聚乙二醇@聚乙烯醇同轴相变纤维的储热特性

以具有高相变焓的聚乙二醇(PEG 4000)为核层相变材料(PCM)、聚乙烯醇(PVA)为壳层支撑材料、绿色溶剂水为壳层和核层材料溶剂,通过同轴静电纺丝制备出不同核层纺丝液浓度、进液速度的核-壳相变纤维。扫描电镜和透射电镜照片显示,在PEG质量分数为45%、进液速度为0.06 mL/h时,PEG@PVA具有良好的形貌及较高含量的PEG,相变纤维核壳分界面明显。红外光谱分析显示,PEG与PVA化学相容性良好;差示扫描量热分析和热重分析表明,PEG@PVA熔融温度为62.8℃,熔融焓为86.40 J/g,封装效率为42.2%,并且相变纤维膜起始热分解温度较高,在经过500次热循环实验后,熔融焓约损失3.1%,仍能保持绝大部分相变能力;导热测试表明,PEG@PVA膜的热导率介于壳层PVA与核层PEG之间;模拟PEG@PVA膜在工作环境中的温度变化得到温度-时间曲线,结果表明,相变纤维膜可以有效地调节微环境的温度。

A hierarchical enhanced data-driven battery pack capacity estimation framework for real-world operating conditions with fewer labeled data

Battery pack capacity estimation under real-world operating conditions is important for battery performance optimization and health management,contributing to the reliability and longevity of batterypowered systems.However,complex operating conditions,coupling cell-to-cell inconsistency,and limited labeled data pose great challenges to accurate and robust battery pack capacity estimation.To address these issues,this paper proposes a hierarchical data-driven framework aimed at enhancing the training of machine learning models with fewer labeled data.Unlike traditional data-driven methods that lack interpretability,the hierarchical data-driven framework unveils the“mechanism”of the black box inside the data-driven framework by splitting the final estimation target into cell-level and pack-level intermediate targets.A generalized feature matrix is devised without requiring all cell voltages,significantly reducing the computational cost and memory resources.The generated intermediate target labels and the corresponding features are hierarchically employed to enhance the training of two machine learning models,effectively alleviating the difficulty of learning the relationship from all features due to fewer labeled data and addressing the dilemma of requiring extensive labeled data for accurate estimation.Using only 10%of degradation data,the proposed framework outperforms the state-of-the-art battery pack capacity estimation methods,achieving mean absolute percentage errors of 0.608%,0.601%,and 1.128%for three battery packs whose degradation load profiles represent real-world operating conditions.Its high accuracy,adaptability,and robustness indicate the potential in different application scenarios,which is promising for reducing laborious and expensive aging experiments at the pack level and facilitating the development of battery technology.

Automatic detection method of bladder tumor cells based on color and shape features

Bladder urothelial carcinoma is the most common malignant tumor disease in urinary system,and its incidence rate ranks ninth in the world.In recent years,the continuous development of hyperspectral imaging technology has provided a new tool for the auxiliary diagnosis of bladder cancer.In this study,based on microscopic hyperspectral data,an automatic detection algorithm of bladder tumor cells combining color features and shape features is proposed.Support vector machine(SVM)is used to build classification models and compare the classification performance of spectral feature,spectral and shape fusion feature,and the fusion feature proposed in this paper on the same classifier.The results show that the sensitivity,specificity,and accuracy of our classification algorithm based on shape and color fusion features are 0.952,0.897,and 0.920,respectively,which are better than the classification algorithm only using spectral features.Therefore,this study can effectively extract the cell features of bladder urothelial carcinoma smear,thus achieving automatic,real-time,and noninvasive detection of bladder tumor cells,and then helping doctors improve the efficiency of pathological diagnosis of bladder urothelial cancer,and providing a reliable basis for doctors to choose treatment plans and judge the prognosis of the disease.

