Assessment of flexural properties of different grade dimension lumber by ultrasonic technique

The dimension lumber （45mm×90mm×3700mm） of plantation Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） was graded to four different classes as SS, No. 1, No.2 and No.3, according to national lumber grades authority （NLGA） for structure light framing and structure joists and planks. The properties of apparent density was determined at 15% moisture content, bending strength and stiffness were tested according to American Society for Testing and Materials （ASTM） D198-99, and dynamic modulus of elasticity （Eusw） was measured by ultrasonic technique, for predicting the flexural properties of different grade lumbers. The results showed that Eosw was larger than the static MOE. The relationship between Eusw and static MOE was significant at 0.01 level, and the determination coefficients （R2） of the four grade lumbers followed the sequence as R^2No.2 （0.616）〉 R^2ss （0.567）〉 R^2No1 （0.366）〉 R^2No.3 （0.137）. The R^2 of Fusw and MOR were lower than that of the Etru and MOR for each grade. The Eusw of all the grade lumbers, except No.3-grade, had significant correlation with the static MOE and MOR, thus the bending strengthof those grade lumbers can be estimated by the E The Etru valuesof four grade lumbers followed a sequence as No.2-grade （10.701 GPa） 〉 SS-grade （10.359 GPa） 〉 No.l-grade （9.840 GPa） 〉 No.3-grade （9.554 GPa）. For the same grade dimension lumber, its Eusw value was larger than static MOE. Mean values of MOR for four grade lumbers follow a sequence as No.2-grade （48.67 MPa） 〉 SS-grade （48.16 MPa） 〉 No.3-grade （46.55 MPa） 〉 No. 1-grade （43.39MPa）.

On the Techniques of Communicative Dimensional Transformation Between Hypotaxis and Parataxis in Tourist Publicity C-E Translation

Communicative dimension,as one of the three key dimensions of eco-translatology,plays a very important role in translating tourist publicity materials.With the communicative dimensional transformation techniques of parataxis and hypotaxis,translators should exert their subjectivity and creativity to achieve in maximizing the degree of holistic adaptation and selection for achieving successful translations.

The Features of Microcontroller EM78P447 and Technique of Port Connection with I^2C Series Bus

By describing the technique of port connection and flow chart ofR/W operation between 24LC01, serial E2PROM, and EM78P447A, features of EM78P447 and its connection with I2C serial bus are introduced. In the end, the programe of writing operation is given.

Multiple Dimensions Convey Design and Application in CIS based on CG Technique

In the art design field, CG technique has been applied in many aspects like third dimension graphical display, human-computer interaction, virtual reality, three-dimensional cartoon and so on. In the meanwhile, the applications reflected in art design was appeared in computer assisted convey design, bothway or multi-ways interactive convey design and multimedia convey design. Computer assisted convey design included the application of the most CG technique in visual. Interactive convey design reflected interaction, which was the most obvious character of CG. However, multimedia convey design was used not only in CG technique, but also in digital media techniaue.

On the Transformation Techniques of Hypotaxis and Parataxis in Tourist Publicity C-E Translation from the Perspective of Linguistic Dimension

This paper, with its basis on linguistic dimension of eco- translatology, aims to present transformation techniques of parataxis and hypotaxis in translating tourist publicity between Chinese and English. It is hoped that translators can exert their subjectivity and creativity to achieve the linguistic dimensional transformations of parataxis and hypotaxis to maximize the degree of holistic adaptation and selection for achieving successful translations.

Cultural Dimensional Transformation Techniques of Hypotaxis and Parataxis in Tourist Publicity C-E Translation

In order to make foreign tourists familiar with China's scenic spots, it is necessary that tourist publicity materials are properly translated. Cultural dimension, as one of the three key dimensions of eco-translatology, plays a very important role in translating. With its basis on cultural dimension of eco- translatology, this paper aims to present transformation techniques of parataxis and hypotaxis between Chinese and English. It is suggested that, with the cultural dimensional transformation techniques of parataxis and hypotaxis, translators should exert their subjectivity and creativity to achieve in maximizing the degree of holistic adaptation and selection for achieving successful translations.

