Industry-Oriented Detection Method of PCBA Defects Using Semantic Segmentation Models

Automated optical inspection(AOI)is a significant process in printed circuit board assembly(PCBA)production lines which aims to detect tiny defects in PCBAs.Existing AOI equipment has several deficiencies including low throughput,large computation cost,high latency,and poor flexibility,which limits the efficiency of online PCBA inspection.In this paper,a novel PCBA defect detection method based on a lightweight deep convolution neural network is proposed.In this method,the semantic segmentation model is combined with a rule-based defect recognition algorithm to build up a defect detection frame-work.To improve the performance of the model,extensive real PCBA images are collected from production lines as datasets.Some optimization methods have been applied in the model according to production demand and enable integration in lightweight computing devices.Experiment results show that the production line using our method realizes a throughput more than three times higher than traditional methods.Our method can be integrated into a lightweight inference system and pro-mote the flexibility of AOI.The proposed method builds up a general paradigm and excellent example for model design and optimization oriented towards industrial requirements.

Magnesium cantharidate suppresses PP2A and ERK1/2 pathway to inhibit hepatocellular carcinoma cells

Background:Magnesium cantharidate(MC)is a protein phosphatase 2A(PP2A)inhibitor antitumor drug.However,its antitumor mechanism in hepatocellular carcinoma cell(HCC)remains unclear.Methods:PP2A lentiviral vector over expression strategy was utilized both in vivo and in vitro to explore the antitumor effect in MC and okadaic acid(OA).Tumor weight was detected in mice after MC and OA exposure.Cell proliferation,cell cycle,apoptosis rate,and western blotting were detected to explore the effects on MC and OA in human hepatocarcinoma SMMC-7721 cells.Results:In vivo results demonstrated that MC inhibited HCC progression while OA promoted tumor growth.In vitro results demonstrated that MC effectively inhibited the growth of SMMC-7721 cells by arresting the cell cycle at the G2/M phase with inhibiting Cdc25C and activating the phosphorylation of the Cdc2 protein.Flow cytometry results further showed that MC increased apoptosis.Furthermore,the expression of phosphorylated ERK1/2 was lower in the MC group but higher in the OA group.Molecular docking results showed that MC docked well with ERK1/2.Conclusions:MC inhibited HCC progression by suppressing the growth and activating the apoptosis of cancer cells and suppressing the expression of PP2A and ERK1/2.

“动之以情”还是“晓之以理”--权力感对消费者产品决策的影响

商家对待不同权力感的消费者是该“动之以情”(强调产品的独特情感体验)还是“晓之以理”(突出产品的优势功能属性)?哪种方式能带来更好的营销绩效?本研究通过4个情景模拟实验和1个行为实验,探讨和阐释权力感如何影响消费者决策方式及产品选择。研究发现:不论是长期权力感(实验2、实验3)还是启动权力感(实验1a、实验1b和实验1c),都会影响消费者的决策模式偏好,高(v s.低)权力感消费者偏好采用感性(v s.理性)模式进行决策;权力感影响决策模式选择的内在机制是消费者对决策合理性的解释需要(实验2);同时权力感对决策模式选择的影响程度取决于消费者的决策聚焦(为自己/为他人)(实验3)。研究结论丰富和拓展了权力感与消费者决策相关领域的文献,对企业有针对性地设计营销策略具有重要的借鉴价值。

Modified inferior oblique anterior transposition for dissociated vertical deviation combined with superior oblique palsy:A case report

BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually provides satisfactory primary position alignment and simultaneously restricts the superior floating phenomenon.However,it also increases the risk of the anti-elevation syndrome and narrowing of the palpebral fissure in straight-ahead gaze,especially after the unilateral operation.CASE SUMMARY We report the outcomes of the modified unilateral IOAT in two patients with unilateral DVD combined with SOP.The anterior-nasal fibers of the inferior oblique muscle were attached at 9 mm posterior to the corneal limbus along the temporal board of the inferior rectus muscle,the other fibers were attached a further 5 mm temporal to the anterior-nasal fibers.Postoperatively,both hypertropia and floating were improved,and no obvious complications occurred.CONCLUSION In these cases,the modified unilateral IOAT was an effective and safe surgical method for treating DVD with SOP.

