Weather-Driven Solar Power Forecasting Using D-Informer:Enhancing Predictions with Climate Variables

Precise forecasting of solar power is crucial for the development of sustainable energy systems.Contemporary forecasting approaches often fail to adequately consider the crucial role of weather factors in photovoltaic(PV)power generation and encounter issues such as gradient explosion or disappearance when dealing with extensive time-series data.To overcome these challenges,this research presents a cutting-edge,multi-stage forecasting method called D-Informer.This method skillfully merges the differential transformation algorithm with the Informer model,leveraging a detailed array of meteorological variables and historical PV power generation records.The D-Informer model exhibits remarkable superiority over competing models across multiple performance metrics,achieving on average a 67.64%reduction in mean squared error(MSE),a 49.58%decrease in mean absolute error(MAE),and a 43.43%reduction in root mean square error(RMSE).Moreover,it attained an R2 value as high as 0.9917 during the winter season,highlighting its precision and dependability.This significant advancement can be primarily attributed to the incorporation of a multi-head self-attention mechanism,which greatly enhances the model’s ability to identify complex interactions among diverse input variables,and the inclusion of weather variables,enriching the model’s input data and strengthening its predictive accuracy in time series analysis.Additionally,the experimental results confirm the effectiveness of the proposed approach.

Pulse-like ground motion observed during the 6 February 2023 M_(W)7.8 Pazarcık Earthquake(Kahramanmaraş,SE Türkiye)

In this study,we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 M_(W)7.8 Pazarcık(Kahramanmaraş)Earthquake in SE Türkiye.The wavelet method was utilized to identify and analyze the characteristics of pulse-like ground motions in the near-fault region,while considering the uncertainty of the pulse orientation during the analysis.Our investigation focused on the effects of the focal mechanism and rupture process on the spatial distribution,pulse orientation,and maximum pulse direction of the observed pulse-like ground motion.We also analyzed the amplitude and period of the observed ground pulses and the effect of long-period amplification on the ground motion response spectra.Our results indicated the following:(1)A total of 21 typical ground velocity pulses were observed during this earthquake,exhibiting complex characteristics due to the influence of the strike-slip mechanism and rupture directivity.Most ground pulses(17 out of 21)were recorded within 20 km of the fault,in a wide range of orientations,including normal and parallel to the fault direction.The waveforms exhibited unidirectional features,indicating the effects of left-lateral fault slip.Distinct pulses observed more than 20 km from the fault were mainly oriented normal to the fault.The waveforms were bidirectional with double-or multi-round trips as a result of rupture directivity.(2)The amplitudes of the observed pulses ranged from 30.5 to 220.0 cm/s,with the largest peak velocity of 220.0 cm/s observed at Station 3138.The pulse periods ranged from 2.3 to 14.5 s,with the longest pulse period of 14.5 s observed at Station 3116.The amplitude and period of the pulses observed during this earthquake were comparable to those of similar-magnitude global earthquakes.The amplitude of the pulses decreased significantly with increasing fault distance,whereas the pulse period was not significantly affected by the fault distance.(3)Compared with non-pulse records,the velocity pulse records had a pronounced amplification effect on the acceleration response spectra near the pulse period,with factors ranging from 2.1 to 5.8.The larger velocity pulses also significantly amplified the velocity response spectra,particularly over the long periods.This significant amplification effect of the pulses on the response spectra leads to empirical models underestimating the long-period earthquake ground motion.

基于Profinet通信协议的多电机运行监控系统设计

随着工业互联网逐步渗透到工业制造各大领域,工业企业迫切需要通过工业互联网加快数字化步伐,以提高生产效率,节省设备运维成本,满足客户个性化需求。研究在工业互联网中通过Profinet通信协议将西门子S7-1200、HMI和G120变频器等设备联网组成异步电动机变频调速监控网络。研究内容包括控制系统硬件构成、变频器参数设置和PLC控制程序设计。该控制系统运行能完全融入工业互联网,且监控方便、成本低廉。

