论“上海五国”机制的产生与发展

上海五国主要是指中、俄、哈、吉、塔 ,由于五国元首首次会晤是在上海举行 ,所以这一合作进程被称为“上海五国”机制。“上海五国”机制的产生与发展是五国面临的内部、地区、国际形势推动的结果。它最初是由五国加强边境地区的信任和裁军开始的。几年来 ,“上海五国”机制通过五国元首每年一次会晤及不同层次和方面的谈判 ,在解决历史遗留问题、确保地区安全稳定、促进各国经济发展、加强国际事务上的共识等方面不断取得成就 ,为在冷战后摈弃冷战思维 ,探索新型的国家关系、安全观、区域合作模式提供了成功的经验 ,而且对世界的和平、稳定、发展产生了积极的影响。     

为社会主义和为和平而斗争的五年

中华人民共和国成立五周年纪念日就要到来了。中华人民共和国的五年,是以工人阶级为领导的中国人民为争取自己国家的社会主义发展和为争取亚洲和世界和平而英勇奋斗的五年,是中国人民在这两方面的斗争中都取得了伟大成就的五年。     

线微机五防应用的重要步骤

随着技术的改进和发展,防误工作获得了很大的进步,特别是线微机五防系统在变电站的运行中发挥了重要的作用。本文笔者从对线微机五防系统的优势着手,分析了其工作原理和分类,探讨了线微机五防系统进行防误操作的重要步骤,目的是为线微机五防系统的应用提供指导和借鉴,进而提高防误操作的效率。     

科技革命与世界现代化——第六次科技革命的方向和挑战

 在过去五个世纪里,世界上大致发生了五次科技革命,第一次是近代物理学诞生,第二次是蒸汽机和机械革命,第三次是电力和运输革命,第四次是相对论和量子力学革命,第五次是电子和信息革命。它们推动了世界现代化的前四次浪潮,包括机械化、电气化、自动化和信息化。目前第六次科技革命正向我们走来,它将推动世界现代化的第五次浪潮。第六次科技革命将是一次新生物学和再生革命,将主要发生在生命科技、信息科技和纳米科技的交叉结合部,将是科学革命、技术革命和产业革命的交叉融合,但也将带来伦理挑战和副作用。     

伟大的中苏同盟五周年

一九五○年二月十四日,中华人民共和国政府同苏维埃社会主义共和国联盟政府签订了中苏友好同盟互助条约,把两国政府和人民之间的密切合作关系和伟大友谊,用条约的形式永久地固定下来。中苏同盟条约的五周年,是中国人民在伟大盟邦的真诚援助下取得光辉成就的五周年,是中苏两国之间的兄弟般友谊不断巩固和发展的五周年,是中苏两国对维护远东和世界和平事业的斗争作出重大贡献的五周年。中国人民怀着欢欣和感激的心情,怀着无限的信心,迎接和庆祝伟大的中苏同盟五周年。     

中国古代是否存在五锭棉纺车

元代王祯《农书》描绘有一具五锭纺车,(传)南宋马和之的《毛诗豳风图》也绘有一具五锭纺车,这两具五锭纺车均非棉纺车。包铭新、于颖在2005年撰文认为中国古代存在五锭棉纺车。经重新分析,文字史料中的五锭棉纺车仅是传闻,证据不足,图像资料被误读。因此,中国古代存在五锭棉纺车的结论无法成立。     

《米》:"性恶"母题的当代阐释--五龙形象管窥

五龙是"性恶"的载体.他的恶不仅仅是先天的动物性所致,更多的是后天生活环境的影响.五龙的一生是与女人相互纠缠的一生,但没有一个女人在他心田播下爱的种子.五龙在充满血腥复仇的男性世界里,将"性恶"的特点发挥得淋漓尽致.即使是在五龙的亲情世界里,温情也被"性恶"排挤得毫无踪影.     

模具型面定位五轴加工刀轴方向的优化措施分析

五轴加工法在制造业的模具加工过程中应用非常广泛.在实际的加工过程中,五轴加工的编程和操作技术是一项非常复杂的工作,稍有不慎就会出现严重的模具质量问题.本文以模具型面定位五轴加工刀轴方向的优化方法和操作流程为中心,论述了五轴加工刀轴方向的优化的流程和方法,指出了刀轴倾角、工作区域的区分等重要技术,为实现模具加工工艺的进步提供参考.     

