高频波导组件复杂连接面导电胶粘接工艺

高频波导组件对构成波导腔的上、下壳体复杂连接面的电连接质量要求极其苛刻,尤其是在Ka频段及以上,常规的工艺方法难以满足高频波导产品的装配要求。分析了高频波导组件特点及装配工艺性,提出了一种涂覆针头内径选择及涂覆路径设计方法,解决了复杂连接面导电胶涂覆不均匀和漫溢的问题。基于导电胶涂覆量的量化控制及工艺参数优化,实现了高频波导功分盖板与壳体复杂连接面的高质量电连接,满足了组件对损耗、驻波指标的高要求。经历200次温循试验,仍满足波导组件的工艺指标及电指标要求,验证了工艺方法的可靠性。

预应力空心板梁混凝土强度大幅度波动的试验研究

对某预应力生产厂的预应力空心板梁进行试验研究,分析空心板梁混凝土强度大幅度波动的原因。试验分析过程包括现场调查、混凝土配合比验证、混凝土抗压强度检测和空心板梁内部质量分析。试验表明,混凝土原材料质量、混凝土振捣方式、混凝土卸料工艺对空心板梁混凝土强度影响较大。本文为厂家的后续生产提供若干可靠建议。

Syntactic Characteristics and a Smart Construction Mechanism for Thematic Map Symbols

The construction of thematic map symbols is a very complex and intellectually demanding process,but thematic symbols can be automatically generated and easily shared on the web using the syntactic structure of semantic symbols.In this paper,the symbol types,inner structure,and design pattern are discussed.A syntactic construction theory based on letter (thematic maps primitive)-word (single thematic symbol)-sentence (combined symbols or complex symbols) structure model is proposed to automate the construction of thematic map symbols.As a result of this research,symbols can be defined using cartographic primitives which are arranged according to syntactic principles.A semiotic model and word-centered construction theory can be integrated into interactive cartography as represented by the technology of Internet.Finally,the concepts and schema of this theory are discussed,and some examples are presented based a web thematic cartographic system to verify its utility.

毫米波构件真空扩散焊工艺及变形控制

文中针对毫米波构件精密连接要求,将分段压力扩散焊应用到多通道毫米波构件生产中,获得了接头变形小、焊缝均匀连续、力学和气密性能符合要求的零件。以接头变形控制为中心,开展扩散焊变形控制试验,得到了多通道接头尺寸变形分布规律,分析了阶段扩散压力对接头变形结果的影响。结果表明:分段压力扩散焊可有效降低零件通道接头变形,随着扩散压力增大,通道长度方向和厚度方向尺寸均先减小后增大;多通道焊接变形时,各通道接头变形量差异小,中间通道变形整体略大于两侧通道,均能满足毫米波构件±0.05 mm的尺寸精度要求。

The influence of the eruption of mandibular third molars on the craniofacial morphology in Han youth of North China

Teeth affect not only oral problems but also facial morphology.In China,there are few reports about the influence of the third molars on the craniofacial morphology of Han youths.Using in vivo imaging software,3D reconstruction of craniofacial CTs were performed on 32 Chinese Han youths without mandibular third molars and 25 Chinese Han youth with full mandibular third molars.The morphology of their mandible and mandibular tissue was measured to identify differences.Among the morphological characteristics of hard tissues,except for∠ANB,people with a full eruption of the mandibular third molars had statistically significantly larger angle indicators than people without the eruption of the third molars.The soft tissue indicators also showed statistically significant discrepancies in terms of morphological facial height,mouth to gnathion distance,lip height,and mouth breadth.The most influential index for mandibular third molars was length of symphysis,followed by the four indicators of soft tissue and mandible length and height.Morphology facial height,mouth to gnathion distance,lip height,and height of symphysis were moderately correlated.The experimental results show that among Han youth in North China,the third molar eruption has a widespread influence on mandibular morphology,especially in angle,length,and height indicators.It also has a certain influence on maxillofacial soft tissue morphology.These results can be applied to future clinical risk assessment of the wisdom teeth and forensic personal identification of the cranial and maxillofacial region.

Body weights in Han Chinese populations

The body weights of 26,954 Han Chinese adults in 67 areas(16,503 in rural areas and 10,451 in urban areas) across China were measured from 2009 to2013.The results showed that in China,the three areas(north China,northeast China,and Jianghuai Plain) were with the greatest body weight.Northwest Han Chinese populations were heavier.Southwestern dialect groups were at the middle level and lighter than northern Han Chinese populations,but were heavier among southern Han Chinese populations.Chinese Han who located in areas of Hangjiahu were the general level,and similar to southwestern dialect groups.The mean values of body weight in Hunan Han and Fujian Han were greater than other Han groups in southern China.Gan dialect groups and Cantonese dialect groups showed the minimum body weightvalue in all Chinese Han groups.Besides,the mean body weight of Hakka was heavier than Gan dialect groups and Cantonese dialect groups which were adjacent to Hakka.Body weight increases with an increase in height,bone diameter,subcutaneous fat on the limbs and trunk,chest circumference,and abdomen circumference.This study revealed that northern Han men were heavier than southern Han men,because the former were taller and had a larger waist circumference as well as thicker subcutaneous fat on their backs.Among women,height,bone diameter of the upper limbs,chest and abdomen circumferences,and subcutaneous fat on the limbs and trunks of northern Han exceeded those of rural southern Han.Consequently,body weight values of northern Han women were higher than those of southern Han women.While a significant difference in these values was found between urban and rural men,no significant difference occurred between urban and rural women.Body weight was associated with age in urban and rural men only in the case of minority groups.However,there was a positive correlation between body weight and age in the majority groups of both urban and rural women.The particular composition of genes involved in body weight traits of Han populations across the country has created a genetic foundation accounting for varying body weights of different Han populations.Environmental factors also play a role.As the Han are widely dispersed,their habitation areas vary according to factors such as topography,temperature,precipitation,humidity,and light.Moreover,labor intensity,food composition,and the intake of various nutrients also differ across Han populations.All of these factors have affected the development of body weight in Han populations living in different locations.

Multiple regression analysis of the craniofacial region of Chinese Han people using linear and angular measurements based on MRI

The purpose of this study was to measure the craniofacial region of Chinese Han people in the linear and angular dimensions,and to analyse the effects on sex,age and body parameters(height and weight).All 250 individuals(86 males,164 females)underwent a three-dimensional magnetic resonance imaging(MRI)scan,and the MRI data were imported into VG Studio MAX 2.2 software.Each linear and angular measurement in the craniofacial region was processed directly.Using SPSS 20.0 software,nine multiple regression equations were constructed,and all the adjusted R^(2) values were statistically significant(0.031-0.311).Multiple regression analysis showed that most craniofacial measurements of Chinese people were significantly correlated with height,weight or age.The multiple regression equations constructed will be helpful in anthropometric analysis and forensic inference.