Transfer matrix method for free and forced vibrations of multi-level functionally graded material stepped beams with different boundary conditions

Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical properties.This study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving method.Under the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable approach.Then,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are presented.To demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also given.On this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried out.The results show the accuracy and efficiency of the TMM.

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

热敏灸治疗颈型颈椎病的Meta分析及GRADE证据等级评价

目的系统评价热敏灸及其综合疗法用于颈型颈椎病的临床效果,为热敏灸治疗颈型颈椎病提供更好的证据来源。方法收集国内外各大数据库热敏灸及其综合疗法用于颈型颈椎病的随机对照试验(RCT),通过Revman 5.3软件进行Meta分析,按照GRADE标准对结局指标进行证据质量评价。结果纳入9篇文献共855例患者,Meta分析结果提示:热敏灸及其综合疗法组在提高总有效率(RR=1.19,P<0.01)和治愈率(RR=1.73,P<0.01)、降低视觉模拟量表(VAS)评分(SMD=-0.73,P<0.01)、简化McGill疼痛问卷(SF-MPQ)评分(SMD=-1.28,P<0.05)以及NPQ颈痛量表评分(SMD=-0.81,P<0.05)方面都优于对照组;GRADE证据等级评价提示:前三者为低质量证据,后二者为极低质量证据。结论热敏灸及其综合疗法用于颈型颈椎病在提高临床效果、镇痛以及改善患者生活质量方面更具优势。

ForceCT双能量与低kV扫描技术在头颈CTA中的对比分析

探索并比较Force CT双能量与低kV扫描技术在头颈CTA中的作用。方法 以系统随机化法,将2022.01-2023.01在我院接受头颈CTA检查的40例患者均分为两组各20例。其中观察组患者采用低kV扫描技术,对照组则进行Force CT双能量扫描。比较两组的辐射剂量、图像质量。结果 观察组的辐射剂量指数低于对照组,P<0.05。观察组的大脑中动脉与颈内动脉图像质量均高于对照组,P<0.05。结论 运用低kV扫描技术,能较好地降低头颈CTA检查时的辐射剂量,与此同时还能得到更为高质量的图像,帮助病情的更快诊断,患者能尽快得到个性化的治疗,早日恢复健康。

Force CT高级建模迭代重建算法对门静脉图像质量的影响

目的:探讨Force CT高级建模迭代重建算法(ADMIRE)对门静脉图像质量影响。方法:回顾性分析2022年1—4月于中山大学附属第八医院行上腹部CT平扫及增强的40例患者影像资料,在syngo.via后处理工作站重建,采用门脉期原始数据重建出滤波反投影算法(FBP)、ADMIRE1、ADMIRE3、ADMIRE5 4组不同重建算法的图像,在4组不同算法图像上测量门静脉干中心位置、肝实质及同层竖脊肌的CT值和噪声值,计算门静脉和肝实质的信噪比(SNR)和对比噪声比(CNR)。此外,由两位具有5年以上诊断经验的医生对图像进行主观评分。结果:随着迭代等级的增高,图像的CNR、SNR呈现上升的趋势,图像的噪声值呈现下降的趋势,其中ADMIRE5组图像中门静脉和肝脏具有最高的CNR和SNR且具有最低的噪声值,以及最高的主观评分,采用ADMIRE5重建算法的门静脉与周围组织对比非常好,门静脉5级分支显示良好。结论:高级建模迭代重建ADMIRE算法相比于FBP重建算法,降噪效果更好,门静脉的显示更加锐利,能提升门静脉的图像质量。

