Effect of granular shape on radial segregation in a two-dimensional drum

Granular segregation is widely observed in nature and industry.Most research has focused on segregation caused by differences in the size and density of spherical grains.However,due to the fact that grains typically have different shapes,the focus is shifting towards shape segregation.In this study,experiments are conducted by mixing cubic and spherical grains.The results indicate that spherical grains gather at the center and cubic grains are distributed around them,and the degree of segregation is low.Through experiments,a structured analysis of local regions is conducted to explain the inability to form stable segregation patterns with obviously different geometric shapes.Further,through simulations,the reasons for the central and peripheral distributions are explained by comparing velocities and the number of collisions of the grains in the flow layer.

Uncovering Small RNAs in Penicillium digitatum by Transcriptome Sequencing

Small RNAs in Penicillium digitatum were identified and analyzed via transcriptome sequencing on the BGISEQ-500 platform. A total of 15 predicted miRNAs and 10718 novel siRNAs were found. Their length distribution, sequence, predicted construction, base bias, expression levels and potential targets were determined as well. Through pathway and KEGG enrichment analysis, the miRNA target genes were mostly involved in carbohydrate metabolism, transport and catabolism, translation and amino acid metabolism. The target genes involved in aflatoxin biosynthesis and proteasome had a higher rich factor value. The results will provide a theoretical foundation for understanding the developmental and pathogenic mechanisms of P. digitatum at the transcriptional level.

Shale gas transport in nanopores with mobile water films and water bridge

Gas flow properties in nanopores are significantly determined by the flow patterns. Slug flow pattern is a potential water–gas two phase flow pattern, in which gas molecules flow in form of gas slugs and water molecules separate gas slugs. Considering water slippage, a portion of water molecules accumulates at the wall with lower mobility, while the remaining water molecules take the shape of a water bridge. Adopting foam apparent viscosity model to represent slug rheological behavior, how water bridge disturbs on gas flow capacity is estimated. The results are compared with the water–gas two phase flow model that assumes annular flow pattern as well as the single gas flow model without the consideration of water. The comparison illustrates that gas molecular movement is significantly hindered by flow space reduction and loss of gas slippage. The impact from water phase of slug flow pattern is more significant than that of annular flow pattern on gas flow capacity. It is discovered that larger nanopores improve gas flow capacity while maintaining bulk water layer thickness and increasing water bridge thickness tend to reduce gas transport ability. A better understanding of the structure and transport of water and gas molecules is conducive to figure out the specific gas–water flow behavior and predict shale gas production.

双层电介质界面极化电流测量装置的设计与实现

界面夹层极化现象是高电压技术中的重要知识点。为了使学生更好地掌握双层电介质界面极化电流的测量,研制了一套界面极化电流测量装置——极化-去极化电流测量装置。基于极化-去极化电流测量原理,设计了无线传输数据的皮安表、可输出0~5 kV电压的程控直流高压电源以及分析显示数据的上位机控制程序,然后基于该测量装置设计了双层电介质界面极化电流测量实验。结果表明,该测量装置解决了双层电介质界面极化电流不易测量、学生理解难的问题。将实验教学与实际工程问题紧密连接,把微观的工程技术问题转变为宏观的实验现象,对于培养学生的科研思维及分析问题、解决问题能力有重要意义。

Rolling velocity and relative motion of particle detector in local granular flow

The velocity of a particle detector in granular flow can be regarded as the combination of rolling and sliding velocities.The study of the contribution of rolling velocity and sliding velocity provides a new explanation to the relative motion between the detector and the local granular flow.In this study,a spherical detector using embedded inertial navigation technology is placed in the chute granular flow to study the movement of the detector relative to the granular flow.It is shown by particle image velocimetry(PIV)that the velocity of chute granular flow conforms to Silbert’s formula.And the velocity of the detector is greater than that of the granular flow around it.By decomposing the velocity into sliding and rolling velocity,it is indicated that the movement of the detector relative to the granular flow is mainly caused by rolling.The rolling detail shown by DEM simulation leads to two potential mechanisms based on the position and drive of the detector.

