环境监测领域固相微萃取技术运用分析

文章结合固相微萃取技术的基本原理,对环境监测的区域当中固相微萃取的技术应用开展了分析,简单的讲述一下固相微萃取技术对环境监测的实践,总结出环境监测在工作中的污染物萃取与检测实验的方法。能够为了后续的环保工作可以获得准确的环境监测数据,还可以进一步优化环境的容物与挥发性的有机物萃取和检测的方案。

小学英语教学中自然拼读法和音标教学的分阶段运用

改革开放以来，我国教育部门对于英语教学的重视程度与日俱增，发展到现在我国英语教学已经到了全国范围内普及的程度，但是现如今我国英语教学中仍然存在着一些问题。本文通过对自然拼读法的概念、应用理念、优势以及音标教学的概念、优势进行了分析和探讨，总结归纳出了小学英语中自然拼读法和音标教学分阶段运用策略，以供相关专业人员参考或采纳。

对分课堂在音乐论文写作课程中的运用研究

针对当前论文写作课堂存在的主要问题,将"对分课堂"教学改革新模式引入到该课程的教学中去,增强了学生课后学习的自主性及课堂学习的积极性与参与度。这种新的教学模式本课程的教学改革提供了新的思路,值得更多教师在不同的课型上进一步探索。

小学英语教学中自然拼读法和音标教学的分阶段运用研究

新课程背景下,自然拼读法和音标教学的分阶段运用,应该引起小学英语教师的高度重视。具体实践中,需要激发学生浓厚的 学习兴趣,让他们养成积极思考、主动参与、小组探究的好习惯;需要鼓励学生自觉投入课堂活动,拼读学习、认识音标,从而更好的提 升认知水平;还应创设情境,提高教学质量,满足不同层次学生的学习需求,这样一来,小学英语教学工作也就有了高效推进的有力支持。 本文对此做了简要论述。

浅谈自然拼读法与音标教学在小学英语教学中的运用

不同的英语教学法在小学英语教学中发挥着不同的作用。音标教学法可以帮助学生准确认读英语单词,把握单词的轻重音,提高学生认读单词的准确率,是一种传统的英语语音教学方法;自然拼读法注重的是字母音和形之间的关系,见其形而知其音,听其音而知其形,是一种从国外引进的英语语音教学法。两种语音教学法各有各的优势,应在小学英语语音教学中根据学生的英语水平灵活运用,以便更加有效地提高小学生记忆单词的能力,进而提高小学生的英语学习水平。

Fruit Photosynthesis and Assimilate Translocation and Partitioning: Their Characteristics and Role in Sugar Accumulation in Developing Citrus unshiu Fruit

Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.

城市绿地系统景观资源整合研究——以扬州市城市绿地系统规划为例

借鉴风景资源评价体系和城市景观评价体系,坚持定性分析与定量评价相结合,以凸显城市差异性,强化系统整体性、可操作性等原则,以构建结构清晰、层次分明、凸显城市特色的城市绿地系统为目的,将城市绿地系统特色景观资源整合归纳为3个步骤,即整理与分类、分析评价、分层次运用;并运用提出的理论方法,对《扬州市城市绿地系统规划(2004—2020)》中的绿地景观风貌规划提出了优化建议。

基于泥沙冲淤数值模拟的水库调度方案研究

以东台子水库为研究对象,基于一维不饱和全沙数值模型,研究蓄洪运用方案、蓄洪排沙运行方案、分阶段蓄洪运用方案、蓄清排浑运用方案等四种水库调度方式下的泥沙淤积情况,力图在兴利防洪的基础上尽量利用弃水排沙,保持有效库容。对不同运行年限的淤积量、水库库容变化和排沙比等要素的模拟研究表明,分阶段蓄洪运用或蓄清排浑运用方案更有利于保持有效库容,对延长水库使用寿命具有一定作用,是较优的水库排沙优化调度方案。

自然拼读法与音标教学在小学英语教学中的分阶段运用

在小学英语的教学过程中,使用不同的教学方法,会产生不同的效果。在带领学生学习英语单词的过程中,适当的加入音标教学法能让学生对单词的轻音和重音更好的把握,能够将学生的认知单词准确率有效提高,这就是传统的英语语音教学方法。现在还有一种新的教学方法,对字母的发音和形状之间的关系更为重视,需要对其形状进行声音的关联,对其声音进行形状的联系,这种教学方法称为自然拼读法。在实际的教学过程中,这两种教学方法都有自己的优势,具体使用的时候应该以不同年龄的学生英语水平为参考标准进行具体的应用,这样能将小学生对单词的记忆能力进行更好的提高,从而提升小学生的英语水平。