2013北京发展回顾与展望

回顾过去五年首都工作取得的成就2008年以来的五年,是首都发展进程中具有重要历史意义、极不平凡的五年;是胜利完成筹办奥运会和国庆60周年庆祝活动等光荣任务,谱写首都科学发展新篇章的五年;是深化改革,扩大开放,转变经济发展方式迈出坚实步伐,综合经济实力显著增强的五年;是城乡面貌发生重大变化,城市管理水平     

传统时间诊疗学中的时间快速推算法

在我国的传统时间诊疗学中,有一类是按照治疗时的年、月、日或时辰的干支或五运实施治疗的方法．快速即时地推算干支或五运是实施这类治疗的前提．本文根据现行公历和农历的编制原理,给出推算年干支、月干支、日干支和五运以及时干支的公式或方法     

广西北海大冠沙白骨壤树上大型固着动物的数量及其分布

本文研究了广西北海大冠沙白骨壤树上大型固着动物的种类组成、数量分布特点及其对植物体的危害。结果表明,大冠沙白骨壤群落中的大型固着生物有10种,分属3门4纲6科,其中在白骨壤植株上的主要种类为白条小藤壶、潮间藤壶、褶牡蛎和黑荞麦蛤4种。危謇程度最大的是白条小藤壶,其湿重生物量占总湿重生物量的百分比高达72.3%～100%。受害程度最大的是向海林带的枝和叶,其动物生物量干重与植物生物量干重的比值(a/p)可达30.49×10~(-2)和30.43×10~(-2)。就整个红树林区而言,危害程度为向海林带(21.68×10~(-2))>中间林带(7.88×10~(-2))>向陆林带(0.01×10~(-2)).同一林带的植株受害程度为较低树层的大于较高树层的.密度和生物量的分布也与此相类似.     

CO2对曲塘区块地层油高压物性影响研究

CO_2能有效降低原油黏度、溶解储层中的胶质、提高储层渗透率,对开采低渗、特低渗透油藏有很好的应用前景;而研究CO_2对地层油高压物性的影响具有重要指导意义。针对曲塘区块这一典型低渗透油藏,采用PVT地层流体分析仪,测定了张3B井地层油溶有不同气量CO_2后的高压物性。结果表明:随地层油中溶解CO_2增多,泡点压力及体积系数大幅升高、地层油密度减小。当CO_2溶解度为44 m3(标)/m3时,泡点压力与CO_2溶解度的关系曲线出现拐点呈"凸"型,说明溶有大量CO_2的地层油对后续注入CO2的溶解起到了促进作用。当压力高于泡点压力时,体积系数和密度与压力呈很好的线性关系,体积系数曲线的斜率(绝对值)、截距与CO_2溶解度呈正比;而密度曲线呈反比。此外,CO_2对地层油具有很好的降黏效果,当CO_2溶解度为83 m3(标)/m3时,其降黏率达到了38%。     

Responses of woody plant root and xylem sap ATP to soil drying

The ATP in roots and xylem sap of two woody plant species, Platycladus orientalis and Acacia auriculiformis, subjected to rapid and slow soil drying has been determined employing firefly luciferase ATP assay method (sensitivity is at 10-12 mol ATP L-1). The ATP levels in the two species were 1.6 nmol·gDW-1 and 0.6 nmol·gDW-1 in roots, and 5.6 μmol·m-3 and 8 μmol ·m-3 in xylem sap, respectively. When plants of P. orientalis and A. auriculiformis were subjected to rapid soil drying, respectively, as soil water content (SWC) decreased from the normal level ( 0. 25 g ·gDW-1) to 0. 02 and 0. 06 g ·gDW-1, separately, plant water potential ( ) dropped to -4 and -3.2 MPa, differently, the ATP in roots decreased 99.7% and 42%, respectively . When the rapidly dried soil was watered for up to 6 d, SWC and were found to recover to their normal levels, but ATP content in roots of P. orientalis and A. auriculiformis recovered by 10% and 23%, respectively. When plants of P. orientalis and A. auriculiformis were subjected to slow soil drying, respectively, as SWC was found to decrease from the normal level to 0.1 and 0.13 g·gDW-1, separately, dropped to - 2.5 and - 2 MPa, differently, the ATP content in roots decreased 98% and 38%, respectively. When the slowly dried soil was watered for up to 8 d, ATP levels in roots of P. orientalis and A, auriculiformis recovered by 30% and 24%, respectively. However, ATP concentrations in xylem sap were not directly influenced by either SWC or . The plot dots of xylem sap ATP concentration versus root ATP content were found to be distributed diagonally. It is concluded that ATP in roots is more sensitive in response to SWC changes than that to and root-sourced ATP is a source of that in xylem sap. When plants are subjected to slow soil drying, the ATP levels in both root and xylem sap are higher than that to rapid soil drying.     

