Gibbons-Maeda Dilation黑洞的量子隧穿效应

运用Parikh的量子隧穿方法,研究了静态球对称Gibbons-Maeda dilation黑洞的量子隧穿效应.当考虑粒子的自引力作用和能量守恒时,Gibbons-Maeda dilation黑洞视界处的粒子隧穿率与Bekenstein-Hawking熵有关,黑洞真实的辐射谱不再是严格的纯热谱.本文所得隧穿率在特殊情况下与Schwarzschild黑洞的结果一致,在忽略ω的高次方项的条件下,可以得到Gibbons-Maeda dilation黑洞辐射的纯热谱.

Failure transition of shear-to-dilation band of rock salt under triaxial stresses

Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily or even hourly,which generates complicated pressures on the salt cavern.Furthermore,the mechanical behavior of rock salt may change and present distinct failure characteristics under different stress states,which affects the performance of salt cavern during the time period of full service.To reproduce a similar loading condition on the cavern surrounding rock mass,the cyclic triaxial loading/unloading tests are performed on the rock salt to explore the mechanical transition behavior and failure characteristics under different confinement.Experimental results show that the rock salt samples pre-sent a diffused shear failure band with significant bulges at certain locations in low confining pressure conditions(e.g.5 MPa,10 MPa and 15 MPa),which is closely related to crystal misorientation and grain boundary sliding.Under the elevated confinement(e.g.20 MPa,30 MPa and 40 MPa),the dilation band dominates the failure mechanism,where the large-size halite crystals are crushed to be smaller size and new pores are developing.The failure transition mechanism revealed in the paper provides additional insight into the mechanical performance of salt caverns influenced by complicated stress states.

Long-term outcomes of urethral balloon dilation for anterior urethral stricture: A prospective cohort study

Objective:To prospectively follow up a cohort of anterior urethral stricture disease patients managed with balloon dilation(BD)for 3 years to evaluate the long-term outcomes and to study factors that contribute to recurrence.Methods:This study included men who had urethral BD for significant anterior urethral stricture disease between January 2017 and March 2019.Data about the patient age,stricture characteristics,and recurrence date were recorded,along with information on postoperative indwelling catheter use and operative complications.Furthermore,information about the self-calibration procedure was collected and where available,free flow(FF)measurements during the follow-up period were recorded and analyzed.Success was defined as a lack of symptoms and acceptable FF rates(maximum flow rate>12 mL/s).Results:The final analysis was conducted on 187 patients.The mean follow-up period was 37 months.The long-term overall success rate at the end of our study was 66.8%.Our recurrence rate was 7.4%at 12 months,24.7%at 24 months,and reached 33.2%at the end of our study.The time to recurrence ranged from 91 days to 1635 days,with a mean of 670 days.The stricture-free survival was significantly shorter with lengthy peno-bulbar(p=0.031)and multiple strictures(p=0.015),and in the group of patients who were not committed to self-calibration protocol(p<0.011).However,post-procedural self-calibration was the most important factor that may have decreased the incidence of recurrence(odds ratioZ5.85).Adjuvant self-calibration after BD not only reduced the recurrence rate from 85.4%in the non-self-calibration group to 15.1%in the self-calibration one(p<0.001),but also improved the overall stricture-free survival and FF parameters.

Dilation,discrimination and Uhlmann's theorem of link products of quantum channels

We establish the Stinespring dilation theorem of the link product of quantum channels in two different ways,discuss the discrimination of quantum channels,and show that the distinguishability can be improved by self-linking each quantum channel n times as n grows.We also find that the maximum value of Uhlmann's theorem can be achieved for diagonal channels.

Effect of endoscopic sphincterotomy and endoscopic papillary balloon dilation endoscopic retrograde cholangiopancreatographies on the sphincter of Oddi

