Numerical Simulation of the Settling Flux of Biodeposition in a Bay with Cage Culture Through Similarity Theory and a Simplified Pollution Source

The settling flux of biodeposition affects the environmental quality of cage culture areas and determines their environmental carrying capacity.Simple and effective simulation of the settling flux of biodeposition is extremely important for determining the spatial distribution of biodeposition.Theoretically,biodeposition in cage culture areas without specific emission rules can be simplified as point source pollution.Fluent is a fluid simulation software that can simulate the dispersion of particulate matter simply and efficiently.Based on the simplification of pollution sources and bays,the settling flux of biodeposition can be easily and effectively simulated by Fluent fluid software.In the present work,the feasibility of this method was evaluated by simulation of the settling flux of biodeposition in Maniao Bay,Hainan Province,China,and 20 sampling sites were selected for determining the settling fluxes.At sampling sites P1,P2,P3,P4,P5,Z1,Z2,Z3,Z4,A1,A2,A3,A4,B1,B2,C1,C2,C3 and C4,the measured settling fluxes of biodeposition were 26.02,15.78,10.77,58.16,6.57,72.17,12.37,12.11,106.64,150.96,22.59,11.41,18.03,7.90,19.23,7.06,11.84,5.19 and 2.57 g d^(−1)m^(−2),respectively.The simulated settling fluxes of biodeposition at the corresponding sites were 16.03,23.98,8.87,46.90,4.52,104.77,16.03,8.35,180.83,213.06,39.10,17.47,20.98,9.78,23.25,7.84,15.90,6.06 and 1.65 g d^(−1)m^(−2),respectively.There was a positive correlation between the simulated settling fluxes and measured ones(R=0.94,P=2.22×10^(−9)<0.05),which implies that the spatial differentiation of biodeposition flux was well simulated.Moreover,the posterior difference ratio of the simulation was 0.38,and the small error probability was 0.94,which means that the simulated results reached an acceptable level from the perspective of relative error.Thus,if nonpoint source pollution is simplified to point source pollution and open waters are simplified based on similarity theory,the setting flux of biodeposition in the open waters can be simply and effectively simulated by the fluid simulation software Fluent.

Observational Evidence for the Monin-Obukhov Similarity under All Stability Conditions

Data collected in the surface layer in a northern suburban area of Nanjing from 15 November to 29 December 2007 were analyzed to examine the MoninObukhov similarity for describing the turbulent fluctu ations of 3D winds under all stability conditions and to obtain the turbulence characteristics under different weather conditions. The results show that the dimensionless standard deviations of turbulent velocity com ponents （σ u /u＊ , σ v /u＊ , σ w /u ＊ ） and dimensionless turbulent kinetic energy （TKE） can be well described by ＂1/3＂ power law relationships under stable, neutral, and unstable conditions, with σ u /u ＊ σ v /u ＊ σ w /u＊ . Land use and land cover changes mainly impact dimensionless standard deviations of horizontal component fluctuations, but they have very little on those of the vertical component. The dimensionless standard devi ations of wind components and dimensionless TKE are remarkably affected by different weather conditions; the deviations of horizontal wind component and dimensionless TKE present fog day clear sky overcast cloudy; the trend of the vertical wind component is the reverse. The surface drag coefficient at a Nan jing suburban measurement site during the observation period was obviously higher than at other reported plains and plateau areas, and was approximately one order larger in magnitude than the reported plains areas. Dimensionless standard deviation of temperature declined with increasing ｜z /L｜ with an approximate ＂1/3＂ slope in unstable stratification and ＂2/3＂ slope in stable stratification.

Load Reduction Test Method of Similarity Theory and BP Neural Networks of Large Cranes

Static load tests are an important means of supervising and detecting a crane＇s lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.

Similarity theory based method for MEMS dynamics analysis

A new method for MEMS dynamics analysis is presented,ased on the similarity theory. With this method, two systems' similarities can be captured in terms of physics quantities/governed-equations amongst different energy fields, and then the unknown dynamic characteristics of one of the systems can be analyzed according to the similar ones of the other system. The probability to establish a pair of similar systems among MEMS and other energy systems is also discussed based on the equivalent between mechanics and electrics, and then the feasibility of applying this method is proven by an example, in which the squeezed damping force in MEMS and the current of its equivalent circuit established by this method are compared.

