Probability Density Analysis of Nonlinear Random Ship Rolling

Ship rolling in random waves is a complicated nonlinear motion that contributes substantially to ship instability and capsizing.The finite element method(FEM)is employed in this paper to solve the Fokker Planck(FP)equations numerically for homoclinic and heteroclinic ship rolling under random waves described as periodic and Gaussian white noise excitations.The transient joint probability density functions(PDFs)and marginal PDFs of the rolling responses are also obtained.The effects of stimulation strength on ship rolling are further investigated from a probabilistic standpoint.The homoclinic ship rolling has two rolling states,the connection between the two peaks of the PDF is observed when the periodic excitation amplitude or the noise intensity is large,and the PDF is remarkably distributed in phase space.These phenomena increase the possibility of a random jump in ship motion states and the uncertainty of ship rolling,and the ship may lose stability due to unforeseeable facts or conditions.Meanwhile,only one rolling state is observed when the ship is in heteroclinic rolling.As the periodic excitation amplitude grows,the PDF concentration increases and drifts away from the beginning location,suggesting that the ship rolling substantially changes in a cycle and its stability is low.The PDF becomes increasingly uniform and covers a large region as the noise intensity increases,reducing the certainty of ship rolling and navigation safety.The current numerical solutions and analyses may be applied to evaluate the stability of a rolling ship in irregular waves and capsize mechanisms.

Chronic effects of stretching on range of motion with consideration of potential moderating variables:A systematic review with meta-analysis

Background:It is well known that stretch training can induce prolonged increases in joint range of motion(ROM).However,to date more information is needed regarding which training variables might have greater influence on improvements in flexibility.Thus,the purpose of this metaanalysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables,such as stretching technique,intensity,duration,frequency,and muscles stretched,as well as sex-specific,age-specific,and/or trained state-specific adaptations to stretch training.Methods:We searched through PubMed,Scopus,Web of Science,and SportDiscus to find eligible studies and,finally,assessed the results from 77 studies and 186 effect sizes by applying a random-effect meta-analysis.Moreover,by applying a mixed-effect model,we performed the respective subgroup analyses.To find potential relationships between stretch duration or age and effect sizes,we performed a meta-regression.Results:We found a significant overall effect,indicating that stretch training can increase ROM with a moderate effect compared to the controls(effect size=-1.002;Z=-12.074;95%confidence interval:-1.165 to-0.840;p<0.001;I^(2)=74.97).Subgroup analysis showed a significant difference between the stretching techniques(p=0.01)indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic stretching.Moreover,there was a significant effect between the sexes(p=0.04),indicating that females showed higher gains in ROM compared to males.However,further moderating analysis showed no significant relation or difference.Conclusion:When the goal is to maximize ROM in the long term,proprioceptive neuromuscular facilitation or static stretching,rather than ballistic/dynamic stretching,should be applied.Something to consider in future research as well as sports practice is that neither volume,intensity,nor frequency of stretching were found to play a significant role in ROM yields.

随方制象——西南地区民族服饰上的十字见方纹样设计

西南地区民族服饰上的许多纹样组合方方正正,以模件化的方式排列,并围绕着特定角度(45度与90度)进行变化。这类纹样使用已久,族中妇女根据传承下来的程序进行制作,并加入创新。见方纹样与古时人们立杆测影得出的方位投影十分相似,以视觉化呈现向后人传达古老的时空观,如今虽已不能肯定地发掘其背后的深意,人们却仍可以从这些布片中看出制衣者是如何理解空间,以及如何对复合纹样与正负形进行处理的。

Foam rolling and stretching do not provide superior acute flexibility and stiffness improvements compared to any other warm-up intervention: A systematic review with meta-analysis

Background:Acute improvement in range of motion(ROM)is a widely reported effect of stretching and foam rolling,which is commonly explained by changes in pain threshold and/or musculotendinous stiffness.Interestingly,these effects were also reported in response to various other active and passive interventions that induce responses such as enhanced muscle temperature.Therefore,we hypothesized that acute ROM enhancements could be induced by a wide variety of interventions other than stretching or foam rolling that promote an increase in muscle temperature.Methods:After a systematic search in PubMed,Web of Science,and SPORTDiscus databases,38 studies comparing the effects of stretching and foam rolling with several other interventions on ROM and passive properties were included.These studies had 1134 participants in total,and the data analysis resulted in 140 effect sizes(ESs).ES calculations were performed using robust variance estimation model with R-package.Results:Study quality of the included studies was classified as fair(PEDro score=4.58)with low to moderate certainty of evidence.Results showed no significant differences in ROM(ES=0.01,p=0.88),stiffness(ES=0.09,p=0.67),or passive peak torque(ES=-0.30,p=0.14)between stretching or foam rolling and the other identified activities.Funnel plots revealed no publication bias.Conclusion:Based on current literature,our results challenge the established view on stretching and foam rolling as a recommended component of warm-up programs.The lack of significant difference between interventions suggests there is no need to emphasize stretching or foam rolling to induce acute ROM,passive peak torque increases,or stiffness reductions.

