一种基于莫顿码及镜像编码的平衡八叉树模型

在接触分析和动画模拟等网格规模庞大、需要实时更新的应用场景下,普遍采用莫顿码实现包围盒层次树结构的快速重构。但现有的层次树由于结构平衡性差,普遍存在搜索效率不稳定的问题,为此本文在莫顿码法的基础上提出了一种兼顾构建与搜索效率的平衡八叉树模型BOT树(Balanced Octree)。设计了镜像编码来保证树的上层节点均有8个分支,且同层树节点所含三角面数之差不超过1。实际算例表明,BOT树与现有模型OIOT树在CUDA并行框架下对比,构建加速比最高可达1.29×,且网格规模越大,BOT树构建效率的优势越明显。同时,与OIOT树相比BOT树的筛除率更高,在凸体接触和边缘接触算例中加速比分别达到1.13×和1.06×。

从信息茧房到多元赋能:知识鸿沟的产生机制及其治理路径研究

[目的/意义]探究大数据环境下信息茧房扩大知识鸿沟的作用机理,有助于预防知识鸿沟的产生,为信息用户营造畅通的信息环境。[方法/过程]从系统论的视角,剖析信息茧房扩大知识鸿沟的作用机理,提出规避策略。[结果/结论]这种作用机理可分为同质化推荐和个性化加工两个子系统,子系统间的内外耦合情况决定了信息茧房扩大知识鸿沟的程度,其中个性化加工的主观因素起主要作用。基于此,对外要求媒体从业者进行创新性的内容生产、优化算法模型、再塑用户新形象以及构建监督约束机制,对内要求用户博观多元信息、强化认知结构、优化记忆图式、丰富行为模式,以有效规避信息茧房对知识鸿沟的扩大效应。

Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles

Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics(CFD) simulations were performed using the k–ε model to calculate the mixing time and simulate turbulent flow field features, such as streamline shape, velocity distribution, vortex core region distribution, and turbulent kinetic energy(TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically, the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore, the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally, the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promising alternative to circular vessels for enhancing mixing performance in USTs.

DMSCs三维培养方法及其在组织再生和疾病治疗中应用的研究进展

牙源性间充质干细胞(DMSCs)是来源于神经嵴外胚层的间充质干细胞,具有优越的自我更新和多向分化的能力,被广泛应用于组织工程和再生医学研究。利用三维培养方法可对DMSCs进行大量体外扩增以满足研究和治疗的需要。与传统的二维培养方法比较,三维培养技术可更有效地模拟干细胞在体内所处的结构和微环境,从时间和空间上共同调控干细胞的增殖及分化。近年来开展的体外三维培养方法较多,悬滴培养法操作简单,但较难控制培养组织的气象环境;微流控芯片可更好地控制细胞参数,但成本高昂,且存在技术平台的难题而难以广泛应用;磁悬浮培养费用低廉,操作简便,细胞成球速度快,但由于磁化作用难以用来定量分析。其他三维培养方法还包括旋转细胞培养系统、离心成球培养法、液体覆盖法和人工支架法等,上述培养方法都存在不同的优势和一定的局限性。现对体外三维培养DMSCs的不同方法及其在不同组织再生和疾病治疗中的应用进行综述,为DMSCs功能的精准调控和再生医学研究提供参考。

Real-time data processing method for CO_(2) dispersion interferometer on EAST

A real-time data processing system is designed for the carbon dioxide dispersion interferometer(CO_(2)-DI)on EAST.The system utilizes the parallel and pipelining capabilities of an fieldprogrammable gate array(FPGA)to digitize and process the intensity of signals from the detector.Finally,the real-time electron density signals are exported through a digital-to-analog converter(DAC)module in the form of analog signals.The system has been successfully applied in the CO_(2)-DI system to provide low-latency electron density input to the plasma control system on EAST.Experimental results of the latest campaign with long-pulse discharges on EAST(2022–2023)demonstrate that the system can respond effectively in the case of rapid density changes,proving its reliability and accuracy for future electron density calculation.