通过扫描光电化学显微镜研究超分子光敏剂-二氧化钛薄膜系统的光诱导电子转移

在基于TiO_(2)的光阳极上枝接电荷转移通道仍然是太阳能到化学转换技术的一个迫切瓶颈。尽管进行了大量的尝试,但TiO_(2)作为有前途的光阳极材料仍然受到电荷传输动力学迟缓的影响。因此,一种组装策略涉及将金属卟啉基光敏剂分子(MP)轴向配位嫁接到表面改性的TiO_(2)纳米棒(TiO_(2)NRs)光阳极上,形成复合MP/TiO_(2)NRs光电极。正如预期的那样,与单独的TiO_(2)NR和MPA/TiO_(2)NRs光电极相比,所得到的独特的MPB/TiO_(2)NRs光电极具有明显提高的光电流密度。采用扫描光电化学显微镜(SPECM)和强度调制光电流光谱(IMPS)系统地评估了MP/TiO_(2)NRs光电极的连续光激发电子转移(PET)动力学信息。通过数据拟合发现,在光照条件下,MPB/TiO_(2)NRs的光电子转移速率(keff)常数比纯TiO_(2)NRs高2.6倍左右。MPB/TiO_(2)NRs的高动力学常数是由于D-A结构的共轭分子MPB可以有效地加速分子内电子转移,以及促进电子在新型电荷转移通道中参与I3-到I的还原反应。本研究展示的结果有望为研究人工光合作用电荷转移过程的机制和构建高效的光电极提供一些启发。

Prediction of Potential Sorghum Suitability Distribution in China Based on Maxent Model

It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were selected to predict the potential habitat distribution of sorghum in China. The potential distribution of sorghum under baseline climate conditions and future climate conditions (2050s and 2070s) under two climate change scenarios, RCP4.5 and RCP8.5, were simulated, and the receiver operating curve under the accuracy of the model was evaluated using the area under the receiver operating curve (AUC). The results showed that the maximum entropy model predicted the potential sorghum habitat distribution with high accuracy, with Bio2 (monthly mean diurnal temperature difference), Bio6 (minimum temperature in the coldest month), and Bio13 (rainfall in the wettest month) as the main climatic factors affecting sorghum distribution among the 22 environmental factors. Under the baseline climate conditions, potential sorghum habitats are mainly distributed in the southwest, central, and east China. Over time, the potential sorghum habitat expanded into northern and southern China, with significant additions and negligible decreases in potential sorghum habitat in the study area, and a significant increase in total area, with the RCP8.5 scenario adding much more area than the RCP4.5 scenario.

EDTA滴定法测药物制剂中的ZnO:定量分析在实践中的应用

氧化锌可作为食品、化妆品和药品中的添加剂。本实验通过乙二胺四乙酸(EDTA)滴定法测定了痱子粉和皮肤软膏中ZnO的含量。以实际生活中的药品作为实验素材,发现配位滴定在质量控制中的实际应用,激发学生的学习兴趣,通过将实验结果与标签信息进行比较,更好地理解和掌握配位滴定法的原理、实验操作和定量分析实验结果的处理。

Recent progress on low dimensional perovskite solar cells

Low dimensional perovskites have recently attracted much attention due to their vertical growth of crys- talline orientation, excellent film morphology, and long-term humidity, light, and heat stability, How- ever, low dimensional perovskites suffer fl＇om low power conversion efficiency （PCE） with respect to their three dimensional analogues. Therefore, it is imperative to find excellent low-dimensional perovskite materials for improving the PCE. Previous work has demonstrated that bulkier organic molecules, e,g., C6Hs（CH2）2NH3＋ （PEA＋）, CH3（CH2）3NH3＋（n-BAT, iso-BA＋）, C2H4NH3 ＋, and polyethylenimine cations （PEI＋）, play an important role in the formation of low-dimensional perovskites. In this review, we review the recent development of low dimensional perovskites for solar cells application in terms of film preparation, photophysics, and stability of perovskites, as well as the related device structure and physics. We have also discussed the future development of low-dimensional perovskites from materials design, fabri- cation processes, and device structure.