The Application of Similarity Theory in Designing Large Deflection Buckling Spring-Piece

Large Deflection Buckling Spring-Piece (LDBSP) refers to the deformation of an end-fixed flat spring-piece under normal loadings. Plastic deformation usually appears in LDBSP.The static characteristic curve is very particular, because within its linear deflection region, the spring constant can be designed to be any value from minus to plus. With its obvious advantages of large liner deflection range, low spring constant, etc., the LDBSP has now been extensively applied to the exciting device, low-frequency shock absorbers and so on. The static characteristic curve of LDBSP belongs to the nonlinear problem of an arch with varying section. Therefore, it is difficult to obtain it theoretically. The formulae for designing LDBSP have not been set up yet. In this study,the authors apply similarity theory to analyze the liner deflection range A and the spring constant K, and derive the relationship of similarity criterion, finally obtain a set of formulae for designing LDBSP by model test and the least square method, which can be applied in engineering design.Through the research, it is proved that it is unnecessary to keep geometrical similarity of spring-piece shape. This fact extends the application scope of the formulae. The proposed formulae for designing LDBSP thereby can be applied for any dimensions within the range allowed.

A Closure for Isotropic Turbulence Based on Extended Scale Similarity Theory in Physical Space

The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou＇s quasi-normal closure method in spectral space, we propose an analytical closure model for isotropic turbulence based on the extended scale similarity theory of the velocity structure function in physical space. The assumptions and certain approximations are justified with direct numerical simulation. The asymptotic scaling properties are reproduced by this new closure method, in comparison to the classical Batchelor model.

Similarities and Differences of Chinese Translation Theories And Western Translation Theories

Translation theories are based on the different languages and cultures.The difference is not clearly defined,so there is a place of mutual integration that can be used interchangeably.Theyall regard author’s meaning and style as a core to translate a good product.Comparatively,Chinese theories focus on expressing the general meaning of the author,but Western theory emphasizes equivalence of details on translation and response of reader.In the translation practice,according to different theoretical texts and different stages of the translation process,the Chinese and Western translation theories are combined to apply them for making up for each other's deficiencies,which can help our translators to solve the problems in the process of translation improve the construction of Chinese theories.

Combination method of conflict evidences based on evidence similarity

Aiming at the problem that the traditional Dempster Shafer (D-S) evidence theory cannot deal with conflicted evidences effectively and correctly, this paper points out that the key issue of this problem is to measure the degree of conflict between evidences correctly after analyzing various improved methods. The existing evidence conflict measure methods are analyzed, and a new evidence conflict measure method called evidence similarity measure based on the Tanimoto measure is proposed, while a new evidence combination method is proposed on the basis of evidence similarity measure. Firstly, the conflict degrees between evidences are obtained through the evidence similarity measure. Then the evidence sources are modified based on the credibility of different evidences and the weights of conflicted parts of evidences on different focal elements are determined. Finally, the fusion result is obtained by this method. Numerical examples show that the proposed method can effectively fuse evidences when evidences are consistent or highly conflicted, and it has a fast convergence speed, a high degree of accuracy and good adaptability.

Complex neutrosophic generalised dice similarity measures and their application to decision making

Complex neutrosophic set(CNS)is a modified version of the complex fuzzy set,to cope with complicated and inconsistent information in the environment of fuzzy set theory.The CNS is characterised by three functions expressing the degree of complex-valued membership,complex-valued abstinence and degree of complex-valued non-membership.The aim of this manuscript is to initiate the novel dice similarity measures and generalised dice similarity using CNS.The special cases of the investigated measures are discussed with the help of some remarks.Moreover,some distance measures based on CNS are also proposed in this manuscript.Then,the authors applied the generalised dice similarity measures and weighted generalised dice similarity measures using CNS to the pattern recognition model to examine the reliability and superiority of the established approaches.The advantages and comparative analysis of the proposed measures with existing measures are also discussed in detail.At last,a numerical example is provided to illustrate the validity and applicability of the presented measures.

Design and Research of Similarity and its Serialization of the Flotation Machine's Key Structure

Aiming at the problems such as more repeatedly design and longer design cycle, in this paper, the similarity theory was introduced to the design process of the key structures of flotation machine. The impeller and U-shaped tank of flotation machine system were analyzed as similarity unit. Meanwhile, the level of similarity of the units and the similarity of the system were calculated. Based on the analysis of the impeller and the size of U-shaped tank, the similarity criteria were derived. The derived conclusions are： （1） The relationship between the diameter of the impeller and the volume of the tank was power function and calculated as the similarity criteria of the impeller; （2） The relationship between the ratio between the U-shaped tank＇s cross-sectional area and impeller＇s diameter and the volume of the tank was power function and calculated as the similarity criterions of the U-shaped tank. Using the similarity criterion combined with computer technology and database technology to realize part and system serialization design. The results show that the research can efficiency. avoid repeatedly design, shorten design cycle, and raise the design

Scale Effects and a Method for Similarity Evaluation in Micro Electrical Discharge Machining

Electrical discharge machining（EDM） is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of ＂scale effects＂ in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM.