刮痧改善腰椎间盘突出疼痛症状的系统评价及GRADE证据质量评价

目的系统评价刮痧干预腰椎间盘突出疼痛症状的疗效与安全性,为其临床治疗提供循证依据。方法计算机检索自建库到2022年8月29日前公开发表在中国知网、万方、维普、中国生物医学文献服务系统、PubMed、Embase、Web of Science、The Cochrane Library数据库,收集关于刮痧干预腰椎间盘突出的随机对照试验(Randomized controlled trial,RCT)。文章由两名研究者独立筛选,根据Cochrane Reviewers Handbook 6.2的偏倚风险评估工具对纳入文献进行质量评价,应用RevMan 5.4软件对纳入文献的结局指标进行Meta分析,并采用GRADE系统对结局指标进行证据质量等级评价。结果最终纳入10篇RCT,共1087例患者。Meta分析结果显示:刮痧试验组治疗腰椎间盘突出患者在疼痛VAS评分[MD=-1.11,95%CI(-1.58,-0.64),P<0.00001]、日本骨科协会(JOA)评分[MD=4.47,95%CI(3.76,5.17),P<0.00001]、临床有效率[relative risk(RR)=1.13,95%CI(1.08,1.19),P<0.00001]和护理满意度[RR=1.21,95%CI(1.09,1.34),P=0.0005]方面,明显优于对照组,差异均有统计学意义(P<0.00001)。本文结局指标的证据质量为极低。结论当前证据表明,刮痧治疗腰椎间盘突出患者的疼痛症状具有良好临床疗效,并有助于提高临床护理满意度。由于部分结局证据质量较低,有待严谨的多中心、大样本随机对照试验来进一步验证其有效性,提升临床证据。

穴位埋线治疗功能性便秘疗效与安全性Meta分析及GRADE评价

目的:系统评价穴位埋线治疗功能性便秘(FC)的疗效和安全性及纳入证据的质量,以期为临床决策提供循证医学证据。方法:检索中国知网(CNKI)、万方知识服务平台(WANFANG)、维普中文期刊数据库(VIP)、中国生物医学文献服务系统(SinoMed)、Embase、PubMed和Cochrane Library数据库,搜集穴位埋线治疗FC的随机对照试验(RCT),检索时间均从建库至2023年10月16日。由2名研究者独立完成文献筛选、资料提取及偏倚风险评估,采用RevMan 5.4软件进行Meta分析,并采用GRADE评价方法对各项结局指标进行证据质量评价。结果:最终共纳入19项RCT,包括1673例患者。Meta分析结果显示,与对照组比较,穴位埋线治疗FC可提高总有效率[RR=1.23,95%CI=(1.17,1.29),P<0.00001],增加完全自发排便(CSBM)次数[MD=0.61,95%CI=(0.11,1.10),P=0.02],改善粪便性状[MD=0.53,95%CI=(0.31,0.76),P<0.00001]及排便困难[MD=-0.71,95%CI=(-1.03,-0.40),P<0.00001],缩短排便时间[MD=-0.50,95%CI=(-0.72,-0.29),P<0.00001],改善便秘生活质量评估量表(PAC-QOL)评分[MD=-7.72,95%CI=(-12.83,-2.61),P<0.003];两组不良反应发生率比较,差异无统计学意义[RR=0.37,95%CI=(0.10,1.38),P=0.14]。GRADE证据级别评价结果显示:总有效率为中级别证据质量,不良反应发生率、粪便性状评分、排便困难评分为低级别证据质量,CSBM次数、排便时间、PACQOL评分为极低级别证据质量。结论:穴位埋线治疗FC具有一定的疗效,可改善便秘相关症状,且未增加不良反应发生率。但纳入研究质量总体偏低,上述结论尚需开展更多高质量的研究予以验证。

