利用高通量测序分析储存喷气燃料中真菌群落多样性

为充分了解我国油库喷气燃料中真菌微生物污染情况,利用第2代Illumina Mi Seq测序技术,针对西南地区6个不同油库喷气燃料样品进行真菌群落多样性分析。通过整理测序数据,并对OTUs进行丰度、多样性指数分析,以及在属水平上进行群落结构的统计分析,确定了喷气燃料中主要污染真菌,并发现了之前报道没有检测到的主要污染真菌Khuskia。同时,通过稀释曲线、Rank Abundance曲线、聚类分析和PCo A等统计比较分析,发现地域差异对喷气燃料中真菌微生物多样性影响明显。     

对个人来说 确保与团队目标一致

自然界中有一种昆虫很喜欢吃三叶草(也叫鸡公叶),这种昆虫在吃食物的时候都是成群结队的,第一个趴在第二个的身上,第二个趴在第三个的身上,由一只昆虫带队去寻找食物。管理学家做了一个实验,把这些像火车车厢一样的昆虫连在一起,组成一个圆圈,然后     

榆林军分区组织现役(专武)干部“四会”集训

前不久,陕西省榆林军分区组织全区现役(专武)干部共466人,进行了以会整组、会组训、会征兵、会参建为主要内容的"四会"基本业务集训。集训采取统一计划、异地同步、网上授课、网上交流、网上考核的方法,系统学习了民兵组织建设、军事训练、征     

党在新世纪的行动纲领——党的最高纲领与最低纲领形成和发展的历史启迪

江泽民在十六大报告提出全面建设小康社会的目标 ,这是党在新世纪向全国人民提出的行动纲领。重温党的最高纲领和最低纲领形成和发展给予我们的启迪是 :最高纲领是党的一面旗帜 ,是党的历史使命 ;最低纲领的制定是中国共产党人充分研究中国国情的结果 ;中国共产党是党的最高纲领和最低纲领的统一论者和具体实践者 ;割裂党的最高纲领和最低纲领的辩证统一关系会给我们的事业带来巨大损失和灾难 ;建设中国特色的社会主义是党的最高纲领和最低纲领的统一。     

6次海战亲历者 常胜将军陈伟文访谈录

1988年3月14日,这是让所有炎黄子孙热血沸腾的一天,时任榆林基地参谋长的陈伟文指挥502、531、556护卫舰编队在赤瓜礁海域痛歼越南侵略者,取得了中国海军自蒸汽舰艇以来抵御外族侵略战斗中最为辉煌的胜利。更为重要的是,南沙海战的胜利收复了9个岛礁,这为我国1992年提出的"主权归我、搁置争议、共同开发"南沙领土争端解决方针提供了现实依据。2011年7月底,《现代舰船》有幸采访了陈伟文将军,听他讲述23年前那场奠定南沙格局的战斗。陈将军一生参加6次海战,全部告捷,国外媒体赠以"常胜将军"称号。     

一种SC-CFDMA卫星通信系统及其性能分析

针对MC-CDMA信号峰均比较大、传输性能易受星上非线性功放影响的问题,提出一种信号呈现单载波特性的MC-CDMA系统,即单载波码分与频分多址(SC-CFDMA)系统。研究了SC-CFDMA系统的数学模型和理论误码率,探讨了其对非线性卫星信道的适应性,分析了其对星地传输时延的敏感性。研究结果表明:在线性信道下,SC-CFDMA与MC-CDMA的误码率性能一致,且理论和仿真误码率曲线吻合;在非线性信道下,若同步理想,则交织式SC-CFDMA具有最低的峰均比和误码率,集中式SC-CFDMA次之,MC-CDMA最高;若同步不理想,则由星地传输时延造成的定时偏差会分别等量和少量地传递至交织式SC-CFDMA和集中式SC-CFDMA的解扩环节,从而产生多用户干扰(MUI),其中交织式SC-CFDMA的性能恶化最明显,而采用零相关区扩频码则可屏蔽这种MUI。     

民族地区中小学民汉双语教师教学效能感特点的调查研究

为全面了解民族地区中小学民汉双语教师教学效能感的个人项特点,本研究以新疆某县从事民汉双语教学的中小学教师为研究对象,在问卷调查的基础上,对可能影响民汉双语教师教学效能感的个人项因素进行了差异性分析。研究结果表明：教师性别因素、所授科目因素、教学模式因素对双语教师教学效能感有不同的影响;女教师的教学效能感要高于男教师;从事文科科目教学的教师教学效能感要高于理科教师;采用模式～教学的教师教学效能感最高,模式二教师次之,模式三教师最低;其它个人项因素对教学效能感不存在显著的影响。     

