氯代聚并苯同系分子的能量和电子极化率与同系序数的相关性研究

氯代聚并苯同系物的能量和电子极化率与同系序数之间满足下列相关方程E=a Nβ+b,　　　　　　　　　R≈ lα(或 απ ) =α′ Nβ′+b′,R≥ 0 .9990απ/ α(% ) =α″Nβ″+b″,R≥ 0 .9999N=2 n+1,为同系序数 ,n为苯环的结构单元数 β、β′、β″随同系分子的类型而变 ,本文的计算值与文献值吻合良好     

最后的敬意

欧阳宜文,"他乡物语"专栏作者,迄今为止已为《英语沙龙》写了近40篇稿件,为读者奉献了一道道丰盛的英伦文化大餐。非常感谢她用真诚的文字让国内读者更多地了解了英国文化,更多地感受到了文字的魅力。当她被"千呼万唤始出来"、以更亲切的形象走近读者时,也是说"再见"的时候了。下面这篇便是欧阳宜文送给大家的"最后的敬意"。     

Exploring coherent topics by topic modeling with term weighting

Topic models often produce unexplainable topics that are filled with noisy words. The reason is that words in topic modeling have equal weights. High frequency words dominate the top topic word lists, but most of them are meaningless words, e.g., domain-specific stopwords. To address this issue, in this paper we aim to investigate how to weight words, and then develop a straightforward but effective term weighting scheme, namely entropy weighting (EW). The proposed EW scheme is based on conditional entropy measured by word co-occurrences. Compared with existing term weighting schemes, the highlight of EW is that it can automatically reward informative words. For more robust word weight, we further suggest a combination form of EW (CEW) with two existing weighting schemes. Basically, our CEW assigns meaningless words lower weights and informative words higher weights, leading to more coherent topics during topic modeling inference. We apply CEW to Dirichlet multinomial mixture and latent Dirichlet allocation, and evaluate it by topic quality, document clustering and classification tasks on 8 real world data sets. Experimental results show that weighting words can effectively improve the topic modeling performance over both short texts and normal long texts. More importantly, the proposed CEW significantly outperforms the existing term weighting schemes, since it further considers which words are informative.     

大型沉井侧壁摩阻力计算模型(英文)

为了克服大型沉井设计和施工控制中存在的问题,对大型沉井侧壁摩阻力的计算模式进行了研究.根据马鞍山长江大桥南锚碇沉井侧壁土压力的现场监测数据,反推出不同下沉深度条件下沉井侧壁摩阻力的统计结果,并研究了大型沉井下沉期侧壁摩阻力的分布特征.分析结果显示:当沉井下沉深度小于某一特定深度H0时,井壁侧阻力基本上随着入土深度呈线性增长;而当沉井刃脚入土深度大于H0时,沉井侧壁摩阻力分布呈现上下小、中间大的分布,上部可近似为线性段,下部则近似为双曲线段;而且随着沉井入土深度的不断增加,沉井侧壁摩阻力峰值基本呈线性增长,且峰值发生的位置也逐渐下移.最后,建立了一种大型沉井侧壁摩阻力的修正计算模式.与现场实测数据的对比结果表明,所提出的修正计算模式是可行的.     

Performance of D-dimer for predicting sepsis mortality in the intensive care unit

IntroductionThe prognostic value of D-dimer (DD) in sepsis remains controversial. This study aimed to investigate the performance of DD for predicting sepsis mortality in the hospital and for identifying its potential correlates.Materials and methodsThe clinical and laboratory data of adult sepsis patients were extracted from the Medical Information Mart for Intensive Care III (MIMIC III, v1.4) database using the structured query language (SQL). The database contains critical illness admitted to the intensive care unit at Beth Israel Deaconess Medical Center between June 2001 and October 2012. The association between DD and mortality was investigated with receiver operating characteristic (ROC) curve, restricted cubic spline and logistic regression analysis. Subgroup analysis was also used for identifying DD correlates.ResultsThe study population consisted of 358 sepsis patients. Those who died during hospital stay (N = 160) had significantly higher DD values than those who survived (N = 198). The area under the ROC curve (AUC) of DD was 0.59 (P < 0.010). In subgroup analysis, white blood cell (WBC) count > 18 x10⁹/L and vasopressor therapy significantly decreased DD diagnostic performance. Categorical DD value was independently associated with hospital mortality after sequential organ failure score (SOFA) and blood lactate adjustment. Restricted cubic spline analysis revealed a U-shape relationship between DD and in-hospital mortality.DiscussionWe conclude that the accuracy of DD for predicting in-hospital sepsis mortality depends on WBC count and vasopressor therapy. Both low and extremely elevated DD values are associated with higher risk of death.     