基于注意力机制的增强视觉追踪网络

为提升传统Transformer结构追踪器的性能并解决与注意力机制结合的问题,提出一种具有注意力机制的Transformer结构视觉跟踪器(称为EVOTA)。提出一个具有局部跨通道的交互策略的通道注意力模块,通过显式建模通道之间的相互依赖关系实现自适应校准通道方向的特征响应。受神经科学理论启发,提出一个能量函数分析神经网络中每个神经元的重要性,进一步推断其相应三维权重。在多个基准数据集上,EVOTA的性能优于多种优秀的追踪器。

农业伦理视域下“藏粮于地”与“藏粮于草”的辩证关系——兼论《粮食安全保障法》第二章“耕地保护”

从农业伦理视角看“藏粮于地”与“藏粮于草”之间的互补共赢关系。聚焦2023年新颁布的《粮食安全保障法》第二章“耕地保护”,认为耕地保护不光是保面积,还要保水、保土、保肥、保多元种植模式、保农业系统多样性等。本研究采用了文献综述、实地调研、案例分析等方法,梳理了耕地面积和耕地质量等资源的刚性约束,种植业的结构性问题和粮食连增的不可持续性,粮草多元种植实现耕地改良和增加后备土地的科研成果、政策共识,并从黄河流域的6个调研县筛选了粮草轮作复种、套作间作、混播混贮等3个典型案例作为佐证。本研究认为种植业结构调整处于农业结构调整的首要位置,尤其是在粮食产量达到人年均400 kg口粮安全点之后,就不应该再制定过高的粮食生产目标,而应适时启动“藏粮于草”计划来保护耕地、增草增粮。“藏粮于草”更符合农业伦理学模式,是伦理学在植物生产层中的创新性应用。建议将口粮、饲粮、饲草种植分别统计,因地制宜开展粮草多元种植模式。

黔东南皂角种群结构和数量动态特征

为揭示黔东南皂角种群结构特征和数量动态变化,采用“空间代替时间”方法和匀滑修正技术,编制径级结构图、种群静态生命表,绘制死亡率曲线、存活曲线、消失率曲线和生存分析函数曲线及时间序列预测模型。研究发现种群径级结构显示总体为衰退型;种群存活曲线呈凹型,属Ⅲ型,在1—3龄级表现为幼树期死亡率较高,3龄级后个体的数量趋于稳定,存活率相对较高;生存率S(i)随着龄级增加而下降,累计死亡率F(i)随着龄级增加而增加,变化幅度均在1—3龄级表现明显;死亡密度f(ti)和危险率λ(ti)在1龄级最大,分别为34%和98.51%,随着龄级增加均呈下降趋势。数量变化动态指数V pi=0.38>0,表明无外界干扰时,种群属于增长型种群,V′pi=0.001>0,说明皂角种群对外界干扰敏感,受外界随机干扰时种群增长趋势不明显;在未来2,4,6,8个龄级时间后,预测结果显示,如果不对皂角进行人工干预、减少外界干扰和增加幼树数量,皂角种群最终走向衰退。

