高地下水位、多变化土质取土时路基施工的质量控制

针对路基施工取土时处于高地下水位、土层为多变化土质的情况,就如何保证施工质量,采用混合取土、满足路基的压实度提出了相应的措施.

基于多变化转矩的汽车电动助力转向电机电流跟踪控制

针对汽车电动助力转向(EPS)系统电机实时操控的问题,提出将自适应滑模控制算法应用于汽车EPS系统中,通过设计PID控制器、滑模控制器及自适应滑模控制器来分析验证自适应滑模控制器的优势,最后通过建立汽车转向系统数学模型,并在多变化转矩条件下进行仿真验证。仿真结果表明,PID控制器控制的实际电流与目标电流误差较大,且在不同变化的转矩下,电流跟踪性能较差;滑模控制器控制的实际电流跟随性能较好,但抖振较大;自适应滑模控制器不仅可以提高实际电流与目标电流的吻合度,还可以削弱滑模控制抖振,使汽车在不同方向盘转矩和车速下的电机电流跟踪能力得到改善。

游戏化、组合化、多变化——小学体育课准备活动有效性研究

一节好的体育课,关键要有一个良好的导入方式,准备活动虽然不是每堂课的主要部分,但却是上好体育课的前提和保证,直接影响课堂的质量和效果。正确地认识准备活动的作用,有效地选择准备活动的内容与组织形式,合理地处理好准备活动的时间、负荷以及与基本部分教学内容之间的联系,是体育教师都应重视的问题。

无线传感器网络在休眠-唤醒机制下的目标同步

依据无线传感器网络(WSNs)的串音与碰撞退避机制(CCAM),提出了基于最大度节点(MDN)与其所有的邻居节点保持相同休眠-唤醒机制的通讯方式(SSAM).在SSAR的通讯方式下,文中给出了相应的控制律.在该控制律下,得到了在多变化时滞和噪声环境中基于马尔可夫切换的系统.P-阶矩指数稳定性理论表明,所得的系统与目标函数保持同步。

“历史与未来共生”的杰作

本文对奈良会议厅一等奖方案在其总平面构思、建筑形态、空间布局、设计特征作了简略而透彻的剖析来阐明方案的作者如何处心积虑地为创造一个以“历史与未来共生”为主题的建筑的设计匠心。本文对方案的结构体系及太阳能系统也作了简单的介绍。

让学生也“动”起来

从问卷调查结果可看出，学生渴望轻松、好玩地去学习，渴望能跳出那种传统、沉闷的课堂教学，他们很想在安静的课堂上“动”起来．而不再是一种受约束的、被动的、灌输式的学习．在此提出：在教学过程中，需要老师“动”——适当的引导．更需要让学生“动”起来——主动地参与，积极地探究．勤于去“动”!

Dynamic of forest landscape in Heilongjiang Province for one century

With the help of GIS tool of ARC/INFO, ARCVIEW and FRAGSTATS, the map of forest resource distribution of Heilongjiang Province was analyzed in 1896, 1949 and 1981. Using total area, mean patch size, patch density, coefficient of patch size variation, mean patch fractal dimension and mean shape index, we studied the change of forest landscape pattern and the change of each patch types in this region. As a result, the total area of forest landscape and mean patch size decreased sharply, the quantity and density of patches increased, the juxtaposition of patches weakened, the shape of patch tended to become regular, and the border of patch simplified. All these showed that the forest landscape of this area tended to fragment gradually, and the fragment of Korean pine forest is the severest. The diversity of whole forest landscape and the evenness of landscape types distribution reduced gradually. Human impact, instead of climate change and forest community succession, is the most important reason for such dramatic changes.

Study on the Biological Diversity of Nematode-trapping Fungi in Erhai Lake

[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classification and identification methods were used to isolate,purify and identify.[Result]3 genera and 22 species of nematode-trapping fungi were isolated.Arthrobotrys oligospora,A.musiformis and Dactylella leptospora were the dominant species,and their detection rates were 28.05%,16.04% and 8.92% respectively.By analyzing the diversity of nematode-trapping fungi in four seasons,it was found that the biological diversity was richer in summer,spring and autumn,and the diversity indexes were 2.59,2.47 and 2.34 respectively.The diversity index in winter was 1.48 and was lower.Species forming the adhesive nets were predominant;positive rate was 41.00%.[Conclusion]The rich nematode-trapping fungi resource existed in Erhai Lake,and its biological diversity had the seasonal variation characteristic.The nematode-trapping fungi which formed the viscous net were the dominant species in Erhai Lake.

