尺规分角法

引入角的比例来研究分角问题,从理论上有机地系统地推导出分比例角的两条公理、一般的与特殊的分比例角的定比点轨迹及其互为逆否的命题关系的比例角定理。从而用尺规作图不但正确地解决了三等分任意角,还正确地解决了n等分任意角问题,且作法统一、精确而实用。

基于第三分角投影法的美国包装机械图样表达研究

随着中美间包装机械技术交流和贸易的日益增长,掌握基于第三分角投影的美国机械图样表达方法是一个较迫切的问题。文中介绍了第三分角投影法的形成和投影特征,结合具体例子,重点分析了与我国采用的第一分角表达方法的异同。

原发性开角型青光眼患者外路巩膜静脉窦精准定位方法

目的探讨原发性开角型青光眼(POAG)患者外路巩膜静脉窦精准定位方法。方法选取2020年8月至2021年10月于潍坊眼科医院就诊,确诊为POAG需行外路巩膜静脉窦相关手术治疗的患者40例(40眼)。根据术中测量方法不同将患者随机分为两组,每组各20例(20眼)患者。高清图像组患者采用显微镜截取高清图像后划线测量;无菌图纸组患者采用测绘圆规标记于无菌图纸后完成显微镜下测量。采用角巩膜分光照明法标记巩膜床半透明与不透明组织交界线并将其作为基线,内窥镜光纤前房内透照可于巩膜床清晰透见巩膜静脉窦返流血带,定位巩膜静脉窦后完整切除其外侧壁进行相关指标的长度测量。术前采用IOL-Master记录患者白到白距离(WTW)、眼轴长度(AL),术中测量患者巩膜静脉窦宽度(SW)、基线到巩膜静脉窦后缘距离(d1)、球结膜反折线到巩膜静脉窦前缘距离(d2)、基线到球结膜反折线距离(d3);分析各指标间差异及相关性。结果高清图像组患者d2[(1.85±0.28)mm]和d3[(2.63±0.30)mm]均高于无菌图纸组[分别为(1.61±0.37)mm和(2.41±0.38)mm],差异均有统计学意义(均为P<0.05)。高清图像组和无菌图纸组患者WTW、d1与AL均呈正相关关系(均为P<0.05),d1、d2与d3亦均呈正相关关系(均为P<0.05),其余指标间均无明显相关性(均为P>0.05)。将40眼按照AL不同划分为3组:AL<23 mm为短眼轴组,23 mm≤AL<25 mm为中眼轴组,AL≥25 mm为长眼轴组。短、中、长眼轴组患者d1分别为(0.30±0.08)mm、(0.37±0.10)mm、(0.57±0.09)mm,组间差异有统计学意义(F=14.915,P<0.05);长眼轴组患者d1较短、中眼轴组更长(均为P<0.05)。结论采用内透照法可于深层巩膜床上清晰透见巩膜静脉窦返流血带从而实现术中对巩膜静脉窦的精准定位;d1与POAG患者AL呈正相关关系。

平面曲线详测新法

在地形复杂的平面曲线施测中 ,运用几何原理提出了分角法。解决了平面曲线起、终点不能直接安置仪器的施测难题 ,并通过实例给出了曲线详测时插点及整桩号的推算方法。

Mesh Generation for Finite Element Analysis of Electric Machines

This paper describes two modified methods for triangular and quadrilateral meshing for finite element analysis of 2D electric machines. One is coupling the classic Delaunay method and advancing front method to generate optimal triangulation; the other is coupling the classic paving and Delaunay triangulation for optimal quadrilateral meshing. Various electric machine models are meshed successfully to demonstrate the robustness and effectiveness of the methods.

Outage Performance of Non-Orthogonal Multiple Access Based Unmanned Aerial Vehicles Satellite Networks

With rapid development of unmanned aerial vehicles(UAVs), more and more UAVs access satellite networks for data transmission. To improve the spectral efficiency, non-orthogonal multiple access(NOMA) is adopted to integrate UAVs into the satellite network, where multiple satellites cooperatively serve the UAVs and mobile terminal using the Ku-band and above. Taking into account the rain fading and the fading correlation, the outage performance is first analytically obtained for fixed power allocation and then efficiently calculated by the proposed power allocation algorithm to guarantee the user fairness. Simulation results verify the outage performance analysis and show the performance improvement of the proposed power allocation scheme.