腕踝针干预术后疼痛疗效的Meta分析和Grade评价

目的运用循证医学方法对腕踝针干预术后疼痛的疗效和安全性进行系统评价和Grade评价。方法计算机检索中国知网、万方、维普、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library中关于腕踝针干预术后疼痛的随机对照试验,检索时限为建库至2023年10月。采用RevMan 5.4软件进行Meta分析。结果纳入23篇文献,共计1968例患者,Meta分析结果显示,与常规治疗相比,腕踝针能够提高术后疼痛患者的总有效率[OR=4.42,95%CI(2.60,7.50),P<0.001],术后镇痛泵药量使用减少[MD=-9.03,95%CI(-12.09,-5.98),P<0.001],术后疼痛评分降低[MD=-1.39,95%CI(-1.68,-1.09),P<0.001],可减少不良反应发生率[RR=0.40,95%CI(0.32,0.48),P<0.001]以及临床满意度[OR=3.94,95%CI(2.40,6.48),P<0.001]。Grade证据分级结果显示:总有效率、不良反应发生率和临床满意度3项结局指标为中等质量证据,VAS评分指标为低质量证据,镇痛泵药量使用指标为极低质量证据。结论腕踝针可提高总有效率,减少术后镇痛药用量,不良反应少,安全性高,为患者提供了一种安全有效的镇痛方式。

医院药学指南制定中的证据与推荐意见GRADE系统评级方法及应用

目前,国际上存在多种证据与推荐意见分级系统,对临床医务工作者阅读指南证据和推荐意见造成困扰。证据推荐分级的评估、制定与评价(GRADE)系统目前是全球使用最为广泛的证据与推荐意见分级系统,本文简单地介绍GRADE系统证据质量评级及影响推荐意见形成的4个主要因素,并结合中国医院药学界发起制定的、在国际上发表的几部药学指南举例阐述,以帮助临床医务工作者了解GRADE系统,以批判性思维运用指南证据和推荐意见指导临床实践行为。

乌梅丸加减治疗帕金森病的Meta分析及GRADE评价

目的 系统评估乌梅丸加减治疗帕金森病(parkinson's disease, PD)的疗效和安全性。方法 计算机检索Cochrane Library、EMBASE、Web of Science、PubMed、CNKI、CBM等中英文数据库及临床试验中心,关于乌梅丸治疗PD的临床随机对照试验(randomized controlled trial, RCT),检索时限从建库至2023年4月。进行资料整理及数据提取等工作后,最终纳入8项研究,治疗组(乌梅丸)和对照组分别纳入226例。使用RevMan 5.3及stata14软件进行荟萃分析,使用GRADEpro GDT评估各项结局指标的证据质量。结果 治疗组降低PD统一评分量表(unified Parkinson's disease rating scale, UPDRS)的各项量表积分较对照组明显,其中在改善UPDRS Ⅰ、Ⅲ、Ⅳ方面具有统计学意义,结果分别为[MD=-0.769,95%CI(-1.213~-0.324),P=0.001]、[MD=-2.211,95%CI(-2.713~-1.708),P=0]、[MD=-0.526,95%CI(-1.041~-0.012),P=0.045]。2组在改善UPDRS总分方面差异无统计学意义[MD=3.964,95%CI(-9.465~17.392),P=0.563]。治疗组能显著提高治疗有效率,差异具有统计学意义[RR=1.709,95%CI(1.361~2.145),P=0]。各项研究均未发现不良事件发生及与治疗有关的检验指标异常。GRADE证据质量分级结果为UPDRS Ⅰ、UPDRS Ⅲ、UPDRS Ⅳ及有效率方面均为中等级别,UPDRS Ⅱ为低等级,UPDRS总分为非常低。结论 乌梅丸加减的应用对PD的治疗有一定效果,且具有良好的安全性。