Research Progress on Acupuncture Therapy in Infertility: A Bibliometric Analysis from 2000 to 2021

Objective: To investigate the research progress and new trend of acupuncture in the treatment of infertility from 2000 to 2021. Methods: The literature review was conducted on acupuncture and moxibustion treatment of infertility from 2000 to 2021 from the Web of Science core collection and PubMed. CiteSpace and VOSviewer were used to analyze the annual number of articles, countries, institutions, authors, journals, references and keywords. Statistical Analysis Toolkit for Informetrics 3.2 (SATI) and IBM SPSS Modeler 18.0 were employed to draw the maps of core acupoints and acupuncture approaches. Results: A total of 316 articles were included. From 2000 to 2021 the number of publications has been ever increased with certain fluctuations. The United States was the most productive country. Heilongjiang University of Chinese Medicine was the most active institution. Stener-Victorin E was the highest cited author. Fertility and Sterility was the most prolific journal. Paulus We, 2002 was the highest co-citation literature. SP6 (Sanyinjiao) was the most commonly used acupoint. Manual acupuncture was the most commonly used method. Conclusions: The study of acupuncture in the treatment of infertility is characterized by multinational, multi-institutional participation and close regional cooperation. Acupuncture is a potentially effective therapy for infertility. Due to a lack of research quality and difficulties in performing double-blind, high-quality clinical evidence is urgently required. A complete acupuncture therapy system for infertility should be gradually constructed.

First Report of a Postharvest Fruit Rot on Apple Caused by <i>Diaporthe phaseolorum</i>var. <i>caulivora</i>in China: A Note

Brown rots of Red Fuji apples were observed in Hangzhou city (Zhengjiang Province, China). The causal agent was isolated and identified in both morphological and molecular genetic levels. The phenotype and phylogenetic analysis revealed that the isolate was Diaporthe phaseolorum var. caulivora, and its pathogenicity on apple fruit was confirmed by re-inoculation experiment. To our knowledge, this is the first report of D. phaseolorum var. caulivora causing postharvest fruit rot on apple in China.

基于参数随机反演的拱坝位移监控指标拟定方法

针对传统混凝土拱坝位移监控指标拟定中未考虑大坝材料参数不确定性的问题,结合贝叶斯推断理论、粒子群优化和长短时记忆网络提出一种基于随机反分析结果的拱坝位移监控指标拟定方法。利用粒子群方法优化长短时记忆神经网络作为代理模型;基于不同监测点实测位移值和代理模型计算位移值建立联合似然函数;在已知材料参数先验分布下,通过贝叶斯推断获得材料参数的后验分布;利用材料参数的后验分布计算监控指标的水压分量,结合实测位移数据确定混凝土拱坝位移监控指标。工程实例分析表明:通过贝叶斯推断方法,可以反演得到准确的材料参数后验结果;以混合法确定的位移监控指标充分利用了材料参数的随机反分析结果,具有更好的预警效果。

面向地铁客流分析场景的弹性集群云平台架构设计及部署方案

[目的]在数字化技术迅速发展的当下,云技术被广泛应用在包括地铁系统在内的各行各业。出于对乘客出行安全的保障,实现大规模客流数据的实时获取和高效分析,需要提出面向客流分析场景的弹性集群云平台方案。[方法]分析了弹性集群云平台的核心功能需求,提出了弹性集群云平台的架构,阐述了弹性集群云平台的独特能力。针对不同发展阶段的地铁系统提出了2个弹性集群云平台部署方案,分析了各部署方案的优劣。以上海地铁为例,基于能力需求对比了部署方案的投资成本。分析了弹性集群云平台架构与地铁客流分析业务特征的匹配性。[结果及结论]地铁客流分析场景具有多系统并发、实时性高、数据量大等特点。弹性集群云平台能满足客流分析业务的多种需求。