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP),with its clinical ad-vantages of less trauma and faster recovery,has become the primary treatment for choledocholithiasis.AIM To investigate the effects of different ERCP procedures on the sphincter of Oddi.METHODS The clinical data of 91 patients who underwent ERCP at Yixing Hospital of Traditional Chinese Medicine between February 2018 and February 2021 were analyzed retrospectively.The patients were divided into endoscopic sphinc-terotomy(EST,n=24)and endoscopic papillary balloon dilation(EPBD,n=67)groups.The duration of operation,pancreatic development,pancreatic sphinc-terotomy,intubation difficulties,stone recurrence,and incidence of reflux cho-langitis and cholecystitis were statistically analyzed in patients with a history of choledocholithiasis,pancreatitis,and Oddi sphincter dysfunction in the EST and EPBD groups.RESULTS Differences in hypertension,diabetes,increased bilirubin,small diameter of the common bile duct,or ampullary diverticulum between the two groups were not significant.Statistically significant differences were observed between the two groups concerning sex and age(<60 years).Patients with a history of choledocholithiasis,pancreatitis,and Oddi sphincter dysfunction were higher in the EST group than in the EPBD group.The number of cases of pancreatic development,pancreatic duct sphincterotomy,and difficult intubation were higher in the EST group than in the EPBD group.The number of Oddi’s sphincter manometries,ERCP surgical outcomes,and guidewires entering the pancreatic duct several times in EST group were lower than those in the EPBD group.The numbers of stone recurrences,reflux cholangitis,and cholecystitis were higher in the EST group than in the EPBD group.CONCLUSION In summary,common bile duct stones,pancreatitis history,and multiple guided wire introductions into the pancreatic duct are independent risk factors for EST and EPBD.Based on this evidence,this study can provide actionable insights for clinicians and researchers.

Balloon dilation of congenital perforated duodenal web in newborns: Evaluation of short and long-term results

BACKGROUND Incomplete congenital duodenal obstruction(ICDO)is caused by a congenitally perforated duodenal web(CPDW).Currently,only six cases of balloon dilatation of the PDW in newborns have been described.AIM To present our experience of balloon dilatation of a perforated duodenal memb-rane in newborns with ICDO.METHODS Five newborns who underwent balloon dilatation of the CPDW along a prein-stalled guidewire between 2021 and 2023 were included.Nineteen newborns diagnosed with ICDO who underwent laparotomy were included in the control group.RESULTS In all cases,good anatomical and clinical results were obtained.In three cases,a follow-up study was conducted after 1 year.The average time to start enteral feeding per os was significantly earlier in the study group(4.4 d)than in the laparotomic group(21.2 days;P<0.0001).The time spent by patients in the intensive care unit and hospital after balloon dilatation was also significantly shorter.We determined the selection criteria for possible and effective CPDW balloon dilatation in newborns as follows:(1)Presence of dynamic radiographic signs of the passage of a radiopaque substance beyond the zone of narrowing or radiographic signs of pneumatisation of the duodenum and small bowel distal to the web;(2)presence of endoscopic signs of CPDW;(3)successful cannulation with a guidewire performed parallel to the endoscope,with holes in the congenital duodenal web;and(4)successful positioning of the balloon performed along a freestanding guidewire on the web.CONCLUSION Strictly following selection criteria for newborns with ICDO caused by CPDW ensures that endoscopic balloon dilatation using a pre-installed guidewire is safe and effective and shows good 1-year follow-up results.

Clinical efficacy of laparoscopic cholecystectomy combined with endoscopic papillary balloon dilation in treatment of gallbladder stones with common bile duct stones: A retrospective study

BACKGROUND The incidence of cholelithiasis has been on the rise in recent years,but the choice of procedure is controversial.AIM To investigate the efficacy of laparoscopic cholecystectomy(LC)combined with endoscopic papillary balloon dilation(EPBD)in patients with gallbladder stones(GS)with common bile duct stones(CBDS).METHODS The clinical data of 102 patients with GS combined with CBDS were selected for retrospective analysis and divided into either an LC+EPBD group(n=50)or an LC+endoscopic sphincterotomy(EST)group(n=52)according to surgical methods.Surgery-related indexes,postoperative recovery,postoperative complications,and expression levels of inflammatory response indexes were compared between the two groups.RESULTS Total surgical time,stone free rate,rate of conversion to laparotomy,and successful stone extraction rate did not differ significantly between the LC+EPBD group and LC+EST group.Intraoperative hemorrhage,time to ambulation,and length of hospitalization in the LC+EPBD group were lower than those of the LC+EST group(P<0.05).The rate of total complications of the two groups was 9.80%and 17.65%,respectively,and the difference was not statistically significant.No serious complications occurred in either group.At 48 h postoperatively,the expression levels of interleukin-6,tumor necrosis factor-α,high-sensitivity Creactive protein,and procalcitonin were lower in the LC+EPBD group than in the LC+EST group(P<0.05).At 3 d postoperatively,the expression levels of aspartate transaminase,alanine transaminase,and total bilirubin were lower in the LC+EPBD group than in the LC+EST group(P<0.05).CONCLUSION LC combined with EPBD and LC combined with EST are both effective procedures for the treatment of GS with CBDS,in which LC combined with EPBD is beneficial to shorten the patient’s hospitalization time,reduce the magnitude of elevated inflammatory response indexes,and promote postoperative recovery.

