A synthetic differencein-differences model for the influence of CR Express on Chongqing's economy

Purpose-The China-Europe Railway Express(CR Express)in Chongqing has operated regularly and undergone large-scale development.Its impact on Chongqing's economic growth has become increasingly evident,necessitating further research in this field.Design/methodology/approach-This study employs the opening of CR Express as a quasi-natural experiment,designating Chongqing,which inaugurated the CR Express in 2011,as the treatment group.13 provinces and cities that had not yet opened the CR Express until 2017 were selected as the control group.Utilizing panel data from 14 provinces across China spanning from 2006 to 2017,the synthetic control method(SCM)is employed to synthetically construct Chongqing.To quantify the difference in economic development levels between Chongqing with the operation of the CR express and Chongqing without its operation.Key metrics such as gross domestic product(GDP),per capita GDP,total retail sales of consumer goods,import and export value and the proportions of the secondary and tertiary industries are employed to measure urban economic development capabilities.Chongqing is designated as the experimental group,and a double-difference model is constructed to regress the operation of the CR Express against economic development capabilities.Robustness tests are conducted to validate the analytical results.Findings-The results indicate that,compared to provinces without the operation of the CR Express,the initiation of the CR Express in Chongqing significantly enhances the economic development level of the city.The opening of the CR Express exhibits a pronounced positive impact on Chongqing's economic development,and these findings remain robust and effective even after parallel trend tests and placebo tests.Originalitylvalue-The study represents an expansion of the theoretical framework.In contrast to previous studies that relied on a single indicator such as GDP,this study selects six indicators from the dimensions of economy,trade and industry to measure regional economic development capabilities.Furthermore,employing the grey relational analysis method,the study screens these indicators,thereby providing a theoretical basis for the selection of indicators for measuring regional economic development capabilities.

Express Methods for Measurement of Electroconductivity of Semiconductor Layered Crystal

We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.

Comparison of Biolistic and Agrobacterium-mediated Transformation Methods on Transgene Copy Number and Rearrangement Frequency in Rice

Transferring foreign DNA into plant cells by biolistic and Agrobacterium _mediated methods may result in random integration of different copy numbers of the transgene, and different proportions of intact vs. rearranged copies of the transgene. This may, in turn, affect transgene expression levels. To test the above hypothesis, we first introduced the same plasmid, pAc1PG_CAM, into rice (Oryza sativa L.) calli separately by the biolistic method and by the Agrobacterium _mediated method. To show whether different plasmids may affect the results, we also introduced pTOK233 by the Agrobacterium _mediated method and pJPM44 by the biolistic method. Transgene expression of R0 plants was monitored by histochemical analysis of GUS activity. Transgene copy number was determined by Southern blot analysis after digesting genomic DNA with an enzyme that has a unique cutting site within the input plasmid. The total genomic DNA was also digested by a two_cut enzyme (the cuts are located at two sides of a given transgene expression cassette), followed by Southern blotting analysis, for determining the number of intact transgene expression cassettes. Our data showed that Agrobacterium _mediated transformation resulted in lower transgene copy number (average between 2.1 and 2.3) in transgenic rice plants, compared with those plants obtained by the biolistic method (average between 4.2 and 5.6). The frequency of DNA rearrangement in expression cassettes is lower in transgenic rice plants obtained by the Agrobacterium _ mediated method than those obtained by the biolistic method. The average rearrangement frequency is 0.07 to 0.106 for the Agrobacterium _mediated method, and 0.57 to 0.66 for the biolistic method. Our results suggest that it is better to compare the number of intact expression cassettes instead of the total copy number of the transgene in demonstrating their influence on the level of transgene expression. This is the first report on the frequency of expression cassette rearrangement in transgenic plants transformed with the same plasmid by two different transformation methods.

Modeling viscosity of methane,nitrogen,and hydrocarbon gas mixtures at ultra-high pressures and temperatures using group method of data handling and gene expression programming techniques

Accurate gas viscosity determination is an important issue in the oil and gas industries.Experimental approaches for gas viscosity measurement are timeconsuming,expensive and hardly possible at high pressures and high temperatures(HPHT).In this study,a number of correlations were developed to estimate gas viscosity by the use of group method of data handling(GMDH)type neural network and gene expression programming(GEP)techniques using a large data set containing more than 3000 experimental data points for methane,nitrogen,and hydrocarbon gas mixtures.It is worth mentioning that unlike many of viscosity correlations,the proposed ones in this study could compute gas viscosity at pressures ranging between 34 and 172 MPa and temperatures between 310 and 1300 K.Also,a comparison was performed between the results of these established models and the results of ten wellknown models reported in the literature.Average absolute relative errors of GMDH models were obtained 4.23%,0.64%,and 0.61%for hydrocarbon gas mixtures,methane,and nitrogen,respectively.In addition,graphical analyses indicate that the GMDH can predict gas viscosity with higher accuracy than GEP at HPHT conditions.Also,using leverage technique,valid,suspected and outlier data points were determined.Finally,trends of gas viscosity models at different conditions were evaluated.