印尼基础教育数字化转型的动因、措施和瓶颈

尽管印尼通过教育数字化行动战略应对教育不公问题取得了实质性进展,但其在数字化转型进程中也遇到教育数字基建的可及性缺陷、教师数字胜任力水平不高、教育数字化治理和监管难题等一系列困境。从战略推进结果来看,成效主要集中在五个方面:一是以信息通信技术作为教育数字基建的重心;二是鼓励多元主体协作;三是加强教师信息通信技术应用培训;四是创新信息通信技术课程内容与标准;五是着力培养儿童的信息通信技术素养。印尼基础教育数字化转型的启示在于:一是应由政府主导教育的数字基建;二是避免教育科技企业的过度渗透;三是强化基础教育数字化服务能力建设。

Dynamic MmWave Channel Reconstruction of MIMO OTA Testing for Handover Scenarios

The evaluation of handover performance is essential for ensuring seamless user experience under innovative application scenarios in the fifth generation(5G)and beyond era,including autonomous driving,mobile augmented and virtual reality.However,due to the hardware constrains of a sectored multiprobe anechoic chamber(SMPAC),switching among multiple channel models is of low precision with a high cost in traditional over-the-air(OTA)test solutions.In this paper,we present an efficient and repeatable emulation strategy to reconstruct dynamic millimeter-wave(mm Wave)channels in laboratories for multiple-input multiple-output(MIMO)mobile devices.Firstly,we propose a novel evaluation metric,called average power angular spectrum similarity percentage(APSP),which minimizes the unexpected impact induced by the indefinite condition of adaptive antenna arrays in mm Wave terminals during handover process.Moreover,we propose a partitioned probe configuration strategy by designing a beam directivitybased switching circuit,which enables quick changes of probe configurations in SMPAC.Simulation results demonstrate the effectiveness of the proposed algorithms,thus providing a guideline for the reconstruction of the dynamic channel in different scenarios with resource limitation.

Surface Quality Improvement in Machining an Aluminum Honeycomb by Ice Fixation

A honeycomb structure is widely used in sandwich structure components in aeronautics and astronautics;however,machining is required to reveal some of its features.In honeycomb structures,deficiencies,such as burrs,edge subsiding,and cracking,can easily appear,owing to poor specific sti ness in the radial direction.Some e ective fixation methods based on a filling principle have been applied by researchers,including approaches based on wax,polyethylene glycol,iron powder,and(especially)ice.However,few studies have addressed the optimization of the cutting parameters.This study focused on optimizing the cutting parameters to obtain a better surface roughness(calculated as a roughness average or Ra)and surface morphology in the machining of an aluminum alloy honeycomb by an ice fixation method.A Taguchi method and an analysis of variance were used to analyze the e ects and contributions of spindle speed,cutting depth,and feed rate.The optimal cutting parameters were determined using the signal-to-noise ratio combined with the surface morphology.An F-value and P-value were calculated for the value of the Ra,according to a"smaller is better"model.Additionally,the optimum cutting parameters for machining the aluminum honeycomb by ice fixation were found at different levels.The results of this study showed that the optimal parameters were a feed rate of 50 mm/min,cutting depth of 1.2 mm,and spindle speed of 4000 r/min.Feed rate was the most significant factor for minimizing Ra and improving the surface morphology,followed by spindle speed.The cutting depth had little e ect on Ra and surface morphology.After optimization,the value of Ra could reach 0.218μm,and no surface morphology deterioration was observed in the verified experiment.Thus,this research proposes optimal parameters based on ice fixation for improving the surface quality.

Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1

Bone regeneration remains a great clinical challenge. Low intensity near-infrared(NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells(BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1(CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein(BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.

Effects of Different Dietary Energy and Protein Levels on Meat Performance and Meat Quality of Jinghai Yellow Chickens