Online AUV Path Replanning Using Quantum-Behaved Particle Swarm Optimization with Selective Differential Evolution

This paper presents an online AUV(autonomous underwater vehicle)path planner that employs path replanning approach and the SDEQPSO(selective differential evolution-hybridized quantum-behaved particle swarm optimization)algorithm to optimize an AUV mission conducted in an unknown,dynamic and cluttered ocean environment.The proposed path replanner considered the effect of ocean currents in path optimization to generate a Pareto-optimal path that guides the AUV to its target within minimum time.The optimization was based on the onboard sensor data measured from the environment,which consists of a priori unknown dynamic obstacles and spatiotemporal currents.Different sensor arrangements for the forward-looking sonar and horizontal acoustic Doppler current profiler(H-ADCP)were considered in 2D and 3D simulations.Based on the simulation results,the SDEQPSO path replanner was found to be capable of generating a time-optimal path that offered up to 13%reduction in travel time compared to the situation where the vehicle simply followed a path with the shortest distance.The proposed replanning technique also showed consistently better performance over a reactive path planner in terms of solution quality,stability,and computational efficiency.Robustness of the replanner was verified under stochastic process using the Monte Carlo method.The generated path fulfilled the vehicle’s safety and physical constraints,while intelligently exploiting ocean currents to improve the vehicle’s efficiency.

Traveling wave for a time-periodic Lotka-Volterra model with bistable nonlinearity

This paper studies bistable wavefronts of a diffusive time-periodic Lotka-Volterra system.We obtain a new condition for the existence,uniqueness and stability of bistable timeperiodic traveling waves.This condition is sharp and greatly improves the result established in the reference(X.Bao and Z.Wang,Journal of Differential Equations,255(2013)2402-2435).An example is given to demonstrate our consequence.

Determination of Parameters Affecting the Estimation of Iceberg Draft

Recent offshore oil and gas loading facilities developed in the Arctic area have led to a considerable awareness of the iceberg draft approximation, where deep keel icebergs may gouge the ocean floor, and these submarine infrastructures would be damaged in the shallower waters. Developing reliable solutions to estimate the iceberg draft requires a profound understanding of the problem’s dominant parameters. As such, the dimensionless groups of the parameters affecting the iceberg draft estimation were determined for the first time in the present study. Using the dimensionless groups recognized and the linear regression(LR) analysis, nine LR models(i.e., LR 1 to LR 9) were developed and then validated using a comprehensive dataset, which has been constructed in this study. A sensitivity analysis distinguished the premium LR models and important dimensionless groups. The best LR model, as a function of all dimensionless parameters, was able to estimate the iceberg draft with the highest level of precision and correlation along with the lowest degree of complexity. The ratio of iceberg length to iceberg height as the “iceberg length ratio” and the ratio of iceberg width to iceberg height as the “iceberg width ratio” was detected as the important dimensionless groups in the estimation of the iceberg draft. An uncertainty analysis demonstrated that the best LR model was biased towards underestimating the iceberg drafts. The premium LR model outperformed the previous empirical models.Ultimately, a set of LR-based relationships were derived for estimating the iceberg drafts for practical engineering applications, e.g., the early stages of the iceberg management projects.

Selected fermented indigenous vegetables and fruits from Malaysia as potential sources of natural probiotics for improving gut health

In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant potentials. Fermented leaves and vegetables can be utilized as a potential source of probiotics as they are host for several lactic acid bacteria such as Lactobacillus confusus, Weissella paramesenteroides, Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus pentosus, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides. These strains may be more viable in metabolic systems whereby they can contribute to a substantial increase in essential biologically active element than industrial starter cultures. This review is aimed to address some essential fermented fruits and vegetables in Malaysia and their remarkable reputations as a potential sources of natural probiotics.

