四川区域中心馆藏文物保存环境监测平台常见故障分析与改进措施

四川省馆藏文物保存环境监测区域中心(简称四川区域中心)平台,经过两年多的运行实践,实现了12家博物馆监测站的集成联网。本研究分析了区域中心监测平台运行中常见故障现象的表现形式、故障原因及故障率。结果表明:监测平台的主要故障现象为传输异常和数据异常;除温湿度外的其他监测终端故障率较高;软件平台建设也不够完善,导致数据利用率低,尚不能实现风险评估、预测预警和预防调控等管理功能。针对分析发现的问题,提出一些相应的技术措施和管理措施,为有效降低故障的发生率,提升国内区域中心平台建设提供一定的指导和参考。     

Low‐temperature catalytic CO2 hydrogenation with geological quantities of ruthenium: a possible abiotic CH4 source in chromitite‐rich serpentinized rocks

Metal‐catalysed CO₂ hydrogenation is considered a source of methane in serpentinized (hydrated) igneous rocks and a fundamental abiotic process germane to the origin of life. Iron, nickel, chromium and cobalt are the catalysts typically employed in hydrothermal simulation experiments to obtain methane at temperatures >200°C. However, land‐based present‐day serpentinization and abiotic gas apparently develop below 100°C, down to approximately 40–50°C. Here, we document considerable methane production in thirteen CO₂ hydrogenation experiments performed in a closed dry system, from 20 to 90°C and atmospheric pressure, over 0.9–122 days, using concentrations of non‐pretreated ruthenium equivalent to those occurring in chromitites in ophiolites or igneous complexes (from 0.4 to 76 mg of Ru, equivalent to the amount occurring approximately in 0.4–760 kg of chromitite). Methane production increased with time and temperature, reaching approximately 87 mg CH₄ per gram of Ru after 30 days (2.9 mgCH₄/g_ru/day) at 90°C. At room temperature, CH₄ production rate was approximately three orders of magnitude lower (0.003 mgCH₄/g_ru/day). We report the first stable carbon and hydrogen isotope ratios of abiotic CH₄ generated below 100°C. Using initial δ¹³C_CO2 of ‐40‰, we obtained room temperature δ¹³C_CH4 values as ¹³C depleted as ?142‰. With time and temperature, the C‐isotope separation between CO₂ and CH₄ decreased significantly and the final δ¹³C_CH4 values approached that of initial δ¹³C_CO2. The presence of minor amounts of C₂‐C₆ hydrocarbons is consistent with observations in natural settings. Comparative experiments at the same temperatures with iron and nichel catalysts did not generate CH₄. Ru‐enriched chromitites could potentially generate methane at low temperatures on Earth and on other planets.     

1992年以来我国城镇居民居住消费的变化趋势

1992年之后,我国明确了建立社会主义市场经济体制的目标,城镇住房制度改革取得了实质性突破,城镇居民居住消费发生了深刻变化。居民购房公平自由,私有住房的比重急剧攀升,住房设施日益完善,居住环境不断优化,居住开支迅猛增长,城镇居民居住水平获得了前所未有的提高。然而受不正确的思想观念的影响,在居民居住消费过程中,一些诸如住宅私有率过高、住宅面积过大、一房伴终身等严重脱离实际需要和基本国情的问题日益突出。     

家庭生命周期对旅游者行为的影响研究

揭示家庭生命周期对旅游者行为的影响可以为家庭旅游精准营销提供依据.将城镇居民的家庭生命周期分为筑巢期、满巢Ⅰ期、满巢Ⅱ期、空巢期4个阶段,探究家庭生命周期对其旅游行为的影响,发现:①家庭生命周期影响旅游者的目的地选择行为,不同家庭生命周期旅游者的景区到访率距离衰减速率不同;②家庭生命周期影响旅游者的旅游活动类型偏好,满...     