Large-Scale Vehicle Platooning:Advances and Challenges in Scheduling and Planning Techniques

Through vehicle-to-vehicle(V2V)communication,autonomizing a vehicle platoon can significantly reduce the distance between vehicles,thereby reducing air resistance and improving road traffic efficiency.The gradual maturation of platoon control technology is enabling vehicle platoons to achieve basic driving functions,thereby permitting large-scale vehicle platoon scheduling and planning,which is essential for industrialized platoon applications and generates significant economic benefits.Scheduling and planning are required in many aspects of vehicle platoon operation;here,we outline the advantages and challenges of a number of the most important applications,including platoon formation scheduling,lane-change planning,passing traffic light scheduling,and vehicle resource allocation.This paper’s primary objective is to integrate current independent platoon scheduling and planning techniques into an integrated architecture to meet the demands of large-scale platoon applications.To this end,we first summarize the general techniques of vehicle platoon scheduling and planning,then list the primary scenarios for scheduling and planning technique application,and finally discuss current challenges and future development trends in platoon scheduling and planning.We hope that this paper can encourage related platoon researchers to conduct more systematic research and integrate multiple platoon scheduling and planning technologies and applications.

Recognition of the major scattering sources on complex targets based on the high frequency radar cross section integrated calculation technique

Based on the high frequency （HF） integrated radar cross section （RCS） calculation approach, a technique of detecting major scattering source is developed by using an appropriate arithmetic for scattering distribution and scattering source detection. For the perfect adaptability to targets and the HF of the HF integrated RCS calculation platform, this technique is suitable to solve large complex targets and has lower requirement to the target modeling. A comparison with the result of 2-D radar imaging confirms the accuracy and reliability of this technique in recognition of the major scattering source on complex targets. This technique provides the foundation for rapid integrated evaluation of the scattering performance and 3-D scattering model reconstruction of large complex targets.

An advanced segmentation using area and boundary tracing technique in extraction of lungs region

A new method is presented for the segmentation of pulmonary parenchyma. The proposed method is based on the area calculation of different objects in the image. The main purpose of the proposed algorithm is the segment of the lungs images from the computer tomography(CT) images. The original image is binarized using the bit-plane slicing technique and among the different images the best binarized image is chosen. After binarization, the labeling is done and the area of each label is calculated from which the next level of binarized image is obtained. Then, the boundary tracing algorithm is applied to get another level of binarized image. The proposed method is able to extract lung region from the original images. The experimental results show the significance of the proposed method.

Novel Path Counting-Based Method for Fractal Dimension Estimation of the Ultra-Dense Networks

Next-generation networks,including the Internet of Things(IoT),fifth-generation cellular systems(5G),and sixth-generation cellular systems(6G),suf-fer from the dramatic increase of the number of deployed devices.This puts high constraints and challenges on the design of such networks.Structural changing of the network is one of such challenges that affect the network performance,includ-ing the required quality of service(QoS).The fractal dimension(FD)is consid-ered one of the main indicators used to represent the structure of the communication network.To this end,this work analyzes the FD of the network and its use for telecommunication networks investigation and planning.The clus-ter growing method for assessing the FD is introduced and analyzed.The article proposes a novel method for estimating the FD of a communication network,based on assessing the network’s connectivity,by searching for the shortest routes.Unlike the cluster growing method,the proposed method does not require multiple iterations,which reduces the number of calculations,and increases the stability of the results obtained.Thus,the proposed method requires less compu-tational cost than the cluster growing method and achieves higher stability.The method is quite simple to implement and can be used in the tasks of research and planning of modern and promising communication networks.The developed method is evaluated for two different network structures and compared with the cluster growing method.Results validate the developed method.

Review of Dimension Reduction Methods

Purpose: This study sought to review the characteristics, strengths, weaknesses variants, applications areas and data types applied on the various Dimension Reduction techniques. Methodology: The most commonly used databases employed to search for the papers were ScienceDirect, Scopus, Google Scholar, IEEE Xplore and Mendeley. An integrative review was used for the study where 341 papers were reviewed. Results: The linear techniques considered were Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Singular Value Decomposition (SVD), Latent Semantic Analysis (LSA), Locality Preserving Projections (LPP), Independent Component Analysis (ICA) and Project Pursuit (PP). The non-linear techniques which were developed to work with applications that have complex non-linear structures considered were Kernel Principal Component Analysis (KPCA), Multi-dimensional Scaling (MDS), Isomap, Locally Linear Embedding (LLE), Self-Organizing Map (SOM), Latent Vector Quantization (LVQ), t-Stochastic neighbor embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP). DR techniques can further be categorized into supervised, unsupervised and more recently semi-supervised learning methods. The supervised versions are the LDA and LVQ. All the other techniques are unsupervised. Supervised variants of PCA, LPP, KPCA and MDS have been developed. Supervised and semi-supervised variants of PP and t-SNE have also been developed and a semi supervised version of the LDA has been developed. Conclusion: The various application areas, strengths, weaknesses and variants of the DR techniques were explored. The different data types that have been applied on the various DR techniques were also explored.

