A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels

According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.

A Practical Approach for Missing Wireless Sensor Networks Data Recovery

In wireless sensor networks(WSNs),the performance of related applications is highly dependent on the quality of data collected.Unfortunately,missing data is almost inevitable in the process of data acquisition and transmission.Existing methods often rely on prior information such as low-rank characteristics or spatiotemporal correlation when recovering missing WSNs data.However,in realistic application scenarios,it is very difficult to obtain these prior information from incomplete data sets.Therefore,we aim to recover the missing WSNs data effectively while getting rid of the perplexity of prior information.By designing the corresponding measurement matrix that can capture the position of missing data and sparse representation matrix,a compressive sensing(CS)based missing data recovery model is established.Then,we design a comparison standard to select the best sparse representation basis and introduce average cross-correlation to examine the rationality of the established model.Furthermore,an improved fast matching pursuit algorithm is proposed to solve the model.Simulation results show that the proposed method can effectively recover the missing WSNs data.

Magnetic Field Curves and Magnetic Equipotential Surfaces around Crossing Electrical Wires Replacing Classical Magnetic Field Lines

This article is based on a recent model specifically defining magnetic field values around electrical wires. With this model, calculations of field around parallel wires were obtained. Now, this model is extended with the new concept of magnetic equipotential surface to magnetic field curves around crossing wires. Cases of single, double, and triple wires are described. Subsequent article will be conducted for more general scenarios where wires are neither infinite nor parallel.

Overall Selection Design Based on the Mega Highway Bridge Project

In the continuous development of the modern highway and bridge engineering industry,the reasonable selection of mega highway bridges and their design is crucial.Based on this,this paper takes the actual bridge project as an example,and analyses the overall selection design of such highway bridges,including the basic overview of the project,the basic selection principle of mega highway bridge project structure and its design strategy,etc.,to provide scientific reference for its selection design.

Crossing Over

Coming to China was the easy part; making meaningful connec- tions with Chinese peo- ple and their culture has proven much trickier. This is partly a uni- versal phenomenon and partly a specifically Chinese conundrum. Forgive the cynicism, but it

Crossing Over In Style

China’s Grammy-nominated soprano Song Zuying and her illustrious friends bring the Bird’s Nest back to life It was a blue-sky summer day in Beijing. In the afternoon sun the metallic twists of the iconic National Stadium of China, also known as the Bird’s Nest,

Evolution of polarization singularities accompanied by avoided crossing in plasmonic system

The evolution of polarization singularities supported in a one-dimensional periodic plasmonic system is studied.The lateral inversion symmetry of the system,which breaks the in-plane inversion symmetry and up-down mirror symmetry simultaneously,yields abundant polarization states.A complete evolution process with geometry for the polarization states is traced.In the evolution,circularly polarized points(C points)can stem from 3 different processes.In addition to the previously reported processes occurring in an isolated band,a new type of C point appearing in two bands simultaneously due to the avoided band crossing,is observed.Unlike the dielectric system with a similar structure which only supports at-Γbound states in the continuum(BICs),accidental BICs off theΓpoint are realized in this plasmonic system.This work provides a new scheme of polarization manipulation for the plasmonic systems.