青藏高原东北边缘云杉-巴山冷杉林火烧迹地草本植物群落主要种生态位特征

特定环境下植物的生态位决定植物群落的相对稳定状态。以空间代替时间方法,采用Levins和Shannon-Wiener生态位宽度指数、Pianka和Schoener生态位重叠指数,分析青藏高原东北边缘云杉-巴山冷杉林火烧迹地4个演替阶段群落的种群生态位宽度和生态位重叠程度,并划分群落特化种和泛化种。结果表明:火烧迹地不同演替阶段的草本层主要物种的Levins和Shannon-Wiener生态位宽度指数结果基本一致,同一物种在不同演替阶段的生态位宽度存在差异,生态位宽度23 a>5 a>15 a>顶级群落(Climax)。5 a群落有2个特化种2个泛化种,15 a群落有4个特化种2个泛化种,23 a群落仅有3个特化种,Climax群落有3个特化种5个泛化种。23 a群落的高生态位重叠指数的种对数占比最小,而Climax群落有着较少低生态位重叠指数的种对数;中等生态位重叠指数的种对数占总对数比值大小顺序为Climax>5 a>15 a>23 a。通过研究分析可以得出:青藏高原东北边缘云杉-巴山冷杉林经过重度火干扰后,火烧迹地演替初期的群落(5 a)和受人为定向干扰的群落(23 a),植物生境资源丰富,各植物种的生态位宽度都相对较大、生态位重叠较小,相应地种间竞争小;演替中期(15 a),生态位重叠分离现象明显,群落中的大多数种在资源利用上具有极大的相似性,种间竞争加剧;而Climax属于顶级群落,各种的生态位宽度相对较宽,大多数植物种间生态位重叠不高,竞争较小,群落处于一个相对稳定的状态。除了Climax群落,其他各演替阶段群落所含特化种占特化种与泛化种之和比≥50%,特定的生境促使特化种的形成。适当的人为干预能够提高群落内种的生态位宽度,降低种间的生态位重叠,形成较为稳定的生态群落。

青藏高原东北边缘云杉-巴山冷杉林火烧迹地植物群落演替的数量研究

[目的]分析青藏高原东北边缘云杉-巴山冷杉林火烧迹地不同演替阶段植物群落物种组成和多样性变化规律,为火烧迹地植物群落的科学管理提供依据。[方法]采用空间代替时间方法,在迭山北坡,选取4个不同演替阶段的植物群落,即火后演替5年(5 a)、火后演替15年(15 a)、火后演替23年(23 a)和森林顶级群落(Climax)作为一个演替序列,采用样方法调查植物群落的物种组成,计算物种重要值、多样性指数和群落相似系数等指标,以揭示火烧迹地植物群落演替的数量特征。[结果]1)随着火烧迹地植物群落演替时间的推移,群落物种丰富度下降,个体数量逐渐减少,其中5 a群落物种丰富度最大,个体数最多(4008±298株·(400 m^(2))^(-1)),Climax的物种丰富度最小,个体数量也最少(1759±90株·(400 m^(2))^(-1));草本层5a群落、灌木层和乔木层Climax群落的Margalef指数和Shannon-Wiener指数最大。2)依据重要值,5 a、15 a、23 a和Climax 4个不同演替阶段的群落可命名为扁刺蔷薇+箭竹+密生薹草、唐古特忍冬+黑水柳+密生薹草、青海云杉-红桦+扁刺蔷薇+密生薹草群落和云杉-巴山冷杉+唐古特忍冬+密生薹草群落。3)不同演替阶段草本植物群落异质性指数5 a(0.07)<15 a(0.12)<23 a(0.19)<Climax(0.22)。4)5 a、15 a和23 a群落的多度为几何级数分布型,表明火烧迹地环境条件有利于草本植物生长,生态位确定性物种在群落构建过程中占据主要地位;而Climax群落的多度呈“S”型分布,“中间类型”物种占据了群落的绝大部分,属于演替晚期群落。5)根据β多样性的差异,可将4个不同演替阶段群落的灌木层划分为初建灌木层(5 a)和稳定灌木层(15 a,23 a,Climax),草本层划分为剧烈变化草本层(5 a和15 a)和稳定草本层(23 a和Climax)。[结论]随着植物群落演替时间越长,青藏高原东北边缘云杉-巴山冷杉林火烧迹地物种丰富度呈递减趋势,群落间的相似性越加接近,群落为正向演替,演替过程为灌木林--落叶阔叶林--针叶林--云杉-巴山冷杉林。

Design of portable and intelligent infuser device for rapid fluid transfusion based on micro-electro-mechanical system

Objective： A novel portable and intelligent fluid resuscitation infuser is proposed in this paper. It satisfies the demands of long time use in harsh environment, such as traffic accident, natural disaster, battlefield, evacuation, pre-hospital emergency and so on. Methods： Miniature linear motor and liquid blood cartridge compose the pump body. It＇s based on the biological impedance method to measure and control, which resolve the disadvantage of traditional infuser device： large power dissipation, big size, AC power supply only and can＇t be use in field. The whole device weights 250 gram and sizes as two mobile phone together Results： Model device experiment shows： six number 7 standard AAA size alkaline batteries will run the pump for approximately 8-10 h at 6 liters per hour; IV bag can be placed at any position of patient, even under the stretcher. Conclusion： It provides accurate and reliable intravenous infusion for fwst-aid treatment in field.

