无线传感器网络中假设检验的传感器选择问题

无线传感器网络通常具有带宽限制和能量约束,这就涉及到传感器的选择问题,即如何在n个传感器中选取p个,使得仅由这p个传感器的观测进行假设检验时虚警率达到最小.这类问题已被证明是NP难的.本文将该问题松弛成一个易处理的新问题,并提出了一个可以达到新问题KKT点的高效算法.通过与已有的算法比较复杂度,本文提出的算法效率更高.同时仿真结果也表明,大多数情况下我们提出的算法均可达到全局最优解.     

汉江中下游硅藻群落时空分布及其影响因素研究

为研究汉江中下游水体和沉积物硅藻的时空分布特征及其影响因素, 于2014年春、秋两季对汉江中下游5个监测断面的硅藻群落进行监测。基于18S rRNA Illumina Miseq高通量测序技术的鉴定结果, 共得到硅藻3纲28目49科111属160种, 其中沉积物硅藻占98.6%。物种丰度显著多于已有研究的结果, 体现了高通量测序技术在硅藻物种鉴定上的优势。水体和沉积物硅藻群落组成和优势种有显著差异, 水体中硅藻优势种为Pinnularia, Cyclotella和Nitzschia, 沉积物中硅藻优势种为Pinnularia, Nitzschia和Navicula。汉江中下游硅藻群落多样性的时空差异明显, 硅藻多样性存在空间异质性, 且沉积物硅藻比水体硅藻多样性丰富; 在季节影响方面, 表现为秋季硅藻物种多样性比春季丰富。总氮、氨氮、硝态氮和总磷等环境因素对硅藻群落组成影响较大, 因此氮磷控制对避免汉江中下游硅藻水华发生具有重要意义。     

大孔树脂纯化天麻多糖的工艺研究

本研究以炮制的干天麻为原料,水提醇沉法提取多糖,大孔吸附树脂纯化,比较了八种大孔树脂(AB-8、D101、LX-17、D301、NKA-9、S-8、LSD-001、ADS-7)对天麻多糖静态吸附-解析效果,筛选出最佳纯化树脂,再研究最佳树脂纯化天麻多糖工艺参数.结果为:八种大孔吸附树脂中D101对天麻多糖的纯化效果最好.样品液浓度、温度、上样速度,洗脱用乙醇浓度、洗脱流速及洗脱体积等因素均对D101树脂吸附分离天麻多糖有影响.所得的最佳纯化工艺为:20℃是较适宜的吸附温度,上样速度1BV/h,上样浓度4mg/mL,进行吸附;吸附饱和平衡后,用解析液浓度60%乙醇,解析速率2BV/h,解析液体积3BV进行动态洗脱.通过该工艺天麻多糖的纯度提高到了65.7%,表明了大孔树脂D101对天麻多糖具有较好的纯化效果.     

铜绿微囊藻与浮萍联合生长的生物学效应及其对污水环境指标的影响

本实验以1/5的Hoagland溶液为培养液,设置0、20、40、60、80、100 mL/L六个铜绿微囊藻（FACHB 930,107 cells/mL）接种梯度与少根紫萍（ZH0051,400 g/m2）共培养.结果发现,少根紫萍的生长速率、抗氧化物酶活性（SOD、APX和CAT）以及培养液中微囊藻毒素含量随着铜绿微囊藻接种量的增加呈现出先升高后降低的趋势,而少根紫萍体内微囊藻毒素却先降低后升高,淀粉累积量呈现出逐渐下降的趋势.铜绿微囊藻的接种量为20 mL/L时,少根紫萍的生长速率达到最大值（3.64 g/m2·d）.当接种量在60~80 mL/L之间时,少根紫萍能从培养液中高效的移除氮、磷.实验结果表明,当水体中铜绿微囊藻浓度在2.0×108 cells/L（接种量为20 mL/L）左右时,少根紫萍能够达到最大的生物量、相对高的淀粉累积量、以及高品质的氮磷去除率,并能有效地抑制铜绿微囊藻的生长.     

Loading-Balance Relay-Selective Strategy Based on Stochastic Dynamic Program

A Relay-Assisted(RA) network with relay selection is considered as a type of effective technology to improve the spectrum and energy efficiency of a cellular network. However, loading balance of the assisted relay node becomes an inevitable bottleneck in RA network development because users do not follow uniform distribution. Furthermore, the time-varying channel condition of wireless communication is also a major challenge for the RA network with relay selection. To solve these problems and improve the practicability of the RA network, a Loading Balance-Relay Selective(LBRS) strategy is proposed for the RA network in this paper. The proposed LBRS strategy formulates the relay selection of the RA network under imperfect channel state information assumption as a Multistage Decision(MD) problem. An optimal algorithm is also investigated to solve the proposed MD problem based on stochastic dynamic program. Numerical results show that the performance of the LBRS strategy is better than that of traditional greedy algorithm and the former is effective as an exhaustive search-based method.     