Real-Time Iterative Compensation Framework for Precision Mechatronic Motion Control Systems

With regard to precision/ultra-precision motion systems,it is important to achieve excellent tracking performance for various trajectory tracking tasks even under uncertain external disturbances.In this paper,to overcome the limitation of robustness to trajectory variations and external disturbances in offline feedforward compensation strategies such as iterative learning control(ILC),a novel real-time iterative compensation(RIC)control framework is proposed for precision motion systems without changing the inner closed-loop controller.Specifically,the RIC method can be divided into two parts,i.e.,accurate model prediction and real-time iterative compensation.An accurate prediction model considering lumped disturbances is firstly established to predict tracking errors at future sampling times.In light of predicted errors,a feedforward compensation term is developed to modify the following reference trajectory by real-time iterative calculation.Both the prediction and compen-sation processes are finished in a real-time motion control sampling period.The stability and convergence of the entire control system after real-time iterative compensation is analyzed for different conditions.Various simulation results consistently demonstrate that the proposed RIC framework possesses satisfactory dynamic regulation capability,which contributes to high tracking accuracy comparable to ILC or even better and strong robustness.

Effects of 3.7 T-24.5 T high magnetic fields on tumor-bearing mice

Since high magnetic field（MF） intensity can improve the image quality and reduce magnetic resonance imaging（MRI） acquisition time, the field intensity of MRIs has continued to increase over the past few decades. Although MRIs in most current hospitals are 0.5 T–3 T, there are preclinical studies have been carried out using 9.4 T MRI, and engineers are also putting efforts on building MRIs with even higher MFs. However, the accompanied safety issue of high-field MRIs is an emergent question to address before their clinical applications. In the meantime, the static magnetic field（SMF） has been shown to inhibit tumor growth in previous studies. Here, we investigated both the safety issue and the anti-tumor potentials of 3.7 T–24.5 T SMFs on GIST-T1 gastrointestinal stromal tumor-bearing nude mice. We followed up the mice three weeks after their exposure to high SMF and found that none of the mice died or had severe organ damage, except for slightly decreased food intake, weight gain, and liver function. Moreover, the tumor growth was inhibited by 3.7 T–24.5 T SMFs（up to ～54%）. It is interesting that the effects are more dependent on MF gradient than intensities, and for the same gradient and intensity, mice responded differently to hypogravity and hypergravity conditions. Therefore, our study not only demonstrated the safeness of high SMFs up to 24.5 T on mice but also revealed their anti-tumor potentials in the future.

Effect of Guhong injection combined with atorvastatin on angina pectoris of coronary heart disease and its influence on Hemorheology and oxidative stress

Objective:To explore the effect of Guhong injection combined with atorvastatin on CHD patients with angina pectoris and its influence on hemorheology and oxidative stress.Methods:80 CHD patients with angina pectoris admitted to our hospital from December 2018 to December 2019 were randomly divided into the observation group(40 cases)and the control group(40 cases)by use of the random number table.The patients in the control group were treated with atorvastatin,while those in the observation group were treated with Guhong injection on the basis of the control group.The course of treatment was 2 weeks for each group.The treatment effect,the frequency of angina pectoris seizure and its duration before and after treatment,the changes of hemorheology indexes and oxidative stress and the occurrence of adverse reactions were compared between the two groups.Results:the total effective rate of the observation group(92.50%)was higher than that of the control group(70.00%)(p<.05).The frequency of angina pectoris seizure and its duration in these two groups after treatment were lower than those before treatment(Observation group:t=25.588,23.009;Control group:t=16.587,16.263;p<.05);After treatment,the frequency of angina pectoris seizure and its duration in the observation group were lower than those in the control group(t=15.191,9.425;p<.05).In the observation group,the hemorheology indexes after treatment were lower than those before treatment(t=6.742,15.224,6.983,23.537,p<.05);the hemorheology indexes after treatment in the observation group were lower than those in the control group(t=5.201,13.913,5.539,13.745;p<.05).In the observation group,the level of serum SOD after treatment was higher than that before treatment,while the levels of LPO and MDA after treatment were lower than those before treatment(t=10.839,6.924,8.466;p<.05);the level of serum SOD after treatment in the observation group was higher than that in the control group,while the levels of LPO and MDA after treatment in the observation group were lower than those in the control group(t=6.171,6.432,5.394;p<.05).The incidence of adverse reactions in the observation group was lower than that in the control group(p<.05).Conclusions:Guhong injection combined with atorvastatin has an obvious clinical effect on CHD patients with angina pectoris,and it can improve hemorheology indexes and oxidative stress reaction with fewer adverse reactions.