Rupture directivity effect on strong ground motion during the 12 May 2008 M_(W)7.9 Wenchuan earthquake

We focus here on the rupture directivity effect on the spatial distribution and attenuation characteristics of near-field ground motions during the 2008 MW7.9 Wenchuan earthquake.We examine the difference between the observed ground motions in and opposite the rupture directions and compare them with Next Generation Attenuation-West2(NGA-West2)ground motion prediction models.The isochrone directivity predictor is used to quantify the band-limited nature of the rupture directivity effect on strong ground motion.Our results show that the observed peak ground velocity(PGV)and spectral accelerations of periods of 1.0 s and longer are significantly amplified in the rupture direction,but de-amplified in the opposite direction affected by rupture directivity effect of this event.In contrast,the effect of rupture directivity on the observed peak ground acceleration(PGA)and periods of shorter than 1.0 s are relatively weak.The rupture directivity of this event shows clear period dependent and band limited characteristics with the strongest effect occurring around the period of 7.5 s.

Research on parametric modeling and computing of multi-tower suspension bridge based on ANSYS

Based on FEM (finite element method) program ANSYS and the OpenGL graphics, this paper develops the parametric modeling module and the computing module of the multi-tower suspension bridge, the modules being embedded into the ANSYS system, and the parametric modeling module parameters can be entered by way of interface, which can fast establish a multi-tower suspension bridge model. Calculation module can establish load conditions for the features of road bridge and specifications, in which multiple conditions can be defined and solved automatically. Post-processing part of the solution also serves the results of the subtotals and selects the output, so that the results of the output and finishing work have become more convenient and easier, and also the results can be saved in word, excel and other different file types.

Impact of prosthesis-patient mismatch on early and late outcomes after mitral valve replacement:a meta-analysis

Background Prognostic significance of prosthesis-patient mismatch(PPM)after mitral valve replacement(MVR)remains uncertain because of the limited studies reporting inconsistent or even contrary results.This meta-analysis pooled results of all available studies comparing early and late prognoses between patients with significant mitral PPM and those without.Methods Studies were identified by searching Pubmed,Excerpta Medica Database,Cochrane Central Register of Controlled Trials,and Clinical Trials.gov.Impact of PPM on postoperative hemodynamic results,thirty-day mortality,overall mortality,mortality of thirty-day survivors,and primary morbidity after MVR was evaluated via meta-analysis.Robustness of pooled estimates,source of heterogeneity,and publication bias were assessed via sensitivity analyses,meta-regression as well as subgroup analysis stratified according to methodological or clinical heterogeneity,or sequential omission method,and funnel plot or Begg's and Egger's tests,respectively.Results Nineteen cohort studies involving 9302 individuals(PPM group:n=5109,Control group:n=4193)were included for meta-analysis.Total PPM and severe PPM prevalence were 3.8%–85.9%and 1%–27%,with a mean value of 54.9%and 14.1%,respectively.As compared with control group,mitral PPM group demonstrated a poorer postoperative hemodynamic status of higher mean and peak residual transprosthetic pressure gradients(TPG),higher postoperative systolic pulmonary artery pressure(SPAP)and less reduction,higher postoperative pulmonary hypertension(PH)prevalence and less PH regression,smaller net atrioventricular compliance,less NYHA class decrease,higher postoperative functional tricuspid regurgitation prevalence and less regression.The PPM group also revealed a higher thirty-day mortality,long-term overall mortality,mortality of thirty-day survivors,and postoperative congestive heart failure prevalence,which were positively correlated with the severity of PPM if it was classified into tri-level subgroups.Left ventricular end-diastolic diameter,postoperative atrial fibrillation(AF)prevalence,and the AF regression were analogous between groups.Most pooled estimates were robust according to sensitivity analyses.Male patients and bioprosthesis implantation proportion were prominent source of between-study heterogeneity on thirty-day mortality.Publication bias was not significant in tests for all the outcomes,except for SPAP and TPG.Conclusions Mitral PPM would result in poorer postoperative hemodynamics and worse early and late prognosis.Severe PPM must be avoided since deleterious impact of mitral PPM was severity dependent.

