The ALMA-QUARKS Survey.Ⅱ.The ACA 1.3 mm Continuum Source Catalog and the Assembly of Dense Gas in Massive Star-Forming Clumps

Leveraging the high resolution,sensitivity,and wide frequency coverage of the Atacama Large Millimeter/submillimeter Array(ALMA),the QUARKS survey,standing for“Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures”,is observing 139 massive starforming clumps at ALMA Band 6(λ~1.3 mm).This paper introduces the Atacama Compact Array(ACA)7 m data of the QUARKS survey,describing the ACA observations and data reduction.Combining multiwavelength data,we provide the first edition of QUARKS atlas,offering insights into the multiscale and multiphase interstellar medium in high-mass star formation.The ACA 1.3 mm catalog includes 207 continuum sources that are called ACA sources.Their gas kinetic temperatures are estimated using three formaldehyde transitions with a non-LTE radiation transfer model,and the mass and density are derived from a dust emission model.The ACA sources are massive(16–84 percentile values of 6–160 M_(⊙)),gravity-dominated(M∝R^(1.1))fragments within massive clumps,with supersonic turbulence(M>1)and embedded star-forming protoclusters.We find a linear correlation between the masses of the fragments and the massive clumps,with a ratio of 6%between the two.When considering fragments as representative of dense gas,the ratio indicates a dense gas fraction(DGF)of 6%,although with a wide scatter ranging from 1%to 10%.If we consider the QUARKS massive clumps to be what is observed at various scales,then the size-independent DGF indicates a self-similar fragmentation or collapsing mode in protocluster formation.With the ACA data over four orders of magnitude of luminosity-to-mass ratio(L/M),we find that the DGF increases significantly with L/M,which indicates clump evolutionary stage.We observed a limited fragmentation at the subclump scale,which can be explained by a dynamic global collapse process.

The ALMA-QUARKS Survey.Ⅰ.Survey Description and Data Reduction

This paper presents an overview of the QUARKS survey,which stands for Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures."The QUARKS survey is observing139 massive clumps covered by 156 pointings at Atacama Large Millimeter/submillimeter Array(ALMA)Band 6(λ~1.3 mm).In conjunction with data obtained from the ALMA-ATOMS survey at Band 3(λ~3 mm),QUARKS aims to carry out an unbiased statistical investigation of massive star formation process within protoclusters down to a scale of 1000 au.This overview paper describes the observations and data reduction of the QUARKS survey,and gives a first look at an exemplar source,the mini-starburst Sgr B2(M).The wide-b and width(7.5 GHz)and high-angular-resolution(~0."3)observations of the QUARKS survey allow for the resolution of much more compact cores than those could be done by the ATOMS survey,and to detect previously unrevealed fainter filamentary structures.The spectral windows cover transitions of species including CO,SO,N_(2)D^(+),SiO,H_(30)α,H_(2)CO,CH_(3)CN,and many other complex organic molecules,tracing gas components with different temperatures and spatial extents.QUARKS aims to deepen our understanding of several scientific topics of massive star formation,such as the mass transport within protoclusters by(hub-)filamentary structures,the existence of massive starless cores,the physical and chemical properties of dense cores within protoclusters,and the feedback from already formed high-mass young protostars.

基于内压法的锆合金薄壁管泊松比试验研究

锆合金包壳管在核电应用中存在变形及破裂等问题,严重影响核电运行安全。为了更好地评价锆合金包壳管等薄壁管材受内压时的变形性能,给燃料组件的设计、计算、验证提供参考,设计基于内压法的泊松比测试方法。根据薄壁圆筒受均匀内压时的应力解,推导出基于内压加载的薄壁管泊松比理论公式。按照该理论公式设计合理的内压试验方法,采用该方法对N36锆合金薄壁管开展20~400℃下的泊松比试验,同时通过拉伸法进行相应温度下的对比试验。结果表明,内压试验方法可以有效获得不同温度下锆合金薄壁管的泊松比,且内压试验方法得到的锆合金薄壁管泊松比与拉伸法结果较为一致,相对误差均在2%以内。试验结果同时表明:N36锆合金薄壁管的泊松比随试验温度的增加呈增大趋势。