初中英语新教材备课应注意的几个问题

在钻研大纲的基础上通读教材,可以增强对教材的理解。只有对教材有较深刻的理解,才能驾驭教材。要理解教材,不能只读一课书或一个单元,必须通读全册教材,有条件时应通读全套教材。

浅谈小学数学教与学

数学源于生活,寓于生活,用于生活。在小学数学教学中,如果能够根据小学生的认知特点,将数学知识与学生的生活实际紧密结合,那么,在他们的眼里,数学将是一门看得见、摸得着、用得上的学科,不再是枯燥乏味的数字游戏。从学生已有的生活经验出发,让学生亲身经历将实际问题抽象成数学模型进行解释与应用的过程。”这就要求在小学数学教学中实施生活化教学。

浅谈小学数学教与学

数学源于生活，寓于生活，用于生活。在小学数学教学中，如果能够根据小学生的认知特点，将数学知识与学生的生活实际紧密结合，那么，在他们的眼里，数学将是一门看得见、摸得着、用得上的学科，不再是枯燥乏味的数字游戏。从学生已有的生活经验出发，让学生亲身经历将实际问题抽象成数学模型进行解释与应用的过程。”这就要求在小学数学教学中实施生活化教学。

Optimization Design of Active Structure of Strained MQW DFB Lasers

The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxation oscillation frequency of over 30GHz MQW DFB laser is presented.

Content Variation of Active Components in Mulberry Fruit During Ripening Process

Ten mulberry species were taken as materials to detect contents of DNJ,polysaccharide and flavonoid.The results indicated that the three active components differed significantly upon species.Hongguo 2 and Shushen 1,which are of high contents of active components,were selected as materials to measure contents change of active components in fresh fruits during ripening process after full-bloom stage.The research suggested that DNJ mass fractions of Hongguo 2 and Shushen 1 on the 3rd d in full-bloom stage were 0.074 1% and 0.072 5%;DNJ declined gradually with growth of the fruit and DNJ contents in the two cultivars decreased by 49.80% and 58.90% on the 31st d in full-bloom stage,compared with the 3rd d.As mulberry grew,polysaccharide contents in Hongguo 2 and Shushen 1 were increasing and achieved peaks on the 27th d in full-bloom stage at 9.570% and 10.276%,respectively.For total flavonoids,the contents in Hongguo 2 and Shushen 1 were both of two peaks on 11th d and 27th d.The mass fractions were 0.313%,0.444%,and 0.264%,0.326%,accordingly.In addition,DNJ contents in ripe seeds of Hongguo 2 and Shushen 1 were significantly higher than those in fruit,but total flavonoid contents were lower.Polysaccharide was not detected.It can be concluded that mulberry fruits growing for 27 d can be either as excellent food or for medicine.

A new optimization algorithm based on chaos

In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones.

Multiobjective optimization and multivariable control of the beer fermentation process with the use of evolutionary algorithms

This paper describes empirical research on the model, optimization and supervisory control of beer fermentation.Conditions in the laboratory were made as similar as possible to brewery industry conditions. Since mathematical models that consider realistic industrial conditions were not available, a new mathematical model design involving industrial conditions was first developed. Batch fermentations are multiobjective dynamic processes that must be guided along optimal paths to obtain good results.The paper describes a direct way to apply a Pareto set approach with multiobjective evolutionary algorithms (MOEAs).Successful finding of optimal ways to drive these processes were reported.Once obtained, the mathematical fermentation model was used to optimize the fermentation process by using an intelligent control based on certain rules.

Community Structure and Seasonal Variation of Soil Arthropods in the Forest-Steppe Ecotone of the Mountainous Region in Northern Hebei,China

Soil fauna have been receiving more and more attention because they play an important role in nutrient cycling.However,there is a lack of information on soil arthropods in the forest-steppe ecotone in the mountainous region of northern Hebei,which makes it difficult to meet the need of protecting biodiversity in this area.Soil arthropod communities were investigated in the forest-steppe ecotone in northern Hebei province to provide basic information on changes in mountain soil fertility,which could promote the development of soil arthropod communities in mountain ecotones.From the preliminary identification,a total of 7994 individual soil arthropods were collected,which belonged to 25 groups,6 classes and 24 orders.Acarina,Hymenoptera and Collembola were the dominant groups in the ecotone.The number of Acarina was higher than Collembola,and this phenomenon was obviously different from other areas in the same climate zone.The increased abundance of rare groups in the Forest zone with the richer vegetation,higher arthropod abundance and more substantial litter depth,could be interpreted as a reaction to the suitable soil environment and food supply.And these rare groups were sensitive to environmental changes,which could be regarded as biotic indicators for evaluating soil quality.The analysis of community diversity showed that the abundance index (d),the Shannon-Wiener index (H'),the evenness index (J) and the density-group index (DG) were significantly higher in the forest zone,lower in the forest-steppe zone,and lowest in the meadow-steppe zone.Seasonal variations in community composition correlated with changes in average air temperature and precipitation in this ecotone.Groups and individuals of soil arthropod communities in the three zones were present in greater numbers in the middle of the rainy season than in the early or late periods of the rainy season as a whole.At the same time,seasonal changes in soil arthropod communities from different plots were also influenced by habitat condition.