A fringe jump counting method for the phase measurement in the HCN laser interferometer on EAST and its FPGA-based implementation

Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been developed to unwrap the phase difference signal in real time using FPGA, specifically designed to handle fringe jumps in the hydrogen cyanide(HCN) laser interferometer on the EAST superconducting tokamak. This method is designed for a phase demodulator using the fast Fourier transform(FFT) method at the front end. The method is better adapted for hardware implementation compared to complex mathematical analysis algorithms, such as field programmable gate array(FPGA). It has been applied to process the phase measurement results of the HCN laser interferometer on EAST in real time. Electron density results show good confidence in the fringe jump unwrapping method. Further possible application in other laser interferometers, such as the POlarimeter-INTerferometer(POINT)system on EAST tokamak is also discussed.

A Yb optical clock with a lattice power enhancement cavity

We construct a power enhancement cavity to form an optical lattice in an ytterbium optical clock.It is demonstrated that the intra-cavity lattice power can be increased by about 45 times,and the trap depth can be as large as 1400Er when laser light with a power of only 0.6 W incident to the lattice cavity.Such high trap depths are the key to accurate evaluation of the lattice-induced light shift with an uncertainty down to~1×10-18.By probing the ytterbium atoms trapped in the power-enhanced optical lattice,we obtain a 4.3 Hz-linewidth Rabi spectrum,which is then used to feedback to the clock laser for the close loop operation of the optical lattice clock.We evaluate the density shift of the Yb optical lattice clock based on interleaving measurements,which is-0.46(62)mHz.This result is smaller compared to the density shift of our first Yb optical clock without lattice power enhancement cavity mainly due to a larger lattice diameter of 344μm.

First results of CO_(2) dispersion interferometer on EAST tokamak

A dispersion interferometer(DI)has been installed and operates on the Experimental Advanced Superconducting Tokamak(EAST).This DI system utilizes a continuous-wave 9.3μm CO_(2)laser source to measure line-averaged electron densities accurately.In contrast to conventional interferometers,the DI does not require substantial vibration isolations or compensating systems to reduce the impact of vibrations in the optical path.It also employs a ratio of modulation amplitudes,ensuring it remains immune to the variations in detected intensities.Without a variation compensation system,the DI system on EAST reaches a density resolution of less than1.8×10^(-2)πrad and a temporal resolution of 20μs.The measurements made by the POlarimeterINTerferometer(POINT)system and the far-infrared hydrogen cyanide(HCN)interferometer are remarkably consistent with the DI’s results.The possibility of fringe jumps and the impact of refraction in high-density discharge can be significantly decreased using a shorter wavelength laser source.A rapid density change of 3×10^(19)m^(-3)during 0.15 s has been measured accurately in shot No.114755 of EAST.Additionally,the DI system demonstrates dependability and stability under 305 s long-pulse discharges in shot No.122054.