理想与现实的统一信念与行动的统一——兵团学习江泽民同志"七一"重要讲话体会之五

江泽民同志在"七一"讲话中指出:"一个政党的纲领就是一面旗帜。在革命、建设和改革的各个历史阶段中,我们党既有每个阶段的基本纲领,也有确定长远奋斗目标的最高纲领。我们是最高纲领和最低纲领的统一论者。"并要求"全党同志既要树立共产主义的远大理想,坚定信念,以高尚的思想道德要求和鞭策自己,更要脚踏实地地为实现党在现阶段的基本纲领而不懈努力,扎扎实实地做好现阶段的每一项工作","不断把建设有中国特色社会主义事业向着未来推进"。这些深刻而精辟的论述,充分反映出中国共产党人既胸怀高远,始终铭记共产主义理     

美“猎鹰9”火箭重返太空

<正>新华社洛杉矶1月14日电,在经历去年9月爆炸事件后,美国私企太空探索技术公司的"猎鹰9"火箭14日重返太空,一箭十星,成功把铱星通讯公司首批卫星发射至目标轨道。此后,火箭第一级首次成功实现在太平洋中一艘无人船上软着陆。当地时间14日上午9时54分(北京时间15日凌晨1时54分),搭载铱星通讯公司10颗卫星的"猎     

动态

“先进海豹输送系统”即将服役近日,美海军“海豹”特种作战部队开始接收首批6套“先进海豹输送系统”(ASDS),预计于今年秋季服役。该系统是一种小型潜艇,长约20米、重60吨,以电池为动力,由2人操控驾驶,最多可以运载14人(由携带装备的多少决定,通常运载8人)。ASDS最大航程200千米、最高     

The demand for military expenditure in authoritarian regimes

This paper examines whether there are systematic differences in military spending between different types of autocratic regimes. We view military expenditure as an instrument a dictator can exploit in order to stay in power. How he utilises this instrument depends on the institutional set-up of his regime. We distinguish between military regimes, single party states and personalist regimes, and predict that military regimes should have the highest, whereas personalist dictatorships should have the lowest level of military spending. Using panel data on 64 dictatorships from 1960 to 2000, we find empirical evidence that our hypotheses are not rejected.     

基于遗传算法的装备维修方案多目标优化

针对装备维修方案规划的特点,构建了以维修费用最低和作战能力最大的多目标装备维修方案优化模型,并提出针对该模型求解的改进多目标遗传优化算法。在遗传算法设计中,为保证解集的均匀性和多样性,避免过早收敛,建立了随机权重适应度函数,引入精英保留机制和小生境技术,通过实例对该模型的求解进行了验证。仿真结果表明,所构建的模型合理可行,算法运行高效,为部队装备维修方案的制定提供了一定的借鉴。     

基于变型设计理论的系列产品平台设计方法研究

应用变型设计理论和方法,对系列产品平台设计方法进行研究,探索覆盖整个产品功能要求的系列产品平台设计方法(Platform Design for Variety简称PDFV)。提出采用量化计算的产品变型指标和关联指标作为外因和内因引起系列产品更新设计的指导工具,获取产品变化的趋势,研究部件所受到的外界因素的影响,用关联指标作为部件之间关联程度的批示器,使开发出的系列产品平台具有柔性,以确保平台以最低的成本派生新产品,为快速实现系列产品的变型设计和配置设计提供科学方法。产品变型指标和关联指标工具的组合完善了PDFV方法。以油料装备系列产品油罐车为实例,论述了产品变型指标和关联指标构建的步骤。阐明基于变型设计理论的系列产品平台的研究,对实现快速设计、降低产品开发成本具有重要意义。     

A platform for initial testing of multiple camouflage patterns

The human visual system is still an important factor in military warfare; military personnel receive training on effective search strategies, and camouflage that can effectively conceal objects and personnel is a key component of a successful integrated survivability strategy. Previous methods of camouflage assessment have, amongst others, used psychophysics to generate distinctiveness metrics. However, the population from which the human observers are drawn is often not well defined, or necessarily appropriate. In this experiment we designed a new platform for testing multiple patterns based on a camouflaged object detection task, and investigate whether trained military observers perform better than civilians. We use a two-alternative forced choice paradigm, with participants searching images of woodland for a replica military helmet displaying Olive Green, Multi Terrain Pattern, US Marine Pattern or, as a conspicuous control, UN Peacekeeper Blue. Our data show that there is no difference in detection performance between the two observer groups but that there are clear differences in the effectiveness of the different helmet colour patterns in a temperate woodland environment. We conclude that when tasks involve very short stimulus presentation times, task-specific training has little effect on the success of target detection and thus this paradigm is particularly suitable for robust estimates of camouflage efficacy.     

