曹娥江大闸闸墩混凝土高温季节温控措施

曹娥江大闸是国内最大的河口大闸,其中闸墩施工在夏季高温季节进行.较全面地阐述了混凝土原材料取料温度值的选取及控制措施,已浇筑混凝土内外温差及降温速率的控制措施等.根据闸墩的结构及边界条件,为了控制温度应力防止裂缝的产生,在施工过程中采取了骨料预冷、冷水拌和、掺冰屑拌和、仓面遮阳、内部通冷却水及外侧保温等综合温控措施,确保了闸墩混凝土的施工质量.     

50年来辽宁省不同等级舒适日数演变及空间区划分析

根据1964—2015年辽宁省23个气象站点的逐日平均气温、相对湿度及平均风速资料,采用人体舒适度指数法计算人体舒适度指数,在季尺度上分析辽宁省不同等级舒适日数演变情况及典型旅游城市最佳旅游期;运用旋转经验正交函数分解法(REOF),分析人体舒适度指数季尺度空间变化特征,并应用ArcGIS软件进行舒适区域划分。结果表明:①辽宁省多年平均冷不舒适日数呈降低趋势,舒适日数呈增加趋势,热不舒适日数也呈微弱增加趋势;舒适程度夏季＞秋季＞春季＞冬季;②除冬季外5座典型旅游城市均适宜旅游,夏季为最佳旅游期;其中,沈阳、本溪更适宜春季旅游,大连更适宜秋季旅游。③辽宁省四季舒适度变化情况可大致划分为辽西、辽中、辽东三个区域,具体划分情况随季节有相应变化,总体舒适度由辽宁东部向西部逐渐递减。     

Quantifying Whitewater Recreation Opportunities in Cataract Canyon of the Colorado River,Utah: Aggregating Acceptable Flows and Hydrologic Data to Identify Boatable Days

The structural norm approach was combined with the Potential for Conflict Index to define recreation streamflow needs for the Colorado River in Utah and Colorado. An online survey was completed by 128 commercial and non‐commercial boaters, who evaluated a range of flows for whitewater boating. For the Cataract Canyon reach, respondents rated the quality of their recreation experience of specific flows, describing the quality of boating opportunities across the full range of historical streamflows. Ranges for both acceptable and optimum flows were defined, as well as thresholds for unacceptable flows. These ranges were then evaluated against historical hydrologic records to quantify the timing, frequency, and duration of days when defined whitewater flows exist across different year types (i.e. average boatable days). Results indicated that on average, a total of 257 boatable days existed in dry years, and 353 total boatable days occurred in dry‐typical years. In wet and wet‐typical years, 362 and 365 total boatable days respectively, occurred on average. Results of the boatable days' analysis indicated that over the 23‐year period of record, whitewater boating opportunities occurred nearly every day of the year in all but the driest year types. Results from this study provide resource managers with information which can be used in the development of annual operating plans for the Colorado River Basin and help managers understand how changes in flow impact the quality of recreational opportunities. This application demonstrates the value of analysing boatable days on any river where recreation management is a priority. Copyright © 2016 John Wiley & Sons, Ltd.     

中国传统岁时节日食俗在餐饮业的应用研究

餐饮企业是中国传统岁时节日食俗在当代有效传承的重要场所和平台之一。文章探讨了研究中国传统岁时食俗在餐饮业应用的积极意义,梳理和总结了中国传统岁时食俗在餐饮业应用的历史和现状,并提出了餐饮业应用中国传统岁时食俗的对策,即以合适的品种为中心、倡导大众餐饮,以成功的经验为基础、加强宣传和营销等,以更好弘扬中国传统文化,促进中国餐饮业的发展。     

Estimation of net radiation from the MODIS data under all sky conditions: Southern Great Plains case study

Net radiation is a key component in the surface radiation budget. Numerous studies have developed frameworks to estimate net radiation or its components (upwelling or downwelling longwave and/or shortwave radiation) from remote sensing data for clear sky conditions. Application of existing methodologies to estimate net radiation for cloudy sky conditions from remote sensing sensors remains a significant challenge. In this paper, we present a framework to estimate instantaneous and daily average net radiation under all sky conditions from using the data from the MODerate Resolution Imaging Spectroradiometer (MODIS), onboard from the Terra satellites. Bisht et al. (2005) methodology is used for the clear sky portion of the MODIS overpass; while for cloudy portion of the MODIS overpass an extension of Bisht et al. (2005) methodology is applied. The extension of Bisht et al. (2005) methodology utilizes the MODIS cloud data product (MOD06_L2) for cloud top temperature, cloud fraction, cloud emissivity, cloud optical thickness and land surface temperature for cloudy days. The methodology is applied over the Southern Great Plains (SGP) for a time period covering all seasons of 2006. During the MODIS-Terra overpasses in 2006 over the SGP, only 24% of day-overpasses and 9% of night-overpasses had 75% or more of the study region as cloud free. Thus, this proposed study is applicable to a large portion of the MODIS-Terra overpasses. The root mean square errors (RMSE) of instantaneous and daily average net radiation estimated under cloudy conditions using the MOD06_L2 product, comparing to ground-based measurements are 37 W m^− 2 and 38 W m^− 2, respectively. The strength of the proposed methodology is that it can rely exclusively on remote sensing data in the absence of ancillary ground observations, thus it has a potential to estimate surface energy budget globally.     