Numerical verification of similar Cam-clay model based on generalized potential theory

From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential theory, has less assumptions,clearer mathematical basis, and better computational accuracy. Theoretically, it is more scientific than the traditional Cam-clay models. The particle flow code PFC3 D was used to make numerical tests to verify the rationality and practicality of the similar Cam-clay model. The verification process was as follows: 1) creating the soil sample for numerical test in PFC3 D, and then simulating the conventional triaxial compression test, isotropic compression test, and isotropic unloading test by PFC3D; 2)determining the parameters of the similar Cam-clay model from the results of above tests; 3) predicting the sample's behavior in triaxial tests under different stress paths by the similar Cam-clay model, and comparing the predicting results with predictions by the Cam-clay model and the modified Cam-clay model. The analysis results show that the similar Cam-clay model has relatively high prediction accuracy, as well as good practical value.

IMPROVEMENT TO THE EVAPORATION DUCT MODEL BY INTRODUCING NONLINEAR SIMILARITY FUNCTIONS IN STABLE CONDITIONS

Modified refractivity (M) profile is an important parameter to describe the atmospheric refraction environment,as well as a key factor in uniquely evaluating electromagnetic propagation effects.In order to improve the model-derived M profile in stable (especially very stable) conditions,three nonlinear similarity functions,namely BH91,CB05,SHEBA07,are introduced in this paper to improve the original Babin_V25 model,and the performances of these modified models are verified based on the hydrometeorological observations from tower platforms,which are finally compared with the original Babin_V25 model and Local_HYQ92 model.Results show that introducing nonlinear similarity functions can significantly improve the model-derived M profile;especially,the newly developed SHEBA07 functions manage to reduce the predicted root mean square (rms) differences of M and M slope (for both 0-5m and 5-40m) by 64.5%,16.6%,and 60.4%,respectively in stable conditions.Unfortunately,this improved method reacts little on the evaporation duct height;in contrast,Local_HYQ92 model is capable of reducing the predicted rms differences of M,M slope (for both 0-5m and 5-40m),and evaporation duct height by 76.7%,40.2%,83.7%,and 58.0% respectively.Finally,a new recommendation is made to apply Local_HYQ92 and Babin_SHEBA07 in very stable conditions considering that M slope is more important than evaporation duct height and absolute M value in uniquely determining electromagnetic propagation effects.

Hans A.Panofsky’s Integral Similarity Function—At Fifty

Fifty years ago, Hans A. Panofsky published a paper entitled Determination of stress from wind and temperature measurements. In his famous paper, he presented a new profile function for the mean horizontal wind speed under the condition of diabatic stratification that includes his integral similarity function. With his integral similarity function, he opened the door for Monin-Obukhov scaling in a wide range of micrometeorological and microclimatological applications. In a historic survey ranging from the sixties of the past century down to the present days, we present integral similarity functions for momentum, sensible heat, and water vapor for both unstable and stable stratification, where on the one hand free convection condition and on the other hand strongly stable stratification are addressed.

A label noise filtering and label missing supplement framework based on game theory

Labeled data is widely used in various classification tasks.However,there is a huge challenge that labels are often added artificially.Wrong labels added by malicious users will affect the training effect of the model.The unreliability of labeled data has hindered the research.In order to solve the above problems,we propose a framework of Label Noise Filtering and Missing Label Supplement(LNFS).And we take location labels in Location-Based Social Networks(LBSN)as an example to implement our framework.For the problem of label noise filtering,we first use FastText to transform the restaurant's labels into vectors,and then based on the assumption that the label most similar to all other labels in the location is most representative.We use cosine similarity to judge and select the most representative label.For the problem of label missing,we use simple common word similarity to judge the similarity of users'comments,and then use the label of the similar restaurant to supplement the missing labels.To optimize the performance of the model,we introduce game theory into our model to simulate the game between the malicious users and the model to improve the reliability of the model.Finally,a case study is given to illustrate the effectiveness and reliability of LNFS.

