A knowledge graph and service for regional geologic time standards

Geologic time is an important dimension in geological research.Geologic time data are commonly collected from multiple sources in data-intensive studies of Earth’s history and raise an issue of data cleansing and integration.A knowledge graph of the international geological time scale has been established to harmonize heterogeneous data to facilitate effective and efficient data-driven discovery.Although many regional geologic time standards are also used in various databases and literature,there is limited discussion or development of knowledge graph for them.In this research,we construct a knowledge graph for the geologic time standards in 17 regions at the Epoch and Age levels.This regional geologic time knowledge graph is integrated with the international geologic time knowledge graph as a comprehensive deep-time knowledge base.A SPARQL endpoint has been established to provide open and free online service to the knowledge base.Several use cases are presented here to demonstrate the functionality of the knowledge graph we built as well as its application in open data exploration.Our work addresses the shortage of machine-readable knowledge graphs for regional geologic time standards and will help accelerate geologic data integration from multiple sources in data-intensive studies.All data and code in this paper are made open source and are accessible on GitHub and Zenodo.

The time and frequency standard system for FAST receivers

This paper reports on the time and frequency standard system for the Five-hundred meter Aperture Spherical radio Telescope(FAST),including the system design,stability measurements and pulsar timing observations.The stability and drift rate of the frequency standard are calculated using 1-year monitoring data.The UTC-NIM Disciplined Oscillator(NIMDO)system improves the system time accuracy and stability to the level of 5 ns.Pulsar timing observations were carried out for several months.The weighted RMS of timing residuals reaches the level of less than 3.0μs.

Noether symmetry and conserved quantity for dynamical system with non-standard Lagrangians on time scales

This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilton prin- ciple based on the action with non-standard Lagrangians on time scales is established, with which the corresponding Euler-Lagrange equation is given. Secondly, according to the invariance of the Hamilton action under the infinitesimal transformation, the Noether theorem for the dynamical system with non-standard Lagrangians on time scales is established. The proof of the theorem consists of two steps. First, it is proved under the infinitesimal transformations of a special one-parameter group without transforming time. Second, utilizing the technique of time-re-parameterization, the Noether theorem in a general form is obtained. The Noether-type conserved quantities with non-standard Lagrangians in both clas- sical and discrete cases are given. Finally, an example in Friedmann-Robertson-Walker spacetime and an example about second order Duffing equation are given to illustrate the application of the results.

Construction and evaluation of reference standards for detection and quantification of Klebsiella pneumoniae using real-time PCR

Objective To construct reference standards for detection and quantification of Klebsiella pneumoniae(K.pneumoniae)with SYBR Green I-based real-time PCR assay.Methods Primers were designed based on the published sequence of the phoE gene of K.pneumoniae.The standard was prepared by cell culture,PCR and T-A clone methods,and was identified by colony PCR and DNA sequencing.Results The standard curve showed a very good linear negative regression between threshold cycle(Ct)and Log starting quantity of copy number.The detection range was from 5.2 to 5.2×106 copies per reaction,and the detection limit was 6 copies per reaction.The coefficients of variance(CVs)of three parallel experiments were in the range of 0.05%-0.91%.Conclusion The reference standards have high stability and reproducibility.They can be used in the quantitative detection of K.pneumoniae.

Estimation of Standard Operation Time of Flight Legs Based on Clustering and Probability Analysis

A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases.

