北京市气温对腹痛急诊日就诊人数的影响

定量分析北京市气温对腹痛急诊日就诊人数的影响.收集2009-2012年北京市海淀区某三甲医院腹痛急诊资料和同期北京市气象、大气污染物资料,采用广义相加模型在控制时间、其他气象要素和大气污染物(SO_2,NO_2,PM_(10))的混杂效应下,拟合日均气温、最高温度、最低温度、气温日较差、24 h变温对腹痛急诊日就诊人数影响的剂量-反应关系.几项气温指标对腹痛急诊日就诊人数均有不同程度影响,日均气温、最高温度和最低温度每增加1℃,腹痛急诊日就诊的相对危险度RR分别为1.0052(95%CI:1.0034~1.0070),1.0049(95%CI:1.003 2~1.0066)和1.004 7(95%CI:1.002 9~1.006 5).温度日较差和24 h变温对腹痛急诊日就诊人数有正向的影响,但结果无统计学意义.研究结果表明腹痛急诊日就诊人数夏季较多,日均气温、最高温度和最低温度对其均有影响.     

人工神经网络在呼吸系统疾病急诊就诊人数预报中的应用

利用北京市2009-2011年呼吸系统疾病急诊就诊人数资料和同期的气象资料及污染资料,分析了气象因素及污染物分别与上感、下感急诊就诊人数的相关性,在此基础上,通过BP人工神经网络分别建立了上感和下感急诊就诊人数的预报模型,并对其效果进行评价.结果表明:气象因素和污染物与上感、下感的发病有密切的关系;建立的上感、下感就诊急诊人数的神经网络预报模型结构分别为13-7-1(即有13个输入、7个隐含节点和1个输出)和13-6-1(即有13个输入、6个隐含节点和1个输出),预测准确率分别为77.11%和75.57%.与统计预报方法相比较,该方法计算简便、误差较小、预测准确率高,对上感和下感急诊人数有较好的预测效果,为医疗气象预报提供了一种新方法,具有进一步的研究价值.     

北京市空气质量指数与气象条件的关系及其对呼吸系统疾病的滞后影响

依据北京市2009年1月1日-2011年12月31日的逐日空气质量指数(AQI)与同时段常规地面气象观测数据,区分污染日与非污染日(以轻微污染下界为分界)、不同季节研究了AQI与气象要素的关系;应用分布滞后非线性模型与广义相加模型,在调整气温、相对湿度、风速等混杂效应的基础上,定量计算了AQI对呼吸系统急诊人数的影响及滞后效应.结果表明,研究时段北京AQI的年际波动并不明显,冬季中、重度污染易发;秋季空气优良率最低;春季易发生轻微污染.污染日AQI与平均气压、最高气压显著正相关,与气温、相对湿度负相关;非污染日,AQI与气压、平均/最大风速和日照时数负相关,而与气温、相对湿度、降水量正相关.就诊当天与滞后1 d的AQI对呼吸系统疾病的影响最显著,且危险度(RR)随污染物质量浓度的增大以接近线性形态增大.AQI指数每增加10,北京市呼吸系统急诊就诊人数的RR为0.22%,其95%置信区间为0.104%~0.342%.     

兰州市大气污染对人体呼吸系统疾病的影响

通过分析2001-2005年兰州市呼吸系统疾病日就诊人数和主要大气污染物的年变化特征,采用时间序列的半参数广义相加模型,在控制人群的长期趋势、节假日效应、星期几效应和气象要素等混杂因素的基础上,定量分析了不同季节兰州市主要大气污染物质量浓度变化与呼吸系统疾病日就诊人数之间的关系.结果表明,兰州市夏、秋季人体呼吸系统疾病受气温、气压等气象要素和其他因素的影响较大,冬、春季受大气污染物的影响较显著,研究兰州市大气污染对人体呼吸系统疾病的影响以冬、春季为主.冬季3种污染物对人体呼吸系统疾病均有一定的影响,春季SO_2和NO_2的影响更明显,当SO_2质量浓度增加10μg/m~3时,呼吸系统疾病影响较大的人群入院人数的相对危险度(RR)依次为:全人群1.015(1.005~1.025),男性1.015(1.001~1.028),60岁人群1.028(1.011~1.046);当NO_2质量浓度增加10μg/m~3时,影响较大人群人院人数的RR依次为:全人群1.039(1.014~1.066),女性1.050(1.009~1.094),≥60岁人群1.038(1.00l~1.075).兰州市大气污染对人体呼吸系统疾病的影响冬、春季比较显著;冬季3种污染物均有一定的影响,春季SO_2和NO_2对人体呼吸系统疾病日入院人数影响较明显,且冬、春季污染物对人体呼吸系统疾病影响的滞后效应具有一定差异;呼吸系统疾病在冬季时3种污染物均是≥60岁的人群比60岁的人群敏感,女性比男性敏感;春季时,女性和≥60岁的人群对NO_2敏感,男性和60岁的人群对SO_2敏感.     