A game-theoretic approach for federated learning:A trade-off among privacy,accuracy and energy

Benefiting from the development of Federated Learning(FL)and distributed communication systems,large-scale intelligent applications become possible.Distributed devices not only provide adequate training data,but also cause privacy leakage and energy consumption.How to optimize the energy consumption in distributed communication systems,while ensuring the privacy of users and model accuracy,has become an urgent challenge.In this paper,we define the FL as a 3-layer architecture including users,agents and server.In order to find a balance among model training accuracy,privacy-preserving effect,and energy consumption,we design the training process of FL as game models.We use an extensive game tree to analyze the key elements that influence the players’decisions in the single game,and then find the incentive mechanism that meet the social norms through the repeated game.The experimental results show that the Nash equilibrium we obtained satisfies the laws of reality,and the proposed incentive mechanism can also promote users to submit high-quality data in FL.Following the multiple rounds of play,the incentive mechanism can help all players find the optimal strategies for energy,privacy,and accuracy of FL in distributed communication systems.

忻州市生态系统服务时空变化及城镇化响应

为探究忻州市生态系统服务(ESs)的时空变化情况,分析ESs对城镇化的响应,以1995~2020年6期土地利用数据为基础,选取3项城镇化指标和4项ESs指标,借助InVEST模型和修正通用土壤流失方程(RUSLE)等评估ESs,并使用K-均值聚类识别生态系统服务簇,采用皮尔逊相关性分析ESs间权衡协同关系及其对城镇化的响应.结果表明:忻州市土地利用类型以草地、耕地和林地为主,1995~2020年建设用地扩张280.7km^(2),林地增加1201.4km^(2),草地增加511.4km^(2),耕地和水域面积减少.有较多耕地向草地、草地向林地转移.建设用地、GDP和人口持续增长,2005~2015年是城镇化较快的时期.1995~2020年食物供给能力稳步提升,碳储量在2015年以后明显提升,生境质量先升后降,水土保持量先降后升.以草地为主的功能复合型服务簇面积占比达51.4%,各ESs间主要呈协同关系,生境质量、土壤保持与城镇化指标间存在负相关.研究结果为忻州市土地管理与生态保护提供决策依据.

针刀调控软骨细胞自噬维持骨关节炎软骨细胞的稳态

背景:针刀是治疗骨关节炎的有效方法,临床疗效肯定,但具体机制尚未明确。目的:探讨针刀调控软骨细胞自噬维持骨关节炎软骨细胞稳态的作用。方法:采用随机数字表法将28只新西兰兔分为对照组、骨关节炎组、针刀组和透明质酸组,每组7只,后3组保持左后肢过伸位采用石膏绷带固定6周建立膝骨关节炎模型,建模成功后,对照组与骨关节炎组不进行任何治疗,针刀组给予针刀治疗(15 min/次,1次/周),透明质酸组膝关节腔内注射透明质酸钠溶液(1次/周),均连续治疗5周。末次治疗后第2天,采用DR片观察兔膝关节宏观结构,透射电镜观察软骨细胞超微结构,Tunel染色检测软骨细胞凋亡,Western blot检测PI3K/Akt/mTOR通路及自噬相关蛋白表达。结果与结论:(1)DR片显示,骨关节炎组兔膝关节间隙变窄、周围骨赘形成;相较于骨关节炎组,透明质酸组、针刀组兔膝关节间隙增宽,周围骨赘减少;(2)透射电镜下可见骨关节炎组兔膝关节软骨细胞内自噬体数量减少,细胞核皱缩、核膜破裂,细胞器形态不完整、细胞呈现明显死亡趋向;相较于骨关节炎组,透明质酸组与针刀组自噬体明显增加,细胞核核膜完整,细胞生存状态良好;(3)Tunel染色结果显示,相较于骨关节炎组,透明质酸组、针刀组凋亡软骨细胞明显减少;(4)Western blot检测结果显示,与对照组比较,骨关节炎组Beclin1、Cath D和LC3Ⅱ/LC3Ⅰ蛋白表达降低(P <0.05),p-Akt/Akt、p-mTOR/mTOR蛋白表达升高(P <0.05);与骨关节炎组比较,透明质酸组和针刀组Beclin1、Cath D和LC3Ⅱ/LC3Ⅰ蛋白表达升高(P <0.05),p-Akt/Akt、p-mTOR/mTOR蛋白表达降低(P <0.05);(5)结果表明,针刀可通过抑制PI3K/Akt/mTOR信号通路传导来提高软骨细胞自噬水平,维持软骨细胞稳态,最终延缓软骨退变。