基于轨迹数据的非机动车左转信号灯安全效应评估

【目的】对城市交叉口采用的左转非机动车信号灯设施进行交通安全性量化评估。【方法】提出一种基于拓展碰撞时间(extended time to collision,ETTC)指标的左转非机动车信号灯安全效应评估方法。针对现有的碰撞时间(time to collision,TTC)指标不适于评估交叉口左转非机动车冲突的问题,考虑非机动车车辆尺寸与加速度对交通冲突的影响,采用拓展碰撞时间指标,评估交叉口非机动车交通冲突。收集长沙市4个信号交叉口的视频大数据,利用视频软件Tracker提取车辆微观轨迹后,开展案例分析。【结果】左转非机动车信号灯在时间上明确了非机动车的通行权,其设置能显著降低非机动车冲突率,在平峰、高峰时段非机动车冲突率分别降低了40.11%、25.27%。在直行相位末期、左转相位即将启亮时,设置组的左转非机动车在待行区等待,冲突率降为0;而对比组近50%的非机动车违规左转,冲突严重。设置左转非机动车信号灯的改善效果随非机动车流量的增大呈先增加后降低趋势,而随机动车流量的增大呈逐步波动下降趋势。【结论】本研究揭示了非机动车左转信号灯的设置对减少交叉口交通冲突的影响,可为城市交叉口非机动车交通安全管控提供有益参考。

闽楠凋落物浸提液对其种子萌发和幼苗生长及生理指标的影响

采用不同浓度凋落枝、凋落叶浸提液处理闽楠(Phoebe bournei(Hemsl.)Yang)种子和幼苗,测定其萌发、生长及生理指标。结果显示:(1)整体上,闽楠凋落枝和凋落叶浸提液对自身种子萌发表现为抑制作用,且抑制作用均随两种浸提液浓度升高而增强,且凋落枝抑制作用大于凋落叶。在发芽指标上,抑制强度表现为枝>叶;在根芽长度上,抑制强度表现为叶>枝;综合化感效应表现为枝>叶。(2)凋落枝浸提液对一年生闽楠幼苗生长指标表现为抑制作用,凋落叶浸提液表现为“低促高抑”的效应。高浓度浸提液可严重抑制幼苗生长,并造成大量叶片出现斑点、萎缩和枯黄;(3)闽楠凋落物浸提液对闽楠幼苗生理的影响较为复杂,高浓度浸提液可造成幼苗生理紊乱,导致其抗氧化系统异常,引起丙二醛含量显著增加,叶片细胞膜通透性增大,导致植株处于非正常生长状态,而长期浇灌低浓度浸提液也会使植物处于胁迫状态而引起相关生理指标变化。

一种柔性太阳电池阵电传输解决方案

柔性太阳电池阵由于其质量轻、收拢体积小、可重复展收等特点,具有极大的创新性和前瞻性,是目前和今后极具竞争力的太阳电池阵构型。针对目前柔性太阳电池阵收拢和折叠特性,传统电缆束和电连接器已经不再适用,急需寻找一种新型薄型结构电传输解决方案。提出了一种柔性电缆电传输方案,这种柔性电缆具有传输功率大、质量轻、收拢体积小、可折叠等特点,非常适合作为大面积、大功率的柔性太阳阵电传输的主方式,可为未来新型太阳电池阵的设计提供新方向、设计参考和技术支撑。

6个谷子品种的适应性及光温敏感性分析

为了探究谷子品种的区域适应性,为谷子新品种培育提供参考,以‘豫谷18’、‘豫谷31’、‘豫谷32’、‘豫谷35’、‘豫谷38’、‘豫谷42’为试材,依据全国谷子品种区域适应性联合鉴定试验调查结果,运用变异系数、高稳系数、回归系数、光温相对敏感度等多种分析方法,对6个品种进行适应性及光温敏感分析。对各品种不同区组内的农艺性状进行统计分析,同时比较了区组间各品种不同性状的变异系数。结果表明6个谷子品种均能适应2个及以上的不同生态区组,尤其是‘豫谷18’在4个不同的生态区组均表现出高产、稳产和广适的特性;6个品种生育期在西北春谷早熟区组均较长,单穗重、单穗粒重和千粒重在西北春谷早熟区组、西北春谷中晚熟区组较高,穗长在东北春谷区组较长,产量及株高和出谷率没有明显的趋势;区组间各品种农艺性状的变异系数均是千粒重最小,抽穗期最大;以夏谷区为参照,‘豫谷18’单穗重、单穗粒重敏感度在不同区组均为最弱。‘豫谷18’在4个不同的生态区组均表现出高产、稳产和广适的特性。

