7 resultados para CPS

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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本研究建立了沉积物中氯化石蜡(CPs)的分析方法,对莱州湾和该区域主要河流的表层沉积物中多氯萘(PCNs),多溴联苯醚(PBDEs)和CPs进行了分析,获得了他们在研究区域的含量水平、空间分布和单体分布模式,并初步探讨了它们在环境中的来源和迁移规律,估算了这三类污染物在莱州湾表层沉积物中的储量,初步评估了莱州湾沿岸的工业排放与人类活动对海洋生态环境的影响。 莱州湾海洋和河流沉积物PCNs的含量分别为65-470 pg/g dw,52-5100 pg/g dw,平均值分别为260 pg/g dw,1100 pg/g dw。莱州湾沉积物中PCNs的含量较低,与发达国家的背景值相当,主要河流沉积物与其他地区的近海、海湾、湖泊沉积物的含量相当。该区域的PCNs主要以5-Cl和6-Cl为主,为工业来源,主要受化工行业的影响。石化工厂热过程产生的低氯组分可能也是该区域PCNs的一个重要来源。莱州湾的PCNs主要来自水体颗粒的输入,而大气沉降来源的贡献不明显。 河流沉积物ΣPBDEs(不包括BDE-209)的含量分别为0.01- 53 ng/g dw,BDE-209的含量为0.74- 280 ng/g dw,平均值分别为4.4 ng/g dw,51 ng/g dw。在组成上,BDE-209占绝对优势,比低溴代BDEs高1-2个数量级,这是由于我国市场上十溴联苯醚是最主要的溴代阻燃剂。ΣPBDEs与亚洲一些地区含量相当,比北美和欧洲一些地区要低;BDE-209含量含量高出北美和欧洲一些地区,处于较高的水平。河流沉积物中BDE-47与-99,BDE-183与-153、-154具有很好的相关性,而且这几种单体质量分数相当,说明莱州湾区域存在五溴和八溴两种工业BDE阻燃剂来源。海洋沉积物中ΣPBDEs的含量为nd- 0.66 ng/g dw,平均值为0.32 ng/g dw,处于较低水平,BDE-209的含量为0.66- 12 ng/g dw,平均值为5.1 ng/g dw,与欧美一些地区相当,主要来自水体颗粒的输入。 本研究用电子捕获低分辨质谱(ECNI-LRMS)建立了沉积物中CPs的分析方法。该方法基于ECNI质谱对SCCP的响应与其氯含量在一定范围内呈线性关系的特性,建立SCCP的总响应因子与氯含量的工作曲线,从而建立定量方法。重点改进了传统方法中由于SCCP标准品和样品中氯含量不同所造成的响应因子的差别,不再要求标准品的含氯量与样品一致,从而提高了SCCP的分析效率与方法准确性。实验发现,当SCCP的实际氯含量在51%-63%之间时,二者线性关系良好(r2>0.96)。用不同氯含量的标准参考品测试,误差为8%-43%。仪器检测限和方法检测限分别为25-400 μg/L,20 ng/g。类似地,建立了中链氯化石蜡(MCCP)的分析方法,工作曲线的实际氯含量范围为44-57%,仪器检测限40-600 μg/L,方法检测限为6 ng/g。通过对比样品与标准品的峰形特征,严格控制保留时间来辨别SCCP与MCCP,实验证明由于二者叠加导致的误差:SCCP为8%,MCCP为14%,总体来说,用该方法得到的CPs数据是可靠的。本文所使用的净化方法能实现CPs与大部分有机氯化合物的分离。 用该方法对莱州湾的沉积物的CPs进行定量,除了两个河流样品MCCP的计算含氯量低于工作曲线以外,其他样品的SCCP和MCCP的计算氯含量都在工作曲线的范围之内。河流沉积物中SCCP和MCCP的含量分别为1-1200 ng/g dw,1-3300 ng/g dw,MCCP/SCCP均值为1.2;含量分布变化较大,一些河段受到工业排放的影响,CPs浓度高出均值1-2个数量级,MCCP/SCCP值也显著高出平均值。莱州湾区域大部分河流的CPs含量与欧洲、北美和日本一些地区相当,而一些受到点源污染的河段则处于较高的水平。河流中SCCP的质量分布在不同的站位不一样,在受到点源影响的样品中,C13的质量分数明显增大,占优势地位,可能是由MCCP携带的SCCP组分所致。MCCP的质量分布在河流和海洋中没有区别,都是C14占绝对优势。从氯取代的组分来讲,所有样品都是以6-8氯取代为主。海洋沉积物中SCCP和MCCP的含量分别为3-18 ng/g dw,1-13 ng/g dw, MCCP/SCCP均值为0.68,显著低于河流沉积物;SCCP的质量分布较为一致,都是以C10和C11为主。研究发现莱州湾区域SCCP与MCCP来源相似,但迁移规律有的不同。海洋环境中的MCCP可能主要来自水体颗粒的输入,而溶解态输入也是海洋环境中SCCP的重要来源。 对这三类污染物在莱州湾表层沉积物中的储量估算得到PCNs、ΣPBDEs、BDE-209、SCCP和MCCP在莱州湾表层0-10 cm沉积物中的储量分别为0.20t,0.25t,3.95t,6.52t,4.30t。拥有10%的渤海海域面积的莱州湾ΣPBDEs和BDE-209的储量分别占渤海海区总量的18-23%,18-32%,远远超过渤海的平均值。

