HPC海量存储系统Pass-Through访问策略研究

为了解决海量信息处理中实时访问中的"I/O墙"的问题,提高海量信息分布式存储系统的性能,提出了一种基于高性能计算(high performance computing,HPC)的存储部件新型访问策略.首先,分析传统访问模型存在的问题;其次,研究存储部件直通路模式的工作机理,建立存储系统分解为多层次、分布式的模型,根据不同的层次和映射策略实现存储空间物理地址、缓存地址、存储系统逻辑空间地址的连续映射;第三,分析直通路访问模式下的存储路径时间开销;第四,在模拟环境下存储部件访问的性能测试,在实际采用该策略的应用系统中进行验证.通过验证测试结果表明,该方法能有效提高存储系统的性能,能够不断满足海量信息处理实时需要.

Pass-through Effects of Global Commodity Prices on China's Inflation:An Empirical Investigation

The present paper uses a two-step approach to estimate the pass-through effects of changes in international commodity prices and the RMB exchange rate on domestic consumer price inflation in China. We first estimate the pass-through effects of international commodity prices on producer prices and then estimate the pass-through effects of producer price inflation on consumer price inflation. We find that a l O-percent increase in international commodity prices would lead to China＇ s producer prices increasing by 1.2 percent 3 months later, which in turn would increase China＇ s domestic inflation by 0.24 percent over the same period. However, a 10-percent appreciation of the RMB exchange rate against the US dollar would help to reduce increases in producer prices by 4.4 percent over the following 3 months, which in turn would lead to a 0. 89-percent decline in consumer price inflation over the same period. Our findings suggest that appreciation of the RMB in an environment of rising global commodity prices and a weak US dollar could be an effective instrument to help contain inflation in China.

Interest Rate Pass-through in a Dual-track System:Evidence from China

Using the Phillips-Loretan approach, this paper verifies the degree and speed of pass- through and rigidity of different interest rates in China, as well as the response of private loan interest rates to other interest rates during 2002-2012. The results indicate that the long-term pass-through from the interbank offered rates and deposit and loan interest rates to the treasury bond rate is incomplete, but that the long-term pass-through to private loan interest rates is overshooting. The long-term pass-through from the deposit and loan interest rates to the overnight interbank offered rate is incomplete, while that to the interbank offered rates of other maturities is complete. The short-term passthrough and adjustment speed of interest rates exhibit asymmetry. Therefore, before considering a full liberalization of interest rates, it is important to further enhance the competition of the financial system and the function of different interest rate systems, such as the interhank market and bond market.

Exchange Rate Pass-through in China

During the second half of 2007 and early part of 2008 when there were intense inflationary pressures in China, RMB appreciation was advocated as a means of helping to curb inflation. The effectiveness of appreciation in controlling inflation depends on the impact of exchange rate movements on import and domestic prices. Our analysis finds fairly large and speedy exchange rate pass-through （ERPT） to import prices： 50 and 60percent for the short run and long run, respectively. However, the degree of ERPT decreases along the price chain from upstream to downstream prices. ERPT for consumer prices, the most downstream prices, is much milder and has substantial lags. A 10-percent rise in the nominal effective exchange rate will dampen consumer prices by 1.1 percent within a year, with very little pass-through in the first half year, and by 2.0percent over the long run. These findings, particularly the ERPT to consumer prices, suggest that RMB appreciation can help to reduce inflationary pressures over the longer term. However, it is unlikely to provide rapid relief to the current round of high inflation because of the long lags in ERPZ. The RMB needs to strengthen in effective terms to exert the desired dampening impact on prices.

Low Inflation,Pass-through,and a Discrete Inflation-targeting Framework for Monetary Policy in China

The performance of inflation in China over the past few decades has been remarkable. This paper characterizes the statistical nature of the inflation series in China over the past quarter of a century and presents an interesting scenario of large decline in inflation passthrough accompanied with low inflation since the end of the 1990s. How should monetary policy in China be conducted under these new economic conditions？ We propose a discrete inflation-targeting framework for monetary policy, which is likely to be suitable for the regime of low inflation and inflation pass-through. The advantages and caveats of adopting such a framework are also discussed.

Interest rate liberalization and pass-through of monetary policy rate to bank lending rates in China

We examine whether the effectiveness of the monetary policy rate transmission differs before and after interest rate liberalization in China using the autoregressive distributed lag (ARDL) bound test and an error correction model (ECM). The results show that after liberalization the mark-up is lower, and both the Iong-run and shortrun interest rate pass-through has become faster and more complete. We attribute our findings to the ongoing reforms of China's banking system, which has improved the competitiveness of Chinese commercial banks.