To investigate the effect of different dietary energy and protein levels on meat performance and meat quality of Jinghai yellow chickens, 480 43-day old Jinghai yellow chickens with similar weight were randomly divided into four experimental groups： experimental group 1 （protein 15%, metabolic energy 9.95 MJ/kg）, experimental group 2 （protein 16%, metabolic energy 10.95 MJ/kg）, experimental group 3 （protein 17%, metabolic energy 12.65 MJ/kg） and experimental group 4 （ protein 18%, metabolic energy 13.95 MJ/kg）, respectively. All chickens were slaughtered at 112-day old. The breast and leg muscles of Jinghai yellow chickens were collected, to determine the slaughter performance, conventional meat quality and muscle chemical indicators. The results indicated that dressing-out percentage and eviscerated yield percentage in four experimental groups were above 87.27% and 67.00%, respectively; other slaughter performance indicators exhibited no significant differences among various groups （P 〉 0.05 ） ; breast muscle color of hens in experimental group 4 varied significantly from that in other three groups （ P 〈 0.05 ） ; leg muscle color of hens in experimental group 2 varied extremely significantly from that in other three groups （ P 〈 0.01 ） ; water-holding capacity of breast muscles of hens in experimental group 3 was significantly higher than that in experimental group 4 （P 〈 0.05 ） ; thiamine content of breast muscles of cocks in experimental group 3 was significandy higher than that in experimental group 2 （ P 〈 0.05 ） ; however, other properties exhibited no significant differenees among various groups （P 〉 0.05 ）.

Linear polarization holography

Polarization holography is a newly researched field,that has gained traction with the development of tensor theory.It primarily focuses on the interaction between polarization waves and photosensitive materials.The extraordinary capabil-ities in modulating the amplitude,phase,and polarization of light have resulted in several new applications,such as holo-graphic storage technology,multichannel polarization multiplexing,vector beams,and optical functional devices.In this paper,fundamental research on polarization holography with linear polarized wave,a component of the theory of polariz-ation holography,has been reviewed.Primarily,the effect of various polarization changes on the linear and nonlinear po-larization characteristics of reconstructed wave under continuous exposure and during holographic recording and recon-struction have been focused upon.The polarization modulation realized using these polarization characteristics exhibits unusual functionalities,rendering polarization holography as an attractive research topic in many fields of applications.This paper aims to provide readers with new insights and broaden the application of polarization holography in more sci-entific and technological research fields.

Research on Optimizing Computer Network Structure based on Genetic Algorithm and Modified Convex Optimization Theory

In this paper, we report in-depth analysis and research on the optimizing computer network structure based on genetic algorithm and modified convex optimization theory. Machine learning method has been widely used in the background and one of its core problems is to solve the optimization problem. Unlike traditional batch algorithm, stochastic gradient descent algorithm in each iteration calculation, the optimization of a single sample point only losses could greatly reduce the memory overhead. The experiment illustrates the feasibility of our proposed approach.

Design of Virtual Simulation Experiment System based on VB and VRML

This paper introduces the design and Realization of NC simulation teaching system based on VB and VRML technology. The paper realize functions using the new Parallel development platform launched by Graphics Company for VRML environment （Cortona SDK）, and uses the object oriented programming method based on ActiveX technology in the technical system. Practice has proved that the system has good stability and strong simulation function.

Design and motion control analysis of double helix wall climbing robot

For the detection environment of complex walls such as high-rise buildings,a double helix wall climbing robot(DHWCR)with strong adsorption force and good stability is designed and developed,which uses symmetrical propellers to provide adsorption force.The symmetrical driving structure can provide smooth thrust for the DHWCR,so that the robot can be absorbed to the wall surface with different roughness.A left and right control frame with multiple degrees of freedom is designed,which can adjust the fixed position of the brushless propeller motor in the front and back directions,realize the continuous adjustable thrust direction of the robot,and improve the flexibility of the robot movement.Using the front wheel steering mechanism with universal joint,the steering control of the DHWCR is realized by differential control.In the vertical to ground transition,the front and rear brushless motors can provide the pull up and oblique thrust,so that the DHWCR can smoothly transition to the vertical wall.The motion performance and adaptability of the DHWCR in the horizontal ground and vertical wall environment are tested.The results show that the DHWCR can switch motion between the horizontal ground and vertical wall,and can stably adsorb on the vertical wall with flexible attitude control.The DHWCR can move at a fast speed.The speed on the horizontal ground is higher than that on the vertical wall,which verifies the feasibility and reliability of the DHWCR moving stably on the vertical wall.

