Assessment of future climate change impacts on hydrological behavior of Richmond River Catchment

This study evaluated the impacts of future climate change on the hydrological response of the Richmond River Catchment in New South Wales (NSW), Australia, using the conceptual rainfall-runoff modeling approach (the Hydrologiska Byrans Vattenbalansavdelning (HBV) model). Daily observations of rainfall, temperature, and streamflow and long-term monthly mean potential evapotranspiration from the meteorological and hydrological stations within the catchment for the period of 1972–2014 were used to run, calibrate, and validate the HBV model prior to the streamflow prediction. Future climate signals of rainfall and temperature were extracted from a multi-model ensemble of seven global climate models (GCMs) of the Coupled Model Intercomparison Project Phase 3 (CMIP3) with three regional climate scenarios, A2, A1B, and B1. The calibrated HBV model was then forced with the ensemble mean of the downscaled daily rainfall and temperature to simulate daily future runoff at the catchment outlet for the early part (2016–2043), middle part (2044–2071), and late part (2072–2099) of the 21st century. All scenarios during the future periods present decreasing tendencies in the annual mean streamflow ranging between 1% and 24.3% as compared with the observed period. For the maximum and minimum flows, all scenarios during the early, middle, and late parts of the century revealed significant declining tendencies in the annual mean maximum and minimum streamflows, ranging between 30% and 44.4% relative to the observed period. These findings can assist the water managers and the community of the Richmond River Catchment in managing the usage of future water resources in a more sustainable way.     

羧甲基淀粉的应用与合成

综述了羧甲基淀粉的发展、合成方法、合成过程中的影响因素以及应用现状。羧甲基淀粉的合成主要分三种类型 :干法、半干法、湿法。综合了反应过程中的影响因素 ,例如醚化剂和催化剂的影响 ,反应时间和温度的关系 ,溶剂、设备对反应的影响 ,以及在食品、医药、钻井、纺织、日化工业中的应用前景     

ASPECTS OF JOINT DESIGN AND EVALUATION IN THICK-ADHEREND APPLICATIONS

Structural adhesives are gaining wide recognition by industry as they offer engineering designers greater flexibility to achieve economic and technical advantages. In the marine industry there are potential applications for adhesives in various types of construction, for example, thick steel and composite adherends, (typically 5-15 mm thick). The applications include panels and large pipes. This article is largely concerned with the use of two-part epoxy adhesives. The purpose of this article is to understand and evaluate the weaknesses of adhesives and adherends, in relation to specific applications and to use design and material selection to alleviate them. This understanding can be extended to other thick adherend applications. This article will also highlight the impact of structural epoxy adhesive technology on the design and fabrication of steel, composite, and hybrid constructions. The benefits and inherent limitations that can accrue are quantified through three case studies related to thick adherend connections.     

Medium chain triglyceride in early life: Effects on growth of adipose tissue

Effects of feeding early in life a diet high in either long chain (LCT) or medium chain triglyceride (MCT) were studied on the development of adipose tissue in post-weanling rats. The diets were similar in calorie distribution and identical in nutrients except for type of fat. The caloric distribution of the two diets by percent was LCT (corn oil)/protein/carbohydrate, 70/18/12 and MCT/corn oil/protein/carbohydrate, 66/4/18/12. Male littermates with less than 5% weight difference were pair-fed the two diets randomly at age 18–20 days. One-fourth of the rats were killed at 10, 16, 22 and 28 weeks of age and analyzed for adipose depots and adipose tissue cellularity. Results showed that the LCT-fed rats were significantly heavier, with larger epididymal, retroperitoneal, omental and subcutaneous fat pads than the respective pair-fed MCT rats. Also, LCT-fed rats had larger size and number of adipocytes than MCT-fed littermates. It is concluded that the type of fat in the diet, namely LCT or MCT, when fed early in life can influence the development of adipose tissue. MCT appears less lipogenic than LCT. The mechanism for the diminished adiposity of MCT-fed rats is related to extensive oxidation of MCT and its enhancement of thermogenesis leading to lessened energy efficiency. Presented at the symposium on “Specialty Lipids and Their Biofunctionality” at the annual meeting of the American Oil Chemists' Society, Philadelphia, May 1985.     

BP网络算法在平面运动测量误差补偿中的应用

在航天对接试验平台开发项目中,针对平面运动物体非接触高精度测量的难点,提出一种针对物体三自由度平面运动的创新性测量方法.利用激光测距传感器的并联组合,实现对物体位置和姿态的非接触式测量.以传感器测量值为输入样本,运用BP神经网络算法建立误差模型,通过调整权值因子使建立的网络模型能够拟合出测量误差,从而修正测量的数学模型.基于BP神经网络的误差补偿方法对平面运动物体测量误差的补偿具有明显的效果,能够满足位姿测量的精度要求.     

天然藻类对废水中 COD 的去除效率研究

目前废水中COD的处理问题是我国乃至世界各国普遍关注的问题,找到一种操作简单、成本低且效果好的处理方法是解决问题的关键所在。利用天然藻类中绿藻、硅藻处理不同类型废水,以COD作为检测指标。结果表明,绿藻对废水中COD的去除率最高。同时探讨了不同初始浓度的COD、不同种类废水中COD的去除效率。     

宁夏黄河段水库泥沙淤积对大坝防渗与结构安全影响研究

以宁夏黄河段某水库为例,在对其泥沙淤积原因进行总结分析的基础上,对其淤积情况下大坝渗流分析、结构分析及抗震安全分析进行了有限元计算。研究表明:(1)泥沙淤积情况下大坝渗漏量减小,大坝稳定性增强,抗震安全系数增大;(2)泥沙淤积导致水库有效库容减小,水库建筑物无法正常工作,水库下游生活用水和农业用水无法满足,应采取必要的清淤措施。     

WSN 中基于粒子滤波的目标跟踪研究

针对无线传感器网络中仅有角度测量的目标跟踪问题,详细分析其定位过程,提出一种基于改进粒子滤波算法的新解决方案.方案采用高斯混合模型(GMM)代替单一模型近似概率密度分布,融入粒子滤波算法,提议分布采用SRUKF-PF算法更新粒子.算法中增加改进措施以提高滤波性能如:残差重采样算法用于重采样、K-means算法用于构建预估起始点、EM算法用于拟合GMM近似等.仿真结果验证了方案的有效性.     

Somatic mutation favors the evolution of diploidy

Explanation of diploidy have focused on advantages gained from masking deleterious mutations that are inherited. Recent theory has shown that these explanations are flawed. Indeed, we still lack any satisfactory explanation of diploidy in species that are asexual or that recombine only rarely. Here I consider a possibility first suggested by Efroimson in 1932, by Muller in 1964 and by Crow and Kimura in 1965: diploidy may provide protection against somatic, not inherited, mutations. I both compare the mean fitness of haploid and diploid populations that are asexual and investigate the invasion of "diploidy" alleles in sexual populations. When deleterious mutations are partially recessive and somatic mutation is sufficiently common, somatic mutation provides a clear advantage to diploidy in both asexual and sexual species.