GPS测量在城市规划中投影长度变形分析

本文简要介绍了GPS测量长度变形问题,阐述了在城市规划测量中GPS测量基线投影长度变形分析。     

论长度计量仪器测量过程中误差控制

长度计量仪器被广泛的应用于人们的实际生活中,在工业中也会经常涉及到,所以长度计量仪器对于生活和工业都具有重要的作用。但是,在长度计量仪器测量的过程中,会受到很多外界因素的影响,从而导致测量结果会有很大的误差,严重影响了长度计量仪器测量的准确性。所以,本文主要就是对长度计量仪器测量过程中存在的误差详细分析,并且提出控制误差的相关措施。     

配网电缆长度测量研究

配网电缆项目完成后,由于其土木工程的隐秘性,电缆沟管道施工中与设计图纸是否匹配,电缆长度使用情况存在确认困难的问题。为了便于验收管理、核定配网电缆施工的工作量。设计了一种配网电缆长度测量装置,对配网电缆测量进行了实际研究,研究结果表明,新设计的配网电缆长度测量装置测量精度高,误差范围在1%以内,为施工后电缆长度复测提供了指导。     

浅谈长度测量在精密加工中的作用

长度测量作为企业测量的重要组成,在企业生产和加工过程中起到了重要作用,生产加工分为普通加工和精密加工,以精密加工为研究对象进行分类阐述,介绍了长度测量在普通加工和精密加工中的应用和作用。     

一种起重机伸缩臂测量长度修正方法

为实现对伸缩臂起重机的力矩保护,需准确测量当前工况下起重机的臂长。目前伸缩臂起重机常采用的机械传动电阻式长度传感器易产生整体漂移,导致长度测量不准。基于此,提出了一种伸缩臂起重机测量臂长自动修正方法。     

浅析长度计量器具的维护与保养

长度计量器不但是一种测量工具,也是一种仪器,它能够准确地测量物体的具体长度值。在科学技术快速发展的同时,测量工具也发展得非常快,由于测量的精度越来越高,所以也能够应用到更多的领域。如今在一些实验室和科研场所的长度计量器都是具有很高精度的大型设备,同时也对这些设备管理人员的操作和维护水平也有了更高的要求。     

干涉法技术在量块长度测量中的应用

量块是重要的长度实物标准,它将长度单位传递到工业生产的各个环节,在产品质量保证体系中发挥着重大作用.本文基于光干涉原理,介绍了干涉法测量量块长度的基本原理,研究了量块长度测量的数字化干涉技术方法.并在此基础上,详细分析介绍奈纹法处理干涉图方法及技术分析.     

一种超高值电阻的测量方法

将绝缘材料超高值电阻的测量转换成高值电阻与长度的测量,其中高值电阻采用伏安法测量。采用该方法测量了纯聚酰亚胺及掺炭聚酰亚胺的电阻。     

多功能电子创口测量尺

在法医学检验过程中,创口或疤痕的检查属于常规项目,其准备测量与致伤物的推断、死亡原因的推断、损伤程度和伤残程度的评定密切相关。鉴定实践中,多数创口和疤痕形态不规则,使用现有的测量工具无法得出准确数值,因此易导致鉴定意见的偏差。多功能电子创口测量尺由测弧线创口长度尺和测深度钝器尺组成。测弧型创口测量尺由带有刻度尺的软铁构成,能随意弯曲测量不规则弧形创口的长度。测深度钝器尺由钝头尺构成,钝头设计不仅可以深入创腔内部进行测量,而且可以避免对创伤带来的二次伤害。此设计旨在解决法医病理和法医临床面对不规则创口长度测量和深度测量带来的一系列问题。     

游标卡尺几种测量方法精确度分析

游标卡尺是长度测量的常用工具,但是,采用不同方法测量,测量结果也不相同,本文以测量方形垫片为例,比较分析了三种不同的测量方法,分析指出辅助垂直测量法精确度最高,有助于减少测量误差。     

告别倦怠 走向幸福

长时间干某一项工作,人容易产生厌烦倦怠的心理,特别是日复一日干重复工作的教师。但是只要我们调整好心态,从工作中寻找快乐,就一定能走出职业倦怠的阴霾,活出自己的精彩。     

融合用户画像与协同过滤的知识付费平台个性化推荐模型

[目的/意义]为提高知识付费平台用户感知服务质量,文章构建了融合用户画像与协同过滤的个性化推荐模型。[方法/过程]首先根据用户特性构建画像标签体系,利用TF-IDF、熵值法、k-means等方法确定用户特征标签;其次分别基于用户画像与改进后的协同过滤算法计算用户相似度,通过调和权重得到用户综合相似度;最后利用Top-N进行个性化推荐。[结果/讨论]通过知乎live付费用户信息进行验证,发现本文算法在推荐结果的准确率以及召回率上,相比其单一方法均有较大提升,且满意度高于知乎live平台。     

高保真语音录放系统的设计

本课题研究的目的就是用单片机控制ISD语音芯片实现语音现场录制及回放。本课题把这一系统以家用留言机的形式做了出来,可以很方便地进行语音留言,为系统录制不同语音即可实现多项功能,例如录入公交站各站语音段即可为公交实现语音报站。因为系统用的是ISD语音芯片的直接语音模拟存储,从而实现了语音的高保真输出。为一些对语音质量要求比较高的场合提供高保真输出。     