Determining Atmospheric Boundary Layer Height with the Numerical Differentiation Method Using Bending Angle Data from COSMIC

This paper presents a new method to estimate the height of the atmospheric boundary layer(ABL) by using COSMIC radio occultation bending angle(BA) data. Using the numerical differentiation method combined with the regularization technique, the first derivative of BA profiles is retrieved, and the height at which the first derivative of BA has the global minimum is defined to be the ABL height. To reflect the reliability of estimated ABL heights, the sharpness parameter is introduced, according to the relative minimum of the BA derivative. Then, it is applied to four months of COSMIC BA data(January, April, July, and October in 2008), and the ABL heights estimated are compared with two kinds of ABL heights from COSMIC products and with the heights determined by the finite difference method upon the refractivity data. For sharp ABL tops(large sharpness parameters), there is little difference between the ABL heights determined by different methods, i.e.,the uncertainties are small; whereas, for non-sharp ABL tops(small sharpness parameters), big differences exist in the ABL heights obtained by different methods, which means large uncertainties for different methods. In addition, the new method can detect thin ABLs and provide a reference ABL height in the cases eliminated by other methods. Thus, the application of the numerical differentiation method combined with the regularization technique to COSMIC BA data is an appropriate choice and has further application value.

Evaluation of mixed-mode stress intensity factors by extended finite element method

Extended finite element method （XFEM） implementation of the interaction integral methodology for evaluating the stress intensity factors （SIF） of the mixed-mode crack problem is presented. A discontinuous function and the near-tip asymptotic function are added to the classic finite element approximation to model the crack behavior. Two-state integral by the superposition of actual and auxiliary fields is derived to calculate the SIFs. Applications of the proposed technique to the inclined centre crack plate with inclined angle from 0° to 90° and slant edge crack plate with slant angle 45°, 67.5° and 90° are presented, and comparisons are made with closed form solutions. The results show that the proposed method is convenient, accurate and computationallv efficient.

Risk assessment of water inrush in tunnels based on attribute interval recognition theory

Water inrush is one of the most serious geological hazards in underground engineering construction.In order to effectively prevent and control the occurrence of water inrush,a new attribute interval recognition theory and method is proposed to systematically evaluate the risk of water inrush in karst tunnels.Its innovation mainly includes that the value of evaluation index is an interval rather than a certain value;the single-index attribute evaluation model is improved non-linearly based on the idea of normal distribution;the synthetic attribute interval analysis method based on improved intuitionistic fuzzy theory is proposed.The TFN-AHP method is proposed to analyze the weight of evaluation index.By analyzing geological factors and engineering factors in tunnel zone,a multi-grade hierarchical index system for tunnel water inrush risk assessment is established.The proposed method is applied to ventilation incline of Xiakou tunnel,and its rationality and practicability is verified by comparison with field situation and evaluation results of other methods.In addition,the results evaluated by this method,which considers that water inrush is a complex non-linear system and the geological conditions have spatial variability,are more accurate and reliable.And it has good applicability in solving the problem of certain and uncertain problem.

Structure of Chinese City Network as Driven by Technological Knowledge Flows

Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results revealed the spatial structure,composition structure,hierarchical structure,group structure,and control structure of Chinese city network,as well as its dynamic factors.The major findings are:1) the spatial pattern presents a diamond structure,in which Wuhan is the central city;2) although the invention patent knowledge network is the main part of the broader inter-city innovative cooperation network,it is weaker than the utility model patent;3) as the senior level cities,Beijing,Shanghai and the cities in the Zhujiang(Pearl) River Delta Region show a strong capability of both spreading and controlling technological knowledge;4) whilst a national technology alliance has preliminarily formed,regional alliances have not been adequately established;5) even though the cooperation level amongst weak connection cities is not high,such cities still play an important role in the network as a result of their location within ′structural holes′ in the network;and 6) the major driving forces facilitating inter-city technological cooperation are geographical proximity,hierarchical proximity and technological proximity.