The Space Dilation: Analyzing Progressive Speed Reduction and Its Relativistic Parallels

This paper presents a conceptual exploration that draws an intriguing parallelbetween a hypothetical travel scenario and the principles of special relativity. The scenario involves a traveler who reduces their speed by an amount proportional to the distance traveled. Despite initially traveling at a high speed towards a given destination, the continual reduction in speed results in an asymptotic approach to the goal, analogous to the unattainable speed of light in relativity. Mathematically, the scenario is expressed through the Harmonic Series, demonstrating that the total travel time increases without bound, making the destination theoretically unreachable within a finite timeframe. This exploration mirrors the relativistic velocity addition and time dilation effects, providing a compelling analogy for understanding asymptotic limits. By highlighting the profound implications of diminishing returns and unattainable goals, this paper aims to stimulate further discussion and exploration of these fascinating parallels.

Time Dilation Cosmology 2

This paper is a further elaboration of the author’s Time Dilation Cosmology (TDC) holographic model that ties gravitation and celestial mechanics and kinematics directly to time dilation, resolving all the major conundrums in astrophysics, and ties astrophysics directly to quantum physics. It begins with a brief summary of the TDC model and contains the new derivation for the time dilation version of the formula for summing relativistic velocities, Einstein’s gravitational constant and the time dilation versions for the Lorentz factor and the Euclidean norm of the 3d velocity vector, the two of which can then be used in the Four-velocity formula. It is demonstrated how orbital curvature is manifested as the resultant of two time dilation-manifested velocities. It also explains why an interferometer cannot distinguish free fall from zero gravity and further elaborates on the author’s previous explanations of how spiral galaxies are formed, and contains mathematical proof that Black Holes are actually Magnetospheric Eternally Collapsing Objects (MECOs) that are massless spacetime vortices.

基于声黑洞设计理论的径向夹心式径-弯复合换能器

基于弯曲波在声黑洞(acoustic black hole,ABH)结构中振幅不断增大的特性,提出了一种新型径向夹心式径-弯复合换能器,该换能器由径向夹心式圆环换能器与外围的环形ABH结构组成.ABH结构的存在实现了换能器径向振动与弯曲振动之间的转换,提高了换能器的声辐射性能.利用几何声学的方法建立了ABH结构弯曲振动的解析模型,给出了其弯曲振动的本征频率,并结合有限元方法讨论了换能器机电转换性能随尺寸变化的关系.通过有限元方法给出了该换能器在空气中的辐射声压场、辐射声强以及辐射指向性,仿真结果表明,ABH结构的存在能够改善换能器弯曲振动的机电转换性能,提高换能器的声辐射性能,使换能器呈现出一定的辐射指向性.最后通过实验对换能器样机的电阻抗特性以及振动模态进行测量,实验结果与仿真相符合.

二维声学黑洞应用于压电振动能量收集

声学黑洞(acoustic black hole,ABH)效应可以产生强烈的能量集中,能够将高频率低振幅的低品质振动能量转化为高振幅的高品质振动能量,从而便于利用。提出并研究了一种环形二维声学黑洞压电能量收集装置。有限元分析结果表明,环形二维ABH结构能在宽频域内显著提高能量收集效率。搭建了环形二维声学黑洞压电能量收集器试验测试平台,通过试验验证了仿真结果的正确性。与经典二维ABH结构相比,环形二维ABH结构具有更好的能量收集效率和结构强度。分析了压电片几何尺寸等因素对装置能量收集效率的影响,得到了能获得较高输出功率的几何尺寸范围,并进行了正交试验设计,研究了截断厚度、压电片尺寸、中央平台直径、幂指数等多因素的综合影响。

渐近安全引力下的黑洞阴影和光环

重点讨论了薄盘吸积与渐近安全(asymptotically safe,AS)引力修正参数对黑洞阴影和光环的影响.对于薄盘吸积,黑洞的暗区就是黑洞的阴影,而明亮的光环则是由直接像、透镜环和光子环组成的.对于吸积盘辐射源比强度,考虑了3个不同辐射轮廓模型.对辐射起始于最内圆轨道的二阶衰减函数模型,直接像、透镜环和光子环可以明显区分.直接像对黑洞光环亮度贡献最大,透镜环对光环亮度贡献很小,而光子环的贡献几乎可以忽略,且对应观测强度的峰值随AS引力参数的增加而减小,即对应光环亮度随修正参数的增大而变暗.对于辐射起始于光子球半径的三阶衰减函数模型,透镜环和光子环叠加在直接像上,使观测强度出现新的极值.这一极值随AS引力修正参数的增加而增加,且使得黑洞光环的亮度更亮.对辐射起始于事件视界的反三角衰减函数模型,透镜环和光子环在直接像上的叠加范围更大,观测到的光环更宽,且AS引力参数值越小,透镜环和光子环越难区分,黑洞光环的亮度越大.总之,研究表明,黑洞阴影半径的大小随AS修正参数的增加而减小,对于不同的AS引力修正参数,辐射源光强度、尤其是观测强度的辐射轮廓存在显著差异,导致黑洞的阴影和亮环明显不同.