RPGR基因新突变的儿童X-连锁视网膜色素变性1例

患儿,男,5岁,因“幼儿园体检发现双眼视力差”至南通大学附属常熟医院眼科就诊。既往有夜盲史;其父母非近亲联姻,否认低视力家族史。眼科检查示:右眼视力0.15,左眼0.2(双眼矫正视力不提高);双眼角膜清,前房清,瞳孔圆,对光反射+。眼底检查示:视乳头界清、色淡红,视网膜血管变细,黄斑区外视网膜可见椒盐样色素紊乱,散在少量骨细胞样色素改变(图1A-B)。眼球位置及运动检查示:双眼眼球活动正常,无眼球震颤。

A review on adhesion behavior of chip seal pavement and aggregate

Chip seal is widely used for preventive maintenance to mitigate pavement deterioration,but it is prone to aggregate loss during pavement service.To further promote the development and application of chip seals in road engineering in China,the research progress of the adhesion behavior of aggregate and binder in chip seals was reviewed in this paper,focusing on the adhesion mechanism of emulsified asphalt and alkaline aggregate.The Influencing factors and evaluation methodology of chip seals'aggregate adhesion behavior were also discussed.The results demonstrate that the adhesion process between emulsified asphalt and alkaline aggregate is divided into three processes including infiltration,demulsification,and cluster,which is more complicated when compared to hot asphalt.When designing a chip seal,not only the characteristics of single material should be paid attention to,but also the combination of binder and aggregate matters a lot.To form good adhesion between aggregate and asphalt binder,various influencing factors such as material selection,design method,and construction technical index should be considered comprehensively in the whole design,construction,and operation process.Three methods for evaluating adhesion behavior are summarized,including macroscopic adhesion performance tests,image analysis technology,and model prediction.It is not objective to evaluate the aggregate adhesion behavior of chip seal only by a single evaluation method.A comprehensive evaluation based on the micro-macro multi-scale method should be considered in the future.

Treating oily solids using a CO_(2)-responsive surfactant-free microemulsion:An enhanced approach for oil removal from solid surfaces

Because switchable water is difficult to apply directly for oil removal,an enhanced approach to improve oil removal is proposed using a surfactant-free microemulsion(SFME)containing switchable water.The SFME is formed using switchable water(aqueous N,N-dimethylethanolamine(DMEA)or N,N-dimethylbutylamine(BDEA))and a hydrophobic amine(N-butyldiethanolamine(DMBA)).The single-phase region for preparing the SFME is determined using a ternary phase diagram,and the microstructure types are distinguished using the con-ductivity method.The pH changes and dynamic laser scattering test results demonstrate that the SFME exhibits irreversible transformation behavior regulated by CO_(2).Moreover,the recovered SFME containing BDEA has a microstructure with a smaller particle size after removing the CO_(2) by bubbling N 2 at 65°C,which is attributed to the higher proportion of DMEA than that of BDEA.In addition,dodecane and diesel oil are shown to dissolve in the SFME,and the oil solubility of the SFME increases with increasing oil phase(DMBA)content.The interface free energy theory reveals that the oil is more easily detached with the addition of SFME than with switchable water only owing to the reduced interface free energy of oil on the solid surface.Thus,an enhanced approach for removing oil is proposed to wash oil sands,where the oil removal efficiency of switchable water can be improved by using SFMEs containing switchable water.

Accurate prediction of pan-cancer types using machine learning with minimal number of DNA methylation sites

DNA methylation analysis has been applied to determine the primary site of cancer;however, robust and accurate prediction of cancer types with a minimum number of sites is still a significant scientific challenge. To build an accurate and robust cancer type prediction tool with a minimum number of DNA methylation sites, we internally benchmarked different DNA methylation site selection and ranking procedures, as well as different classification models. We used The Cancer Genome Atlas dataset (26 cancer types with 8296 samples) to train and test models and used an independent dataset (17 cancer types with 2738 samples) for model validation. A deep neural network model using a combined feature selection procedure (named MethyDeep) can predict 26 cancer types using 30 methylation sites with superior performance compared with the known methods for both primary and metastatic cancers in independent validation datasets. In conclusion, MethyDeep is an accurate and robust cancer type predictor with the minimum number of DNA methylation sites;it could help the cost-effective clarification of cancer of unknown primary patients and the liquid biopsy-based early screening of cancers.