Predicting pavement condition index based on the utilization of machine learning techniques:A case study

Pavement management systems(PMS)are used by transportation government agencies to promote sustainable development and to keep road pavement conditions above the minimum performance levels at a reasonable cost.To accomplish this objective,the pavement condition is monitored to predict deterioration and determine the need for maintenance or rehabilitation at the appropriate time.The pavement condition index(PCI)is a commonly usedmetric to evaluate the pavement's performance.This research aims to create and evaluate prediction models for PCI values using multiple linear regression(MLR),artificial neural networks(ANN),and fuzzy logic inference(FIS)models for flexible pavement sections.The authors collected field data spans for 2018 and 2021.Eight pavement distress factors were considered inputs for predicting PCI values,such as rutting,fatigue cracking,block cracking,longitudinal cracking,transverse cracking,patching,potholes,and delamination.This study evaluates the performance of the three techniques based on the coefficient of determination,root mean squared error(RMSE),and mean absolute error(MAE).The results show that the R2 values of the ANN models increased by 51.32%,2.02%,36.55%,and 3.02%compared toMLR and FIS(2018 and 2021).The error in the PCI values predicted by the ANNmodel was significantly lower than the errors in the prediction by the FIS and MLR models.

Associations of self-reported and device-assessed physical activity with fatigue,quality of life,and sleep quality in adults living with and beyond cancer

Background Greater physical activity is associated with improved outcomes in people living with and beyond cancer.However,most studies in exercise oncology use self-reported measures of physical activity.Few have explored agreement between self-reported and device-based measures of physical activity in people living with and beyond cancer.This study aimed to describe physical activity in adults affected by cancer across self-reported and device-assessed activity,to explore levels of agreement between these measures in terms of their utility for categorizing participants as meeting/not meeting physical activity guidelines,and to explore whether meeting guidelines is associated with fatigue,quality of life,and sleep quality.Methods A total of 1348 adults living with and beyond cancer from the Advancing Survivorship Cancer Outcomes Trial completed a survey assessing fatigue,quality of life,sleep quality,and physical activity.The Godin-Shephard Leisure-Time Physical Activity Questionnaire was used to calculate a Leisure Score Index(LSI)and an estimate of moderate-to-vigorous physical activity(MVPA).Average daily steps and weekly aerobic steps were derived from pedometers worn by participants.Results The percentage of individuals meeting physical activity guidelines was 44.3%using LSI,49.5%using MVPA,10.8%using average daily steps,and 28.5%using weekly aerobic steps.Agreement(Cohen'sκ)between self-reported and pedometer measures ranged from 0.13(LSI vs.average daily steps)to 0.60(LSI vs.MVPA).After adjusting for sociodemographic and health-related covariates,meeting activity guidelines using all measures was associated with not experiencing severe fatigue(odds ratios(ORs):1.43–1.97).Meeting guidelines using MVPA was associated with no quality-of-life issues(OR=1.53).Meeting guidelines using both self-reported measures were associated with good sleep quality(ORs:1.33–1.40).Conclusion Less than half of all adults affected by cancer are meeting physical activity guidelines,regardless of measure.Meeting guidelines is associated with lower fatigue across all measures.Associations with quality of life and sleep differ depending on measure.Future research should consider the impact of physical activity measure on findings,and where possible,use multiple measures.

Quantification of radiation damage in natural and synthetic zircon by Raman spectroscopy:application to low-temperature thermochronology

Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological community.Nevertheless,the decay of U and Th causes radiation damage to the zircon structure,resulting in various degrees of metamictization,which can affect the accuracy of U–Pb dates and Hf and O isotope results.If the degree of zircon radiation damage can be quantified,the influence on geochemical analyses can be evaluated,and the results can be corrected more precisely.In this paper,synthetic and natural zircon crystals with different crystallization ages were selected for Raman spectroscopy analysis,cathodoluminescence imaging,and determination of the U and Th concentrations.The results show that Raman FWHM(full width at half bandmaximum)and Raman shift correlate with alpha dose(Da)ofzirconsfollowingtheseequations,FWHM=44.36(±2.32)×[1-exp(-2.74×Da)]-+1.7(±0.19),Raman Shift=-6.53×Da+1007.69.Analysis of synthetic zircon crystals shows that doped REEs(rare earth elements and P)can also lead to an increase in the FWHM.However,this effect can be ignored for natural zircon samples with REE contents at a normal level of hundreds to a few thousand ppm.The FWHM and Raman shift can be used as proxies to measure the degree of zircon radiation damage.Using the updated equations to calculate the latest age when zircon began to accumulate radiation damage,a more accurate and more meaningful“radiation damage age”can be obtained.