关于现代河流生态保护的哲学思考

从矛盾观、自然观、系统观等唯物辩证法的方法论入手,对河流生态保护进行了哲学反恩。必须运用系统的观点来看待河流系统,保护河流系统的完整性和连续性;必须减轻人类活动对河流自然形态的限制,恢复河流的千姿百态;必须深刻认识河流的演化规律,正确处理好人类和河流之间的关系,不断实现人水和谐;必须尊重河流生命,从辩证的角度在河流开发利用与河流保护之间不断寻求折中点,通过最大努力保护和修复河流生态。     

区域蒸散发分析及模型研究——以河套灌区义长灌域永联试验区为例

以河套灌区义长灌域永联试验区为例,对水均衡法中采用不同时间和空间尺度时的蒸散发估算结果进行了比较分析.然后借鉴由参考作物腾发量(ET0)计算实际蒸散发量的思路,以区域平均埋深和累积生长度日(GDD)为变量,建立综合因子,再结合参考作物腾发量估算出区域蒸散发.利用永联试验区的数据对模型进行检验,结果可靠.该模型需要数据较少,易应用,为实时估算农田区域蒸散发量提供了一种方法.     

水解酸化SBR工艺处理污泥的研究

为了提高污泥水解酸化产酸率,采用SBR工艺处理污水厂污泥,研究了不同水力停留时间时间隔排泥天数(决定生物固体停留时间)对污泥水解酸化过程的影响。结果表明,在HRT 6.6d和HRT 3d时,污泥产酸率随着排泥间隔天数的增加而增加。排泥间隔天数2d时达最大,分别为135.62mg/g、125.61mg/g;排泥间隔天数3d时,污泥产酸率稍有下降。HRT 4.4d,污泥产酸率随着排泥间隔天数的增加而增加。排泥间隔天数3d时,污泥产酸率达57.88mg/g。所以,最优工况为HRT6.6d、排泥间隔天数2d的运行方式。     

短期负荷预测的组合数据挖掘算法

给出了一种短期电力负荷预测的组合数据挖掘算法.通过日负荷特性分析,在设定长度的最近历史日期中选择与预测日天气最相似的为基准日,通过该模式下天气相似日的相关影响因素差异与相应负荷变化率关联规则挖掘建模,挖掘模型算法采用C4.5和CART算法的基于BP网络加权组合,算法还基于范例推理给出节假日调整因子校正节假日的影响,设计出一种高精确度短期负荷预测系统.实际应用结果表明该组合算法预测精确度高、效果良好.     

Prepartum nutritional strategy affects reproductive performance in dairy cows

Negative energy balance during early postpartum is associated with reduced reproductive performance in dairy cows. A pooled statistical analysis of 7 studies completed in our group from 1993 to 2010 was conducted to investigate the association between prepartum energy feeding regimen and reproductive performance. The interval from calving to pregnancy (days to pregnancy, DTP) was the dependent variable to assess reproductive performance. Individual data for 408 cows (354 multiparous and 54 primiparous) were included in the analysis. The net energy for lactation (NE_L) intake was determined from each cow’s average dry matter intake and calculated dietary NE_L density. Treatments applied prepartum were classified as either controlled-energy (CE; limited NE_L intake to ≤100% of requirement) or high-energy (HE; cows were allowed to consume >100%) diets fed during the far-off (FO) or close-up (CU) dry periods. Cow was the experimental unit. The Cox proportional hazard model revealed that days to pregnancy was shorter for CE (median = 157 d) than HE (median = 167 d) diets during the CU period [hazard ratio (HR) = 0.70]. Cows fed HE diets during the last 4 wk prepartum lost more body condition score in the first 6 wk postpartum than those fed CE diets (−0.43 and −0.30, respectively). Cows fed CE diets during the FO period had lower nonesterified fatty acids concentrations in wk 1, 2, and 3 of lactation than cows fed HE diets. Higher nonesterified fatty acids concentration in wk 1 postpartum was associated with a greater probability of disease (n = 251; odds ratio = 1.18). Cows on the CE regimen during the FO period had greater plasma glucose concentrations during wk 1 and 3 after calving than cows fed the HE regimen. Higher plasma glucose (HG) concentration compared with lower glucose (LG) in wk 3 (HG: n = 154; LG: n = 206) and wk 4 (HG: n = 71; LG: n = 254) after calving was associated with shorter days to pregnancy (wk 3: median = 151 and 171 d for HG and LG, respectively, and HR = 1.3; wk 4: median = 148 and 167 d, respectively, and HR = 1.4). In the first 2 wk after calving, cows that received HE diets in the FO period had higher concentrations of total lipids and triglyceride and greater ratio of triglyceride to glycogen in liver than cows fed CE diets. In conclusion, cows fed CE diets during the CU period had a shorter interval between parturition and conception, which may be explained by increased NE_L intake during the first 4 wk postpartum and lower incidence of peripartal diseases. Lower body condition score loss during the first 6 wk postpartum and slightly higher glucose concentration at wk 3 likely contributed to improved reproductive performance.