实验室安全理论课程建设与管理

为了完善实验室安全课程体系,建立健全实验室安全教育培训与准入机制,围绕高校实验室安全特点和规律,参考安全工程专业学生培养方案,建设实验室安全理论课程,阐明实验室安全的科学原理与实现路径,弥补以安全培训为框架的传统课程体系中理论支撑不足的短板,让安全素养落地,为知识运用赋能,使不同学科专业的实验人员融会贯通并用于实验实践。建设面向一流人才培养的大学生实验室安全教育平台,加大实验室安全教育力度,提高师生安全意识,按照“全员、全程、全方位”的要求,创新教育形式,建设有特色的实验室安全文化。

航空发动机可调静叶调节机构WC-Co强化层摩擦学性能研究

航空发动机可调静叶(VSV)调节结构为影响航空发动机正常工作以及飞行安全的重要结构,在VSV调节角度的过程中,转轴-衬套的磨损是影响角度调节精度的重要因素。为提高VSV系统转轴-衬套摩擦副的抗磨损性能,利用大气等离子喷涂技术在转轴表面制备WC-Co抗磨损涂层,采用自主研发的转轴-衬套摩擦磨损试验机针对转轴-衬套进行模拟工况磨损性能评价。结果表明:在模拟工况下,转轴-衬套摩擦副的摩擦力矩与载荷关系最为密切,随载荷增大,摩擦力矩增大。对磨损后的表面进行表面成分分析及微观形貌观察可以得出:温度升高摩擦副发生黏着磨损现象,导致磨损加剧,引起颗粒断裂;在相同温度条件下,载荷增大导致接触应力增大,接触面被磨损;而磨损系数随温度升高呈先减后增的趋势。研究结果为VSV系统转轴-衬套设计提供参考依据。

城市更新背景下非法定化古建筑保护研究--以东莞城区为例

城市更新背景下,非法定化古建筑面临保护不足的困境。以东莞城区为例,总结非法定化古建筑保护现存问题,提出构建非法定化古建筑价值评估体系、做好规划衔接工作、建立多渠道资金保障体系、建设全链条实施体系的保护策略,以期为其他城市非法定化古建筑保护提供参考。

Soybean(Glycine max)rhizosphere organic phosphorus recycling relies on acid phosphatase activity and specific phosphorusmineralizing-related bacteria in phosphate deficient acidic soils

Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the bacterial community modifications are poorly understood. Here, six soybean(Glycine max) genotypes with differences in P efficiency were cultivated in acidic soils with long-term sufficient or deficient P-fertilizer treatments. The acid phosphatase(AcP) activities, organic-P concentrations and associated bacterial community compositions were determined in bulk and rhizosphere soils. The results showed that both soybean plant P content and the soil AcP activity were negatively correlated with soil organic-P concentration in P-deficient acidic soils. Soil P-availability affected the ɑ-diversity of bacteria in both bulk and rhizosphere soils. However, soybean had a stronger effect on the bacterial community composition, as reflected by the similar biomarker bacteria in the rhizosphere soils in both P-treatments. The relative abundance of biomarker bacteria Proteobacteria was strongly correlated with soil organic-P concentration and AcP activity in low-P treatments. Further high-throughput sequencing of the phoC gene revealed an obvious shift in Proteobacteria groups between bulk soils and rhizosphere soils, which was emphasized by the higher relative abundances of Cupriavidus and Klebsiella, and lower relative abundance of Xanthomonas in rhizosphere soils. Among them, Cupriavidus was the dominant phoC bacterial genus, and it was negatively correlated with the soil organic-P concentration. These findings suggest that soybean growth relies on organic-P mineralization in P-deficient acidic soils, which might be partially achieved by recruiting specific phoCharboring bacteria, such as Cupriavidus.

血管钙化抑制因子BMP-7的研究进展

血管钙化是一个主动可调控的心血管系统异位钙化过程,目前尚无可逆转的有效干预手段。血管钙化和骨形成具有共同的调控机制,骨形态发生蛋白7(bone morphogenetic protein 7,BMP-7)可维持血管平滑肌细胞的收缩表型抑制血管钙化。同时,BMP-7可刺激成骨细胞分化过程,增加骨形成,减少骨吸收降低异位钙化压力。该文系统综述BMP-7影响血管钙化的作用与机制及其目前的临床应用现状。这将有助于以BMP-7为新的分子标志物与潜在药物靶标,研发早期诊断试剂盒及治疗药物,以期实现血管钙化的早期预防与干预,改善患者预后。