China's Share of US Imports and Exchange Rate Pass-through to US Import Prices

The present paper investigates the effect of China＇s share of US imports on the aggregatelevel exchange rate pass-through to US import prices over the period from January 1999 to December 2008. The paper also focuses on the post-reform period, after 2005, allowing greater ftexibility of the RMB to explore the change in the role of the Chinese import share in determining the trend in the US exchange rate pass-through. Evidence reveals that China＇s share of US imports has a negative effect on the exchange rate pass-through. However, this negative effect has been moderated to a negligible level since China＇s exchange rate reform. An important implication is that the exchange rate flexibility of the RMB has been raised to a significant level may no longer cause distortion in the US competitive environment and prevent the USA from adjusting current accounts.

Exchange Rate Pass-through to China＇s Export Price： A Product-level Investigation

Exchange rate movement usually results in changes in the production costs of exporting firms, and, therefore, the prices and the quantity of traded products. The present paper constructs a theoretical model to demonstrate that export products with higher productivity, or with larger market share, or of higher quality will experience a less complete passthrough. Using the six-digit harmonized system export data from the CEPII database over the period of 2000 to 2013, the present paper examines how product heterogeneity affects the exchange rate pass-through of Chinese exports. The empirical results show that the most competitive Chinese export products, or those least affected by exchange rate risks, are those of higher quality, with higher technological complexity and at the high end of the international value chain. Therefore, Chinese exporting firms should pay more attention to improving export quality and upgrading technology to better cope with exchange rate risks and to enjoy more bargaining power in the international market.

Correlation between pass-through flux of cobalt target and microstructure and magnetic properties of sputtered thin films

Cobalt thin films were deposited on silicon substrates by magnetron sputtering two commercial cobalt targets with different pass-through fluxes(PTFs).The influences of PTF on the magnetic properties of sputtered thin films were investigated.The results indicate that under the same sputtering conditions,cobalt thin film deposited by Co target with high PTF(84.21%) has lower remanence ratio(0.65),while cobalt thin film prepared by Co target with low PTF(69.13%) has higher remanence ratio(0.87).Through introducing an external magnetic field parallel to the film surface during sputtering processes,both the remanence ratios of cobalt thin films prepared by the two targets can be enhanced to approach 1.High-resolution transmission electron microscopy(HRTEM) images show that in the absence of the external magnetic field during sputtering,cobalt thin film deposited by the target with high PTF is randomly oriented in crystallographic orientations,which is due to that Co atoms have no enough time to migrate and diffuse on substrate and the atomic stacking is disordered.It is worth mentioning that crystallographic orientations of cobalt thin film deposited by target with low PTF are relatively consistent,resulting in relatively higher remanence ratio.In addition,HRTEM analysis indicates that the external magnetic field during sputtering drives the Co grains to arrange in a regular order with(002) orientation,leading to the improvement in remanence ratios.

Minimum Wages,Cost-Price Pass-Through and Real Welfare Effect of Households

The minimum wage policy should take into account production costs of enterprises and welfare benefits of families.This paper describes the pass-through process of the minimum wage costs in the enterprise sector and the household sector by building a theoretical model,investigates the impact of the minimum wage adjustment on urban household consumption utility and its price pass-through mechanism from the perspective of living costs based on several sets of databases,such as household survey,supermarket prices and industrial enterprises for the first time,and further estimates the net welfare changes including income compensation and consumption utility loss.The findings of the study are as below:(1)The price transfer behavior of enterprises is the main cause of the loss of household consumption utility.The average wage level and labor costs of enterprises rise with the increase of minimum wages.Both the cost-price pass-through elasticity estimated based on the theoretical model and the minimum wage price elasticity coefficient obtained by empirical estimation show that the price transfer behavior of enterprises leads to the rise of final consumer prices;(2)With a 10% increase in minimum wages,the overall household living costs increase by 2.47%-6.76%,and the economic living costs increase by about 122-334 yuan per quarter,among which the living costs are most affected in terms of food,shoes and clothing;(3)Under the combined effect of income compensation and consumption utility loss,the bottom 20% of households and middle 60% of households will get 658 yuan and 469-556 yuan per quarter,respectively.The findings of this paper are conducive to improving the supporting minimum wage policy by taking a number of measures simultaneously,so as to provide a path reference for promoting the realization of Chinese modernization and expanding domestic demand for common prosperity for all.

