基于西门子PLC的自动化装配联轴器的系统设计

随着工业自动化的不断发展,可编程逻辑控制器在自动化装配系统中的应用越来越广泛。基于目前新能源汽车企业自动化装配联轴器生产的需要,采用西门子1200PLC联合法奥机器人、康耐视Insight2000智能工业相机以及MCGS昆仑通泰触摸屏设计一款自动化联轴器装配系统。实验证明:该系统性能良好,操作简单,功能完善,能够有效提高装配效率和产品质量。

长白山森林水源涵养力与区域经济的关系

以吉林省东部长白山区29个县市区域为研究对象,通过水分平衡模型,对区域内森林2014年的水源涵养力(WCA)进行了估测,并对当地统计部门所公布的2014年30组农林经济指标数据进行归档记录。分别利用Pearson相关分析和极大似然估计回归分析的方法,研究WCA与区域经济指标之间的关系。研究结果表明:以水稻、玉米和大豆为主的粮食作物耕作面积以及总产量,均与WCA之间呈显著负相关关系。此外,大牲畜头数和猪年末存栏数与WCA之间的负相关关系也达到显著水平,而林业产值与WCA之间呈正相关关系。农业人口数量和以大豆为主的粮食单产量对WCA具有促进作用,而农机动力和总人口数却对WCA具有极大的负面影响。

Optimizing the growth and N status of containerized Australian Blackwood(Acacia melanoxylon)seedlings with exponential nitrogen loading

Exponential nitrogen(N) loading approach has been used to optimize seedling growth in container seedling production. However, the response of seedling growth to N loading and optimal N loading rates are species-dependent. There is a lack of information on optimal N loading in container production of Australian Blackwood(Acacia melanoxylon) seedlings. In this study, 7 exponential N loading at rates of 0, 50, 100, 200, 300, 400, and 600 mg N seedling-1, respectively, were applied at the week 3, 6, 9, 12 and 14 after transplanting to determine optimal loading approach based on seedling height, root collar diameter(RCD), biomass accumulation and N uptake in tissue-cultured Australian Blackwood(A. melanoxylon) seedlings. Seedlings did not respond to N loading 3 wk after transplanting, then the accumulative addition of N loading for improved RCD and seedling height was 12.99 and 28.02 mg N seedlings-1 in the 100 N and 400 N treatment 6 wk after transplanting, respectively, and on 9 and 12 wk, that for improved seedling growth was 63.64 and 400 mg N seedling-1 in the 200 N and 400 N treatment, respectively. Vector diagnosis of final biomass and N status indicated that the dose of 100 and 400 mg N seedling-1 was characterized to be "deficient" and "optimum" dose of exponential N loading for Blackwood seedlings. These conclusions promise to figure out a precise fertilization regime for Blackwood seedlings and the demonstration of dynamic seedling performance could be used for other tree species.

Chitosan oligosaccharide addition modifies nutrient utilization in highly-valued ornamental tree seedlings

Forestation in the increasingly urbanized area generates a huge demand for ornamental tree stocks, requiring new approach to promote the cultural efficiency of highly valued seedlings. Chitosan oligosaccharide(COS) is one of biodegradable natural plant growth modifier derived from chitin and an abundant water insoluble biopolymer. In this study, Buddhist pine(Podocarpus macrophyllus)(PM) and Northeast yew(Taxus cuspidata)(TC) were cultured with or without COS addition from 1 July to 17 November 2016. Relative to the TC seedlings, the PM seedlings had greater growth of height and biomass which was found to be negatively correlated with the changes of nitrogen(N) and phosphorus(P) concentrations in shoot during the culture. Only those TC seedlings treated without COS addition had higher proportion of decline in the initial N concentration than that in the PM seedlings. Root P concentration declined less in Buddhist pine seedlings than that in Northeast yew seedlings treated with COS. By 17 of November 2016, both N and P seemed to have been diluted in the PM seedlings and exceed the demand in the TC seedlings. In conclusion, COS had the potential to be used for the culture of ornamental tree seedlings to promote nutrient utilization for shoot biomass accumulation, but more specific effect on nutrient allocation and utilization need to be confirmed by more studies.