乡村振兴战略下乡村教育转型衔接的三重向度与现实进路

乡村教育是实现农业农村现代化的重要支撑,是脱贫攻坚与乡村振兴有机衔接的重要领域。在全面推进乡村振兴战略下,乡村教育转型衔接既是立足时代的应然之变,也是现实观照的必然之举,其“价值-功能-实践”的三重向度面临深刻转变,应朝着“价值理性”、“三生空间”“长效性治理”的方向发展。然而,乡村教育“为农”与“离农”的冲突博弈,教育资源有限供给与乡村发展复杂需求的供需矛盾,以及治理手段的外源依附惯性和内生动能不足问题,为转型衔接带来了诸多难点与挑战。为此,要进一步深化“一体融合”的发展理念,进行“统一灵活”的规划部署,完善“多元共治”的体制机制,以乡村教育振兴带动乡村全面振兴。

Dimensional Measurement of Complete-connective Network under the Condition of Particle’s Fission and Growth at a Constant Rate

We construct a complete-connective regular network based on Self-replication Space and the structural principles of cantor set and Koch curve. A new definition of dimension is proposed in the paper, and we also investigate a simplified method to calculate the dimension of two regular networks. By the study results, we can get a extension: the formation of Euclidean space may be built by the process of the Big Bang's continuously growing at a constant rate of three times.

马鞍山长江公铁大桥Z3号桥塔施工关键技术

巢马城际铁路马鞍山长江公铁大桥主航道桥为(112+392+2×1120+392+112)m三塔钢桁梁斜拉桥,Z3号桥塔为超高多肢钢-混组合塔,高308 m。上塔柱钢结构高87.5 m,分13个吊装节段,最重505 t;中、下塔柱混凝土结构高217.5 m,分38个节段液压爬模施工;钢-混结合段高3 m,内部采用PBL键+剪力钉+高强度钢锚杆+高强度混凝土结构形式。在中塔柱设置钢管临时横撑控制塔柱线形及应力;下横梁采用落地支架法分层施工,与对应塔柱同步浇筑;钢-混结合段混凝土采用C60细石补偿收缩混凝土+高强度灌浆料,保证了混凝土施工质量;采用工厂“2+1”立体匹配制造、“提升站+运输栈桥”钢塔节段转运等技术,并研制15000 t•m超大型塔吊,实现了钢塔柱大节段的制造、整体滩地运输和吊装;钢塔节段间采用栓焊组合连接形式,通过设置工艺隔板、双面坡口等措施控制了钢塔焊接变形;利用定位桁架临时锁定钢塔合龙段实现了钢塔的精确合龙,定位桁架受力及变形均满足要求。

轴压下掺铁尾矿砂和水泥的生土材料细观损伤演化研究

为研究铁尾矿砂改性生土基材料在轴压下的损伤演化性能,采用CT技术,对不同应力状态下材料内部二值化图像进行分析.通过阈值分割,从细观上数值化各应力状态断面图像.研究材料分形维数、孔隙率和应力-应变(ε-σ)曲线演化规律,并阐明材料从受荷直至破坏的细观机理.结果表明:分形维数随受荷增大显著增加,σ=2.38 MPa时,分形维数最大.分形维数的变化趋势可间接表征试件受压时各扫描断面的不规则程度、粗糙度、裂缝与孔隙的发展情况.材料孔隙率随应力增大明显增加.以孔隙率为指标的材料损伤因子变化趋势与孔隙率变化规律相同,可有效反映材料在轴压下的破坏发展规律,也可作为研究改性生土试件损伤演化的定量参数.

云南永胜古滑坡堰塞湖沉积物粒度多重分形特征及其指标适用研究

本文以云南永胜县下院滑坡堰塞湖沉积物为研究对象,依据粒度测试结果采用传统粒度指标与分形理论相结合的方式对其沉积环境进行系统化研究,探讨各传统指标在堰塞湖沉积解析中的适用性,探索多重分形理论在沉积学中的应用价值。研究结果表明:①堰塞湖沉积物粒度统计参数明显不同于其他环境下的沉积物,具有河湖相沉积独特的分布曲线形式、分选状态和分形特征。优势粒级在分形计算中起主导地位,全局分形维数与分选系数有着良好的对应关系。不同的分形维数对应着不同的堰塞湖沉积条件,分形维数在堰塞湖粒度解析中有着很好的运用前景;②多重分形结果显示2种不同时期的堰塞湖沉积物均以高聚集度组分为主体,表明粒径分布集中,反映出堰塞湖沉积过程中水动力的稳定性,沉积来源的唯一性,进一步证明了该堰塞湖曾长期存在。细粒组沉积粒径分布范围较窄,分布相对集中,优势粒组多但单个含量低,尾端含量低,内部分异较大;粗粒组分布呈局部集中整体分散的趋势,高聚集度粒组数量少但含量高,低聚集度粒组数量多但单个含量低,呈现中间高,四周低的特点。③多重分形分析表明Δα、Δf在沉积物粒度分析中能够解析粒组内部分布特征,具有传统指标不可替代的作用,D_(0)和D_(1)两者结合可作为沉积环境解析的替代指标,与其他q阶多重分形联合可进一步作为堰塞湖解析指标,而D_(1)/D_(0)和D2则存在一定局限。