肌肉收缩中横桥间的协作行为

根据横桥模型,肌肉中的横桥分子对细纤丝的周期性作功导致肌肉收缩,研究了在一维情况下,肌肉等张收缩(即外界的负荷F是常量)时,其横桥分子间的两种协作行为。首先,假设了单个横桥分子在作功过程中的能量与时间关系。在此基础上,考察了横桥分子间的两种协作行为:(1 )n0 个处于接触状态的横桥分子同步的工作,其作功过程与外界影响无关;(2 )n0 个处于接触状态的横桥分子同步的工作,但它们作功的频率正比于细纤丝在肌肉收缩中的速率V。计算了这两种假设情况下肌肉的外界负荷F与其收缩速率V的关系。发现,在第一种情况下,F V的关系曲线形状上类似于实验上得到的希尔曲线;在第二种情况下,肌肉收缩的速率V反比于外界负荷F。     

Microwell perfusion array for high-throughput, long-term imaging of clonal growth

Continuous cell tracking by time-lapse microscopy has led to detailed study of cell differentiation pathways using single cell fate maps. There are a multitude of cell fate outcomes, so hundreds of clonal division histories are required to measure these stochastic branching processes. This study examines the principle of condensing cell imaging information into a relatively small region to maximize live cell imaging throughput. High throughput clonal analysis of non-adherent cells by continuous live cell tracking was possible using a microwell perfusion array with an internal volume of 16 μl and 600 microwells at the base. This study includes examination of biocompatibility of buffer systems, connecting tubing, cell culture substrates, and media degradation. An intermittent perfusion protocol was selected for long-term time-lapse imaging of KG1a cells in the microwell array; 1500 clones were simultaneously cultured and scanned every 3 min at 100 × magnifications for 6 days. The advantages of perfusion microwell culture are continuous long-term cell tracking, higher cell imaging throughput, and greater control over cell microenvironment. Microwell devices facilitate high throughput analysis of cell lineage development and measurement of the probability distribution for cell life events such as mitosis.     

Cell chip array for microfluidic proteomics enabling rapid in situ assessment of intracellular protein phosphorylation

We discuss the ability to perform fluorescent immunocytochemistry, following cell fixation, using a microfluidic array of primary, nonadherent, single CD34+ stem cells. The technique requires small cell samples and proceeds with no cell loss, making it well-suited to monitoring these rare patient-derived cells. The chip allows us to correlate live cell dynamics across arrays of individual cells with post-translational modifications of intracellular proteins, following their exposure to drug treatments. Results also show that due to the microfluidic environment, the time scale of cell fixation was significantly reduced compared to conventional methods, leading to greater confidence in the status of the protein modifications studied.     

院线直播制作系统IP链路浅析——以2019年国庆阅兵活动的院线直播为例

针对2019年国庆阅兵的院线直播使用的4K超高清IP化移动外场直播制作系统,阐述系统的整体构架、IP主链路的构成及设备配置,剖析演练、直播过程中出现的问题及解决方案。     

Rodents,evolution, and prehistory

The rodents, especially voles, evolved very rapidly during the Quaternary era. Their remains, particularly the teeth, were fossilised by the thousand in prehistoric deposits. The sites can be dated from the degree of evolution attained by the teeth. Since rodents are closely adapted to their biotopes and live under well defined climatic conditions, they are extremely valuable for reconstructing the landscapes and climates of prehistory. In many cases, a single rodent tooth can be used to assess the age of a human skull or a prehistoric settlement, and throw light on the environment and climate of the time.     

Why viewers send paid gifts: The role of social influence on massively multiplayer online games live streaming

Virtual paid gifts from viewers are the main revenue source for the live streaming gaming industry, with massively multiplayer online games (MMOG) currently representing the most profitable game type. However, there is little understanding regarding what drives gifting behavior in the MMOG live streaming social environment. This study develops a research model for analyzing the antecedents of virtual gifts in the MMOG live streaming context, with monetary value used for quantification. This model builds on the theory of social influence and social impact literature, and it has been validated through an empirical study including 988,829 observations of real-time viewer data that were collected from the Douyu live streaming platform. Our study examines micro-, meso-, and macro-level social influences (i.e., self-presentation, parasocial relationship, and MMOG live streaming loyalty) on viewer gifting behavior and how the presence of others (i.e., social crowdedness of viewers on the live streaming channel) represents a contextual cue that moderates the effects of social influence on gifting behavior. The results reveal that self-presentation, parasocial relationships, and MMOG live streaming loyalty positively affect the monetary value of viewers’ paid gifts. Although the presence of others can strengthen the impact of parasocial relationships and MMOG live streaming loyalty on viewer gifting behavior, it negatively moderates the relationship between self-presentation and gifting behavior. This study theorizes the features of MMOG live streaming and extends the applicability of social influence theory and social impact theory to this context. Finally, we provide insights into how game practitioners facilitate viewer gifting behavior.     

华中地区生猪疾病防控技术对策与措施

猪肉是我国居民的主要肉食源,生猪产业在我国畜牧业生产中占有较大的比重,生猪的疾病防控是生猪养殖业的重点。近年来,特别是2006年的蓝耳病和2009年猪H1N1流感发生后,我国生猪产业防疫和检疫所暴露出来的问题受到了社会的广泛关注。对华中地区生猪疾病防控工作进行了研究,并以生猪产业发展、动物疾病发生与危害情况为重点,提出政府宏观调控、散养户和规模化养殖防疫控疫建议以及生猪疾病防控技术对策与措施,对保障我国猪粮安全有重要意义。