Advantages of the latest Los Alamos Sea-Ice Model(CICE):evaluation of the simulated spatiotemporal variation of Arctic sea ice

The Los Alamos Sea-Ice Model(CICE)is one of the most popular sea-ice models.All versions of it have been the main sea-ice module coupled to climate system models.Therefore,evaluating their simulation capability is an important step in developing climate system models.Compared with observations and previous versions(CICE4.0 and CICE5.0),the advantages of CICE6.0(the latest version)are analyzed in this paper.It is found that CICE6.0 has the minimum interannual errors,and the seasonal cycle it simulates is the most consistent with observations.CICE4.0 overestimates winter sea-ice and underestimates summer sea-ice severely.Meanwhile,the errors of CICE5.0 in winter are larger than for the other versions.The main attention is paid to the perennial ice and the seasonal ice.The spatial distribution of root-mean-square errors indicates that the simulated errors are distributed in the Atlantic sector and the outer Arctic.Both CICE4.0 and CICE5.0 underestimate the concentration of the perennial ice and overestimate that of the seasonal ice in these areas.Meanwhile,CICE6.0 solves this problem commendably.Moreover,the decadal trends it simulates are comparatively the best,especially in the central Arctic sea.The other versions underestimate the decadal trend of the perennial ice and overestimate that of the seasonal ice.In addition,an index used to objectively describe the difference in the spatial distribution between the simulation and observation shows that CICE6.0 produces the best simulated spatial distribution.

Investigation of Dynamic Multivariate Chemical Process Monitoring

Chemical process variables are always driven by random noise and disturbances. The closed-loop con-trol yields process measurements that are auto and cross correlated. The influence of auto and cross correlations on statistical process control (SPC) is investigated in detail by Monte Carlo experiments. It is revealed that in the sense of average performance, the false alarms rates (FAR) of principal component analysis (PCA), dynamic PCA are not affected by the time-series structures of process variables. Nevertheless, non-independent identical distribution will cause the actual FAR to deviate from its theoretic value apparently and result in unexpected consecutive false alarms for normal operating process. Dynamic PCA and ARMA-PCA are demonstrated to be inefficient to remove the influences of auto and cross correlations. Subspace identification-based PCA (SI-PCA) is proposed to improve the monitoring of dynamic processes. Through state space modeling, SI-PCA can remove the auto and cross corre-lations efficiently and avoid consecutive false alarms. Synthetic Monte Carlo experiments and the application in Tennessee Eastman challenge process illustrate the advantages of the proposed approach.

Existence of multi-bump solutions for coupled Schr dinger systems

The Schrodinger equation -△u＋λ2u=｜u｜2q-2u has a unique positive radial solution Uλ, which decays exponentially at infinity. Hence it is reasonable that the Schrolinger system -△u1＋u1=｜u1｜2q-1u1-εb（x）｜u2｜1｜u1｜q-1u1,-△u2＋u2=｜u2｜2q-2u2-εb（x）｜u1｜1｜u2｜q-1u2 has multiple-bump solutions which behave like Uλ in the neighborhood of some points. For u=（u1,u2）∈H1（R3）×H1（R3）, a nonlinear functional Iε（u）=I1（u1）＋I2（u2）-ε/q∫R3b（x）｜u1｜q｜u2｜qdx,is defined,where I1（u1）=1/2｜｜u1｜｜2-1/2q∫R3｜u1｜2qdx and I2（u2）=1/2｜｜u2｜｜2ω-1/2q∫R3｜u2｜2qdx. It is proved that the solutions of the system are the critical points of I,. Let Z be the smooth solution manifold of the unperturbed problem and TzZ is the tangent space. The critical point of I is rewritten as the form of z ＋ w, where w ∈ （TzZ）⊥. Using some properties of Iε, it is proved that there exists a critical point of I, close to the form which is a multi-bump solution.

Spatio-seasonal patterns of fish diversity,Haizhou Bay,China

Spatial-seasonal patterns in fish diversity in Haizhou Bay were studied based on stratified random surveys conducted in 2011.Principal component analysis was conducted to distinguish different diversity components,and the relationships among 11 diversity indices were explored.Generalized additive models were constructed to examine the environmental effects on diversity indices.Eleven diversity indices were grouped into four components:(1) species numbers and richness,(2) heterogeneous indices,(3) evenness,and(4) taxonomic relatedness.The results show that diversity indices among different components are complementary.Spatial patterns show that fish diversity was higher in coastal areas,which was affected by complex bottom topography and spatial variations of water mass and currents.Seasonal trends could be best explained by the seasonal migration of dominant fish species.Fish diversity generally declined with increasing depth except for taxonomic distinctness,which increased with latitude.In addition,bottom temperature had a significant effect on diversity index of richness.These results indicate that substrate complexity and environmental gradients had important influences on fish diversity patterns,and these factors should be considered in fishery resource management and conservation.Furthermore,diversity in two functional groups(demersal/pelagic fishes) was influenced by different environmental factors.Therefore,the distribution of individual species or new indicators in diversity should be applied to examine spatio-seasonal variations in fish diversity.