基于KPCA特征量降维的风电并网系统暂态电压稳定性评估

针对电力系统暂态电压稳定性评估中所需特征量数据庞大,影响模型训练时间,降低计算效率等问题,提出了一种基于核主成分分析方法KPCA和CPSO-BP组合的风电并网系统暂态电压稳定性评估方法.首先根据输入特征采集原始特征集,采用核主成分分析算法对特征量进行非线性数据处理,提取出最优的特征集.然后将降维后的特征集作为CPSO-BP神经网络输入量进行监督学习,将得到的模型按照临界故障切除时间裕度值的大小进行分类,将分类后的样本进行风电并网系统的暂态电压稳定性评估和临界故障切除时间裕度值预测.仿真分析结果表明,对输入特征进行降维,保留重要输入特征量,剔除冗余特征量,不仅简化了模型,还提高了网络评估的准确性和计算效率.

基于点云技术的汽车外廓尺寸测量方法研究

针对《机动车安全技术检验项目和方法》(GB 38900—2020)中对于汽车外廓尺寸测量的新要求,采用整车点云数据技术,对牵引车与各类挂车连接后外形上的共性和外廓分割的关键位置进行了研究。通过改进三维点云分割算法,提出一种一并式测量汽车列车和挂车外廓尺寸的测量新方法。该方法可在不改变硬件的前提下,仅通过软件和算法升级,实现一次测量即可测得汽车列车(牵引车、半挂车组合)外廓尺寸参数。以多种结构挂车为试验案例验证了所提方法的可行性,并通过适应性试验分析了所提方法的有效性。研究结果表明,该方法完全能够满足GB 38900—2020中的新增要求,具有广泛的适用性与较高的测量精确度。该方法可将传统方法测量耗时从“小时级”提升为“秒级”,显著提高相关机构的工作效率。

盾构隧道长联络通道冻结法施工技术与应用

本文以郑州市轨道交通8号线五龙口站—同乐站区间隧道3#联络通道冻结工程为背景,详细总结了长距离联络通道施工关键技术,包括冻结加固方案、冻结施工技术要点、施工风险及应对措施等,并通过现场施工情况及实测数据进行了验证。针对长距离联络通道的冻结施工,采用双侧搭接布置冻结管、实时压力监测并打设泄压孔、解冻期及时跟进补浆、必要情况下施作钢拱架等措施,可以有效降低长距离联络通道冻结施工中的风险。在本工程冻结施工期间,实测地表冻胀位移及管片竖向隆起位移均小于6mm,解冻后融沉量小于10mm,联络通道初期支护竖向位移小于2.1mm,验证了本工程施工技术的可靠性,可以为类似的长联络通道冻结开挖工程提供参考。

基于“三维五法”治疗顽固性面瘫的临床研究

目的:观察“三维五法”治疗周围性顽固性面瘫的临床疗效。方法:40例周围性顽固性面瘫的患者随机分为治疗组20例与对照组20例。治疗组给予“三维五法”操作,对照组采用安慰剂和常规治疗,两组均治疗4周。比较两组治疗后的临床疗效,观察两组House-Brackmann面神经瘫痪分级、面部残疾指数[包括躯体功能(FDIP)和社会生活功能(FDIS)]、患者闭眼时上下眼睑距离、患者健侧与患侧口角距前正中垂线距离差值的变化。结果:治疗组总有效率为90.00%(18/20),明显高于对照组的60.00%(12/20),差异有统计学意义(P<0.05);治疗后,两组H-B评分、FDIS、上下眼睑距离、健侧与患侧口角距前正中垂线距离差值均减小(P<0.05),且治疗组明显优于对照组,差异有统计学意义(P<0.05);治疗后,两组FDIP评分明显增加,差异有统计学意义(P<0.05),且治疗组显著高于对照组,差异有统计学意义(P<0.05)。结论:“三维五法”能有效改善顽固性周围性面瘫患者临床症状,提高面神经传导功能,促进面肌功能恢复,疗效显著。