Learning Discriminatory Information for Object Detection on Urine Sediment Image

In clinical practice,the microscopic examination of urine sediment is considered an important in vitro examination with many broad applications.Measuring the amount of each type of urine sediment allows for screening,diagnosis and evaluation of kidney and urinary tract disease,providing insight into the specific type and severity.However,manual urine sediment examination is labor-intensive,time-consuming,and subjective.Traditional machine learning based object detection methods require hand-crafted features for localization and classification,which have poor generalization capabilities and are difficult to quickly and accurately detect the number of urine sediments.Deep learning based object detection methods have the potential to address the challenges mentioned above,but these methods require access to large urine sediment image datasets.Unfortunately,only a limited number of publicly available urine sediment datasets are currently available.To alleviate the lack of urine sediment datasets in medical image analysis,we propose a new dataset named UriSed2K,which contains 2465 high-quality images annotated with expert guidance.Two main challenges are associated with our dataset:a large number of small objects and the occlusion between these small objects.Our manuscript focuses on applying deep learning object detection methods to the urine sediment dataset and addressing the challenges presented by this dataset.Specifically,our goal is to improve the accuracy and efficiency of the detection algorithm and,in doing so,provide medical professionals with an automatic detector that saves time and effort.We propose an improved lightweight one-stage object detection algorithm called Discriminatory-YOLO.The proposed algorithm comprises a local context attention module and a global background suppression module,which aid the detector in distinguishing urine sediment features in the image.The local context attention module captures context information beyond the object region,while the global background suppression module emphasizes objects in uninformative backgrounds.We comprehensively evaluate our method on the UriSed2K dataset,which includes seven categories of urine sediments,such as erythrocytes(red blood cells),leukocytes(white blood cells),epithelial cells,crystals,mycetes,broken erythrocytes,and broken leukocytes,achieving the best average precision(AP)of 95.3%while taking only 10 ms per image.The source code and dataset are available at https://github.com/binghuiwu98/discriminatoryyolov5.

Effects of Tongluo Jiedu prescription on immune function and oxidative stress in patients with oral cancer

BACKGROUND Oral cancer,which is caused by mucous membrane variation,represents a prevalent malignant tumor in the oral and maxillofacial region,posing a significant threat to patients’lives and safety.While surgical intervention stands as a cornerstone treatment for oral cancer patients,it carries the risk of incomplete treatment or high rates of postoperative recurrence.Hence,a multifaceted approach incorporating diverse treatment modalities is essential to enhance patient prognosis.AIM To analyze the application effect of Tongluo Jiedu prescription as adjuvant therapy and its influence on patient prognosis in patients with oral cancer.METHODS Eighty oral cancer patients in our hospital were selected and divided into the observation group and control group by a random number table.The control group was treated with continuous arterial infusion chemotherapy of cisplatin and 5-fluorouracil.The observation group was additionally given Tongluo Jiadu prescription.The inflammatory stress level,peripheral blood T-cell subsets,and immune function of the two groups were subsequently observed.SPSS 21.0 was used for data analysis.RESULTS The observation group demonstrated lower levels of interleukin-6 and C-reactive protein,and a higher level of tumor necrosis factor in comparison to the control group.After treatment,the immune function in the observation group was significantly better than in the control group.CONCLUSION Tongluo Jiedu prescription can improve the immune function and oxidative stress level of patients with oral cancer and accelerate the recovery process.

宏基因组二代测序在重症肺炎病原学诊断中的价值

目的探讨宏基因组二代测序(mNGS)对重症肺炎患者病原学诊断的价值。方法选择2021年5月至2023年5月宁波市泌尿肾病医院收治的60例重症肺炎患者。收集肺泡灌洗液5~10 mL分别行常规检测与m NGS检测。比较mNGS检测与常规检测病原微生物阳性率。结果mNGS检测病原微生物阳性率为81.67%,显著高于常规检测的58.33%(P=0.002)。mNGS检测细菌阳性率为53.33%,显著高于常规检测的35.00%(P=0.005);检测真菌阳性率为36.67%,显著高于常规检测的20.00%(P=0.005);检测病毒阳性率为21.67%,显著高于常规检测的8.33%(P=0.011)。结论mNGS对重症肺炎病原学诊断阳性率较高,具有临床意义。

汽车异响自动识别研究

针对目前汽车异响(BSR)诊断的人工主观评价方法的识别不稳定、效率低等问题,提出了一种汽车异响自动识别系统。通过实验对比了异响识别系统和人工主观评价两种检测方法的识别成功率,实验结果表明,人工主观评价的综合识别成功率只有66.2%,而所设计的异响识别系统综合识别率高达93.6%,并且稳定性也优于人工识别。所设计的汽车异响识别系统消除了经验差异所造成的人工识别准确率低问题,具备一定的市场推广价值。