Nonlinear Random Motion Analysis of Coupled Heave-Pitch Motions of a Spar Platform Considering lst-Order and 2nd-Order Wave Loads

In this study, the coupled heave-pitch motion equations of a spar platform were established by considering lst-order and 2nd-order random wave loads and the effects of time-varying displacement volume and transient wave elevation. We generated random wave loads based on frequency-domain wave load transfer functions and the Joint North Sea Wave Project （JONSWAP） wave spectrum, designed program codes to solve the motion equations, and then simulated the coupled heave-pitch motion responses of the platform in the time domain. We then calculated and compared the motion responses in different sea conditions and separately investigated the effects of 2nd-order random wave loads and transient wave elevation. The results show that the coupled heave-pitch motion responses of the platform are primarily dominated by wave height and the characteristic wave period, the latter of which has a greater impact. 2nd-order mean wave loads mainly affect the average heave value. The platform＇s pitch increases after the 2nd-order low frequency wave loads are taken into account. The platform＇s heave is underestimated if the transient wave elevation term in the motion equations is neglected.

Numerical Simulation of the Spreading Dynamic Responses of the Multibody System with a Floating Base

To simulate the dynamic responses of the multibody system with a floating base when the upper parts spread with a certain sequence and relative speed, the homogeneous matrix method is employed to model and simulate a four-body system with a floating base and the motions are analyzed when the upper parts are spread sequentially or synchronously. The rolling, swaying and heaving temporal variations are obtained when the multibody system is under the conditions of the static water along with the wave loads and the mean wind loads or the single pulse wind loads, respectively. The moment variations of each joint under the single pulse wind load are also gained. The numerical results showed that the swaying of the floating base is almost not influenced by the spreading time or form when the upper parts spread sequentially or synchronously, while the rolling and the heaving mainly depend on the spreading time and forms. The swaying and heaving motions are influenced significantly by the mean wind loads. The single pulse wind load also has influences on the dynamic responses. The torque of joint 3 and joint 4 in the single pulse wind environment may be twice that in the windless environment when the system spreads with 60 s duration.

A gait planning method applied to hexapod biomimetic robot locomotion

In order to fulfill the goal of autonomous walking on rough terrain,a distributed gait planningmethod applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait co-ordination mechanism of stick insect.The mathematical relation of walking velocity and gait pattern wasdepicted,a set of local rules operating between adjacent legs were put forward,and a distributed networkof local rules for gait control was constructed.With the interaction of adjacent legs,adaptive adjustmentof phase sequence fluctuation of walking legs resulting from change of terrain conditions or variety of walk-ing speed was implemented to generate statically stable gait.In the simulation experiments,adaptive ad-justment of inter-leg phase sequence and smooth transition of velocity and gait pattern were realized,andstatic stableness was ensured simultaneously,which provided the hexapod robot with the capability ofwalking on rough terrain stably and expeditiously.

Thermal Transport in One-Dimensional FPU-FK Lattices

Thermal transport in the FPU model with Kutta algorithm. The heat flux, local temperature profile, that temperature gradient scales behave as N-1 linearly. FK on-site potential is studied by using fourth-order Runge- and heat conductivity axe simulated and analyzed. It is found The divergence of heat conductivity ~ with system size N is in term of κ ∝ N^α with α = 0.44. It is shown that thermal transport is mainly dependent on the FPU nonlinear and the FK interactions.

Effects of a flexible net barrier on the dynamic behaviours and interception of debris flows in mountainous areas

Flexible net barriers are a new type of effective mitigation measure against debris flows in valleys and can affect the kinematic energy and mass of debris flows. Here, ten flume tests were performed to study the dynamic behaviours of debris flows with differences in volumes, concentrations(solid volume fraction), and travel distances after interception by a uniform flexible net barrier. A high-speed camera was used to monitor the whole test process, and their dynamic behaviours were recorded. A preliminary computational framework on energy conversion is proposed according to the deposition mechanisms and outflow of debris flow under the effects of the flexible net barrier. The experimental results show that the dynamic interaction process between a debris flow and the flexible net barrier can be divided into two stages:(a) the two-phase impact of the leading edge of the debris flow with the net and(b) collision and friction between the body of the debris flow and intercepted debris material. The approach velocity of a debris flow decreases sharply(a maximum of 63%) after the interception by the net barrier, and the mass ratio of the debris material being intercepted and the kinetic energy ratio of the debris material being absorbed by the net barrier are close due to the limited interception efficiency of the flexible net barrier, which is believed to be related to the flexibility. The energy ratio of outflow is relative small despite the large permeability of the flexible net barrier.