An improved formula for standard hypoxia tolerance time to evaluate hypoxic tolerance in mice

Background: Hypoxia is a primary cause of mountain sickness and a common pathological condition in patients with heart failure, shock, stroke, and chronic obstructive pulmonary disease(COPD). Thus far, little advancement in countering hypoxic damage has been achieved, and one of the main reasons is the absence of an ideal algorithm or calculation method to normalize hypoxia tolerance scores when evaluating an animal model. In this study, we improved a traditional calculation formula for assessment of hypoxia tolerance.Methods: We used a sealed bottle model in which the oxygen is gradually consumed by a mouse inside. To evaluate the hypoxia tolerance of mice, the survival time(ST) of the mouse is recorded and was used to calculate standard hypoxia tolerance time(STT) and adjusted standard hypoxia tolerance time(ASTT). Mice administered with methazolamide and saline were used as positive and negative controls, respectively.Results: Since mice were grouped according to either body weight(BW) or bottle volume, we found a strongly negative correlation between STT and BW instead of between STT and bottle volume, suggesting that different BWs could cause false positive or negative errors in the STT results. Furthermore, both false positive and negative errors could be rectified when ASTT was used as the evaluation index. Screening for anti-hypoxic medicines by using mice as the experimental subjects would provide more credible results with the improved ASTT method than with the STT method.Conclusions: ASTT could be a better index than STT for the evaluation of hypoxia tolerance abilities as it could eliminate the impact of animal BW.

Investigating the Use of <i>Jatropha</i>Biodiesel in Compression Ignition Engines by Comparing Effects of Storage Time on Its Properties with the Standard Properties of Fossil-Diesel and Properties of Quality Biodiesel

Effects of storage time on some properties of jatropha biodiesel were investigated over the storage time of 0 to 8 weeks at the temperature of 25℃. Such properties as water content and density were found to increase at the rates of 5 ppm and 14 kg/m3 per week respectively. These rates translate into property values which compare closely with the standard properties of fossil-diesel and properties of quality biodiesel. As a result, the jatropha biodiesel can be used as alternative fuel to fossil-diesel in compression ignition engines within 8 weeks of its production. However, the calorific value and flash point of the biodiesel decreased at the rate of 1.4℃ and 2.5 MJ/kg per week respectively. Although the flash point was within the acceptable level for quality biodiesel, the calorific values were abnormally higher than the values for quality biodiesel of about 38.7 MJ/kg. With the exception of the calorific values, the other properties were not reasonably affected.

China National Standards on Nano-Materials Issued for the First Time

On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.

不同比对方式下的洲际标准时间复现性能分析

中国科学院国家授时中心研制的标准时间复现系统具备支持洲际用户对标准时间频率信号的需求。本文以位于欧洲白俄罗斯明斯克的复现终端为分析对象,分析了共视、全视不同比对方式对复现时频信号性能的影响。对于洲际范围的时间复现,复现终端与参考端共同可视卫星数变少。单一卫星导航系统可利用的共视卫星数明显减少,GPS/BDS共视可明显增加可视卫星数量,提高共视时间比对精度,全视比对对两地共同可视卫星数没有要求。分析结果表明,单GPS全视比对就可以达到优于GPS/BDS的共视比对复现效果。受BDS卫星星间偏差的影响,基于单BDS全视比对的复现效果比GPS稍差,GPS/BDS全视比对效果略有改善。复现终端运行在GPS/BDS共视比对融合GPS全视比对模式复现的时频信号的性能最优,可以满足洲际范围内5 ns的时间同步要求,为后续洲际大尺度范围的标准时间复现终端的运行模式提供参考。

低温弱光胁迫下茄子幼苗实时荧光定量PCR内参基因的筛选与评价

为了探索茄子Solanum melongena L.的基因表达模式,利用qRT-PCR方法分析了茄子ACT、EF1α、TUA、TUB、GAPDH、eIF、UBQ、UBI3、PP2A、CYP、RPL28、L25、SAND、TBP、DNAJ、APRT、EXP、CAC、HSP20和CysPro 20个候选内参基因mRNA的表达差异情况,并运用GeNorm、NormFinder和BestKeeper 3种计算方法评价茄子20个候选内参基因在低温、弱光、低温弱光叶片样品中的表达稳定性。结果表明:茄子20个候选内参基因荧光定量引物扩增效率(E)数值在96.8%~117.6%,相关系数(R^(2))介于0.9688~0.9999,扩增效率良好,扩增反应具有高度的专一性,引物能特异性扩增,特异性好,均为单峰,样品间扩增曲线重复性强,可用于qRT-PCR扩增。茄子20个候选内参基因C_(T)值表达丰度分析,发现茄子20个候选内参基因平均CT值在19.76~31.20。3种计算方法的综合评价分析结果显示,TBP基因在所有样本中为最稳定的内参基因。研究可为茄子低温、弱光和低温弱光胁迫下基因特异性表达研究提供了合适的内参基因。

Generation and Application of A Standardized Load-Time History to Tubular T-joints in Offshore Platforms

Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.

