与野生品刺五加叶中主要活性成分的含量差异,利用高效液相色谱法测定仿生栽培与野生刺五加叶中金丝桃苷与绿原酸的含量。在仿生刺五加叶中,金丝桃苷与绿原酸分别在6月8日、5月19日达到最高值,含量分别为0.478%、0.899%;在野生刺五加叶中,金丝桃苷与绿原酸分别在5月29日、5月19日达到最高值,含量分别为0.156%、0.704%。仿生栽培刺五加叶与野生刺五加叶主成份含量差异显著,且仿生栽培刺五加叶主成份明显高于野生刺五加叶主成份,因此仿生栽培刺五加叶可以替代野生刺五加叶作药用。这不但为日益减少的野生资源开辟了新药源,而且为刺五加叶的进一步开发应用及质量控制奠定了基础。     

Spatial and Seasonal Variation of Dissolved Organic Carbon (DOC) Concentrations in Irish Streams: Importance of Soil and Topography Characteristics

Dissolved organic carbon (DOC) concentrations have increased in many sites in Europe and North America in recent decades. High DOC concentrations can damage the structure and functions of aquatic ecosystems by influencing water chemistry. This study investigated the spatial and seasonal variation of DOC concentrations in Irish streams across 55 sites at seven time occasions over 1 year (2006/2007). The DOC concentrations ranged from 0.9 to 25.9 mg/L with a mean value of 6.8 and a median value of 5.7 mg/L and varied significantly over the course of the year. The DOC concentrations from late winter (February: 5.2 ± 3.0 mg/L across 55 sites) and early spring (April: 4.5 ± 3.5 mg/L) had significantly lower DOC concentrations than autumn (October: mean 8.3 ± 5.6 mg/L) and early winter (December: 8.3 ± 5.1 mg/L). The DOC production sources (e.g., litterfall) or the accumulation of DOC over dry periods might be the driving factor of seasonal change in Irish stream DOC concentrations. Analysis of data using stepwise multiple linear regression techniques identified the topographic index (TI, an indication of saturation-excess runoff potential) and soil conditions (organic carbon content and soil drainage characteristics) as key factors in controlling DOC spatial variation in different seasons. The TI and soil carbon content (e.g., soil organic carbon; peat occurrence) are positively related to DOC concentrations, while well-drained soils are negatively related to DOC concentrations. The knowledge of spatial and seasonal variation of DOC concentrations in streams and their drivers are essential for optimum riverine water resources management.     

发动机机油净化装置的研制与应用

车辆发动机每年在换季时都需要更换不同牌号的机油。为了使换下来的机油能够在第二年重复再利用,中原油田分公司采油五厂研制了污油机油净化处理装置。实践证明,净化后的机油完全可以达到使用技术要求。这样既能减少浪费,又能保护环境不受污染,经济效益也十分明显。     

Wildlife management: Managing the hunt versus the hunting experience

Deer hunter satisfaction is investigated from two perspectives, (1) satisfaction with the hunt/harvest and (2) satisfaction with the overall hunting trip experience. Regression analysis is used to determine what variables best predict satisfaction with the hunt and the hunting experience. Results indicate that animal population variables (number of deer seen, shot at, bagged) are the best determinants of a quality deer hunt, while environmental (outdoors) and social (crowding and hunter behavior) are the best predictors of a quality hunting trip experience. Wildlife managers and researchers need to realize that deer hunters view the hunt/harvest as different from the hunting trip experience and need to manage for both aspects of hunter satisfaction.     

LONG TERM TRENDS OF ANNUAL AND MONTHLY PRECIPITATION IN JAPAN1

ABSTRACT: Long term trends in Japan's annual and monthly precipitation are investigated in this study. The statistical significance of a trend at a study site is assessed by the Mann‐Kendall (MK) test, and field significance of trends in climatic Regions II, III, and IV is evaluated using the bootstrap test preserving cross correlation. The practical significance of a trend is judged by a percentage change of the sample mean over an observation period. The field significance assessment demonstrates that annual precipitation in Region II did not show any significant change, but regional precipitation shifts occurred in different months. Precipitation significantly increased by 12.2 percent in May, while it significantly decreased by 12.0, 10.5, 15.6, and 19.7 percent, respectively, in April, September, October, and December. In Region III, annual precipitation declined by 11.8 percent, and monthly precipitation significantly decreased from September through January and in April, with the greatest decrease (38.2 percent) in December. In Region IV, significant reductions occurred in both annual precipitation (by 15.6 percent) and monthly precipitation from September through February and in June and July, with the worst reduction (44.7 percent) in December.     

