四川盆地震旦系灯影组丘滩体发育分布及对储层的控制

四川盆地震旦系灯影组储层主要发育于微生物丘滩体中，但不同成因类型丘滩体对储层的影响尚不明确。通过钻井岩心和野外露头观测、岩石薄片分析和物性测试等手段，将丘滩体划分为丘基、丘核、丘翼和丘坪4种微相，并根据微相的组合划分出台缘并进型丘滩体、台缘追补型丘滩体和台内饥饿型丘滩体3种丘滩体类型。台缘并进型丘滩体的生长速率快，与可容空间的增加速率相同步，其微相组合以"丘基+丘核"垂向加积为主，在海平面升降过程中易暴露于大气淡水环境，造成海水胶结作用弱、淡水溶蚀作用强，形成以格架溶蚀孔洞为主的储集空间，储层物性好，储集性能最优。台缘追补型丘滩体的生长速率次之，其早期的生长速率滞后于可容空间增长速率但后期逐渐同步，呈现出"丘基+丘核+丘翼/丘坪"侧向加积的微相组合；由于暴露于大气淡水环境的几率减小，其海水胶结作用强，淡水溶蚀作用减弱，储集性能稍差。台内饥饿型丘滩体的生长速率最慢，严重滞后于可容空间的增长速率，呈"云坪（丘基）+丘核+丘坪"微相组合，难以暴露于大气淡水环境，淡水溶蚀作用最弱，储集性能也最差。台缘带古地貌对丘滩体的生长速率影响较大，可控制丘滩体的沉积样式。陡坡台缘带有利于台缘并进型丘滩体发育，缓坡台缘带主要发育台缘追补型丘滩体，台内高地中发育台内饥饿型丘滩体。胡家坝-阆中-安岳地区一带的震旦系灯影组四段发育于典型的陡坡台缘带，是储层发育的最有利相带。     

南阳盆地北缘更新世以来的构造演化特征

南阳盆地是白垩纪晚期以来持续发育的断陷盆地，通过对南阳盆地钻孔及河流阶地的研究，并结合ESR测年方法，对南阳盆地北缘更新世以来的构造演化特征进行了分析。结果表明：研究区冲洪积层主要由全新统、上更新统、中更新统组成，分别构成了湍河的Ⅰ级、Ⅱ级、Ⅲ级阶地；中更新统以来，研究区垂直升降运动较为明显，湍河下蚀作用十分强烈，多级阶地的结构体现了更新世中晚期以来的总体持续下蚀过程，且时间和空间上表现出不均衡性，其下蚀速率由慢至快又逐渐减缓。     

A weakly supervised large margin domain adaptation method for isolated handwritten digit recognition

Learning handwriting categories fail to perform well when trained and tested on data from different databases. In this paper, we propose a novel large margin domain adaptation algorithm which is able to learn a transformation between training and test datasets in addition to adapting the parameters of classifier using a few or even no training labeled samples from target handwriting dataset. Additionally, we developed a framework of ensemble projection feature learning for datasets representation as a front end for our algorithm to utilize the abundant unlabeled samples in target domain. Experiments on different handwritten digit datasets adaptations demonstrate that the proposed large margin domain adaptation algorithm achieves superior classification accuracy comparing with the state of the art methods. Quantitative evaluation of the proposed algorithm shows that semi-supervised adaptation utilizing one sample per class of target domain set reduces the error rates by 64.72% comparing with a corresponding SVM classifier.     

大规模光伏并网系统谐振机理及稳定性分析

在弱电网下或者装机容量增加时,大规模光伏并网系统易引发谐波谐振,危及光伏电站的正常稳定运行。针对上述问题,以大规模光伏并网系统为研究对象,分别从系统阻尼、闭环控制等角度揭示了大型光伏电站和电网之间的谐振机理。研究结果表明:LCL滤波器自身的有源阻尼策略并不会导致大规模光伏并网系统引发谐振,引发谐振的关键因素在于并网逆变器自身的稳定裕度。电网阻抗、装机容量、系统参数设计、控制策略等因素的综合效应可以使并网逆变器在某一特定条件下运行到临界稳定状态附近而引发谐振,谐振将导致入网电流在相应谐振频段产生大量谐波。如果稳定裕度进一步减小,系统将逐步由谐振状态过渡到振荡、发散等不稳定状态。仿真与实验结果验证了理论分析的正确性。     

Assessment of safety margins of exposure to non-genotoxic chemical substances in food