青藏高原东北边缘云杉-巴山冷杉林火烧迹地草本植物群落构建机理

群落构建机制是生态学研究的核心论题。生态位理论和中性理论是阐明群落构建的两种主要理论,但这两种理论分别强调的环境过滤和扩散限制对群落构建的影响尚存争议。该研究以青藏高原东北边缘云杉-巴山冷杉林火烧迹地不同演替阶段草本群落为研究对象,应用扩散-生态位连续体指数(DNCI)和校正随机率(MST),分析不同演替阶段草本植物群落的主导构建机制。研究结果显示:1)5、15和23 a群落与Climax群落之间的DNCI分别为-22.6169、-21.7507和-8.2594,都远小于0,表明不同演替阶段草本植物群落构建的主要驱动作用是扩散过程;2)5 a-Climax组和23 a-Climax组的MST值均高于50%阈值线,这表明随机性过程在两组群落构建中均占支配地位;对于15 a-Climax组,15 a的MST值为0.6664,Climax的MST值等于0.4927,说明15 a植物群落构建以随机性为主,而Climax群落构建以确定性为主;由于15 a的MST值远高于50%,而Climax的MST值较接近于50%的阈值,也可说明15 a-Climax组群落构建仍以随机性为主。在青藏高原东北边缘云杉-巴山冷杉林火烧迹地,随机扩散主导了草本植物群落的构建过程。

青藏高原东北边缘云杉属-冷杉属林火烧迹地枯落物持水特征

以青藏高原东北边缘云杉属-冷杉属林火烧迹地为研究对象,基于典型抽样法于2020年8月和2021年7—8月在火烧迹地和未过火天然林采集枯落物样品,采用室内浸泡法测定分析枯落的蓄积量、持水量、有效拦蓄量等指标,探究林火干扰下不同坡位枯落物的水文效应,为更好地促进森林水源涵养以及水土保持功能提供依据。结果表明:(1)在植被恢复过程中,枯落物的厚度和蓄积量随着恢复年限的增加而增加,且厚度为3.75~8.31 cm,蓄积量为6.16~8.13 t/hm^(2)。恢复5,15年火烧迹地上、中、下坡枯落物厚度和蓄积量与天然林差异显著。(2)枯落物的最大持水量为20.94~26.22 t/hm^(2),恢复5,15年火烧迹地枯落物最大持水量与天然林差异达显著水平。在枯落物持水达到饱和前,不同恢复年限下各坡位枯落物持水量与浸水时间呈对数函数关系,吸水速率与浸水时间呈幂函数关系。(3)枯落物的有效拦蓄量为14.58~16.95 t/hm^(2),有效拦蓄深为1.44~1.78 mm。恢复5年火烧迹地枯落物有效拦蓄量表现为中坡>上坡>下坡,恢复15年火烧迹地和天然林有效拦蓄量均为下坡>中坡>上坡。综上所述,在植被恢复过程中,枯落物的厚度、蓄积量、持水性能都随着恢复年限的增加而提高,呈现天然林>恢复15年>恢复5年;火烧迹地枯落物的持水性能及持水过程呈现中、下坡大于上坡,即枯落物的水文效应受坡位和火烧干扰的影响。

基于遗传算法优化单类支持向量机的油田离心泵注水站异常检测

目前油田离心泵注水站多采用传统的人工巡检等方式进行异常检测,存在浪费大量资源且检测精度不高的情况。针对此问题,提出一种基于遗传算法优化单类支持向量机(genetic algorithm optimized one-class support vector machine,GA-OC-SVM)的注水站异常检测方法。首先,对注水站数据进行标准化、归一化处理以及特征提取;其次,使用遗传算法进行寻优得到最佳种群个体值作为单类支持向量机的参数,建立检测模型;最后,将GA-OC-SVM算法与孤立森林算法、局部离群因子算法等主流方法用于测试数据集的异常检测对比,并分析算法的精度,采用接受者操作特征(receiver operating characteristics,ROC)曲线进行模型评价。结果表明所提出的GA-OC-SVM算法更优,检测精度达到99%,同时能够节省大量的人力物力资源。