Fluoride ions adsorption from water by CaCO_(3)enhanced Mn-Fe mixed metal oxides

Novel CaCO_(3)-enhanced Mn-Fe mixed metal oxides(CMFC)were successfully prepared for the first time by a simple-green hydrothermal strategy without any surfactant or template combined with calcination process.These oxides were then employed as an adsorbent for adsorptive removal of excess fluoride ions.The adsorbent was characterized by SEM,XPS,XRD,FTIR,and BET analysis techniques.The adsorption property of CMFC toward fluoride ion was analyzed by batch experiments.In fact,CMFC exhibited adsorption capacity of 227.3 mg∙g^(-1)toward fluoride ion.Results showed that ion exchange,electrostatic attraction and chemical adsorption were the main mechanism for the adhesion of large amount of fluoride ion on the CMFC surface,and the high adsorption capacity responded to the low pH of the adsorption system.When the fluoride ion concentration was increased from 20 to 200 mg∙L^(-1),Langmuir model was more in line with experimental results.The change of fluoride ion adsorption with respect to time was accurately described by pseudosecond-order kinetics.After five cycles of use,the adsorbent still maintains a performance of 70.6%of efficiency,compared to the fresh adsorbent.Therefore,this material may act as a potential candidate for adsorbent with broad range of application prospects.

A study on predicting crisis information dissemination in epidemic-level public health events

Crisis information dissemination plays a key role in the development of emergency responses to epidemic-level public health events.Therefore,clarifying the causes of crisis information dissemination and making accurate predictions to effectively control such situations have attracted extensive attention.Based on media richness theory and persuasion theory,this study constructs an index system of crisis information dissemination impact factors from two aspects:the crisis information publisher and the published crisis information content.A multi-layer perceptron is used to analyze the weight of the index system,and the prediction is transformed into a pattern classification problem to test crisis information dissemination.In this study,COVID-19 is considered a representative event.An experiment is conducted to predict the crisis information dissemination of COVID-19 in two megacities.Data related to COVID-19 from these two megacities are acquired from the well-known Chinese social media platform Weibo.The experimental results show that not only the identity but also the social influence of the information publisher has a significant impact on crisis information dissemination in epidemic-level public health events.Furthermore,the proposed model achieves more than 95%test accuracy,precision rate,recall value and f1-score in the prediction task.The study provides decision-making support for government departments and a guide for correctly disseminating crisis information and public opinion during future epidemic-level public health events.

新疆阿尔泰山喀纳斯河谷鸟兽物种的红外相机监测

2014年6月至2016年8月,利用红外相机技术对新疆喀纳斯国家级自然保护区内喀纳斯河谷的兽类和鸟类多样性进行了调查,共布设36个相机位点,累计12,006个拍摄日,收集独立有效照片2,038张,共鉴定野生动物51种,其中兽类4目8科15种,鸟类9目15科36种。记录到国家I级重点保护野生动物3种,即紫貂(Marteszibellina)、貂熊(Gulo gulo)和黑鹳(Ciconia nigra);国家II级保护动物11种。9种被中国脊椎动物红色名录列为受威胁物种,其中极危(CR)1种,即驼鹿(Alces alces);濒危(EN)3种,即貂熊、马鹿(Cervus canadensis)和松鸡(Tetrao urogallus);易危(VU)5种。白背啄木鸟(Dendrocoposleucotos)等14种鸟类为保护区新记录,我们首次在野外拍摄到驼鹿指名亚种(A.a.alces)。物种相对多度指数(relative abundance index,RAI)分析结果显示,马鹿为喀纳斯河谷兽类优势种(RAI=9.878),鸟类中星鸦(Nucifragacaryocatactes)相对多度最高(0.258)。我们建议保护区进一步对雪豹(Panthera uncia)、原麝(Moschus moschiferus)等物种开展专项调查和评估。本论文为阿尔泰山喀纳斯河谷鸟兽多样性研究提供了基础数据,有助于后续物种保护和管理计划的开展。

Research on the Surface Subsidence Monitoring Technology Based on Fiber Bragg Grating Sensing

In order to monitor the process of surface subsidence caused by mining in real time, we reported two types of fiber Bragg grating （FBG） based sensors. The principles of the FBG-based displacement sensor and the FBG-based micro-seismic sensor were described. The surface subsidence monitoring system based on the FBG sensing technology was designed. Some factual application of using these FBG-based sensors for subsidence monitoring in iron mines was presented.