Fullerenes and derivatives as electrocatalysts: Promises and challenges

Carbon-based metal-free nanomaterials are promising alternatives to precious metals as electrocatalysts of key energy storage and conversion technologies.Of paramount significance are the establishment of design principles by understanding the catalytic mechanisms and identifying the active sites.Distinct from sp2-conjugated graphene and carbon nanotube,fullerene possesses unique characteristics that are growingly being discovered and exploited by the electrocatalysis community.For instance,the well-defined atomic and molecular structures,the good electron affinity to tune the electronic structures of other substances,the intermolecular self-assembly into superlattices,and the on-demand chemical modification have endowed fullerene with incomparable advantages as electrocatalysts that are otherwise not applicable to other carbon ma-terials.As increasing studies are being reported on this intriguing topic,it is necessary to provide a state-of-the-art overview of the recent progress.This review takes such an initiative by summarizing the promises and challenges in the electrocatalytic applications of fullerene and its derivatives.The content is structured according to the composition and structure of fullerene,including intact fullerene(e.g.,fullerene composite and superlattices)and fullerene derivatives(e.g.,doped,endohedral,and disintegrated fullerene).The synthesis,characterization,catalytic mechanisms,and deficiencies of these fullerene-based materials are explicitly elaborated.We conclude it by sharing our perspectives on the key aspects that future efforts shall consider.

Emission and capture characteristics of deep hole trap in n-GaN by optical deep level transient spectroscopy

Emission and capture characteristics of a deep hole trap(H1)in n-GaN Schottky barrier diodes(SBDs)have been investigated by optical deep level transient spectroscopy(ODLTS).Activation energy(Eemi)and capture cross-section(σ_(p))of H1 are determined to be 0.75 eV and 4.67×10^(−15)cm^(2),respectively.Distribution of apparent trap concentration in space charge region is demonstrated.Temperature-enhanced emission process is revealed by decrease of emission time constant.Electricfield-boosted trap emission kinetics are analyzed by the Poole−Frenkel emission(PFE)model.In addition,H1 shows point defect capture properties and temperature-enhanced capture kinetics.Taking both hole capture and emission processes into account during laser beam incidence,H1 features a trap concentration of 2.67×10^(15)cm^(−3).The method and obtained results may facilitate understanding of minority carrier trap properties in wide bandgap semiconductor material and can be applied for device reliability assessment.

萧绍平原第四纪工程地质年代测定与地层划分

萧绍平原地区第四纪海陆交互频繁、沉积环境复杂,开展该地区第四纪工程地质层位划分研究对于城市地下空间建设具有重要的参考价值和实践意义.基于萧绍平原第四纪沉积物的颜色及岩性特征,选取典型层位的土样,进一步研究不同地层的放射性碳年龄和微体古生物种类、丰度、分布特征.试验结果表明:萧绍平原地区共包含了3个全新世时期沉积层、4个晚更新世时期沉积层和2个中早更新世沉积层;该地第四纪共经历了4次海侵,由此形成了4个冲海相-海相沉积地层和3个冲洪积、冲湖积陆相沉积地层.分析了各个地层成因,构建了萧绍平原标准工程地质分层,为实际工程中地质勘查提供参考依据.

TDI-Tei指数联合NT-proBNP对急性心肌梗死患者预后的预测价值

目的 探讨TDI-Tei指数(tissue doppler imaging-Tei index)联合血清N-端脑利钠肽前体(N-terminal pro-Btype brain natriuretic peptide,NT-proBNP)对经皮冠状动脉介入(percutaneous coronary intervention,PCI)治疗术后的急性心肌梗死(acute myocardial infarction,AMI)患者远期预后的预测价值。方法 选取2021年3月1日至2022年6月30日在济南市人民医院接受急诊PCI治疗术的201例AMI患者,术后随访12个月,根据是否发生不良心血管事件(major adverse cardiovascular events,MACEs)将其分为发生组(n=50)与未发生组(n=151)。收集患者临床资料,采用多因素logistic回归,分析术后72 h内的TDI-Tei指数、血清NT-proBNP水平与AMI患者PCI术后发生MACEs的关系,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析两者分别以及联合对AMI患者PCI术后发生MACEs的预测价值。结果 发生组年龄、门-导丝时间、糖尿病、冠脉Gensini评分、术后心率、心肌钙蛋白I(cardiac troponin I,cTnI)、尿酸、TDI-Tei指数、NT-proBNP均高于未发生组,左室射血分数低于未发生组,差异均有统计学意义(P <0.001);多因素logistic回归分析显示,术后心率、TDI-Tei指数及NT-proBNP是AMI患者PCI术后12个月内发生MACEs的独立预测因素(P <0.001);ROC曲线分析显示,血清NT-proBNP的曲线下面积(area under curve, AUC)为0.86,敏感度为76%,特异度为82.8%。TDI-Tei指数的AUC为0.940,敏感度为80%,特异度为94.7%。两指标联合预测的AUC更高,为0.961,敏感度为86%,特异度为97.4%。结论 TDI-Tei指数及NT-proBNP是AMI患者PCI术后12个月内发生MACEs的独立预测因素,两者联合对AMI患者PCI术后12个月内发生MACEs的预测价值更具临床意义。