On the Out-of-Plane Vibration of Rotating Circular Nanoplates

A rotating axisymmetric circular nanoplate is modeled by the Mindlin plate theory.The Mindlin plate theory incorporates the nonlocal scale and strain gradient effects.The shear deformation of the circular nanoplate is considered and the nonlocal strain gradient theory is utilized to derive the governing differential equation of motion that describes the out-of-plane free vibration behaviors of the nanoplate.The differential quadrature method is used to solve the governing equation numerically,and the natural frequencies of the out-of-plane vibration of rotating nanoplates are obtained accordingly.Two kinds of boundary conditions are commonly used in practical engineering,namely the fixed and simply supported constraints,and are considered in numerical examples.The variations of natural frequencies with respect to the thickness to radius ratio,the angular velocity,the nonlocal characteristic scale and the material characteristic scale are analyzed in detail.In particular,the critical angular velocity that measures whether the rotating circular nanoplate is stable or not is obtained numerically.The presented study has reference significance for the dynamic design and control of rotating circular nanostructures in current nano-technologies and nano-devices.

From the Manipulation of Literary Translation to the Manipulation of Literary Creation： A Case Study

Manipulation always means a kind of extraordinary alteration for some purposes. All translation implies a degree of manipulation of the source text for a certain purpose. Liang Shih-chiu＇s literary translation serves for his literary creation which aims to promote colloquialism and to construct New Literature in the May Fourth Movement. Literary translation is the foundation of literary creation, or rather, its important strategy. The paper, from the perspective of Manipulation Theory, analyzes the purpose and strategy of Liang Shih-chiu＇s literary translation and explores the influence of his literary translation upon his literary creation in terms of ideology, poetics and patronage.

Another Form for LAMBDA Method

The LAMBDA method that was proposed by Teunissen is introduced. Then, on the basis of both the back-sequential conditional LS technique and the upper-triangular Cholesky decomposition, another form for LAMBDA method is proposed. This new form for LAMBDA method has the same principle and calculation speed as the traditional LAMBDA method.

Torsional inertia moment of beam element with complex section analysis based on FEM

Currently, for the analysis of complex bridge based on beam element, the calculation of cross-section torsional inertia moment is still an unresolved technical problem. Most current calculation of section torsional inertia moment is an approximate analytic method for two-dimensional cross-section, which is not fully consistent with the actual situation, and do not consider the effects of diaphragm in bridge. In order to analyze accurately cable-stayed bridge, suspension bridge and other complex bridge structures based on beam element, the calculation method of section torsional inertia moment based on finite element method (FEM) is invented in this paper. Firstly, setting up local cantilever fine model with solid element or shell element and applying torsion on the end of cantilever. Secondly, calculating the torsion angle of cantilever by FEM method and then the torsional moment through equivalent beam method. Finally, the examples of the section torsional moment calculation of concrete model with solid element with diaphragm and steel girder box model with shell element with diaphragm are used to verify the calculation method, which is applied to the suspension bridge design and construction control special software SBNA developed by Research Institute of Highway Ministry of Transport. Taizhou Bridge under construction is one of the examples.

Novel Quantum Phases of Ultracold Bosonic Atoms in Honeycomb Optical Lattice

We study the quantum phase transition of ultracold atoms in the honeycomb optical lattice. The Hamiltonian of ultracold bosonic atoms in the honeycomb optical lattice is derived. We take the mean-field approximation and further solve the Hamiltonian with the numerical diagonalization method. We obtain the phase diagram and find that the Mort-insulator （MI）, density wave （DW） and modulated superfluid （MS） phases appear. Furthermore, the phase diagram is analyzed according to the order parameter and the average number of particles.

BLIND SIGNAL SEPARATION OF LINEAR MIXTURE USING TRILINEAR DECOMPOSITION

This paper introduces a new source separation technique exploiting the time coherence of the source signals. The proposed approach relies only on stationary second order statistics. Blind Signal Separation (BSS) method using trilinear decomposition is proposed in this paper. Simulation results reveal that our proposed algorithm has the better blind signal separation performance than joint diagonalization method. Our proposed algorithm does not require whitening processing. Moreover, our proposed algorithm works well in the underdetermined condition, where the number of sources exceeds than the number of sensors.