美国加州车网互动政策、标准与市场机制最新进展及其启示

电动汽车与电网互动(简称“车网互动”)可以释放电动汽车作为灵活性资源的潜力,能够有效提升电网调峰能力、促进高比例可再生能源消纳、提升电动汽车用户经济收益,日益受到各方重视。美国加利福尼亚州(简称“加州”)近些年在推动电动汽车与电网互动发展方面做了大量工作,取得了重要进展。首先,文中介绍了加州在电动汽车与电网互动配套政策法规方面的最新动向;之后,从技术标准、市场机制两方面介绍了加州在电动汽车与电网互动相关基础工作方面的最新进展;最后,结合中国电动汽车与电网互动发展实际提出了有关建议。

多维邻近性对国际技术标准生存时间的影响研究——基于ITU国际技术标准生存分析

在技术快速变革和迭代的时代背景下,构建技术标准联盟是各类组织适应技术快速发展的必要手段。技术标准联盟的组织构成正在朝着跨国化和多样化发展,联盟成员间特征差异程度的提升对技术标准生存时间产生了重要影响。根据协同创新理论,基于2010—2021年ITU国际技术标准联盟的相关数据,运用生存分析方法,分析多维邻近性与技术标准生存时间的内在关联。结果表明,地理邻近性与技术邻近性能显著提高ITU国际技术标准生存时间;组织邻近性与制度邻近性对ITU国际技术标准生存时间具有显著负向影响;地理邻近性与技术邻近性、组织邻近性与制度邻近性的交互作用对ITU国际技术标准生存时间具有显著负向影响,地理邻近性与组织邻近性、地理邻近性与制度邻近性、技术邻近性与组织邻近性以及技术邻近性与制度邻近性的交互作用对ITU国际技术标准生存时间具有显著正向影响。研究有助于深化对技术标准联盟协同创新的理论解释,丰富了技术标准生存时间驱动因素的理论成果,可为我国信息和通信技术行业国际技术标准制定的管理实践提供重要参考。

面向可配置复合磨削中心的监控系统设计与实现

智能制造的大环境不断推动先进制造装备和信息通信技术的进一步融合,面向可配置复合磨削中心,设计开发监控系统实现对复合磨削中心加工状态的监控功能。针对复合磨削中心可配置的不同数控系统,标准化封装其通信接口;同时,设计开发基于C/S架构的监控系统,实时读写接口数据,达到监测复合磨削中心加工状态的目的。

NIM5驾驭氢钟守时能力分析

时间频率量值源头的独立自主是建设我国综合PNT体系的重要基础。为进一步评估基于我国国家秒长基准的原子时标守时能力,利用改进的有限脉冲响应钟差预测与频率调控方法,对激光冷却铯原子喷泉钟与氢钟的频差实测数据进行后处理,分别产生了自主型时标和溯源型时标。通过国际原子时合作链路将两个时标与协调世界时进行了长期比对实验,结果表明:2021年12月~2022年12月期间,两个时标的时间偏差均优于±4 ns、频率稳定度均优于8×10^(-16)/5 d。