度拉糖肽治疗2型糖尿病的快速卫生技术评估

目的 对度拉糖肽治疗2型糖尿病(T2DM)的有效性、安全性和经济性进行快速卫生技术评估,为临床治疗提供循证证据。方法 计算机检索PubMed、Embase、The Cochrane Library、CNKI、WanFang Data、VIP、SinoMed数据库及相关卫生技术评估(HTA)网站、数据库,搜集度拉糖肽治疗T2DM的高质量临床证据、药物经济学评价文献,检索时限均从建库至2023年3月31日。由2名研究者独立筛选文献、提取资料和评价纳入研究的质量后,对结果进行定性描述与分析。结果 共纳入22篇文献,其中HTA报告1篇,系统评价/Meta分析13篇,药物经济学研究8篇。有效性方面,度拉糖肽能有效降低T2DM患者的糖化血红蛋白和空腹血糖水平,提高糖化血红蛋白达标率,对体重影响优于磺脲类药物和胰岛素。安全性方面,度拉糖肽导致低血糖及胰腺炎发生风险较低,但胃肠道不良反应发生率明显增加,能降低心血管不良事件及卒中发生,无心脑血管不良影响。经济学研究显示,国内外研究提示度拉糖肽具有一定的成本-效用优势,但目前国内经济学研究数据有限。结论 度拉糖肽治疗T2DM具有一定的有效性和安全性,需进一步开展该药在国内的经济学评价以评估其经济性。

消费者知识共享的直播电商企业行为决策研究

价值共创时代,消费者角色从价值接受者向价值共创者转变,企业如何依托消费者参与价值共创并获取相关知识资源,以满足日趋多元化的消费需求,对企业生存与发展至关重要。通过信息系统成功模型(D&M)与技术接受模型(TAM),借助问卷调查收集数据,探寻直播电商消费者知识共享的影响因素。研究表明:服务质量对消费者知识共享意愿有显著正向影响,服务质量和消费者的知识共享意愿对直播电商消费者知识共享影响最大。因此,企业应重视消费者价值共创行为,提高服务质量,积极与消费者互动交流,强化主播专业性,减少消费者隐私担忧,从而促进消费者知识共享。获取消费者相关知识资源,进一步丰富企业知识储备,提升企业知识创新能力,是保持企业获得持续竞争优势的关键。

《反对本本主义》对马克思主义大众化的积极探索及当代启示

《反对本本主义》一书是毛泽东思想的奠基性著作,纠正了教条主义的错误思想倾向,蕴含了实事求是的基本思想,是毛泽东调查研究思想在哲学层面的高度总结。这一著作从哲学基础、引领方式以及工作方法三个层面对马克思主义大众化进行了积极探索,深化了对马克思主义大众化的理解,为做好马克思主义大众化工作拓宽了实践路径,有益于进一步将马克思主义理论与人民群众紧密联系起来,真正让马克思主义走进人民群众的实际生活,不断开创马克思主义中国化时代化的新境界。

黑龙江省电子商务与物流协同发展研究

电子商务与物流协同发展是黑龙江经济高质量发展的必然选择。基于协同理论,选取黑龙江省电子商务与物流的代表性指标,构建协同发展测度指标体系,实证分析黑龙江省2010—2020年电子商务与物流发展水平,探究两者协同对地区经济增长的效应差异。研究结果表明:从2010开始,黑龙江电商与物流复合系统协同从中度不协同稳步提升到轻度协同,电商与物流的协同发展促进了龙江经济增长,实现了行业结构转型升级、扩展了上下行渠道、释放了消费潜力,为黑龙江经济高质量发展提供助力。