广义相加模型在高温热浪对呼吸系统疾病影响研究中的应用

运用广义相加模型探讨南京市高温热浪对当地居民每日呼吸系统疾病死亡人数的影响,结果表明呼吸系统疾病总人数受到当日最高温度、死亡前1d、6d的日最高气温的影响。影响最大的因素是当日最高温度,其RR值为0.886(95%CI:0.771～0.972)。男性主要受到死亡前6d的日最高气温影响,女性受到当日最高温度以及死亡前1d的日最高气温的影响。60岁以上的老年人主要受到当日的平均温度、死亡前1d以及死亡前6d的日最高气温的影响。影响最大的因素是死亡前1d的日最高温度,其RR值1.095(95%CI:1.03～1.163)。广义相加模型预测的呼吸系统疾病死亡人数与实际死亡人数较相近,上升与下降的变化趋势基本一致。     

北京市上呼吸道感染与气象环境关系及其冬季天气分型初探

上呼吸道感染(简称上感)是常见的多发病,它与气象、环境(污染)条件密切相关.选取北京市2009年1月1日-2011年12月31日的上感急诊就诊人数资料和同期气象、环境资料,在去除就诊人数资料周末效应的基础上,采用Pearson与Spearman相关分析方法,综合分析了四季中各气象要素和污染物浓度与上呼吸道感染就诊人数的关系,并用聚类分析法对冬季上感多发期的天气形势进行了分型.结果表明:春季上感就诊人数与湿度和降水量呈负相关;夏季就诊人数与平均温度、最低温度呈正相关,与最大风速呈负相关;秋季就诊人数与温度、降水量呈负相关,与3种污染物浓度呈正相关;冬季就诊人数与温度、相对湿度、降水量呈负相关,与气压呈正相关.春、夏、冬3季气象条件对上感发病的影响大于环境条件的影响,秋季环境空气质量的作用大于气象条件的作用.对冬季上感多发期天气分型后发现,降温剧烈、高压、干燥、晴朗、风较大的天气条件下就诊人数最多,处于升温过程、较湿润的天气条件下上感就诊人数最少,可为当地居民相关疾病的预防提供参考依据.     

空气主要污染因子对常见呼吸系统疾病影响调查

目的了解本地区空气污染对呼吸系统常见疾病的影响。方法收集2014-2016空气质量监测报告以及当地医疗机构的诊疗资料进行分析,统计工具为SPSS17.0。结果 1.近3年本区域空气优良天数占90.5%。2.呼吸系统疾病患病占3.71%,常见呼吸系统疾病主要为:咳嗽、急性支气管炎、急性咽炎、急性扁桃腺炎。3.小于6岁和大于18岁的男性呼吸系统疾病患病比女性高。结论 1)本区域空气质量总体良好;2)辖区常见呼吸系统疾病仍处于低患病水平。3)空气污染对呼吸系统疾病有滞后影响,经统计AQI,PM_(2.5),PM_(10),CO,NO_2,SO_2,O_3与5 d后的呼吸系统疾病变化均呈线性相关关系。     

南京市呼吸系统疾病死亡人数与气象因子的关系

利用2005年1月1日-2008年12月31日南京市逐日呼吸系统疾病死亡人数资料和同期气象资料,研究了气象要素变化对呼吸系统疾病死亡人数的影响.结果表明:南京市呼吸系统疾病死亡人数冬季最高,其次是春季,秋季和夏季较少;南京市逐日呼吸系统疾病死亡人数对气象要素变化的响应存在滞后性,春季滞后6-7 d,夏秋季滞后8-10 d,冬季滞后2-5 d;对风寒指数响应的滞后响应时间,春季7-8 d,夏季和秋季相关弱,冬季2-3 d;前期的空气污染和后期的剧烈降温叠加,可能是南京冬季呼吸系统疾病患者死亡的重要诱因;春季随着气温的回升,空气污染程度减轻,患者对气温变化的耐受性也延长了,但响应敏感性比冬季增强了;通过逐步回归,建立了冬季和春季南京呼吸系统疾病的死亡人数预报方程.     

气象条件对北京市消化系统疾病的滞后性影响

收集北京市某三级甲等医院2009-2011年消化系统疾病急诊就诊资料93 301例,在Spearman相关分析的基础上,用分布滞后非线性模型与广义相加模型相结合,对气温、相对湿度、风速对急诊人数的影响和滞后效应进行分析.就诊人数与气温、相对湿度、水汽压、降水量等均为显著正相关,而与气压、风速为显著负相关.20℃附近是最不利于消化系统疾病发病的气温条件;气温高于25℃时高温效应明显,累积效应在滞后4~7 d时最明显.最不利于发病的湿度条件为相对湿度50%左右,滞后0~1 d的湿度效应不明显;滞后2~3 d时相对湿度为70%的危险度高;滞后3~5 d时低于阈值的相对湿度危险度最大.4 m/s左右的风速下发病数较少,而风速为1~2 m/s时在滞后0~4 d会增加消化系统疾痫风险;6 m/s及以上的风速危险度大且作用持久,但其本身出现频次低.主要气象要素对消化系统疾病的发病影响显著且各要素均具有不同的滞后效应.     

南京市呼吸系统疾病死亡人数预测方法研究

利用2004年1月-2009年12月南京市呼吸系统疾病死亡资料和2003年12月-2009年12月南京地面气象观测站逐日气象资料,分析呼吸系统疾病死亡人数与同期和前期气象因素的关系,通过逐步回归按月份建立南京市呼吸及系统疾病逐日死亡人数的预测方程,利用2010年的资料检验预测效果,得出了以下结论:过去2~7 d气温平均值、过去3~7 d气压平均值与死亡人数之间的相关程度均通过了α=0.001水平的相关显著性检验,过去6~7 d的气温48、72 h变幅与死亡人数之间的相关程度也通过了α=0.001水平的相关显著性检验;死亡人数对气温平均值的最强响应在滞后6 d,气压平均值在滞后5 d,风速平均值在滞后1~2 d,过去72 h变温在滞后1~2 d,过去48、72 h气温变幅在滞后6~7 d.回归方程预测的死亡人数与实际死亡人数平均相差2人左右,预测效果优于按季节建立的模型.气象要素及其变化与呼吸系统疾病逐日死亡人数呈显著相关,气象要素对死亡人数的影响具有累积效应,并存在滞后性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the