中国沙棘幼苗对土壤镉生理耐性和富集转运特征的性别差异

为探究中国沙棘对土壤镉(Cd)胁迫的性别响应差异,该研究以中国沙棘2年生幼苗为材料,利用盆栽试验研究在不同浓度Cd处理下(0(CK)、25、50、100和200 mg·kg^(-1))雌、雄株幼苗的生长、叶片生理特性以及Cd富集特征的差异。结果表明:(1)Cd处理下中国沙棘幼苗雌、雄株的株高和基径生长以及各器官生物量均表现出低浓度(<50 mg·kg^(-1))促进,高浓度(> 100 mg·kg^(-1))抑制的现象;低浓度Cd处理下雌株的株高、基径增长率和生物量的增幅均高于雄株;高浓度Cd处理下(200 mg·kg^(-1))雄株株高增长率、叶生物量和总生物量分别较CK显著降低,而雌株均未显著下降。(2)随着Cd浓度升高,雌、雄株叶片光合色素含量和抗氧化酶活性呈先升后降的变化趋势,丙二醛(MDA)和渗透调节物质含量呈上升趋势;Cd浓度为50~200 mg·kg^(-1)时,雌株叶片的光合色素含量、抗氧化酶活性和渗透调节物质含量均高于雄株,而MDA含量始终低于雄株。(3)随着Cd浓度升高,雌、雄株各器官Cd含量均逐渐上升且表现为根>茎>叶,雌株各器官Cd含量均高于雄株;雌、雄株地上和地下部分富集系数呈先增后减的变化趋势且均大于1,转移系数逐渐降低且均小于1;雌株地上和地下部分Cd富集系数以及转移系数均高于雄株,且地上部分Cd富集系数在Cd浓度为25~100 mg·kg^(-1)时显著高于雄株。研究发现,中国沙棘幼苗在土壤Cd浓度小于50 mg·kg^(-1)时表现出一定的Cd耐受性,当土壤Cd浓度大于100 mg·kg^(-1)时其Cd耐受性减弱,雌株对土壤Cd的生长适应性、生理耐性和富集转运能力较雄株强。

基于CJS-SLLE降维与即时学习的转炉炼钢终点碳温软测量方法

转炉炼钢中碳温的准确检测是终点判断的关键,基于数据驱动的终点碳温软测量方法是一种有效途径,但转炉炼钢生产过程数据存在高维度、非线性和数据波动大的问题.针对这一问题,本文提出一种降维与即时学习的终点碳温软测量(CJS-SLLE)算法用于过程数据的监督降维.通过在距离度量中引入量化后的碳温标签信息,从而构造了一种带有监督信息的度量方式实现类内类间方差的调整,然后在带标签信息的基础上引入数据间方向信息,从而实现了样本标签、方向和距离三者信息融合的一种新型(CJS)相似性度量策略,应用到局部线性嵌入中获得高维训练样本低维坐标;其次,提出一种自适应局部线性投影策略用于无标签待测样本,实现其低维坐标中同样包含标签信息;最后,根据即时学习算法选取样本子集建立偏最小二乘局部回归模型对终点碳温预测.在实际转炉炼钢生产过程数据仿真下,碳含量在±0.02%误差范围内预测精度达到90%,温度在±10℃误差范围内预测精度达到87%.