二次回收PP无纺布条单螺杆挤出技术研究

阐述了单螺杆挤出机中PP无纺布条二次塑化过程中的进料连续性及塑化过程,研究存在的问题与解决方法,指出螺杆进料段、压缩段、计量段参数设计及螺筒外部段冷却是实现无纺布条不间断进料及塑化稳定挤出的关键要素。通过增加进料段摩擦力、调整压缩段压缩比和长度占比、调整计量段缝隙和屏障以及外部段控制温度解决关键问题。

改进MobileViT网络识别轻量化田间杂草

为解决现有的田间杂草识别方法无法兼顾高准确率与实时性的问题,该研究提出了一种基于改进MobileViT网络的轻量化杂草识别方法。首先,该方法使用高效的MobileViT网络构建杂草特征提取网络,在保证特征提取能力的同时实现更少的模型参数量与计算量;其次,通过高效通道注意力机制加强下采样后特征图中的重要特征,进一步提升模型的特征提取能力;最后,特征提取网络中的MobileViT模块被用于同时学习局部语义信息和全局语义信息,仅通过少量模块的组合便能够准确地捕捉到不同类别杂草与作物间细微差异。为验证该方法的有效性,该研究以农田环境下采集的玉米幼苗及其4类伴生杂草图像为数据进行了模型训练,试验结果表明,该方法的识别准确率、精准度、召回率和F1分数分别为99.61%、99.60%、99.58%和99.59%,优于VGG-16、ResNet-50、DenseNet-161、MobileNetv2等常用卷积神经网络;同时,可视化结果表明该方法能够有效提取杂草图像中的关键特征,并抑制背景区域对识别结果的影响。该研究提出的方法能够精准、快速地区分出农田环境下形态相似的多种杂草与作物,可为智能除草设备中的杂草识别系统设计提供参考。

19个谷子新品种农艺性状与适应性综合分析

利用变异系数、高稳系数和回归分析法对2022年参加全国谷子品种区域适应性联合鉴定试验(华北夏谷区组)的19个谷子品种丰产性、稳产性、适应性进行综合分析评价,筛选更适宜华北夏谷地区种植的谷子新品种。相关性分析结果表明单穗重与穗粒重呈极显著正相关并均与穗粗、穗长呈极显著正相关,产量与单穗重、穗粒重呈显著正相关。丰产性、稳产性、适应性分析表明中杂谷72、中杂谷76、K175-2H、郑18H1260、冀研谷3号均表现较好,适宜在华北夏谷地区推广种植。

不同浓度肝素钠封管液应用于手臂输液港封管的效果比较

目的比较不同浓度肝素钠封管液应用于植入手臂输液港肿瘤患者中的临床效果。方法选取2021年12月至2022年9月在某三级甲等医院肿瘤科住院首次植入手臂输液港的肿瘤患者320例为研究对象。采用随机数字表法,将患者分为A、B两组,分别使用100 U·mL^(-1)肝素钠封管液和50 U·mL^(-1)肝素钠封管液各2 mL进行输液港封管。其中每组分a组和b组,a组在患者每次用药后和治疗周期结束时均使用10 mL预充式导管冲洗器和肝素钠封管液进行封管;b组在患者每次用药后仅使用10 mL预充式导管冲洗器封管,治疗周期结束时使用10 mL预充式导管冲洗器和肝素钠封管液封管。比较各组患者手臂输液港堵管和血栓发生率。结果各组手臂输液港堵管及血栓发生率比较,差异无统计学意义(P>0.05)。结论在患者每次用药后仅使用10 mL预充式导管冲洗器封管,治疗周期结束时使用10 mL预充式导管冲洗器和50 U·mL^(-1)肝素钠封管液2 mL封管能够满足治疗需要,不会导致患者手臂输液港堵管及血栓发生率的升高。