标准化卒中疏导员制度促进溶栓治疗的作用研究

目的:评价标准化卒中疏导员制度促进溶栓治疗的作用。方法:主要方法为回顾性分析,选取2021年3月至2021年11月通过常规绿色通道流程进行溶栓的急性卒中病例为对照组,2021年12月至2022年8月实施卒中疏导员制度溶栓的急性卒中病例为观察组,比较两组患者入院到开始静脉溶栓治疗时间(DNT)差异,统计分析DNT时间延长原因。结果:观察组DNT时间显著短于对照组,差异有统计学意义(P<0.05),影响DNT时间的因素主要有6个方面,其中患方、抢救人力、CT检查为主要原因。结论:卒中疏导员制度不仅能有效改善卒中关键指标,还能发现过程短板并提出改进措施,对改进效果进行评价,有利于卒中救治质量的提升。

什么是好的课后服务:德国全日制小学课后服务质量标准研究

目前我国中小学的课后服务进入了由探索性实践向扩优提质转变的过渡性阶段,在此阶段需要回答的核心问题是“什么是好的课后服务”,即课后服务的质量评价,这也是中小学课后服务的利益相关者需要面对的核心问题。课后服务在德国经历了百余年的发展,已然形成了完善的课后服务模式和科学的运行机制。从2026年起德国将逐步引入小学生全天课后服务的法定权利,而全日制小学是课后服务的主要承担者。为保障全日制小学课后服务的质量,德国分别从联邦政府和州政府层面制定了全日制小学课后服务质量标准,用以指导各联邦州开展课后服务质量提升计划,而且质量标准呈现出四个典型特征:突出课后服务质量标准制定过程的科学性与全面性;突出课后服务质量标准对教育公平的维护;突出课后服务质量标准对家庭与事业的平衡;突出课后服务质量标准对学生个性与全面发展的重视。基于对德国全日制小学课后服务质量标准的分析,可以得出三点启示:首先健全制度规范,做好国家与地方层面课后服务质量标准的制定与落实工作;其次铸牢育人理念,将以学生为中心的教育理念作为构建课后服务质量标准的基本原则;最后加强内外合作,将学校教育与社会教育的统一作为保障课后服务质量的重要举措。

气象业务综合监视数据标准化设计与应用

打造开放的气象综合业务实时监控体系,全面提升气象业务的运行质量与效率是气象信息化发展的重要工作。针对气象综合业务监视范围广泛、内容多样以及传输密集等特性,为实现海量监视数据高效、完整及准确的采集、传输与处理,本文设计了一种基于标准化数据分类的可扩展的监视数据内容模型。该模型对种类繁多的监视数据进行抽象与概括,划分了监视数据的类别;描述了每一类别监视数据的通用属性;同时依据核心监视功能的数据需求,在通用属性的基础上进一步设计了典型的监视数据属性域内容。该模型具备通用性、可扩展性特点,在中国气象局“气象综合业务实时监控系统(天镜)”的建设中得到广泛应用,并在2022年发布为气象行业标准,为国省共有核心监控功能的实现以及各省特有监控范围的扩充提供了有效的监视数据支撑。

基于改进PCA的复杂多阶段过程故障检测

为解决复杂多阶段过程难以进行有效监控的问题,提出了时空近邻标准化和主成分分析的故障检测方法。TSNS使用从时间到空间上嵌套近邻集的均值和标准差标准化各阶段样本,能够将多阶段数据高斯化为单一阶段的数据,分离故障样本,同时去除前后时刻样本间的时序相关性。TSNS能帮助PCA有效克服动态性、非线性和多阶段特征的影响,显著提高PCA的故障检测率。通过使用青霉素发酵过程设计故障检测实验,将TSNSPCA与一些经典方法进行比较,发现其具有更高的故障检测率。

天然气净化行业氧化吸收尾气处理装置全时段达标排放经验浅谈

文章介绍了氧化类尾气处理装置的工艺原理和特点,分析了氧化类尾气处理装置在天然气净化行业正常工况、开停产期间,以及异常工况情况下尾气超标原因,提出了硫磺回收装置精准配风、控制尾气处理装置溶液浓度等具体解决措施,并从工艺流程优化、联锁设置、自动化改造等方面提出优化建议,确保氧化类尾气处理装置实现全时段达标。