Solution processed nano-ZnMgO interfacial layer for highly efficient inverted perovskite solar cells

Interfacial layer has a significant impact on the achievement of highly efficient organic–inorganic hybrid perovskite solar cells(PSCs). Here, we introduced a nano-ZnMgO(magnesium doped ZnO, abbreviated as ZnMgO) as interfacial layer between [6, 6]-Phenyl C_(61) butyric acid methyl ester(PC_(61) BM) layer and Al electrode to replace LiF or ZnO interlayer and enhance device performance. The device efficiency has been improved from 11.43% to 15.61% and the hysteresis was decreased dramatically. Such huge enhancement of power convert efficiency(PCE) can be attributed to the low dark current density, enhancement of electron-selective contact, and low energy barrier at the PC_(61) BM/Al interface. We suggest that this simple nano-scale interlayer can provide an efficient charge transport and extraction for highly efficient PSCs.

Direct Observation of Transition Metal Dichalcogenides in Liquid with Scanning Tunneling Microscopy

We present atomic-resolution images of TiSe2,MoTe2 and TaS2 single crystals in liquid condition using our home-built scanning tunneling microscopy(STM).By facilely cleaving of single crystals in liquid,we were able to keep the fresh surface not oxidized within a few hours.Using the high-stable home-built STM,we have obtained atomic resolution images of TiSe2 accompanied with the single atom defects as well as the triangle defects in solution for the first time.Besides,the superstructure of MoTe2 and hexagonal chargedensity wave domain structure in nearly commensurate phase of TaS2 were also obtained at room temperature(295 K).Our results provide a more efficient method in investigating the lively surface of transition metal dichalcogenides.Besides,the high stable liquid-phase STM will support the further investigations in liquid-phase catalysis or electrochemistry.

Growth of Ag/g-C_(3)N_(4) nanocomposites on nickel foam to enhance photocatalytic degradation of formaldehyde under visible light

Formaldehyde is a pollutant that significantly affects the indoor air quality.However,conventional remediation approaches can be challenging to deal with low-concentration formaldehyde in an indoor environment.In this study,Photocatalysts of Ag/graphitic carbon nitride(g-C_(3)N_(4))/Ni with 3D reticulated coral structure were prepared by thermal polymerization and liquid phase photo-deposition,using nickel foam(NF)as the carrier.Experiments demonstrated that when the Ag concentration was 3%,and the relative humidity was 60%,the Ni/Ag/g-C_(3)N_(4)showed the maximum degradation rate of formaldehyde at 90.19%under visible light irradiation,and the formaldehyde concentration after degradation was lower than the Hygienic standard stated by the Chinese Government.The porous structure of Ni/Ag/g-C_(3)N_(4)and the formation of Schottky junctions promoted the Adsorption efficiency and degradation of formaldehyde,while the nickel foam carrier effectively promoted the desorption of degradation products.Meanwhile,the degradation rate was only reduced by3.4%after 16 recycles,the three-dimensional porous structure extended the lifetime of the photocatalyst.This study provides a new strategy for the degradation of indoor formaldehyde at low concentrations.