基于叶天士“凡病宜通”思想论治大肠腺瘤

基于叶天士“凡病宜通”思想,认为大肠腺瘤的基本病机为中焦气虚湿滞,湿邪壅盛日久而为湿毒,湿酿成痰,邪气交结,久病入络,气血不通,肠瘤乃生。叶天士善用“通法”,在腑病,络病治疗中较多体现,其认为“腑宜通即是补”,“久病入络”,故从腑病,络病两方面以“通法”论治大肠腺瘤。以健脾通胃;利湿化痰散结;宣降肺气;化瘀通络等方法通腑消瘤,“通法”贯穿治疗始终,腑通邪除,肠道通利,从而扶正祛邪,调畅气血,减少复发,以期为临床论治大肠腺瘤提供新思路。

通过型固相萃取-超高效液相色谱-串联质谱法同时测定中华鳖中8种抗病毒药物及2种代谢物

本研究以中华鳖中8种抗病毒药物(antiviral drugs,ATVs)及2种代谢物为研究对象,采用Wallelut Lipoclean磷脂去除小柱净化样品,建立了通过型固相萃取净化模式与超高效液相色谱-串联质谱法(UHPLC-MS/MS)相结合的快速检测方法。样品在37℃下经酸性磷酸酯酶酶解,1%乙酸乙腈提取,通过型固相萃取小柱净化,40℃下氮吹浓缩后采用UHPLC-MS/MS检测,多反应监测(MRM)模式采集数据,内标法定量。针对不同ATVs之间极性差异大的特点,实验优化了仪器参数和前处理条件,重点对色谱柱进行了筛选并排除了生物内源性物质尿苷对利巴韦林的分析干扰,同时讨论了前处理过程中提取液和净化小柱选择对提取效率和净化效果的影响。在最优实验条件下,10种目标物在一定质量浓度范围内线性关系良好,相关系数(r 2)为0.994~0.998,方法检出限(MDL)为0.05~1.1μg/kg,方法定量限(MQL)为0.18~3.8μg/kg。在低、中、高3个添加水平下10种目标物的平均回收率范围为82.5%~103%,相对标准偏差(RSD)为3.11%~12.1%。该方法操作简便、快速、灵敏,重复性好,可用于大批量样品的同时快速检测,并成功应用于省级水产品质量安全风险监测工作。

葛渣膳食纤维对小鼠胃肠蠕动促进作用研究

目的:检验葛渣中水不溶性膳食纤维是否具有促进肠胃蠕动的作用,并检测不同浓度的葛渣膳食纤维对肠胃蠕动促进效果的差异。方法:建立小肠正常蠕动的抑制模型(便秘模型),然后采用小肠运动实验和小鼠排便实验2个实验检测葛渣的水不溶性膳食纤维是否具有促进胃肠蠕动的作用,从而判断葛渣膳食纤维是否具有润肠通便的效果。结果:与模型对照组比较,小肠运动实验中高、中、低剂量组的小肠墨汁推进长度和推进率均有显著性差异,小鼠排便实验的高、中、低剂量组小鼠在首便时间、6 h粪便粒数和6 h粪便总量均有显著性差异(P<0.05)。结论:葛渣水不溶性膳食纤维具有润肠通便的作用。

三峡-葛洲坝两坝间航道汛期船舶适航流量研究

三峡—葛洲坝梯级枢纽两坝间航道汛期适航流量标准是大流量时安排船舶过闸计划的依据。在分析两坝间船型现状、枢纽调度运行情况的基础上,根据实测水文资料、数学模型和实船试验成果,对不同水情条件船舶在两坝间河段的航行性能进行综合评估,针对干散货船、液货船和集装箱船提出以满载排水量、主机功率和单位功率装载量为控制因素的适航流量标准。研究结果对两坝间航道的通航管理具有重要的参考价值。

密贴下穿既有地铁车站的新建通道拆撑影响分析

依托成都地铁8号线倪家桥站零距离密贴下穿既有地铁1号线倪家桥车站工程,采用数值模拟方法对比分析“先施作二衬再拆撑”和“先拆撑再施作二衬”对既有和新建结构的力学差异,并基于“先拆撑再施作二衬”工况进一步分析拆撑方案,最后通过实测现场实施的“先施作二衬再拆撑”工序下的既有车站底板沉降数据验证相关结论。研究结果表明:“先施作二衬再拆撑”既有车站弯矩及沉降、新建通道初支弯矩及二衬沉降变化不明显;“先拆撑再施作二衬”对于既有车站及新建通道影响则较为显著,一次性全部拆撑后既有及新建结构弯矩沿断面分布形态变化明显,在结构沉降方面,拆撑后既有车站及新建通道初支最大沉降突变量分别达4.86,7.30 mm;“先拆撑再施作二衬”工况下,采用顺序拆撑与跳仓拆撑,最不利部位出现在下穿通道纵向中部,跳仓拆撑引起新建通道初支沉降量大于顺序拆撑,但其施工效率更高,具体拆撑方式应根据施工安全控制标准及经济性要求合理选择。