Experimental study on the effect of unloading rate on gneiss rockburst

Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in real-time.The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection velocity.The mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst.This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack propagation.Then,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation process.The enlightenments of reducing the unloading rate for the project are also described quantitatively.The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

中国褶蜢属Ptygomastax Bey-Bienko一新种(直翅目:蜢科)

记述采自中国青海的褶蜢属Ptygomastax Bey-Bienko1新种:久治褶蜢Ptygomastax jiuzhiensis sp.nov.。该新种与黑马河褶蜢Ptygomastax heimahoensis Cheng&Han相似,但新种颜面隆起在触角间近平行,后头和背板中间纵条纹的颜色明显不同于体色,后头纵条纹黑色,背板纵条纹淡绿色,而体黑褐色。

从“平滑感”到“异质性”:韩炳哲的审美救赎思想探析

韩炳哲的审美救赎思想与法兰克福学派的审美救赎理论一脉相承,但具有鲜明的时代特点。韩炳哲直面当今数字社会的审美异化:具有“阻拒性”的他者在当代艺术和身体中的消失,审美距离和内在意义也随之消逝,审美进入“肯定性”的平滑状态。面对这一审美困境,韩炳哲认为“否定性美学”蕴含的“异质性”是审美救赎的核心,呼吁通过遮蔽和创伤重返艺术本质。但仅仅借助感性的审美救赎,无法真正解决数字时代的审美问题,仍不免走向乌托邦的迷途。

The Velocity Aberration Effect of the CSST Main Survey Camera

In this study,we conducted simulations to find the geometric aberrations expected for images taken by the Main Survey Camera of the Chinese Space Station Telescope(CSST)due to its motion.As anticipated by previous work,our findings indicate that the geometric distortion of light impacts the focal plane's apparent scale,with a more pronounced influence as the size of the focal plane increases.Our models suggest that the effect consistently influences the pixel scale in both the vertical and parallel directions.The apparent scale variation follows a sinusoidal distribution throughout one orbital period.Simulations reveal that the effect is particularly pronounced in the center of the Galaxy and gradually diminishes along the direction of ecliptic latitude.At low ecliptic latitudes,the total aberration leads to about a 0.94 pixel offset(a 20 minute exposure)and a 0.26 pixel offset(a 300 s exposure)at the edge of the field of view.Appropriate processings for the geometric effect during the CSST pre-and post-observation phases are presented.

Preparation for CSST:Star-galaxy Classification using a Rotationally Invariant Supervised Machine Learning Method

Most existing star-galaxy classifiers depend on the reduced information from catalogs,necessitating careful data processing and feature extraction.In this study,we employ a supervised machine learning method(GoogLeNet)to automatically classify stars and galaxies in the COSMOS field.Unlike traditional machine learning methods,we introduce several preprocessing techniques,including noise reduction and the unwrapping of denoised images in polar coordinates,applied to our carefully selected samples of stars and galaxies.By dividing the selected samples into training and validation sets in an 8:2 ratio,we evaluate the performance of the GoogLeNet model in distinguishing between stars and galaxies.The results indicate that the GoogLeNet model is highly effective,achieving accuracies of 99.6% and 99.9% for stars and galaxies,respectively.Furthermore,by comparing the results with and without preprocessing,we find that preprocessing can significantly improve classification accuracy(by approximately 2.0% to 6.0%)when the images are rotated.In preparation for the future launch of the China Space Station Telescope(CSST),we also evaluate the performance of the GoogLeNet model on the CSST simulation data.These results demonstrate a high level of accuracy(approximately 99.8%),indicating that this model can be effectively utilized for future observations with the CSST.