基于虚拟仿真平台的线上线下混合式教学研究

伴随着大数据时代的来临,高等教育模式正面临着重大改革。为提高相似理论与相似方法课程的教学效果与质量,该文构建基于虚拟仿真平台的线上线下混合式教学模式,从课前学习、课上教学、课堂讨论和课后辅导等方面对混合式教学进行综合的论述,通过教学反思,对教学模式提出相应建议与心得,以期更好地提高学生学习的效率,为混合式教育模式的改革分享经验。

螺杆挤出机相似放大理论的研究进展

总结了近些年来国内外提出的螺杆挤出机相似放大准则,并对比分析了常用的放大系数和适用范围,同时,介绍了相似放大理论在螺杆挤出机中的优化挤出机的结构参数、工艺条件的实际应用,最后指出了螺杆挤出机相似放大理论进一步探索和优化,为螺杆挤出机行业的可持续发展提供更加有效的理论支持。

综采工作面垮落带注浆充填开采覆岩采动裂隙定量表征试验研究

为定量表征冒落区注浆充填对覆岩采动损伤程度的影响,以任家庄煤矿110903工作面为研究背景,开展垮落法开采和垮落带充填法开采物理相似模拟实验,运用分形理论研究两者覆岩裂隙演化特征,并对其覆岩运移规律进行对比分析。研究结果表明,垮落法开采后采动裂隙分形维数变化规律为迅速上升-缓慢下降-缓慢上升-急剧上升,注浆充填开采后变化规律呈迅速上升-迅速下降-缓慢下降-缓慢上升;将采动裂隙发育网络划分为离层裂隙区、离层压实区、垮落裂隙区、竖向破断裂隙区四个区域,对比垮落法开采和垮落带充填法开采,充填后采场覆岩裂隙不发育,离层压实区范围较小,发育高度仅为21.96 m;注浆充填开采后各关键层下沉量显著减小,关键层2最大下沉量出现在顶板初次破断处,垮落法开采后关键层2最大下沉量出现在采空区中部。垮落带注浆充填开采能有效改善覆岩裂隙损伤、控制覆岩裂隙发育、减缓覆岩下沉,该成果可以为任家庄煤矿充填开采控制地表沉降提供一定的理论依据。

隧道突涌水灾害缩尺物理模型试验研究综述

随着我国经济的快速发展,隧道工程建设越来越多地面临着大埋深、高地应力、高地温、高渗透压力等复杂地质环境,运用物理模型试验开展复杂环境下隧道突涌水灾变机理与安全防控研究已成为岩石力学的热点问题。结合近年来国内外针对隧道突涌水灾变缩尺物理模型试验开展的研究工作,重点对该类物理模型的流固耦合相似理论、相似材料研制、渗透压加载方法等内容进行了系统梳理,并对下一步的可能发展方向进行展望。参考部分文献和突水典型案例后,总结了流固耦合相似准则和高地应力下的相似准则、相似材料选用方案及材料配比、试验中的水压加载方案,认为未来关注的重点包括考虑温度场的物理模型试验相似准则的研究和涌水涌泥与突水突泥间渐变过程的研究2个方面。

地下洞室变形破坏物理模拟的力学相似畸变映射原理与实例分析

相似物理模拟是研究地下工程变形破坏问题的重要手段,然而经典相似理论关于相似模型与工程原型之间的几何相似比和材料力学参数相似比的相互约束,导致室内物理相似模型尺寸和材料力学参数一直面临难以完全满足相似准则的困局,从而产生力学畸变和模拟试验结果解译困难。为此,提出了地下洞室变形破坏物理模拟的力学相似畸变映射处理方法,引进畸变系数和映射系数,通过耦合解析法或数值法来映射畸变效应,实现地下洞室物理模拟结果对原型力学行为的定量解译;以圆形隧洞为工程原型,采用水泥基3D打印隧洞物理模型进行相似物理超载试验,基于提出的耦合力学相似畸变法与解析法对物理模拟结果进行了定量分析和对比验证;以某水电站地下洞室群为研究原型,通过砂岩3D打印洞室群物理模型的超载试验获得洞室破坏的变形值,采用耦合力学相似畸变法与数值方法对物理模拟结果进行定量分析。实例分析结果表明,在物理相似模拟中几何相似比和力学相似比不满足经典相似准则条件下,该方法可实现圆形隧洞或复杂洞室群原型的相似物理模拟结果的定量映射分析,对非恒定相似比的地下洞室物理模拟畸变分析具有普适性。