粮食产量预测理论、方法与应用Ⅳ.粮食估产理论、模型及其应用

粮食估产的“通道-概率”理论：把属于最近通道的历年来的产量划分为5个气候年型通道,即丰产年、偏丰年、平产年、偏欠年、欠产年;计算产量出现在5个气候年型中的频率作为概率使用,估产年的初始估产值等于预测年各通道内平均产量与概率之积的和;估产值等于初始估产值与气候年型修正参数之积,专家根据当年气候条件和作物长势实时确定修正参数。预报单元为全国、省和县。应用结果表明：国家尺度上不需要修正,省和县级尺度需要气候年型参数修正;预测误差在3％以内;所述估产理论严谨、方法简单,参数少,参数来自原始数据本身和专家经验,易于推广使用。     

THE EFFECTS OF RECENT CHANGES IN ATMOSPHERIC CIRCULATION ON THE HYDROLOGY OF THE KANKAKEE RIVER1

ABSTRACT: In North America the four successive winters from 1974-1975 through 1977–1978 were very different from each other in terms of atmospheric circulation and resulting surface weather conditions. The first year of the sequence there was a near normal circulation pattern. The following years were characterized by the gradual amplification of an upper atmosphere ridge over the West Coast coupled with an eastward displacement of a long-wave trough east of the Rocky Mountains. These changes in circulation brought below normal temperatures to the Midwest, below normal precipition and increasing snowfall which reached record levels in February 1978. These atmospheric changes brought about changes in the flow of the Kankakee River-Total runoff in the winter half-year dropped as precipitation and temperatures dropped; there was a marked retarding of winter runoff and the yield of the watershed increased.     

Effects of low concentrations of herbicides on full-season, field-grown potatoes

Current phytotoxicity plant test protocols for US pesticide registration require testing for effects on seedling emergence and early growth without regard to other important factors, such as plant reproduction. Yield and quality reduction can have significant economic and ecological effects. Therefore, field trials were conducted to determine if potato (Solanum tubersum L.) vegetative growth and tuber yield and quality were affected by herbicides at below recommended field rates. Potatoes were grown in fields at the Oregon State University Horticulture Farm with herbicides applied at below recommended field application rates 14 d after emergence (DAE) or at 28 DAE. Plant height was measured before and 14 d after application. Visual foliar injury was rated 14 d after application, and tuber yield and quality parameters were measured at harvest (120 DAE). Some tubers were grown in the greenhouse the following year to determine if there were carry-over effects. Potato vegetation and tuber yield quality were generally more affected by herbicides applied at 14 DAE than at 28 DAE. Tuber yield and quality parameters were more affected by lower herbicide rates than were plant height or injury. There were significant yield losses caused by low rates of sulfometuron methyl and imazapyr and, to a lesser extent, with glyphosate and cloransulam-methyl. Bromoxynil and MCPA ((4-chloro-2-methylphenoxy)acetic) acid had little effect on the plants. Vegetative responses did not accurately predict yield and quality responses of tubers; therefore, reproductive responses should be considered in phytotoxicity test protocols for pesticide registration in the USA.     

IMPACTS OF SILVICULTURE ON FLATWOODS RUNOFF,WATER QUALITY,AND NUTRIENT BUDGETS1

ABSTRACT: Three forest watersheds were isolated by roads in poorly drained flatwoods of Florida. After 12 months of baseline calibration the forest in one watershed was harvested and regenerated with minimum disturbance, in the second watershed with maximum disturbance from common practices, and in the third watershed left intact as a control. Water yields from the maximum treatments increased a significant 250 percent while that from the minimum treatments increased 117 percent as compared to the control. Weed vegetation remaining after the minimum treatment continued significant water use. The water yield increases lasted only for one year. Water quality was reduced by both treatments with the most effect immediately after the maximum disturbance. Absolute levels of suspended sediments, potassium, and calcium remained relatively low. The maximum treatment caused significant changes in net cation balances only for one year. The information shows relative little effect of silvicultural practices in flatwoods on water quality as compared to data from upland forests. Water yield increases may be manipulated by the degree of harvest and weed control practices.     