General Expression of LRC Method in Estimation of Bridge’s Equivalent Static Wind Load

According to the relationship between load and response, the equivalent static wind load(ESWL) of a structure can be estimated by load-response correlation(LRC) method, which can be accurately used to estimate the background ESWL of a structure. The derivation of the classical expression of LRC formula is based on a specific command response at a critical position, and the ESWL distribution has only one form in this case. In this paper, a general expression of LRC formula is derived based on a specific command response at all positions. For the general expression, ESWLs can be expressed by load-response correlation coefficients, response-response correlation coefficients, RMS values of the fluctuating wind loads, and peak factor in the form of matrices. By comparing the expressions of LRC method, it was found that the classical expression was only one form of the general one. The general expression which introduces the response-response correlation coefficients provided more options for structural engineers to estimate ESWLs and offered further insights into the LRC method. Finally, a cable-stayed bridge, a rigid three span continuous girder bridge, and a suspension bridge were used to verify the correctness of the general expression of LRC method.

Research on the Novel Facial Expression Modelling Method

In this paper, we conduct research on novel and new facial expression modelling method. Although human facial expression recognition ability is stronger, but the computer to implement is a lot of diffi culties and the displays in: establish facial expression model and sentiment classifi cation, and put them with the changes in the facial features and expressions. Face is a fl exible body instead of rigid body, it is diffi cult to relate facial movement and facial expression change, according to the characteristics of the face image sequence established dynamic expression model that is a complete description of the dynamic expression of the process. Under this condition, in this paper, we propose the novel perspectives of the issues that are meaningful and innovative.

基于设计值法的结构可靠性设计实用性研究

目前,结构设计主要采用基于概率的分项系数法,而随着材料强度、施工工艺、设备性能的改善以及荷载作用的变化,该法在使用过程中因分项系数的取值固定而缺乏灵活性、通用性、并且可靠度控制精度不足.为此,国际上提出了设计值法.该法可从根本上解决目前设计方法的缺陷,但仍缺乏足够的工程实用性,尚未全面推广.鉴于此,根据工程设计习惯,以结构可靠度理论和设计值法为基础,建立基于设计值法的实用设计表达式,并结合工程实际给新的设计表达式选取最优的灵敏度系数,从而建立新的实用性设计值法的应用研究理论.结果表明,新的实用设计值法在工程应用中提高了可靠度控制精度和实用性.

基于随机动力分析的高土石坝极限抗震能力研究

地震动的随机性对大坝的动力响应影响较大,极限抗震能力作为大坝抗震安全性能的重要环节,在评估过程中也应该充分考虑荷载随机性的影响。基于大量高土石坝随机动力有限元计算,探究坝顶震陷率和坝坡累计滑移量两个重要坝体变形指标之间的关系,并建议了土石坝安全控制标准。利用概率密度演化法对高土石坝进行极限抗震能力分析。结果表明:震陷率随着累计滑移量的增大而增大,二者之间符合逻辑斯蒂增长模型;取10%的超越概率,以250m规则高面板堆石坝和高心墙堆石坝为例,极限抗震能力分别为0.7g~0.75g和0.8g~0.85g;从概率角度提出了评估大坝极限抗震能力的新方法。

中欧班列开行带来的港口城市居民健康效益研究

中欧物流货运方式自中欧班列开行后在逐步发生变化,中欧班列承担着越来越多的货运运输任务,同时,国际航运带来的污染物排放一直被低估。经过测算,中欧班列比国际海运产生的大气污染物少,采用中欧班列运输的货物能够减少沿海港口居民因大气污染带来的就医费用,因此可以视为中欧班列的开行给沿海港口城市居民带来了健康效益,以此为我国继续大力推行中欧班列建设提供依据。

基于改进卷积神经网络的心理状态预警技术

针对传统问卷法难以真实反映被调查者心理状态的问题,基于光流法和卷积神经网络提出了一种微表情判断方法,并将其作为心理状态预警技术的核心模块。对于数据集中人脸数据离散的问题,该方法采用人眼权重法对图像进行预处理,且通过金字塔光流算法提取预处理图像序列的光流特征,再利用三维卷积神经网络对该特征加以训练。与传统算法相比,所提方法在减少模型训练参数与运算时间的同时还具有更优的学习能力。实验测试结果表明,该算法在CASME数据集上的微表情识别准确率为89.2%,F1值为0.6751,均优于其他对比方法。由此证明,该算法可实现对人脸微表情的准确识别,进而为学生心理状态预警提供客观的数据支撑。