WSN中融合优选机制和变螺旋策略的自适应黑洞覆盖策略

在无线传感器网络节点覆盖优化过程中,黑洞算法往往会陷入局部最优解,导致节点分布不均,后期收敛缓慢。因此提出一种融合优选机制和变螺旋策略的自适应黑洞算法,建立具有最优解的黑洞种群,引入黑洞优选机制,使星体种群在迭代过程中不再围绕一个黑洞进行寻优,经过多次迭代,黑洞种群数量减少,即最优解所在区域更加精确,算法不易陷入局部最优,并围绕最优解附近进行局部搜索,从而实现全局和局部优化能力的平衡。其次,动态调整星体位置更新过程中的螺旋形状,黑洞种群规模不断减小的同时螺旋形状也逐渐变小,即星体能够在更靠近最优解的区域进行开采,提高优化精度。仿真结果显示,改进后的黑洞算法能使节点覆盖率显著提升,覆盖盲区和重叠区域面积大幅减少,节点的移动距离也明显缩减。

de Rham-Gabadadze-Tolley(dRGT)黑洞的热力学与弱宇宙监督假设

有质量引力理论作为修正引力理论之一,对探究宇宙加速膨胀,以及解释暗能量和暗物质问题等有重要意义.本文研究了在常规相空间中de Rham-Gabadadze-Tolley(dRGT)有质量引力下球对称黑洞的热力学第一定律、热力学第二定律与弱宇宙监督假设是否成立;并通过图像探究熵的微分变化量随事件视界r_(d)变化的影响,以及与dRGT黑洞无量纲自由参数α,β与引力子质量对该图像的影响.在研究过程中,通过引入标量粒子的能量G动量关系,来验证黑洞热力学第一定律是否成立,通过观察事件视界对熵的微分变化量的影响,来验证黑洞热力学第二定律是否成立.研究发现,黑洞在吸收粒子的同时,其视界半径始终存在,从而使奇点始终没有裸露出来.结果表明,在dRGT有质量引力下球对称黑洞的热力学第一定律,热力学第二定律与弱宇宙监督假设均成立.

Long-term outcomes of endoscopic papillary large-balloon dilation(12-15 mm)with or without limited sphincterotomy for removal of bile duct stones

Background:Limited endoscopic sphincterotomy with large balloon dilation(ES-LBD)and endoscopic papillary large-balloon dilation(EPLBD)have been proven safe and effective for removal of bile duct stones.However,the long-term outcomes are not clear.The aim of this study was to assess the long-term outcomes of EPLBD(12-15 mm)with or without limited sphincterotomy for removal of common bile duct(CBD)stones.Methods:Patients with EPLBD or ES-LBD referred for the removal of bile-duct stones between June 2008 and August 2020 were retrospectively reviewed.Complete stone clearance,endoscopic retrograde cholangiopancreatography(ERCP)-related adverse events,and late biliary complications during long-term follow-up were analyzed.Results:Basic patient characteristics were not significantly different between the groups that underwent EPLBD(n=168)and ES-LBD(n=57).EPLBD compared with ES-LBD resulted in similar outcomes in terms of overall successful stone removal(99.4%vs.100%,P=1.00)and ERCP-related adverse events(7.7%vs.5.3%,P=0.77).The mean duration of the follow-up were 113.6 months and 106.7 months for patients with EPLBD and ES-LBD,respectively(P=0.13).There was no significant difference between EPLBD and ES-LBD in the incidence of stone recurrence[20(11.9%)vs.9(15.8%);P=0.49].Multivariate analysis showed that a diameter of CBD≥15 mm(OR=3.001;95%CI:1.357-6.640;P=0.007)was an independent risk factor for stone recurrence.Conclusions:The application of a large balloon(12-15 mm)via EPLBD is an effective and safe alternative to ES-LBD for extraction of large CBD stones.Endoscopic sphincterotomy prior to EPLBD may be unnec-essary.A diameter of CBD≥15 mm is a risk factor of stone recurrence.