Undergraduate disarmament and nonproliferation education: gaps,opportunities, and new approaches

ABSTRACT

Despite living in a nuclear-weapon state, young Americans are generally ill-informed about weapons of mass destruction (WMD) and their means of control. The result is both widespread apathy toward nonproliferation and disarmament decision making among the general public and a looming personnel crisis within government sectors that enact policy in these domains. Considering that 67 percent of high school graduates in the United States go on to pursue a bachelor’s degree, exposing more undergraduates to nonproliferation and disarmament issues could contribute to addressing both of these challenges. The present study analyzes how these issues are already being taught at select US colleges and universities and explores ways to introduce them to more students that align with current priorities in higher education, such as interdisciplinary learning, digital humanities, and data-science learning. It also proposes concrete steps that the WMD policy community can take to help institutions of higher education integrate these topics more broadly into their curricula. The anticipated result is greater support for education in this important issue area across different stakeholders in academia, as well as increased engagement with these critical issues among a more diverse population of young people.     

Chirp信号参数估计算法性能比较

通过数值仿真定量地比较了三种Chirp信号参数估计算法——解线调法、迭代估计法和局部搜索最大似然法的性能,并定性地比较了算法的运算量。仿真结果表明,在三种算法中,局部搜索最大似然法的估计性能最好,而运算量居中;解线调法运算量最大,但估计性能居中;迭代估计法的估计性能最差,但运算量最小。对于实际系统,应根据不同的估计精度和运算量要求,灵活选择不同的算法。综合考虑估计性能和运算量之间的折衷可以得到结论,在三种算法中局部搜索最大似然法是一种相对较好的选择。     

On the effectiveness of returns policies in the price‐dependent newsvendor model

We study in this paper the price‐dependent (PD) newsvendor model in which a manufacturer sells a product to an independent retailer facing uncertain demand and the retail price is endogenously determined by the retailer. We prove that for a zero salvage value and some expected demand functions, in equilibrium, the manufacturer may elect not to introduce buybacks. On the other hand, if buybacks are introduced in equilibrium, their introduction has an insignificant effect on channel efficiency improvement, but, by contrast, may significantly shift profits from the retailer to the manufacturer. We further demonstrate that the introduction of buybacks increases the wholesale price, retail price, and inventory level, as compared to the wholesale price‐only contract, and that the corresponding vertically integrated firm offers the lowest retail price and highest inventory level. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.     

MF-CFI: A fused evaluation index for camouflage patterns based on human visual perception

The evaluation index of camouflage patterns is important in the field of military application. It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism. In order to make the evaluation method more computationally intelligent, a Multi-Feature Camouflage Fused Index (MF-CFI) is proposed based on the comparison of grayscale, color and texture features between the target and the background. In order to verify the effectiveness of the proposed index, eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index (UIQI), Camouflage Similarity Index (CSI) and Structural Similarity (SSIM). Twenty-four different simulated targets are designed in a grassland background, 28 observers participate in the experiment and record the eye movement data during the observation process. The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data, both in the designed digital camouflage patterns and large-spot camouflage patterns. Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception, the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms.     

某军事区域土壤重金属污染状况及其评价

以华北某军事区域的打靶场为研究对象,监测并分析了土壤中重金属Pb和Cu的质量比,分别为25.90～396.50mg/kg,12.13～5173.00mg/kg;并采用单因子指数法和内梅罗综合污染指数法评价了采样区的污染状况。评价结果表明:Pb和Cu的单因子污染指数在落弹区最高,分别达到了390.12和4.61,内梅罗综合污染指数达到了308.88;落弹区剖面分析结果显示打靶场土壤1m左右深度的重金属含量依然很高,表明在落弹区Pb和Cu的污染尤为严重。分析认为弹头是重金属污染的主要来源,残留在土壤中的弹头会给土壤带来持久性的重金属污染。     

多传感器量测融合算法的性能比较

归纳三类多传感器量测融合算法,即扩维滤波法、伪序贯滤波法和复合量测滤波法。采用协方差分析的方法比较各类算法的滤波精度,证明它们均能在各自给定的条件下实现线性最小均方意义上的最优滤波。仿真实例对各类算法的计算量和灵活性等性能进行比较,结果表明扩维型信息滤波器的计算量最小、灵活性最高,扩维型Kalman滤波器、伪序贯滤波器的计算量较大,而两种复合量测滤波器对各传感器的量测矩阵有一定要求,以致灵活性较差。所得结论对量测融合算法的实际应用具有一定的指导意义。