Thermodynamic Analysis of Alternative Marine Fuels for Marine Gas Turbine Power Plants

The marine shipping industry faces challenges to reduce engine exhaust emissions and greenhouse gases （GHGs） from ships, and in particular, carbon dioxide. International regulatory bodies such as the International Maritime Organization and National Environmental Agencies of many countries have issued rules and regulations to drastically reduce GHG and emissions emanating from marine sources. This study investigates the possibility of using natural gas and hydrogen as alternative fuels to diesel oil for marine gas turbines and uses a mathematical model to assess the effect of these alternative fuels on gas turbine thermodynamic performance. Results show that since natural gas is categorized as a hydrocarbon fuel, the thermodynamic performance of the gas turbine cycle using natural gas was close to that of the diesel case. However, the gas turbine thermal efficiency was found to be slightly lower for natural gas and hydrogen fuels compared to diesel fuel.

Kinematic Analysis of Persian Joint Using 3D Rotation Matrix

This paper has been done on study kinematic problem of Persian joint in a general way. In this study, instead of using simulation analysis method as in the previous researches, the 3D rotation matrix method is applied to present the relationship of angular velocities of input shaft and output shaft. The result shows that when the angle between intersecting shafts changes from 0 to 135°, the angular velocity is maintained constant. This new result completely matches with analysis from kinematic simulation of this mechanism. The obtained result is an important base to solve dynamic problem in order to develop the applicability of this joint in reality.

Research on Regional Industrial Solid Waste Comprehensive Utilization Ability Influencing Factors based on Panel Data

On the basis of panel data from 29 provinces and cities throughout the country in 2006-2010, a research is made on factors influencing regional industrial solid waste comprehensive utilization ability through a regression analysis method. Research result shows that a positive influence will generate on the comprehensive utilization ability of the industrial solid waste by three factors： regional industrial soldi waste treatment earning level, regional industrial soldi waste treatment investment level and regional industrial pollution treatment subsidy strength. And this thesis will propose suggestions from improving earning ability, enhartcing treatment investment and increasing government subsidy depending on result of empirical analysis.

An Overview of Social Analysis from Mobile Telephone Calls of Different Operators

We construct a call network digraph G with attribution using mobile phone call records within 21 days collected by three operators and analyze the social call behavior features through analyzing the degree distribution of nodes of the network digraph under the help of Graphx based on the Spark Platform.We get the following social conclusions from the communication relationship between phone users:on average,users make about5~7 mobile telephone calls and connect about2~3 persons one day;on weekends,people make less calls but spend longer time on each call,revealing that working calls account for a large part of calls on weekdays;among these telephone calls on weekdays,most are less than one minute,and on average,mobile users that call more people also tend to be called by more individuals.

Iranian English Foreign Language Learners＇ Learning Style Sensory Preferences and Their Speaking Strategy Use Across Proficiency

This study investigates the relationship between Iranian EFL （English as a Foreign Language） learners＇ sensory preferences： Visual, Audial, and Haptic （VAH） and the learners＇ speaking strategy use across proficiency. To this end 146 Iranian EFL learners studying English at different levels of language proficiency, participated in this study. O＇Brien＇s （1990） learning channel preference checklist was given to students to determine their sensory preferences In addition, a Speaking Strategy questionnaire （an adaptation of strategy inventory for language learning （SILL）, focusing on strategies used at the time of Speaking） was also given to the students in another session. The data were analyzed using multivariate ANOVA （MANOVA） in order to probe the relationship between Iranian EFL Learners＇ Learning Style Sensory Preferences and their speaking strategy use across proficiency. Based on the results, it can be claimed that there was a weak to moderate interaction between the proficiency levels and preference of speaking strategies on the learning styles of the Iranian EFL learners.