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网络应用程序中为了保持程序的交互性,服务器端的控制程序如CGI(command gateway interface)程序需要在不同的脚本程序之问切换,这样不可避免的会造成控制信息的丢失.为了避免这些问题,介绍了将函数式程序设计语言的一些方法,如Continuation、CPS(eontinuationpassing style)等,并将它们应用到网络程序设计中,不仅简化了设计过程,也提高了程序的安全性,并可以在更一般的语言中实现.

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由于HTTP 天生的无状态性质,Web 程序设计中产生了这样一个问题:在两个连续的用户交互之间会遗忘状态信息。一个交互性的 Web 应用程序由一组脚本构成,每个交互都包含两个脚本,一个脚本向浏览器递交页面(然后结束),用户及时完成并提交表单,然后另一个(可能是不同的)脚本处理提交的表单。所以,应用程序逻辑分布在多个脚本之间。 由于浏览器还允许用户在交互中回溯,或者克隆一个正在处理中的交互过程,之后并行执行这两个交互过程,所以问题变得更加复杂。Web 开发框架(例如 Spring 和 Struts)允许处理多个交互,但是它们进一步提高了整体上已经很复杂的代码库的复杂性。 在本文中,我们将几种函数式方法应用到Web程序设计中,从而简化复杂 Web 应用程序的开发。我将从介绍 continuation 的应用开始,逐步引入CPS,Trampoline,Lambda Lifting等函数式方法,通过用Scheme语言编写的一个CGI实例详细展示函数式方法的效果,并进一步将这些方法在C语言中实现。

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Comb-like polymers (CPs) based on modified alternating methyl vinyl ether/maleic anhydride copolymer with oligo(oxyethylene) side chains of the type -O(CH2CH2O)(n)CH3 were synthesized and characterized, and complexed with lithium salts to form amorphous polymer electrolytes. Maximum conductivity close to 1.38 x 10(-4) S/cm was achieved at room temperature and at a [Li]/[EO] ratio (EO = ethylene oxide) of about 0.066. The temperature dependence of ionic conductivity suggested that the ion transport was controlled by segmental motion of the polymer, shown by linear curves obtained in Vogel-Tammann-Fulcher plots. The ionic conductivity maximum moved to a higher salt concentration as the temperature increased, indicating that a larger number of charge carriers can be transferred through polymer chains, of which free volume is increased at higher temperature. IR results indicated that the ester in CPs might decompose at 140 degrees C and reproduce the maleic anhydride ring.