中国碳市场下发电企业碳成本传导率及动态特征

深化中国碳市场建设、促进发电企业碳排放成本向下游需求侧科学传导是加快经济社会全面绿色低碳转型的重要政策着力点。合理的碳成本传导率不仅能激发企业减排动力,还可以将碳排放成本通过提高电力价格的方式向消费端转嫁,引导其节约用电,从而推动碳市场在更大范围内形成减排效应。该研究基于发电企业经营行为的微观视角,将碳排放成本纳入企业的投资决策范畴,在充分考虑排放强度、风险偏好和采纳低碳技术意愿等异质性因素的基础上,构建了基于Agent的碳成本传导评估模型。通过模拟发电企业在面对有限信息时的策略选择,探讨了2021—2030年中国碳市场下发电企业碳成本传导率的变化趋势,并分析了不同的市场机制设计和低碳技术对碳成本传导率的作用影响。研究发现:①发电企业碳成本传导率呈现“缓慢增长—快速上升—保持高位”的动态特征。②初始碳价、市场规制系数和拍卖比例等市场机制设计均对发电企业碳成本传导率产生正向作用。具体地,初始碳价的增长会在短期内推高碳成传导率,作用效果在中长期将逐渐减弱;市场规制系数对碳成本传导率的推动作用存在门槛效应;随着拍卖比例的提高,企业的排放成本将会增加,进而引起碳成本传导率升高。③低碳技术能够缓解碳排放约束下发电企业的经营成本压力,避免碳成本传导率过度上升。该研究不仅为发电企业碳成本传导问题的探究提供了理论支撑,还为健全中国碳市场的机制设计提供了实践指引。

砂土层中类矩形盾构施工对邻近既有隧道造成影响的模型试验研究

为探究砂土层中考虑新建类矩形盾构隧道施工过程中土体的损失和新建隧道与既有盾构隧道不同位置时,新建类矩形盾构隧道对既有隧道的围压、隧道拱底应变和拱顶位移的影响,采用室内模型试验的方法,进行新建类矩形隧道重叠下穿、夹穿和不同隧道间距下正交90°下穿的试验。研究结果表明:1)各种工况下新建类矩形盾构隧道在夹穿既有隧道时对上线既有隧道的影响最大;2)夹穿工况下,新建类矩形盾构隧道开挖到既有隧道下方时,上线既有隧道拱底围压发生突变且数值极大;3)隧道的间距是新建类矩形盾构隧道施工时引起既有盾构隧道围压、拱底应变、拱顶位移等发生改变的重要影响因素,实际施工时应尽可能保持新建隧道与原有盾构隧道的间距足够大;4)新建类矩形盾构隧道下穿既有隧道过程中,既有隧道拱顶存在快速变形的阶段,在实际工程中需要重视这一过程中对隧道拱顶变形速率的控制。

基于静态磁源通过特性的磁定位导航气管插管装置的研制

目的基于静态磁源的通过特性,设计磁定位导航气管插管装置,以提高声门暴露困难情况下的气管插管成功率。方法本磁定位导航气管插管装置由柔性磁定位脖套、主控制器、磁引导条、导航磁体组成。通过硬件设计和软件编程,本装置主控单元以STM32F103C6T6微控制器为核心,利用磁定位脖套采集的磁感应强度数据,采用基于静态磁源通过特性的磁定位算法对柔性磁引导管条尖端进行定位。本装置通过可编程光源和蜂鸣器实现报警功能,借助导航磁体诱导磁引导条尖端响应磁体以实现磁导航。结果在磁定位导航系统的辅助下,相较于无磁定位导航系统辅助,非麻醉专业背景的医学生在模拟声门暴露困难条件下进行气管插管的一次成功率明显提高,差异有统计学意义(P<0.05),且平均插管用时保持在气管插管安全时限内,差异有统计学意义(P<0.05)。结论本研究设计的磁定位导航气管插管装置操作简便,在声门暴露困难条件下的气管插管中优势明显,可有效提高困难气道气管插管的一次成功率,减少并发症的发生,提高医疗质量安全,促进我国生命急救体系高水平发展。

“船闸+升船机”协同控制下的船舶调度优化

为提高“船闸+升船机”协同控制模式下的内河水运枢纽通航设施工作效率,分析该模式下通航设施和船舶过坝特点,提出一种用于“船闸+升船机”协同控制的基于滑动时间窗的船舶调度两阶段双目标整数规划优化模型。第一阶段采用滑动时间窗和先到先服务规则,设计不同船型的船舶过闸编队方案;第二阶段仍采用滑动时间窗,建立以船舶平均延误时间最短和最大泊位占用数最小为目标的双目标整数规划优化模型。使用带精英策略的非支配排序遗传算法(elitist non-dominated sorting genetic algorithm,NSGA-Ⅱ)进行求解,分别对船舶稀疏过坝、船舶密集过坝、船舶部分时段集中过坝3种情形进行仿真分析,并与不采用滑动时间窗的排队论模型进行比较。结果表明,3种情形下船舶平均延误时间均缩短了15%以上。