基于PCNN的角色表情动画去毛刺生成方法

为实现角色表情动画的情感体现,并有效去除动画边缘产生的锯齿形状的毛刺,提出基于PCNN的角色表情动画去毛刺生成方法。该方法采用PCNN网络分割采集的视频帧图像,去除图像中背景部分。将保留的部分人脸表情输入改进的深度学习模型中,提取人脸表情特征。引入风格和内容的双向约束,确定模型损失函数。融合提取的全部表情特征,生成角色表情动画。采用区域重构算法去除生成动画的边缘锯齿毛刺,保证动画生成效果。测试结果表明:图像分割性能良好,区域内部均匀性准则指标结果均在0.924以上,可清晰地保留部分人脸表情图像,能够依据真实人脸表情生成不同角色的表情动画;形状测度准则和皮尔逊相关系数指标最大值分别为0.994和0.957,可有效去除动画边缘毛刺,保证动画质量。

Anisotropic shearing mechanism of Kangding slate:Experimental investigation and numerical analysis

The shear mechanical behavior is regarded as an essential factor affecting the stability of the surrounding rocks in underground engineering.The shear strength and failure mechanisms of layered rock are significantly affected by the foliation angles.Direct shear tests were conducted on cubic slate samples with foliation angles of 0°,30°,45°,60°,and 90°.The effect of foliation angles on failure patterns,acoustic emission(AE)characteristics,and shear strength parameters was analyzed.Based on AE characteristics,the slate failure process could be divided into four stages:quiet period,step-like increasing period,dramatic increasing period,and remission period.A new empirical expression of cohesion for layered rock was proposed,which was compared with linear and sinusoidal cohesion expressions based on the results made by this paper and previous experiments.The comparative analysis demonstrated that the new expression has better prediction ability than other expressions.The proposed empirical equation was used for direct shear simulations with the combined finite-discrete element method(FDEM),and it was found to align well with the experimental results.Considering both computational efficiency and accuracy,it was recommended to use a shear rate of 0.01 m/s for FDEM to carry out direct shear simulations.To balance the relationship between the number of elements and the simulation results in the direct shear simulations,the recommended element size is 1 mm.

EXPRESS数据模式在关系数据库上的实现

实现形式是ＳＴＥＰ标准的主要内容之一，本文通过分析ＥＸＰＲＥＳＳ语句结构特点，对ＥＸＰＲＥＳＳ数据模式在关系数据库上的实现进行了研究，提出了ＳＴＥＰ集成系统的实现框架，并定义了ＥＸＰＲＥＳＳ数据模式向关系模式转换的规则和方法，为ＳＴＥＰ产品数据库在关系数据库上的实现创造了条件。

新时代我国快递业监管问题及对策研究

进入新时代,我国快递业规模持续领跑全球,快递业在推动经济增长、稳定就业等方面影响显著。结合2018-2023年快递业统计数据,从快递业监管现状出发,分析当前快递业监管存在监管人员数量与能力不足、监管方式落后单一、行业协会自律作用不明显等问题,探索并针对性提出了增加监管人员数量,提升监管人员能力;丰富快递业监管方式;加强行业协会建设,增强行业自律作用等对策建议。

非洲猪瘟病毒P54蛋白原核表达及间接ELISA检测方法建立

【目的】建立一种具有良好特异性和敏感性的非洲猪瘟病毒(African swine fever,ASFV)抗体间接ELISA检测方法。【方法】根据ASFV P54蛋白基因序列进行大肠杆菌密码子优化,将优化后的P54序列克隆到pET-28a(+)质粒中,构建重组质粒pET28a-P54,利用大肠杆菌表达系统表达目的蛋白并用His镍柱进行纯化,经SDS-PAGE和Western blotting鉴定后,以纯化的P54蛋白作为检测抗原进行包被,建立一种间接ELISA方法,对包被条件、封闭液、封闭时间和血清孵育等反应条件进行优化后,对其临界值、特异性、灵敏性和重复性进行验证。【结果】SDS-PAGE结果显示,P54蛋白分子质量为42 ku,纯度在95%以上;Western blotting结果显示,P54蛋白与ASFV阳性血清能产生特异性反应。优化后的ELISA反应条件为:0.3125μg/mL抗原37℃包被1 h,5%脱脂奶粉37℃封闭1 h,1∶800稀释的血清37℃孵育2 h,1∶15000稀释的酶标二抗37℃孵育1 h。该ELISA检测方法仅与ASFV阳性血清产生特异性反应,与猪瘟病毒、猪细小病毒、猪繁殖与呼吸综合征病毒、猪圆环病毒2型、牛病毒性腹泻病毒、猪伪狂犬病病毒和乙型脑炎病毒的阳性血清均无明显交叉反应;该方法灵敏性较高,ASFV阳性血清稀释度为1∶3200时仍有明显反应。批间重复和批内重复变异系数均<10%;与商品化试剂盒相比,其阳性符合率为95.45%,阴性符合率为96.05%,总符合率为95.83%。【结论】本研究建立了一种以ASFV P54蛋白为检测抗原的ASFV间接ELISA方法,该方法具有良好的特异性和敏感性,能运用于ASFV的血清学检测,为非洲猪瘟的快速诊断提供更多选择。