Effect of inorganic arsenic in paddy soil on the migration and transformation of selenium species in rice plants

Selenium(Se)in paddy rice is one of the significant sources of human Se nutrition.However,the effect of arsenic(As)pollution in soil on the translocation of Se species in rice plants is unclear.In this research,a pot experiment was designed to examine the effect of the addition of 50 mg As/kg soil as arsenite or arsenate on the migration of Se species from soil to indica Minghui 63 and Luyoumingzhan.The results showed that the antagonism between inorganic As and Se was closely related to the rice cultivar and Se oxidation state in soil.Relative to the standalone selenate treatment,arsenite significantly(p<0.05)decreased the accumulation of selenocystine,selenomethionine and selenate in the roots,stems,sheaths,leaves,brans and kernels of both cultivars by 21.4%-100.0%,40.0%-100.0%,41.0%-100%,5.4%-96.3%,11.3%-100.0% and 26.2%-39.7% respectively,except for selenocystine in the kernels of indica Minghui 63 and selenomethionine in the leaves of indica Minghui 63 and the stems of indica Luyoumingzhan.Arsenate also decreased(p<0.05)the accumulation of selenocystine,selenomethionine and selenate in the roots,stems,brans and kernels of both cultivars by 34.9%-100.0%,30.2%-100.0%,11.3%-100.0% and 5.6%-39.6%respectively,except for selenate in the stems of indica Minghui 63.However,relative to the standalone selenite treatment,arsenite and arsenate decreased(p<0.05)the accumulation of selenocystine,selenomethionine and selenite only in the roots of indica Minghui 63 by 45.5%-100.0%.Our results suggested that arsenite and arsenate had better antagonism toward Se species in selenate-added soil than that in selenite-added soil;moreover,arsenite had a higher inhibiting effect on the accumulation of Se species than arsenate.

Stable alkali halide vapor assisted chemical vapor deposition of 2D HfSe2 templates and controllable oxidation of its heterostructures

Two-dimensional hafnium-based semiconductors and their heterostructures with native oxides have been shown unique physical properties and potential electronic and optoelectronic applications.However,the scalable synthesis methods for ultrathin layered hafnium-based semiconductor laterally epitaxy growth and its heterostructure are still restricted,also for the understanding of its formation mechanism.Herein,we report the stable sublimation of alkali halide vapor assisted synthesis strategy for high-quality 2D HfSe_(2) nanosheets via chemical vapor deposition.Single-crystalline ultrathin 2D HfSe_(2) nanosheets were systematically grown by tuning the growth parameters,reaching the lateral size of 6‒40μm and the thickness down to 4.5 nm.The scalable amorphous HfO_(2)and HfSe_(2)heterostructures were achieved by the controllable oxidation,which benefited from the approximate zero Gibbs free energy of unstable 2D HfSe_(2) templates.The crystal structure,elemental,and time dependent Raman characterization were carried out to understand surface precipitated Se atoms and the formation of amorphous Hf−O bonds,confirming the slow surface oxidation and lattice incorporation of oxygen atoms.The relatively smooth surface roughness and electrical potential change of HfO_(2)−HfSe_(2) heterostructures indicate the excellent interface quality,which helps obtain the high performance memristor with high on/off ratio of 105 and long retention period over 9000 s.Our work introduces a new vapor catalysts strategy for the synthesis of lateral 2D HfSe_(2) nanosheets,also providing the scalable oxidation of the Hf-based heterostructures for 2D electronic devices.

Analyzing Nitrogen Effects on Rice Panicle Development by Panicle Detection and Time-Series Tracking

Detailed observation of the phenotypic changes in rice panicle substantially helps us to understand the yield formation.In recent studies,phenotyping of rice panicles during the heading–flowering stage still lacks comprehensive analysis,especially of panicle development under different nitrogen treatments.In this work,we proposed a pipeline to automatically acquire the detailed panicle traits based on time-series images by using the YOLO v5,ResNet50,and DeepSORT models.Combined with field observation data,the proposed method was used to test whether it has an ability to identify subtle differences in panicle developments under different nitrogen treatments.The result shows that panicle counting throughout the heading–flowering stage achieved high accuracy(R^(2)=0.96 and RMSE=1.73),and heading date was estimated with an absolute error of 0.25 days.In addition,by identical panicle tracking based on the time-series images,we analyzed detailed flowering phenotypic changes of a single panicle,such as flowering duration and individual panicle flowering time.For rice population,with an increase in the nitrogen application:panicle number increased,heading date changed little,but the duration was slightly extended;cumulative flowering panicle number increased,rice flowering initiation date arrived earlier while the ending date was later;thus,the flowering duration became longer.For a single panicle,identical panicle tracking revealed that higher nitrogen application led to earlier flowering initiation date,significantly longer flowering days,and significantly longer total duration from vigorous flowering beginning to the end(total DBE).However,the vigorous flowering beginning time showed no significant differences and there was a slight decrease in daily DBE.