我国公共图书馆法人治理结构改革的问题与对策

[目的/意义] 理事会的建立与有效运行是公共图书馆法人治理结构改革的根本标志与核心,能较为直观地反映改革现状与问题,对其进行研究具有重要意义。[方法/过程] 通过图书馆官网、政府官网、学术论文、新闻媒体以及电话调查等多种渠道,对全国市（地）级以上365家公共图书馆的理事会建立与运行情况展开调研。[结果/结论] 发现在理事会设立及运行方面,存在设立比例偏低、区域差异较大、职能定位模糊、理事长来源单一、信息公开程度低等问题。因此,在深化改革过程中,要坚持"掌舵"与"服务"相结合、"公益性"与"竞争性"相协调、"舶来品"与"本土化"相兼容等原则。通过完善制度设计,提升改革成效;加快改革进程,促进区域协调发展;明确职能定位,优化决策支撑机制;优化成员构成,拓宽理事长产生方式及来源渠道;加大信息公开,健全内外监督机制等对策为改革保驾护航。     

小组学习与考核法在独立学院“基础护理学”实训中的应用

目的：院为使独立学院培养的护生能更好地适应临床需求,探索更为适合的实训教学方法。方法院以“基础护理学”课程为基础,将2011级学生作为实验组,2010级学生作为对照组,实验组采用小组学习与考核的方法,对照组采用传统的教学法,通过小组式技能考核来比较两组学生的学习效果。结果院实验组的学生成绩优于对照组,且实验组的学生对小组学习与考核法认可度较高。结论院小组学习与考核法可提高学生的技术操作水平、提高学生的综合素质,同时可有效解决独立学院专职专任教师相对不足的问题。     

Applying regression models to query-focused multi-document summarization

Most existing research on applying machine learning techniques to document summarization explores either classification models or learning-to-rank models. This paper presents our recent study on how to apply a different kind of learning models, namely regression models, to query-focused multi-document summarization. We choose to use Support Vector Regression (SVR) to estimate the importance of a sentence in a document set to be summarized through a set of pre-defined features. In order to learn the regression models, we propose several methods to construct the “pseudo” training data by assigning each sentence with a “nearly true” importance score calculated with the human summaries that have been provided for the corresponding document set. A series of evaluations on the DUC data sets are conducted to examine the efficiency and the robustness of the proposed approaches. When compared with classification models and ranking models, regression models are consistently preferable.     

EPO对全脑缺血后低氧诱导因子1α及存活素表达的调节

[目的]研究促红细胞生成素对全脑缺血再灌注大鼠缺氧诱导因子1α和凋亡相关蛋白存活素的调节,探讨其抗凋亡的可能机制。[方法]将成年雄性SD大鼠75只按随机数字表法分为全脑缺血组（n=35）和全脑缺血EPO干预组（n=35）,然后按再灌注时间不同又分为6h、12h、24h、48h、72h、5d和7d七个亚组。采用改良的Pu刘lsineli 4-VO法制作全脑缺血大鼠模型。应用TUNEL染色检测再灌注后不同时间点海马CA1区的神经元凋亡水平,免疫组织化学方法检测再灌注后不同时间点海马CA1区缺氧诱导因子1α和存活素表达水平的变化。[结果]全脑缺血EPO干预组24h至7d亚组TUNEL阳性神经元计数分别为1.50±0.73、3.14±0.88、5.78±1.03、7.78±1.79、10.34±1.82.与全脑缺血组相应时间点亚组相比明显减少,差异均有统计学意义（P〈0.05）。全脑缺血EPO干预组48h至5d亚组HIF-1α表达阳性细胞计数分别为11.26±0.02、20.28±2.03、3.33±0.04,与全脑缺血组相应时间点亚组相比明显减少,差异均有统计学意义（P〈0.05）.全脑缺血EPO干预组24h至5d亚组survivin蛋白表达阳性细胞计数分别为12.21±1.04、16.34±4.02、24.33±3.03、30.52±5.04,与全脑缺血组相应时间点亚组相比明显增高,差异均有统计学意义（P〈0.05）。[结论]在全脑缺血急性期,EPO抑制HIF-1α的表达而使存活素表达升高,具有一定的神经保护作用.