PrepFiler Express BTA^(TM)裂解液联合硅珠法快速提取骨骼DNA

目的建立方便、快捷的提取骨骼DNA的方法。方法对15份长骨样本清洗消毒后,采用电钻钻取骨屑,使用PrepFiler Express BTA^(TM)裂解液进行裂解消化后,应用手工硅珠吸附纯化进行DNA提取检验。结果有14份样本获得满意的STR分型,仅1份样本未获得STR分型,检出率为93.33%。结论本研究建立的骨骼DNA快速提取方法操作简单、便捷、有效,适应性强,值得推广应用。

客观赋权对快捷货运各方式间临界运距影响分析

我国交通运输已由各方式间独立发展向一体化融合发展转变,快捷货物运输是综合交通运输融合发展的新兴关键领域,其各运输方式间临界运距的研究对合理运输结构的确定具有重要意义。针对既有研究对于临界运距问题主观赋权的不足,本文首先基于快捷货运分担率模型建立临界运距与服务属性及权重系数表达式,然后基于CRITIC(Criteria Importance Though Intercriteria Correlation)法对权重系数进行客观测算,最后通过实例进行模型分析验证及结果对比。实例结果表明:客观赋权法可以使各服务属性权重系数随运距增加而产生异质性;经济性在300~400 km和900~1100 km内波动幅度最大;便捷性与经济性的运距临界点为327 km,其重要程度随运距增加会高于经济性;客观赋权对快捷货运各方式间临界运距的影响主要体现在高铁快运绝对优势运距区间的扩大,由主观赋权下700~1500 km转变为400~2000 km。

景观设计中的地域文化表达探索——以克拉玛依市经三路绿廊为例

以地域文化为视角,以城市绿廊为研究对象,对克拉玛依市绿廊景观地域文化表达进行探索,探究景观设计中地域文化表达的基本要素,提出了地域文化在景观设计中的表达手法,并以克拉玛依市经三路绿廊景观设计为例,将“地域文化”表达在具体设计实践中,以此揭示地域文化对于城市景观设计的重要性,有助于展示城市特色,为以后的景观“地域文化”传承表达提供思路。

针对小目标要素的目视航空图增强方法

增强地图是增强现实与地图学结合的新产物,由于跟踪注册算法不易识别小目标特征,已有研究多集中在全局的面状要素增强表达上。针对小目标点状符号的识别和增强设计两个问题,基于YOLOv3目标检测模型利用航空图数字影像数据实现以检索、阅读和多元化符号表达为主的目视航空图要素增强。通过深度卷积神经网络解决航空要素的符号识别问题;基于检测结果设计3类增强功能。经实验验证,该方法可以实时准确地增强航空要素,检测模型有较好的准确率和召回率,能满足目视航空图要素的小目标增强需求。

基于智能感知的人脸细微表情情绪推定算法

人脸局部纹理的细微变化是判定情绪的关键视觉线索,但是表情的细微变化捕捉难度较大,且特征提取易出现偏差,提出一种基于智能感知的人脸细微表情情绪推定算法。通过滤波去除人脸图像干扰,采用差分法提取出连续图像中的人脸区域。使用Fisher线性变换确定RGB向量的最佳投影方向,区分人脸局部特征区域,提取细微表情特征。加入变分自编码器,将注意力模型嵌入到变分自编码网络中,根据网络关注推定不同类型情绪的重要特征。将未标记的特征输入到变分编码器中展开训练,同时将提取到的特征作为特征提取器,智能感知不同类型的面部表情,最终实现人脸细微表情情绪推定。仿真测试结果表明,所研究算法能够精准提取人脸细微表情特征,通过细微表情推定的情绪精度也较高,查全率和查准率可达97%,验证了该算法的可应用性。