Application of response surface methodology for the optimization of biodiesel production from yellow mustard (Sinapis alba L.) seed oil

In the present study, response surface methodology (RSM) involving central composite design (CCD) was applied to optimize the reaction parameters of biodiesel production from yellow mustard (Sinapis alba L.) seed oil during the single-step transesterification process. A total of 30 experiments were designed and performed to determine under the effects of variables on the biodiesel yield such as methanol to oil molar ratio (2:1–10:1), catalyst concentration (0.2–1.0 wt.% NaOH), reaction temperature (50–70°C), and reaction time (30–90 min). The second order polynomial model was used to predict the biodiesel yield and coefficient of determination (R²) was found to be at 0.9818. The optimum biodiesel yield was calculated as 96.695% from the model with the following reaction conditions: 7.41:1 of methanol to oil molar ratio, 0.63 wt. % NaOH of catalyst concentration, 61.84°C of reaction temperature, and 62.12 min of reaction time. It is seen that the regression model results were in agreement with the experimental data. The results showed that RSM is a suitable statistical technique for optimizing the reaction parameters in the transesterification process in order to maximize the biodiesel yield.     

Stream Temperature Relationships to Forest Harvest in Western Washington1

Abstract: We compared summer stream temperature patterns in 40 small forested watersheds in the Hoh and Clearwater basins in the western Olympic Peninsula, Washington, to examine correlations between previous riparian and basin‐wide timber harvest activity and stream temperatures. Seven watersheds were unharvested, while the remaining 33 had between 25% and 100% of the total basin harvested, mostly within the last 40 years. Mean daily maximum temperatures were significantly different between the harvested and unharvested basins, averaging 14.5°C and 12.1°C, respectively. Diurnal fluctuations between harvested and unharvested basins were also significantly different, averaging 1.7°C and 0.9°C, respectively. Total basin harvest was correlated with average daily maximum temperature (r² = 0.39), as was total riparian harvest (r² = 0.32). The amount of recently clear‐cut riparian forest (<20 year) within 600 m upstream of our monitoring sites ranged from 0% to 100% and was not correlated to increased stream temperatures. We used Akaike’s Information Criteria (AIC) analysis to assess whether other physical variables could explain some of the observed variation in stream temperature. We found that variables related to elevation, slope, aspect, and geology explain between 5% and 14% more of the variability relative to the variability explained by percent of basin harvested (BasHarv), and that the BasHarv was consistently a better predictor than the amount of riparian forest harvested. While the BasHarv is in all of the models that perform well, the AIC analysis shows that there are many models with two variables that perform about the same and therefore it would be difficult to choose one as the best model. We conclude that adding additional variables to the model does not change the basic findings that there is a relatively strong relationship between maximum daily stream temperatures and the total amount of harvest in a basin, and strong, but slightly weaker relationship between maximum daily stream temperatures and the total riparian harvest in a basin. Seventeen of the 40 streams exceeded the Washington State Department of Ecology’s (DOE) temperature criterion for waters defined as “core salmon and trout habitat” (class AA waters). The DOE temperature criterion for class AA waters is any seven‐day average of daily maximum temperatures in excess of 16°C. The probability of a stream exceeding the water quality standard increased with timber harvest activity. All unharvested sites and five of six sites that had 25‐50% harvest met DOEs water quality standard. In contrast, only nine of eighteen sites with 50‐75% harvest and two of nine sites with >75% harvest met DOEs water quality standard. Many streams with extensive canopy closure, as estimated by the age of riparian trees, still had higher temperatures and greater diurnal fluctuations than the unharvested basins. This suggests that the impact of past forest harvest activities on stream temperatures cannot be entirely mitigated through the reestablishment of riparian buffers.