LEO支架构建crossing Y形支架辅助栓塞治疗颅内动脉分叉部宽颈动脉瘤的安全性和有效性分析

目的探讨使用LEO支架构建crossing Y形支架辅助栓塞治疗颅内动脉分叉部宽颈动脉瘤的安全性和有效性。方法收集2018-2022年陆军军医大学第一附属医院神经外科收治的336例颅内动脉分叉部宽颈动脉瘤患者的临床资料及随访影像,其中55例患者采用LEO支架构建crossing Y形支架辅助栓塞治疗。观察使用LEO支架构建crossing Y形支架辅助栓塞治疗动脉瘤的成功率、手术相关并发症、围手术期缺血和出血并发症的发生率。采用改良Rankin评分(modified Rankin scale,mRS)量表评价患者出院及临床随访时的神经功能恢复情况,使用术后即刻及随访脑血管造影Raymond分级评估栓塞效果、术后随访CTA及MRA评估有无复发。结果55例颅内动脉分叉部宽颈动脉瘤患者均成功栓塞,未见支架打开不良、支架打折等不良事件;术中支架内血栓形成1例(1.82%),迟发性缺血2例(3.64%),未见围手术期出血事件。术后即刻造影致密栓塞(RaymondⅠ级)50例(90.91%),瘤颈残留(RaymondⅡ级)3例(5.45%),RaymondⅢ级2例(3.64%)。40例患者于术后6~24个月获得影像随访,造影RaymondⅠ级38例(95%),RaymondⅡ级2例(5%);9例患者行CTA或MRA复查未见复发;术后随访动脉瘤栓塞效果较术后即刻好转。出院时mRS评分0~1分50例,2分1例,3分1例,4分2例,5分1例。获得4~24个月临床随访预后,mRS评分0~1分50例,2分2例,3分1例,4分1例,6分1例;出院时mRS评分较差患者临床随访mRS评分好转。结论使用LEO支架构建crossing Y形支架辅助栓塞治疗颅内动脉分叉部宽颈动脉瘤成功率及安全性高,复发率低,围手术期缺血事件发生率低,近期疗效可,远期疗效待进一步观察。

The asymptotic relation between the first crossing point and the last exit time of Gaussian order statistics sequences

In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained.

Seasonal Prediction of Tropical Cyclones and Storms over the Southwestern Indian Ocean Region Using the Generalized Linear Models

Tropical cyclones (TCs) and storms (TSs) are among the devastating events in the world and southwestern Indian Ocean (SWIO) in particular. The seasonal forecasting TCs and TSs for December to March (DJFM) and November to May (NM) over SWIO were conducted. Dynamic parameters including vertical wind shear, mean zonal steering wind and vorticity at 850 mb were derived from NOAA (NCEP-NCAR) reanalysis 1 wind fields. Thermodynamic parameters including monthly and daily mean Sea Surface Temperature (SST), Outgoing Longwave Radiation (OLR) and equatorial Standard Oscillation Index (SOI) were used. Three types of Poison regression models (i.e. dynamic, thermodynamic and combined models) were developed and validated using the Leave One Out Cross Validation (LOOCV). Moreover, 2 × 2 square matrix contingency tables for model verification were used. The results revealed that, the observed and cross validated DJFM and NM TCs and TSs strongly correlated with each other (p ≤ 0.02) for all model types, with correlations (r) ranging from 0.62 - 0.86 for TCs and 0.52 - 0.87 for TSs, indicating great association between these variables. Assessment of the model skill for all model types of DJFM and NM TCs and TSs frequency revealed high skill scores ranging from 38% - 70% for TCs and 26% - 72% for TSs frequency, respectively. Moreover, results indicated that the dynamic and combined models had higher skill scores than the thermodynamic models. The DJFM and NM selected predictors explained the TCs and TSs variability by the range of 0.45 - 0.65 and 0.37 - 0.66, respectively. However, verification analysis revealed that all models were adequate for predicting the seasonal TCs and TSs, with high bias values ranging from 0.85 - 0.94. Conclusively, the study calls for more studies in TCs and TSs frequency and strengths for enhancing the performance of the March to May (MAM) and December to October (OND) seasonal rainfalls in the East African (EA) and Tanzania in particular.

Frequent recombination in Cynoglossus abbreviatus(Pleuronectiformes:Cynoglossidae)ribosomal 18S rDNA

The conventional theory of concerted evolution has been used to explain the lack of sequence variation in ribosomal RNA(rRNA)genes across diverse eukaryotic species.However,recent investigations into rRNA genes in flatfish genome have resulted in controversial findings.This study focuses on 18S rRNA genes of the widely distributed tongue sole,Cynoglossus abbreviatus(Pleuronectiformes:Cynoglossidae),aiming to explore sequence polymorphism.Five distinct 18S rDNA sequence types(Type A,B,R1,R2,and R3)were identified,suggesting a departure from concerted evolution.A combination of general criteria and variations in highly conserved regions were employed to detect pseudogenes.The results pinpointed Type A sequences as potential pseudogenes due to significant sequence variations and deviations in secondary structure within highly conserved regions.Three types(Type R1,R2,and R3)were identified as recombinants between Type A and B sequences,with simple crossing over and gene conversion as the most likely recombination mechanisms.These findings not only contribute to rRNA pseudogene identification but also shed light on the evolutionary dynamics of rRNA genes in teleost genomes.

Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions:theoretical basis

Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great significance.To address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion reactors.At the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He reaction.The^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of Sciences.The neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb reaction.The measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature data.The newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental values.The obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

Mitotic crossover- an evolutionary rudiment which promotes carcinogenesis of colorectal carcinoma

Mitotic crossover is a natural mechanism that is a main source of the genetic variability of primitive organisms.In complex organisms such as mammals,it represents an evolutionary rudiment which persisted as one of the numerous DNA repair mechanisms,and results in the production of homozygous allele combinations in all heterozygous genes located on the chromosome arm distal to the crossover.This event is familiar as loss of heterozygosity,which is one of the key mechanisms responsible for the development and progression of almost all cancers.We propose the hypothesis in which mitotic crossover is a principal source of the increased loss of heterozygosity that leads to the initiation and progression of colorectal carcinoma.The hypothesis could be tested by in vitro inhibition of Rad51 protein,orthotopic grafting of human colon cancer tissue into the gut of mice,and treatment with potential inhibitors.After these procedures,the frequency of mitotic crossover would be estimated.The development of selective inhibitors of mitotic crossover could stop further carcinogenesis of colorectal carcinoma,as well as many other neoplastic events.Loss of heterozygosity is an event responsible for carcinogenesis,its reduction by selective inhibitors of mitotic crossover could have a positive effect on cancer chemoprevention,as well as on growth reduction and a cessation in the progression of earlier developed tumors.

Floquet spectrum and universal dynamics of a periodically driven two-atom system

We investigate the Floquet spectrum and excitation properties of a two-ultracold-atom system with periodically driven interaction in a three-dimensional harmonic trap.The interaction between the atoms is changed by varying the s-wave scattering length in two ways,the cosine and the square-wave modulations.It is found that as the driving frequency increases,the Floquet spectrum exhibits two main features for both modulations,the accumulating and the spreading of the quasienergy levels,which further lead to different dynamical behaviors.The accumulation is associated with collective excitations and the persistent growth of the energy,while the spread indicates that the energy is bounded at all times.The initial scattering length,the driving frequency and amplitude can all significantly change the Floquet spectrum as well as the dynamics.However,the corresponding relation between them is valid universally.Finally,we propose a mechanism for selectively exciting the system to one specific state by using the avoided crossing of two quasienergy levels,which could guide preparation of a desired state in experiments.

Sacrificial piles as a countermeasure against local scour around underwater pipelines

Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.

The n-resolved single-electron capture in slow O^(6+)-Ne collisions

A study of single-electron capture(SEC) in 18-240 keV O^(6+)-Ne collisions has been conducted employing a combination of experimental and theoretical methodologies.Utilizing a reaction microscope,state-selective SEC cross sections and projectile scattering angle distributions were obtained.The translational energy spectra for SEC reveal the prevailing capture into n=3 states of the projectile ion,with a minor contribution from n=4 states.Notably,as the projectile's energy increases,the relative contribution of SEC n=4 states increases while that of SEC n=3 states diminishes.Furthermore,we computed state-selective relative cross sections and angular differential cross sections employing the classical molecular Coulomb over-the-barrier model(MCBM) and the multichannel Landau-Zener(MCLZ) model.A discernible discrepancy between the state-selective cross sections from the two theoretical models is apparent for the considered impact energies.However,regarding the angular differential cross sections,an overall agreement was attained between the current experimental results and the theoretical results from the MCLZ model.

Cr-induced fusion reactions to synthesize superheavy elements

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 range.The cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior experiments.The estimated cross sections from this analysis are consistent with the findings of prior studies.From the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+250Cf.Consequently,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.