青藏高原东北边缘云杉-冷杉林火烧迹地的灌木群落特征

【目的】探究青藏高原东北边缘云杉-冷杉林火烧迹地植被恢复与重建过程中的灌木群落特征动态,阐明火烧迹地灌木群落多样性格局和维持机制的生态过程,为在火烧迹地恢复与重建过程中对植被进行合理干预、尽快恢复生态效益提供合理依据。【方法】以空间代时间方法,分析恢复5年和15年火烧迹地灌木群落和未过火林地林下灌木层物种组成特征、α物种多样性和β物种多样性。【结果】在5年、15年火烧迹地灌木群落与未过火林地林下灌木层之间,植物种类组成存在差异,5年火烧迹地共调查到11科17属24种,15年火烧迹地共调查到8科10属17种,未过火林地共调查到12科19属35种。5年、15年火烧迹地和未过火林地的物种丰富度指数与Pielou均匀度指数,以及5年火烧迹地的物种丰富度指数与Simpson指数、物种丰富度指数与Shannon-Wiener指数的相关性均不强(P<0.1或P>0.1),其他指数间的相关性均较强(P<0.001或P<0.01)。物种丰富度指数为5年火烧迹地>15年火烧迹地>未过火林地,Shannon-Wiener指数和Simpson指数均为15年火烧迹地>未过火林地>5年火烧迹地,Pielou均匀度指数为15年火烧迹地>未过火林地>5年火烧迹地。5年、15年火烧迹地灌木群落的物种组成最相似,未过火林地林下灌木层物种组成和15年火烧迹地灌木群落的相似度大于5年火烧迹地。【结论】青藏高原东北边缘云杉-冷杉林经重度林火干扰后,在不同恢复时间梯度上的物种组成存在差异。火后短时间内局部生境范围内物种丰富度增加,火烧迹地的物种多样性和优势度较低,物种分布不均匀。随着演替进行,物种丰富度减小,物种多样性和优势度上升,物种分布较均匀。随着火烧迹地演替正常进行,火烧迹地与未过火林地物种组成相似度增加,火烧迹地灌木群落朝着正向演替。

装配式混凝土T梁桥荷载横向分布系数预测

荷载横向分布系数是桥梁横向传力性能的重要指标,传统计算方法多采用单一变量的简化数学公式,基于此提出了一种基于可解释性机器学习的荷载横向分布系数预测方法。首先建立了基于有限元模拟的荷载横向分布系数计算方法,分析了跨径、宽跨比、单板宽/板间距、悬臂长、悬臂惯性矩、主梁抗弯惯性矩和抗扭惯性矩7维输入参数影响;然后采用支持向量机器学习方法对装配式混凝土T梁桥荷载横向分布系数进行预测,利用遗传算法对支持向量机超参数进行优化;最后,采用Shapley加性解释器分析了多维参数对预测结果的敏感性。结果表明,所提改进支持向量机模型能够实现装配式混凝土T梁桥荷载横向分布系数预测,且具有较高的预测精度。跨径和宽跨比参数对双车道和三车道荷载横向分布系数预测最为重要。

反向穿刺引导装置在腹腔镜全腹膜外疝修补术中的应用价值分析

目的:探讨反向穿刺引导装置在腹腔镜全腹膜外疝修补术(TEP)中完成套管穿刺的应用价值。方法:回顾分析2021年10月至2022年10月为80例腹股沟疝患者行TEP的临床资料,按手术方法分为实验组(n=40,采用反向穿刺引导装置完成第二、第三穿刺点的建立)与对照组(n=40,采用标准正向穿刺法),比较两组穿刺效果、手术相关指标及并发症。结果:78例患者完成TEP,实验组无中转手术,对照组2例中转为经腹腹膜前疝修补术。实验组腹直肌损伤率、腹壁小血管损伤导致出血率低于对照组,术中擦拭镜头次数少于对照组,建立腹膜前间隙时间、手术时间均短于对照组,差异有统计学意义(P<0.05)。两组腹膜穿破率、术后住院时间、术后12 h与24 h疼痛评分、术后并发症发生率差异无统计学意义(P>0.05)。结论:使用反向穿刺引导装置在TEP术中完成套管穿刺具有显著效果,能提高套管穿刺的安全性,降低腹直肌、腹壁小血管损伤率,缩短手术时间,利于TEP的推广与普及。