Radiation dose rate estimates to marine biota resulting from the routine radioactive releases of the nuclear power plants in Daya Bay

Five marine organisms in Daya Bay are selected for estimating the dose rates. Internal exposure and its 5 pathways are also considered. The concentrations of 43 kinds of background and additional radionuclides in seawater are from the survey of background radioactivity and the prediction of routine radioactive releases of the 4 reactors. Point source dose distribution functions are used to estimate the dose rates to various organisms from α and β radiation. Monte-Carlo method is used to determine the absorbed fractions in the organisms from γ radiation. Results indicate that the background dose rates are 2.72 mGya · a^-1 to phytoplankton and 1.75 mGy · a^-1 to zooplankton. The dose rates to other organisms are in the range of 0.31–0. 49 mGy · a^-1. The additional dose rates from the routine releases are varied to different organisms. They reach the range of 5.7–6.1 times of the background dose rates to benthic crustaceans and mollusks, which are 8.3%–15.3% to fishes, and only 0.2% to plankton. β internal irradiation from additional radionuclides is the critical pathway to plankton.¹³¹I and⁶⁰Co are the major contributors to zooplankton, while¹⁰³Ru,⁶⁰Co and⁵⁸Co are the main contributors to phytoplankton. γ external irradiation from sediment is the critical pathway to benthic organisms.⁵⁸Co and⁶⁰Co are the main contributors. The main pathways to fishes are internal β and γ irradiation.¹²⁴Sb is the critical radionuclide.     

马尾松、尾赤桉木材蠕变特性常数研究

在马尾松 ( Pinusmasoniana )、尾赤桉 ( Eucalyptusurophylla× camaldulensis)板材不同部位以径切面切取小试件各 30枚 ,并各分为 3组 ,分别按材料极限强度的 2 0 %、30 %及 4 0 %进行加载 ,测量木材的蠕变特性曲线 ,确定木材的蠕变特性常数。结果是 :马尾松、尾赤桉抗瞬间弹性变形能力随载荷的增加而增强 ;在相同的载荷下 ,马尾松的抗瞬间弹性变形能力、抗长期粘性蠕变能力及抗延迟弹性蠕变能力均比尾赤桉强 ;应力水平占极限强度比例相同时 ,马尾松的抗瞬间弹性变形能力比尾赤桉强 ,而抗长期粘性蠕变能力及抗延迟弹性蠕变能力在总体上亦比尾赤桉强     

The diversity of denitrifying bacteria in the alpine meadow soil of Sanjiangyuan natural reserve in Tibet Plateau

Denitrification is a dissimilatory biological process of denitrifying bacteria where oxidized nitrogen com- pounds (NO3? and NO2?) are used as alternative electron acceptors and fixed nitrogen is transferred into the at- mosphere in form of N2, finally. I…     