胆红素氧化终产物通过巨噬细胞影响炎症反应

胆红素氧化终产物(Bilirubin oxidation end products,Boxes)是影响高胆红素血症/高胆红素脑脊液疾病发生和发展的重要因子。目前有关Boxes对炎症反应的影响尚不清楚。为了研究Boxes是如何调控炎症反应的,我们以脂多糖(Lipopolysaccharide,LPS)作为炎性诱导因子,以Boxes作为干扰因素,观察了Boxes对小鼠巨噬细胞、树突状细胞功能的影响。结果发现Boxes对树突状细胞分泌的肿瘤坏死因子α(Tumor Necrosis Factor-α,TNF-α)和白介素-1β(Interleukin-1β,IL-1β)并没有影响,但可以显著减少巨噬细胞TNF-α、IL-1β、CXCL10、iNOS,Cox-2等炎性因子的表达。这个影响是通过下调MAPK/NF-κB信号通路实现的。因此,胆红素氧化终产物是通过巨噬细胞而不是树突状细胞影响炎症反应的。

±800kV换流变压器空载运行振动特性

为研究换流变压器空载运行下振动特性,该文结合某±800kV直流工程调试,监测采集换流器充电、空载加压等不同空载工况下的换流变压器振动数据,研究不同工况下换流变压器振动特性与影响机理,提出换流变压器振动测点选取以及监测评估策略,建立空载下振动特征量的波动范围。结果表明:换流器充电等暂态时刻,换流变压器振幅增大,之后呈指数规律降低,振动主频以50Hz奇倍频为主,且YD换流变压器50Hz奇倍主频分量比YY换流变压器衰减更慢。带换流器空载运行后,换流变压器振动特性与其单独空载运行时明显不同,但无法表征换流器站内空载加压过程;而在换流器带线路空载加压到800kV阶段,约5%~7%的振动功率从400~1000Hz变化到1000~4000Hz频段。研究成果可为评估换流变压器振动状态提供参考。

Q960E超高强钢焊接接头组织和性能研究

目的对Q960E超高强钢的焊接工艺进行研究以获得高强高韧的焊接接头。方法选择超高强钢Q960E作为母材、FK1000ER120S–G焊丝作为填充材料进行MAG焊,采用改变焊接电流的方式来研究焊接热输入对焊接接头组织和性能的影响。结果当焊接电流为155~230 A时,均获得了全焊透无明显缺陷的焊缝。随着焊接热输入的增大,焊接接头中各亚区宽度增大,其中焊缝区变化最为显著,在最小热输入条件下焊缝宽度为3.98 mm,在最大热输入条件下焊缝宽度增至5.53 mm。对焊接接头进行组织分析发现,焊缝组织主要为针状铁素体和板条马氏体;完全相变区组织主要为板条马氏体;未完全相变区组织主要为回火马氏体和部分重结晶形成的马氏体。硬度测试表明,在热影响区的回火区发生了软化现象,最低硬度仅为290HV;在完全相变区发生了硬化现象,硬度最大值可达500HV。在不同热输入条件下,焊接接头各亚区硬度变化趋势一致,焊接接头抗拉强度为995~1076 MPa,拉伸试验均断裂在热影响区,断后伸长率为9.33%~10.21%,断裂时存在颈缩现象,为韧性断裂。随着热输入的增加,粗晶区马氏体板条束宽度增大,未完全相变区马氏体含量上升。结论在所选焊接工艺窗口内焊接均能获得高强高韧的焊接接头。

侧向进水泵站前池流动特性及调控措施分析

为解决江苏省扬州市施桥泵站侧向进水前池大范围回流的问题,以施桥翻水站进水建筑物为研究对象,基于雷诺时均N-S方程和RNG k-ε模型,采用CFD软件对侧向进水前池和进水池进行联合数值计算,分析了不同整流措施时前池和进水池的流动特性,提出了若干整流措施并定量分析了流态调控效果,结果表明:无整流措施时,侧向进水泵站2号和6号进水池流态较为紊乱,流线分布不均;通过3个方案整流措施分析,在前池增设底坎时进水池流线分布均匀,流速分布合理,且各水泵机组的进水池进口特征断面轴向流速分布均匀度平均提高了约30%,整流效果显著。研究成果可为类似泵站工程流态改善提供参考。