Finite Element Analysis of Polygon Shaped Shell Roof

A new spherical triangular finite element based on shallow shell formulation is developed in this paper. The element has six degrees of freedom at each comer node, five of which are the essential external degrees of freedom and the additional sixth is associated with the in-plane shell rotation. The displacement fields of the element satisfy the exact requirement of rigid body modes of motion. The element is based on independent strain assumption insofar as it is allowed by the compatibility equations. The element developed herein is first validated by applying it to the analysis of a benchmark problem involving a standard spherical shell with simply supported edges. The results of the analysis showed that reasonably accurate results were obtained even when modeling the shells using fewer elements compared to other shell element types. The element is then used in a finite element model to analyze polygon shaped spherical roof structures. The distribution of the various components of deflection and stress is obtained. Furthermore, the effect of introducing circular arched beams as stiffeners spanning the two diagonally opposite end comers is investigated. It is found that the stiffeners reduced the deflections and the stresses in the roof structure by considerable value.

Evaluation of Rural Tourism Resources based on the Tourists Perspective: A Case Study of Lanzhou City, China

Rural tourism has become a hot spot in China’s tourism development. Based on the AHP model and the comprehensive evaluation method of fuzzy cognition, this paper builds an evaluation system for the evaluation of rural tourism resources, including resource value, environmental factors, reception conditions with three criterion layers, and 25 evaluation factors. We recovered 574 valid questionnaires through two online forms and field research in Lanzhou city, and then used them to complete the empirical analysis. The results show four main aspects of the tourists’ perspective on rural tourism resources. Firstly, rural tourists are concerned about higher service facilities. The evaluation of rural tourism resources pays more attention to the reception conditions, and tourists pay more attention to the facilities of the reception conditions. In addition, the reception condition value accounts for a more concentrated 8–10 points(61.4%), which is higher than environmental elements(58.87%) and the value of the resource itself(54.26%). Secondly, tourists’ attention to rural tourism resources mainly focuses on the pleasurable(0.1152), tour line design(0.1014), experience(0.0765), ornamental(0.0747) and other aspects. Thirdly, the degree of cognition mainly focuses on nature(4508), environmental safety(4469), pleasantness(4387), accommodation conditions(4367), tour line design(4363) and other aspects of the rural tourism resources. Fourthly, the cognition of rural tourism resources is basically given priority with 6–9 points, and environmental factors accounted for the highest portion. However, rural tourists have higher expectations for the popularization and education of rural tourism resources, but the sense of acquisition is relatively low. Through the further improvement and improvement of the naturalness of environmental resources, environmental safety of reception conditions, and the enjoyment of external traffic and resource value, the overall benefit of rural tourism resources is maximized. The results of this study can provide reference for the theoretical foundation of rural tourism resources.

A new method of block shape classification

The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distribution of the block. The previous methods to classify rock block shape are based on the assumption that a block shape is approximately orthogonal, which is acceptable in only a few rock masses. This paper proposes a new method for block shape classification using triangular diagram together with parameters of co-linearity e and volume coefficient K, which combines the shape categorization with block volume for statistical analysis. Rock block equivalent size calculation methods based on block shape is proposed and the block cumulative percentage of total volume statistical analysis is given. In order to verify this block shape classification method, three ideal rock masses with approximately orthogonal joint sets have been generated and simulated.

Analytical Investigation of Soliton Solutions to Three Quantum Zakharov-Kuznetsov Equations

In the present paper, the two-dimensional quantum Zakharov-Kuznetsov(QZK) equation, three-dimensional quantum Zakharov-Kuznetsov equation and the three-dimensional modified quantum Zakharov-Kuznetsov equation are analytically investigated for exact solutions using the modified extended tanh-expansion based method. A variety of new and important soliton solutions are obtained including the dark soliton solution, singular soliton solution, combined dark-singular soliton solution and many other trigonometric function solutions. The used method is implemented on the Mathematica software for the computations as well as the graphical illustrations.