用于实验教学的数字化MEMS地震仪开发

开发了基于全数字化MEMS的实验教学用地震仪,该仪器采用AS3002A芯片作为数字化检波器,直接输出数字信号,无需传统地震仪的前级输入电路和模数转换电路;利用STM32作为主控芯片,通过STM32的串行外设接口(SPI)通信读取MEMS的采集数据,并将数据分包存储到SD卡;采用WIFI或4G无线通信等模块传输到上位机进行实时显示,也可利用该仪器开展脚步声采集等实验。通过室内实验测试了该仪器的各项性能指标,结果表明,该地震仪能长时稳定地实现震动信息的实时采集、传输和存储。该仪器较传统地震仪无需单独的前级输入和模数转换电路,大大降低了成本和体积,且性能满足实验教学要求。

Effect of Short-term Forest Bathing in Urban Parks on Perceived Anxiety of Young-adults: A Pilot Study in Guiyang, Southwest China

Forest can be taken as a natural therapy to alleviate perceived anxiety of visitors. Given the geographical difference between urban and rural forest environments, little is known about the urban forest therapy effect of anxiety alleviation with reference to the rural forest. In this study, forty-three university students(aged from 19 to 23) were recruited as participants to visit the forest parks at urban and rural areas of Guiyang City on 21 and 23 December 2016. The forest experience was separated by four sceneries. Participants were asked to complete questionnaires by self-evaluating specific anxiety change from 12 questions with scores from 1 to 10 at both entrance and exit of the parks. The Wilcoxon signed-rank test and paired t-test were used to compare the change of anti-anxiety scores during forest bathing and between urban and rural forests, respectively. Results revealed that forest bathing in the urban park can alleviate the anxiety from financial state(P = 0.0028), exam-pass pressure(P = 0.0040) and love-affair relationship(P = 0.0286). Although rural forest bathing can also alleviate the anxiety from financial state(P = 0.0222), meanwhile, it maintained the anxiety about campus life(P < 0.0001). Forest tree richness tended to be higher in the rural forest park than in the urban one, which in contrast decreased the anxiety alleviation from inter-communication in the rural forest park(P = 0.0487). Principle component analysis indicated that participants tended to perceive more decline of anxiety from social contact in the urban forest. In conclusion, university students were recommended to pay a short visit to the urban forest with partners if they felt anxious about personal affairs and felt necessary to talk with others. For general people's visiting, urban forest trees can be controlled in diversity to some extent to look orderly and alleviate perceived anxiety.

基于AdaGrad+的自适应Heavy-Ball动量法及其最优个体收敛性

自适应策略与动量法是提升优化算法性能的常用方法。目前自适应梯度方法大多采用AdaGrad型策略,但该策略在约束优化中效果不佳,为此,研究人员提出了更适用于处理约束问题的AdaGrad+方法,但其与SGD一样在非光滑凸情形下未达到最优个体收敛速率,结合NAG动量也并未达到预期的加速效果。针对上述问题,文中将AdaGrad+调整步长的策略与Heavy-Ball型动量法加速收敛的优点相结合,提出了一种基于AdaGrad+的自适应动量法。通过设置加权动量项、巧妙选取时变参数和灵活处理自适应矩阵,证明了该方法对于非光滑一般凸问题具有最优个体收敛速率。最后在l∞∞范数约束下,通过求解典型的hinge损失函数优化问题验证了理论分析的正确性,通过深度卷积神经网络训练实验验证了该方法在实际应用中也具有良好性能。

Can forest bathing in spring enhance the positive psychological response of university students: A pilot study in Northeast China

Forest bathing is well known to be beneficial of the visitors’psychological changes with better emotion and mood.Most understanding about the psychological change of university students in response to forest bathing is mainly obtained by the profile of mood states(POMS)method:a psychological rating scale to assess the transient and distinct mood states.Although some other studies explored to use a new questionnaire to assess the psychological change of university students in the urban park,more detailed information is scarce.In this study,23 university students(12 female;aged 20-23)were recruited to walk for 3.5 hours in Nanhu forest park,Changchun,China on 22 and 23 May 2018,when they were arranged to walk in an urban routine simultaneously.It was found that these students instantiated more positive emotion in the urban forest.These positive psychological changes were accompanied by improved perception about personal details and school work.In contrast,participants walking in the urban environment did not feel any psychological change.Therefore,forest bathing can be taken as an active way to stimulate more positive psychological changes compared to the urban experience.However,as a pioneer project,this study suggests more studies by designing more specific questions about social contact affairs for university students’forest bathing.

激发进程监控系统在地震勘探中的应用

地震勘探中,野外数据采集的进程,一直为相关人员所关心,其不仅关系到单个项目是否可以按计划完成勘探任务,更影响到了多个项目间设备及人员流通计划的制定以及部署,因此以往的日报周报模式已经不能满足当今的高效采集需求。激发进程监控系统的使用,真正实现了对野外采集进度的远程遥控指挥和掌控,加速了信息化地震队的进程。