The concept of Food Safety Margin (FSM) was introduced in microbiological risk analysis as an alternative approach to risk characterization within the informed-risk decision-making process. Its aim was to verify compliance with food safety objectives by assessing the effects of uncertainties. This paper describes the fundamentals and develop a new formulation of safety margins to verify compliance with food safety goals in relation to exposure to non-genotoxic chemical hazards. Both classical and probabilistic metrics were used to compare a given exposure to an estimated daily intake (EDI) with a given safety goal, the acceptable daily intake (ADI). The safety margins of these metrics were assessed in the exposure of peaches to organophosphorus pesticides. The pesticides considered were Azinphos-methyl, Chlorpyrifos, Diazinon, Dimethoate, Methamidophos, Parathion-methyl and Phosmet. The concentrations were obtained from the USDA pesticide database. The study period included the 11 years in which peaches were analysed from 1994 to 2014. The results show the importance of using the effect of uncertainty instead of mean values for risk characterization and that not only safety margins increased during this period but also that uncertainty was reduced. In general, large safety margins were observed in the period studied and few situations were found in which exposure was outside the safety limits.     

考虑系统静态电压稳定性的电动汽车充电设备 就地控制方法研究

随着电动汽车的大规模发展,其峰值充电负荷占全网负荷的比例日益上升,给电网的静态电压稳定带来了负面影响。试图将电动汽车充电设备纳入电力系统安稳控制,从而减少这一影响。提出了电动汽车充电设备的三种控制方法：灵敏度控制方法、理想控制方法以及下垂控制方法,并对其控制效果进行了对比。三种方法都能够达到提升系统负荷裕度的目的,但其中的下垂控制方法更适合实际控制应用。将下垂控制应用到新英格兰39节点系统,在不同渗透率和不同充电速率情况下分析其对系统电压稳定性的影响。结果表明下垂控制能够明显提高系统负荷裕度,是一种有效的电动汽车充电设备就地控制方法。     

考虑系统静态电压稳定性的电动汽车充电设备就地控制方法研究

随着电动汽车的大规模发展,其峰值充电负荷占全网负荷的比例日益上升,给电网的静态电压稳定带来了负面影响。试图将电动汽车充电设备纳入电力系统安稳控制,从而减少这一影响。提出了电动汽车充电设备的三种控制方法:灵敏度控制方法、理想控制方法以及下垂控制方法,并对其控制效果进行了对比。三种方法都能够达到提升系统负荷裕度的目的,但其中的下垂控制方法更适合实际控制应用。将下垂控制应用到新英格兰39节点系统,在不同渗透率和不同充电速率情况下分析其对系统电压稳定性的影响。结果表明下垂控制能够明显提高系统负荷裕度,是一种有效的电动汽车充电设备就地控制方法。     

Automating the sizing of transistors in CMOS gates for low‐power and high‐noise margin operation

This paper presents an automatic method for sizing the transistors in CMOS gates. The method utilizes a feedback control system to efficiently optimize the transistor sizes in small and large fan‐in gates, with the primary goal of enhancing noise robustness (as characterized by the static noise margin). The gates retain their robustness under threshold‐voltage variations over a range of supply voltages. The optimized gates not only expend reduced power and energy, but also take up less area than the conventional ones. These multi‐faceted gains, however, do incur some performance loss. Copyright © 2014 John Wiley & Sons, Ltd.     

考虑区域负荷无功裕度的无功电压优化分区方法

考虑到无功电压分区控制对区域无功平衡能力的要求,提出了区域负荷无功裕度的概念,并建立了同时考虑节点间电气耦合程度、区域静态无功平衡能力与无功储备分区要求的无功电压优化分区模型。模型包括使各分区区域电气半径平方和最小与使所有分区中区域负荷无功裕度值最小的分区无功裕度值最大两个目标函数,约束方面要求各分区内静态无功平衡。针对所建模型的特点采用了多目标自适应进化规划算法求解,并基于IEEE 39节点算例系统,仿真对比分析了所提方法的特点,仿真结果验证了方法的有效性。     

考虑电压稳定裕度约束的点估计随机最优无功调度方法

传统无功优化方法通常采用确定型的模型,但新能源大量接入以后,节点注入功率并不确定,针对其随机性,提出一种考虑电压稳定裕度约束的随机无功优化方法,使用基于点估计的随机潮流方法将机会约束转换为确定型约束,并采用带共轭梯度算子的改进遗传算法对优化问题进行求解。数值计算的结果表明该方法可以降低电压的越限风险。相比于确定型方法,使用该方法后网损优化结果略有增加,但同时电压稳定裕度得到了较大的提升。