我国自然旅游资源私有化后果动态管理研究

通过对"自然旅游资源私有化(NBTRP)"现象的机会和危险分析。NBTRP产生的影响既有正面影响也有负面影响,因此"NBTRP净影响监管模型"被设计用以动态综合评价目标目的地NBTRP的成效。

基于管治理论的中央垂直管理型国家公园PAC模式研究

中央垂直管理型的国家公园系统是西方发达国家重要的自然资源管理制度安排,本研究选取加拿大BPNP/FFNMP为研究案例,引入管治理论作为分析工具,详细探讨了公园咨询委员会(PAC)这种非政府组织共管国家公园的模式。结果表明PAC管治模式能够实现管治的核心理念——相关利益单位的互动和达成共识,主要结论包括:(1)PAC模式的特性是具有克服集体利己主义的合作型模式管治模式;(2)PAC模式是具有内外部有效性的管治模式。我国现阶段采用的是属地管理型系统,在借鉴PAC模式时应该主要吸收不同层次和不同利益诉求的NGO,特别是以保护资源和环境为宗旨的ENGO。

脑囊虫病的CT和MR诊断价值

目的探讨和研究脑囊虫病的CT和MR诊断价值。方法回顾分析经临床病理证实的120例脑囊虫患者的(7F与MRI资料。结果120例均完成CF与MRI检查的脑囊虫患者中：MR显示囊虫头节84例．CT显示26例；MR显示囊虫钙化12例，CT显示30例。结论MR与CF对脑囊虫病的诊断均有特异性表现，MR对病变的定位和定性方面优于CT，特别是对非钙化性囊虫病变的敏感性能于CT，而CT对显示脑囊虫钙化敏感性高，二者在脑囊虫诊断方面可以互补。

从基于EO_(76)PO_(29)EO_(76)的丁醇-水乳液体系合成中空二氧化硅巨球

利用廉价的水玻璃为二氧化硅前驱体,在三嵌段高分子EO76PO29EO76/正丁醇/乙醇/水的乳液体系中,能够使二氧化硅快速沉降,缩聚并形成中空的氧化硅巨球,球径达30～40μm左右,用SEM、TEM、BET、光学显微镜、SAXS、29SiMASNMR详细考察了产物的形貌特点以及形成过程。

Persistent occult hepatitis B virus infection:Experimental findings and clinical implications

Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection (SOI). The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection (POI) where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.

基于非结构网格的三维大地电磁法有限内存拟牛顿反演研究（英文）

相比于传统的基于结构化网格的三维大地电磁法正反演算法,基于非结构网格的算法可以更高精度地模拟复杂的地下电性结构,克服了传统的基于规则网格算法提高计算精度代价高和难以适应实现直接带地形反演的缺陷。结合基于非结构网格的有限元法,本文采用有限内存拟牛顿(L-BFGS)方法,进行三维大地电磁法反演。该方法不需要显式计算海森矩阵,只需要存储约2×M×m个数据(其中M为反演单元个数,m为值较小的数,本文设为5),因此极大地减少内存需求,在第一次迭代后,近似海森矩阵的逆已经逼近了真实值,牛顿步长(设定值为1)即可保证充分下降,每次迭代只需要计算一次目标函数和梯度,提高了计算效率,适合于大规模大地电磁法数据反演。我们分别对带地形和不带地形的理论数据进行反演,结果与实际模型吻合较好,验证了基于非结构有限元法和有限内存拟牛顿法对地形和地下复杂目标体进行反演的有效性。

Micro- and nanoporous materials capable of absorbing solvents and oils reversibly： the state of the art

Treatment of petroleum spills and organic solvent pollution in general is an important issue; several techniques are under development to remove oil from water. The use of absorbents is one of the most common techniques to tackle this problem. These absorbents can be classified based on their characteristics of recyclability into irreversible and reversible ones. In this review, we discuss the application of several materials as oil absorbents, according to their classification and characteristics such as hydrophobicity, surface area and oil absorption capacity. Also, the fabrication methods for some materials are presented and analyzed.

Analysis for the Deployment of Single-Point Mooring Buoy System Based on Multi-Body Dynamics Method

Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components, anchor and so on is modeled by applying multi-body dynamics method. The motion equations are developed in discrete node description and fully Cartesian coordinates. Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board. The trajectories and velocities of different nodes without current and with current in buoy system are obtained. The transient tension force of each part of the cable is analyzed in the process of deployment. Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration. This work is helpful for design and deployment planning of buoy system.