A Generic TC-Based Method to Find the Weakness in Different Phases of Masking Schemes

Masking is one of the most commonly used Side-Channel Attack(SCA) countermeasures and is built on a security framework, such as the ISW framework, and ensures theoretical security through secret sharing.Unfortunately, the theoretical security cannot guarantee practical security, because several possible weaknesses may exist in the actual implementation. These weaknesses likely come from the masking schemes or are introduced by the implementation methods. Finding the possible weakness of the masking scheme is an interesting and important issue for real applications. In this paper, the possible weaknesses for masking schemes in FieldProgrammable Gate Array(FPGA) design are discussed. It was found that the combinational circuit is the key to the security of masking schemes. The Toggle Count(TC) method and its extension are utilized to evaluate the security of masking schemes in the design phase and the implementation phase separately. Comparing different logic-level simulators for the Xilinx FPGA platform, the behavioral and post-translate simulations are considered as the analysis method in the design phase, while the post-map and the post-route simulations are used to find the weakness during the implementation phase. Moreover, a Standard Delay Format(SDF) based improvement scheme is proposed to significantly increase the effectiveness of the TC model.     

Integrated heat and power dispatch model for wind-CHP system with solid heat storage device based on robust stochastic theory

This paper built a combined heat and power (CHP) dispatch model for wind-CHP system with solid heat storage device (SHS) aiming at minimizing system coal consumption, and set system demand-supply balance and units’ operation conditions as the operation constraints. Furthermore, robust stochastic optimization theory was used to describe wind power output uncertainty. The simulation result showed that SHS increased CHP peak-valley shifting capability and reduced abandoned wind rate from 12% to 6%, and reduced 5% coal consumption, compared with the original system operation by flexible charging electric power and heating. The payback period of employing SHS in wind-CHP system is far shorter than SHS expected service life.     

1996-2016年五味子在国产保健食品中的应用与分析

目的 分析五味子21 a间在国产保健食品中作为原料的应用情况,为进一步研发五味子保健食品提供参考.方法 利用回顾性调查方法,抽取国家食品药品监督管理总局(CFDA)网站中1996—2016年已注册的保健食品信息,建立五味子保健食品专题数据库,分析五味子相关保健食品的功能分布、与之配伍的中药种类、频次、功效成分(或标志性成分)、地区分布及年代分布等.结果 1996—2016年期间含五味子的国产保健食品共有351个,涉及功能20种,配方原料数量最多6种,与五味子配伍使用的原料前5位为枸杞子、酸枣仁、人参、葛根、黄芪,功效成分涉及118种,申请地中前5位依次为北京市、广东省、陕西省、吉林省及黑龙江省.结论 含五味子保健食品的开发总量不足,档次较低,接近食品形态的剂型较少,没有形成基于五味子医药文化及民俗文化的品牌优势.     

角膜神经纤维形态参数变化在早期T2DM视网膜病变的应用价值

目的探讨角膜神经纤维形态参数变化在早期发现Ⅱ型糖尿病(T2DM)视网膜病变的应用价值.方法选取T2DM患者236例,其中合并糖尿病视网膜病变114例(Ⅰ期36例,Ⅱ期50例,Ⅲ期28例),无糖尿病视网膜病变122例;另收集同期健康志愿者120例为对照组.使用共焦激光角膜显微镜检测角膜神经纤维形态变化,分析与T2DM视网膜病变临床指标的关系.结果视网膜病变组神经长度、神经纤维密度、神经分支密度明显低于无视网膜病变组和对照组,神经纤维弯曲度明显高于无视网膜病变组和对照组,差异均具有统计学意义(P0.05).无视网膜病变组神经纤维弯曲度、神经分支密度明显高于对照组,差异具有统计学意义(P0.05);无视网膜病变组与对照组神经长度、神经纤维密度之间差异均无统计学意义(P0.05).Ⅲ期视网膜病变患者神经长度、神经纤维密度、神经分支密度均明显低于Ⅰ期和Ⅱ期患者,神经纤维弯曲度明显高于Ⅰ期和Ⅱ期患者,差异均具有统计学意义(P0.05).视网膜病变组患者病程明显长于无视网膜病变组,空腹C肽、GLU明显低于无视网膜病变组,差异均具有统计学意义(P0.05).T2DM患者病程与角膜神经纤维长度和分支密度均呈负相关;T2DM患者空腹C肽水平与角膜神经纤维弯曲度呈负相关,与神经纤维密度呈正相关.结论 T2DM视网膜病变患者角膜神经纤维形态参数发生异常变化,有助于早期发现视网膜病变;对病程较长和空腹C肽水平较低的T2DM患者应用价值更高.     

向海自然保护区昆虫资源调查

湿地是一种特殊的土地资源和生态环境,具有调节水分循环、维持湿地特有动植物生存等基本生态功能.调查向海国家级自然保护区昆虫资源,共采集昆虫114种,隶属12目63科.在物种组成上,以鳞翅目、鞘翅目和直翅目为主要优势类群,主要优势种有中华蚱蜢(Acrida cinerca Thunberg)、黑足婪步甲(Harpalus roninus Bate)、榆紫叶甲(Ambrostoma quadriimpressum(Motschulsky)).沙丘榆林生境有11目51科95种,其中,鞘翅目有16科31种;芦苇沼泽生境有9目33科56种,其中,鳞翅目有9科20种;羊草草原生境有8目32科67种,其中,鳞翅目有9科17种.对向海自然保护区主要害虫种类及资源昆虫进行了初步分析.