银元主币流通与上海洋厘行市的更替

墨西哥鹰洋成为近代中国流通最广的银元主币,历时长达60余年之久。1914年后开铸的袁世凯像新币,逐渐取代鹰洋成为流通中的主币。上海钱业公所和其后的上海钱业公会深谙流通中主币的消长变化态势,审时度势,先后于1915年和1919年取消龙洋和鹰洋行市。鹰洋行市的取消进一步促使国币通行成为主币,使货币兑换市场逐步走向统一,降低社会交易成本;同时也为废两改元准备了条件,促进了近代货币统一化进程。     

明代科举各级考试的规模及其录取率

明中叶后,各省直的科考规模在四五千人至数万人之间,平均录取率估计在10%上下。乡试录取率,明初一般在10%上下;成、弘间定为5.9%;嘉靖末年又降为3.3%;而实际录取率又低于此。会试录取率,自洪武至万历中平均为8.6%;其中,洪武至永乐二年平均为21.7%,永乐四年至万历中期平均为8.4%。殿试规模和录取数在理论上皆等于同科会试录取数。永乐二年后,明廷共在51科14938名二、三甲进士中考选了1277名庶吉士,平均录取率为8.55%。上述录取率,都是在朝廷调控下形成的,并非完全自由竞争的结果。而之所以进行调控,又是由官缺的有限性和科举取士用途的单一性矛盾造成的。     

The Impact of Global Financial Crisis on the Mechanism of Economic Growth in Russia

A noted specialist on the Russian economy presents an assessment of the impact of the global financial crisis on the mechanism of the country's economic growth. Focusing on the demand side of the economic ledger, the author explores the question of whether Russia will be able to re-attain the high economic growth rates of the period from 2000 to 2007 after recovering from the crisis. The paper analyzes the sharp drop in production in 2008 and the first quarter of 2009, attributing most of the damage to liquidity problems and declines in the price of oil. Empirical evidence is based primarily on data collected by the author from the Central Bank of Russia and the country's federal bureau of statistics (Rosstat). Journal of Economic Literature, Classification Numbers: E010, E200, E660, F210, G010. 11 figures, 3 tables, 29 references.     

China's Exchange Rate Controversy: A Balanced Analysis

A noted American authority on China's economy and monetary policy presents a statistical as well as theoretical analysis of a variety of perspectives on the controversy surrounding China's currency, basing his paper on both. The author provides the historical background and comprehensive summaries, focusing on different viewpoints about whether China's currency is undervalued, and thus may contribute to global imbalances. In the paper, he divides observers involved in the controversy into two main camps, namely the ones who find China's trade balances to be sensitive to price effects through exchange rate adjustments and those who emphasize other factors as bearing the responsibility for China's large surpluses, including the U.S. credit bubble emerging before the global financial crisis, as well as a version of Dutch disease.     

Ancient DNA in human bones from Neolithic and Bronze Age sites in Greece and Crete

Attempts were made to detect ancient DNA (aDNA) in samples of 88 human skeletons from eight Neolithic and Bronze Age sites in Greece and Crete. Ancient DNA was absent in specimens from Nea Nikomedia, Lerna, Karaviádena (Zakro), Antron Grave Circle A and Mycenae Grave Circle A. For each of three skeletons from Antron Grave Circle B that were sampled, polymerase chain reactions (PCRs) gave products for nuclear but not mitochondrial DNA, but amplicon yield was low and inconsistent with replicate PCRs failing to give reproducible results. With specimens from Mycenae Grave Circle B, evidence for mitochondrial aDNA was obtained for four of the 22 skeletons that were studied, and at Kouphovouno evidence for mitochondrial and/or nuclear aDNA was obtained with eight of the 20 skeletons that were examined. We conclude that, although aDNA might be present in some Eastern Mediterranean skeletons from later centuries of the Bronze Age, it is not commonly found in material from this period and is likely to be absent from older material.     

驳唐代进士难、明经易说

近几十年流行唐代进：仁难、明经易说,所持理由一是两科录取率相差悬殊,二是两科考试内容不同,难易有差。考察具体情况,不是这么回事。实际情况是,进士、明经,难易相当。