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Seismic Numerical Modeling is one of bases of the Exploratory Seismology and Academic Seismology, also is a research field in great demand. Essence of seismic numerical modeling is to assume that structure and parameters of the underground media model are known, simulate the wave-field and calculate the numerical seismic record that should be observed. Seismic numerical modeling is not only a means to know the seismic wave-field in complex inhomogeneous media, but also a test to the application effect by all kinds of methods. There are many seismic numerical modeling methods, each method has its own merits and drawbacks. During the forward modeling, the computation precision and the efficiency are two pivotal questions to evaluate the validity and superiority of the method. The target of my dissertation is to find a new method to possibly improve the computation precision and efficiency, and apply the new forward method to modeling the wave-field in the complex inhomogeneous media. Convolutional Forsyte polynomial differentiator (CFPD) approach developed in this dissertation is robust and efficient, it shares some of the advantages of the high precision of generalized orthogonal polynomial and the high speed of the short operator finite-difference. By adjusting the operator length and optimizing the operator coefficient, the method can involve whole and local information of the wave-field. One of main tasks of the dissertation is to develop a creative, generalized and high precision method. The author introduce convolutional Forsyte polynomial differentiator to calculate the spatial derivative of seismic wave equation, and apply the time staggered grid finite-difference which can better meet the high precision of the convolutional differentiator to substitute the conventional finite-difference to calculate the time derivative of seismic wave equation, then creating a new forward method to modeling the wave-field in complex inhomogeneous media. Comparing with Fourier pseudo-spectral method, Chebyshev pseudo-spectral method, staggered- grid finite difference method and finite element method, convolutional Forsyte polynomial differentiator (CFPD) method has many advantages: 1. Comparing with Fourier pseudo-spectral method. Fourier pseudo-spectral method (FPS) is a local operator, its results have Gibbs effects when the media parameters change, then arose great errors. Therefore, Fourier pseudo-spectral method can not deal with special complex and random heterogeneous media. But convolutional Forsyte polynomial differentiator method can cover global and local information. So for complex inhomogeneous media, CFPD is more efficient. 2. Comparing with staggered-grid high-order finite-difference method, CFPD takes less dots than FD at single wave length, and the number does not increase with the widening of the studying area. 3. Comparing with Chebyshev pseudo-spectral method (CPS). The calculation region of Chebyshev pseudo-spectral method is fixed in , under the condition of unchangeable precision, the augmentation of calculation is unacceptable. Thus Chebyshev pseudo-spectral method is inapplicable to large area. CFPD method is more applicable to large area. 4. Comparing with finite element method (FE), CFPD can use lager grids. The other task of this dissertation is to study 2.5 dimension (2.5D) seismic wave-field. The author reviews the development and present situation of 2.5D problem, expatiates the essentiality of studying the 2.5D problem, apply CFPD method to simulate the seismic wave-field in 2.5D inhomogeneous media. The results indicate that 2.5D numerical modeling is efficient to simulate one of the sections of 3D media, 2.5D calculation is much less time-consuming than 3D calculation, and the wave dispersion of 2.5D modeling is obviously less than that of 3D modeling. Question on applying time staggered-grid convolutional differentiator based on CFPD to modeling 2.5D complex inhomogeneous media was not studied by any geophysicists before, it is a fire-new creation absolutely. The theory and practices prove that the new method can efficiently model the seismic wave-field in complex media. Proposing and developing this new method can provide more choices to study the seismic wave-field modeling, seismic wave migration, seismic inversion, and seismic wave imaging.

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The aim of the present study was to explore whether the CPS (Closure Positive Shift) which reflected prosodic processing will be elicited when listeners perceived different hierarchical prosodic boundaries in Chinese sentence and discourse (Quatrain). In addiction, the similarity and difference in amplitude, onset latency and scalp distribution between these CPS were investigated. The nature of the CPS and its relationship to acoustic parameters was also explored systematically. The main results and conclusions of the present study were: (1) Phonological phrase boundaries and intonational phrase boundaries in Chinese sentences both elicited the CPS; however, phonological word boundaries can't evoke it. The CPS induced by phonological phrase boundaries was earlier than the one related to intonational phrase boundaries in onset latency, and the amplitude was also somewhat lower. When the pauses in the vicinity of these two boundaries were removed, the onset latency difference disappeared while amplitude in the new conditions was also lower. This indicates that whenever listeners segment sentence into phrases, the CPS will be elicited. Besides, pause was not the decisive factor to elicit the CPS, but can modify its onset latency and amplitude effectively. (2) The different hierarchical prosodic boundaries in seven character quatrain including phonological phrase boundaries, intonational phrase boundaries and sentence pair boundaries elicited the CPS respectively. Furthermore, just like in the sentence level, onset latency of the CPS induced by the prosodic boundaries in the discourse was also influenced by the length of pause: the shorter the pause was, the earlier the onset latency. For the comparison between the CPS evoked by the same and different hierarchical prosodic boundaries, its amplitude was influenced by the extent to which prosodic representations were activated. Thus, the condition of the CPS elicitation was extended to the prosodic bounaries in discourse, and further indicated that it was influenced by acoustic parameters. (3) No matter what task the participants completed, just like word detection or rythem matching task, the CPS will be evoked. However, its amplitude was larger in the anterior region, when listeners completed the word detection task which needed more attention and higher load of working memory. The present result indicated that the elicitation of the CPS was not influenced by the task the participants completed, but different task influence its scalp distribution. (4) The final syllable of the sentence and quatrain can't elicit the CPS, but a P300-like positive component. Although the scalp distribution was similar to the CPS, it was much higher in amplitude. The present result suggested that only the prosodic boundaries reflecting not only the closure of the former prosodic unit but also integrating the later one will elicit the CPS.