All-sky Guide Star Catalog for CSST

The China Space Station Telescope(CSST)is a two-meter space telescope with multiple back-end instruments.The Fine Guidance Sensor(FGS)is an essential subsystem of the CSST Precision Image Stability System to ensure the required absolute pointing accuracy and line-of-sight stabilization.In this study,we construct the Main Guide Star Catalog for FGS.To accomplish this,we utilize the information about the FGS and object information from the Gaia Data Release 3.We provide an FGS instrument magnitude and exclude variables,binaries,and high proper motion stars from the catalog to ensure uniform FGS guidance capabilities.Subsequently,we generate a HEALPix index,which provides a hierarchical tessellation of the celestial sphere,and employ the Voronoi algorithm to achieve a homogeneous distribution of stars across the catalog.This distribution ensures adequate coverage and sampling of the sky.The performance of the CSST guide star catalog was assessed by simulating the field of view of the FGS according to the CSST mock survey strategy catalog.The analysis of the results indicates that this catalog provides adequate coverage and accuracy.The catalog's performance meets the FGS requirements,ensuring the functioning of the FGS and its guidance capabilities.

Electroencephalogram findings in 10 patients with post-stroke epilepsy:A retrospective study

BACKGROUND Post-stroke epilepsy is a common and easily overlooked complication of acute cerebrovascular disease.Long-term seizures can seriously affect the prognosis and quality of life of patients.Electroencephalogram(EEG)is the simplest way to diagnose epilepsy,and plays an important role in predicting seizures and guiding medication.AIM To explore the EEG characteristics of patients with post-stroke epilepsy and improve the detection rate of inter-seizure epileptiform discharges.METHODS From January 2017 to June 2020,10 patients with post-stroke epilepsy in our hospital were included.The clinical,imaging,and EEG characteristics were collected.The stroke location,seizure type,and ictal and interictal EEG manifestations of the patients with post-stroke epilepsy were then retrospectively analyzed.RESULTS In all 10 patients,epileptiform waves occurred in the side opposite to the stroke lesion during the interictal stage;these manifested as sharp wave,sharp-wave complex,or spike discharges in the anterior head lead of the side opposite to the lesion.CONCLUSION In EEG,epileptiform waves can occur in the side opposite to the stroke lesion in patients with post-stroke epilepsy.

Primary large cell neuroendocrine carcinoma of the bladder:A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)of the bladder is a rare nonurothelial tumor of the bladder.The treatment of LCNEC of the bladder is different from that of urothelial carcinoma(UC);therefore,early and accurate diagnosis is particularly important.As LCNEC of the bladder is rare and its clinical symptoms and radiographic features are similar to those of urothelial tumors,the clinical diagnosis of the disease remains challenging.CASE SUMMARY We report a 72-year-old female patient who presented with gross hematuria for 3 mo.A solitary tumor located in the anterior wall of the bladder was found by cystoscopy.Pathological examination after biopsy suggested UC of the bladder in the absence of immunohistochemical assessment.The patient underwent partial cystectomy and was finally diagnosed with LCNEC(pT2bN0M0)based on the results of postoperative immunohistochemical examination.During the 10-mo follow-up,no signs of tumor recurrence or metastasis were found.CONCLUSION Immunohistochemical examination is essential for diagnosing LCNEC of the bladder.Accurate diagnosis and multidisciplinary treatment in the early stage of the disease are crucial for improving the prognosis.