燃煤电厂锅炉PM2.5现场实测与排放特征研究

采用自设固定源PM_2.5稀释采集系统对陕西省关中地区多个燃煤电厂烟气中的颗粒物开展了现场实测与样品化学源组分分析。结果表明：4个燃煤电厂PM_2.5、PM₁₀占颗粒物比重差异较大（PM_2.5占比范围为6.92%~54.34%,PM₁₀占比范围为36.36%~73.02%）;4个燃煤电厂数浓度水平最高值（2.0×10⁴~4.0×10⁵个/cm³）差异较大,相差约1个数量级;燃煤电厂PM_2.5小粒径段颗粒物质量浓度占比大多较低,但其对PM_2.5数浓度贡献却很大（最小值>95%）,大粒径段颗粒物则相反;煤粉炉PM₁/PM_2.5较大,占比范围为35.29%~51.35%,循环流化床锅炉PM₁/PM_2.5较小,占比范围为16.62%~21.47%;SO₄^2-是燃煤电厂PM_2.5中最丰富的离子成分,各电厂SO₄^2-占总离子浓度比重范围为50.02~65.52%,Na⁺和Ca²⁺位于第2或第3位;各燃煤电厂主要检出无机元素是Si、Al、Ca、Na、Fe、Na等地壳元素;燃煤电厂PM_2.5、PM₁₀和颗粒物的排放因子范围分别为0.001~0.028 kg/t、0.002~0.086 kg/t、0.003~0.236 kg/t;除尘设施组合越复杂先进,排放因子就可能越小。     

Development of multi-functional nano-paint for energy harvesting applications

The multi-functionality of lead magnesium niobate-lead titanate/paint(PMN-PT/paint) nanocomposite films for energy harvesting via piezoelectric and pyroelectric effects is described. PMN-PT/paint films have been fabricated by a conventional paint-brushing technique to provide a low-cost, low-temperature and low–energy route to create multi-functional films. The properties investigated included dielectric constants, ε' and ε', as a function of temperature, frequency and composition. From these parameters, it is indicated that the dielectric constants and AC conductivity(σ_(AC)) increase with an increase of filler content and temperature, implying an improvement of the functionality of the films. The results revealed that σ_(AC) obeyed the relation σ_(AC) =Aω~s, and exponents, was found to decrease by increasing the temperature. The correlated barrier hopping was the dominant conduction mechanism in the nanocomposite films. The efforts were made to investigate the performance of nanocomposite films to mechanical vibrations and thermal variations. A cantilever system was designed and examined to assess its performance as energy harvesters. The highest output voltage and power for a PMN-PT/paint based harvester with a broad frequency response operating in the-31-piezoelectric mode were 65 mV and 1 nW, respectively.Voltage and power were shown to be enhanced by application of thermal variations. Thus, films could be utilized for combined energy harvesting via piezoelectric and pyroelectric characteristics.     

The evolution of local structure of Mo6S8 during Li+ electrochemical storage studied by in-situ tender X-ray absorption spectroscopy

Chevrel phase Mo₆S₈ has attracted great interest because of its capability to accommodate different types of small cations through reversible topotactic redox reactions. However, the intercalation mechanism of Mo₆S₈ is still far from being fully understood owing to the complexity of the crystal structure and limitation of the probe tools. In our study, the reaction mechanism of Li ?⁺ ?intercalation into Mo₆S₈ was studied as a model by in-situ tender X-ray absorption spectroscopy (itXAS) in the viewpoint of local structure. According to the isobestic points of the 1st derivative, the discharge process is divided into five regions while the charge process is divided into four regions, where most of the regions are assigned to the two-phase transition reactions. The intensity change of the two spectroscopic features of the 1st derivative is found to be correlated, implying that the intercluster bond length directly affects the localization of the unoccupied states of the intracluster bond. The asymmetric evolution of the intensity of a’ and b’ as well as the asymmetric partition of reaction regions demonstrate the asymmetry of the reaction path in discharge and charge process. The results help to clarify the remaining debates on the phase transitions. Besides, itXAS is demonstrated to be a powerful tool to study the reaction mechanism of Mo₆S_8, which is complementary to NMR, XRD and so on.     

氢化钛的分解行为及其在制备泡沫铝中的应用

测定了TiH2在不同温度下的分解曲线,从热力学和动力学的角度对TiH2的分解规律进行了研究,并分析了使用TiH2制备泡沫铝时的应用方式.结果表明:TiH2的分解率随着温度的升高而逐步提高,TiH2的分解过程大致可分为三个阶段.在620~680℃范围内,TiH2在前10 min分解激烈,在10~20 min内TiH2的分解速度变得缓慢,在20 min以后TiH2的分解逐渐趋于停滞.在700~720℃之间,TiH2在前6 min内的分解速度很快,在6~10 min之间分解速度降低,在10 min以后分解反应出现停滞.