附加式声学黑洞对悬臂板振动寿命影响研究

结构在振动条件下的疲劳破坏对其自身的使用寿命以及使用者的人身安全均带来了隐患,目前对于解决结构振动疲劳有添加加强筋、敷设大量阻尼材料等方法,但往往效率较低,附加质量过大。为解决上述问题,提出将附加式声学黑洞(ABH)安装在结构上,通过降低结构响应达到降低应力幅值,延长使用寿命的目的。以悬臂板为基准结构,利用有限元方法进行了稳态动力学分析。结果表明,在附加矩形声学黑洞(RABH)后,悬臂板缺口处的应力响应明显降低。通过应力实验以及疲劳实验,验证了附加RABH可以降低结构危险点处应力响应,并延长悬臂板结构的振动疲劳寿命。

Advanced Face Mask Detection Model Using Hybrid Dilation Convolution Based Method

A face-mask object detection model incorporating hybrid dilation convolutional network termed ResNet Hybrid-dilation-convolution Face-mask-detector (RHF) is proposed in this paper. Furthermore, a lightweight face-mask dataset named Light Masked Face Dataset (LMFD) and a medium-sized face-mask dataset named Masked Face Dataset (MFD) with data augmentation methods applied is also constructed in this paper. The hybrid dilation convolutional network is able to expand the perception of the convolutional kernel without concern about the discontinuity of image information during the convolution process. For the given two datasets being constructed above, the trained models are significantly optimized in terms of detection performance, training time, and other related metrics. By using the MFD dataset of 55,905 images, the RHF model requires roughly 10 hours less training time compared to ResNet50 with better detection results with mAP of 93.45%.

基于环状螺旋声学黑洞的管道结构振动抑制研究

传统的附加式声学黑洞(ABH)结构主要针对板状结构的振动抑制进行设计,对于工程中广泛存在的管道结构难以适用。为解决管道结构的振动抑制问题,提出了一种能够应用在管道结构上的附加式ABH装置“环状螺旋式ABH减振器(CSABH)”。通过将ABH区域设计成螺线形式,增加了减振器的模态密度,使其与主结构更好地耦合。以铝管为基准结构,利用有限元方法探究了CSABH的动力学特性,进行了时域波聚集分析与频域响应分析。结果表明,CSABH具有良好的波聚集特性,能实现对管道20~5000 Hz的振动抑制,且当管道的约束条件和温度条件发生改变时,相同参数的CSABH仍然能够发挥良好的宽频减振效果,展现了减振的鲁棒性。通过实验验证了CSABH在管道结构的振动控制中具有宽频、高效和鲁棒性高的特点。

黑洞X射线双星中X射线反射成分的研究进展

反射是研究黑洞X射线双星的一个重要工具,有助于理解强引力场中所独有的许多物理过程。综合了观测和理论方面的研究,探讨了黑洞X射线双星中X射线反射成分的最新进展:(1)介绍了反射成分的相关物理过程和能谱形态特征;(2)回顾了近年来在黑洞X射线双星不同能谱态中发现的反射成分及其特征;(3)回顾了反射模型的发展历史,并着重介绍了现有的反射模型,其中特别关注了最近发展起来的relxill模型;(4)探究了反射成分研究中的一些难点和挑战,例如吸积盘厚度和冕区性质的不确定性;(5)对未来黑洞X射线双星反射成分的研究进行了展望。

基于声学黑洞的谷物流量传感器支架减振优化

为减少联合收获机振动对谷物流量传感器监测结果的干扰,设计了一种基于声学黑洞(ABH,acoustic black hole)原理的谷物流量传感器龙门支架减振结构,通过有限元方法分析减振结构的振动特性,分析了二维声学黑洞比例系数ε、幂函数指数m和半径R对其减振性能的影响规律。结果表明,声学黑洞能够显著降低龙门支架的振动,ε、m和R对声学黑洞减振性能的影响均未表现出明显线性关系,当ε=0.001 2、m=2.5、R=15 mm时声学黑洞的减振效果最好。以振动速度平方和作为优化目标,建立了多项式回归代理模型,通过遗传算法对声学黑洞比例系数ε、幂函数指数m和半径R的取值进行了优化。相比于未添加声学黑洞的原始龙门支架和初始声学黑洞方案,优化后龙门支架的振动速度平方和分别降低68.92%和2%,表明优化方案具有更佳的减振性能。提出的基于声学黑洞的减振结构和优化设计方法为农业机械被动宽频减振研究提供了理论参考。