基于电刺激的导电水凝胶用于糖尿病伤口修复中的免疫调节、神经再生和快速血管生成

糖尿病创面是难以愈合的慢性创面,主要由创面感染、过度炎症、糖尿病神经病变、外周血管病变等引起.因此,全面改善糖尿病创面愈合在临床上具有重要意义.然而,目前对糖尿病创面的研究主要集中在创面感染和血管生成方面,缺乏对神经再生和免疫调节的探索.在这项研究中,我们开发了多功能导电水凝胶作为一种有效的伤口敷料.该水凝胶具有多种功能,包括优异的机械性能、组织粘附性、导电性和广谱抗菌活性.受内源性电场的启发,我们提出了将水凝胶与电刺激相结合的策略来加速糖尿病伤口的愈合.值得注意的是,电刺激结合导电水凝胶的治疗手段可有效促进神经修复,实现巨噬细胞向M2表型的极化以及快速血管生成,从而全面改善糖尿病创面的愈合.这种先进的协作策略为治疗糖尿病伤口开辟了一种新途径.

Advances in thermal-related analysis techniques for solid-state lithium batteries

Solid-state lithium batteries(SSLBs)have been broadly accepted as a promising candidate for the next generation lithium-ion batteries(LIBs)with high energy density,long duration,and high safety.The intrinsic non-flammable nature and electrochemical/thermal/mechanical stability of solid electrolytes are expected to fundamentally solve the safety problems of conventional LIBs.However,thermal degradation and thermal runaway could also happen in SSLBs.For example,the large interfacial resistance between solid electrolytes and electrodes could aggravate the joule heat generation;the anisotropic thermal diffusion could trigger the uneven temperature distribution and formation of hotspots further leading to lithium dendrite growth.Considerable research efforts have been devoted to exploring solid electrolytes with outstanding performance and harmonizing interfacial incompatibility in the past decades.There have been fewer comprehensive reports investigating the thermal reaction process,thermal degradation,and thermal runaway of SSLBs.This review seeks to highlight advanced thermal-related analysis techniques for SSLBs,by focusing particularly on multiscale and multidimensional thermal-related characterization,thermal monitoring techniques such as sensors,thermal experimental techniques imitating the abuse operating condition,and thermalrelated advanced simulations.Insightful perspectives are proposed to bridge fundamental studies to technological relevance for better understanding and performance optimization of SSLBs.

Biological Vibration Damping Strategies and Mechanisms

Excessive vibration in civil and mechanical systems can lead to structural damage or harmful noise.Structural vibration can be mitigated by reducing the energy of the vibration source or by isolating the external disturbance from the target structure.Depending on the tunability and power consumption of the system,existing vibration control strategies are divided into active,passive and semi-active types,providing a more stable and efficient solution for vibration control.However,conventional damping structures have difficulty in meeting the requirements of wide frequency range and high precision damping under complex operating conditions.Therefore,the design of efficient damping structures is one of the key challenges in the development of vibration control technology.Organisms have evolved over millions of years to effectively damp vibrations through special structures and composite materials to ensure their survival.Opening up damping vibration isolation technology from a bionic perspective can meet the frequency requirements of vibration damping and guarantee higher output accuracy of machinery.This review summarizes the basic principles of vibration control and analyses the vibration control strategies for different damping materials and damping structures.Meanwhile,various models of bio-damped structures are outlined.Moreover,the current status and recent progress of research on bionic damped structures based on bio-vibration control strategies are discussed.Finally,new perspectives on future developments in the field of bionic damped vibration control techniques are also presented.A comprehensive understanding of existing vibration damping mechanisms and new methods of bionic damping design will certainly trigger important applications of precision vibration control in the fields of aerospace,rail transportation and mechanical systems.