参芪扶正注射液辅助治疗慢性阻塞性肺疾病的Meta分析与GRADE评价

为了系统评价参芪扶正注射液联合常规治疗作为干预措施对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者的临床疗效和安全性。检索中国国家知识基础设施(China national knowledge infrastructure,CNKI)、PubMed、万方数据知识服务平台(Wanfang Data)、维普中文科技期刊数据库(Weipu China science and technology journal database,VIP)等数据库,筛选并纳入2023年6月18日以前发表的参芪扶正注射液联合常规疗法治疗COPD患者的随机对照试验(randomized controlled trials,RCT),采用Cochrane风险评价工具及评估、发展和评价建议分级(grading of recommendations assessment,development and evaluation,GRADE)系统进行文献证据质量评价,用RevMan 5.4软件对临床疗效及安全性指标进行Meta分析。结果表明,共纳入16项RCTs,1 486例患者。Meta分析结果显示,参芪扶正注射液辅助治疗可提高患者总有效率和第1秒用力呼气容积/用力肺活量比值(forced expiratory volume in one second/forced vital capacity,FEV1/FVC)指标,与对照组相比具有优势(P<0.000 01、P<0.000 1);不良反应少,无严重不良反应(adverse drug reactions,ADR),两组对比无统计学差异(P=0.32);GRADE评价结果显示,有效率及不良反应指标的证据质量均为中等级,肺功能为低等级。可见参芪扶正注射辅助治疗COPD可以提高患者临床疗效,改善肺功能,且具有良好的安全性。但所纳入研究具有局限性,证据质量不高,仍需结合中药辨证使用特点,规范实验方案,开展更多的高质量RCT研究。

补肾方剂改善高龄女性自然妊娠结局的Meta分析及GRADE质量评价

目的系统评价补肾方剂改善高龄女性自然妊娠结局的临床疗效和安全性。方法检索中国知网、万方数据库、维普数据库、SinoMed、PubMed、Web of Science、Cochrane Library、Embase等数据库建库至2022年6月收录的补肾方剂改善高龄女性自然妊娠结局的随机对照研究(RCT)。运用偏倚风险工具进行质量评估,使用RevMan软件进行Meta分析。结果共纳入14篇RCT。Meta分析结果显示:补肾方剂联合西药治疗在提高妊娠率[RR=1.71,95%CI(1.45,2.01),P<0.00001]、降低卵泡刺激素(FSH)水平[SMD=-1.63,95%CI(-2.84,-0.43),P=0.008]、提高雌二醇(E_(2))水平[SMD=3.97,95%CI(1.76,6.17),P=0.0004]、增加排卵期子宫内膜厚度[SMD=2.12,95%CI(1.07,3.18),P<0.0001]方面均优于西药组;且补肾方剂单独使用在提高妊娠率[RR=1.94,95%CI(1.31,2.88),P=0.001]、降低FSH水平[SMD=-0.48,95%CI(-0.74,-0.22),P=0.0003]方面也具有显著疗效。结论与西医治疗比较,补肾方剂可以显著改善高龄女性自然妊娠结局,且不良反应较少,但仍需更多高质量、大样本、多中心的RCT予以验证。

温针灸治疗原发性痛经有效性和安全性的系统评价及GRADE评价

目的:评价温针灸治疗原发性痛经的有效性和安全性。方法:根据PRISMA指南进行系统综述和荟萃分析。收集PubMed、Web of Science、EMBASE、Cochrane Library、中国知网、维普、万方、中国生物医学数据库自建库至2023年5月的随机对照试验。使用Review Manager 5.4对所有获得的数据进行分析。结果:温针灸治疗原发性痛经在提高临床疗效{风险比(RR)=1.21,95%置信区间(CI)[1.16,1.25],P<0.00001},改善阻力指数(RI){均数差(MD)=-0.14,95%CI[-0.19,-0.08],P<0.00001}、搏动指数(PI)(MD=-0.55,95%CI[-0.69,-0.40],P<0.00001)、β-内啡肽(β-EP){标准化均数差(SMD)=1.36,95%CI[0.90,1.82],P<0.00001}、痛经证候积分(MD=-1.82,95%CI[-2.77,-0.87],P=0.0002)、疼痛视觉模拟评分法(VAS)评分(MD=-1.16,95%CI[-1.48,-0.83],P<0.00001)方面的作用优于单独的常规治疗,并且在不良反应发生率(P=0.01)方面低于对照组。证据质量等级评价结果显示临床疗效为中级,其他多为低级。结论:温针灸治疗原发性痛经的疗效明确,并且具有一定的安全性。

基于GRADE证据质量评级的小青龙汤治疗过敏性鼻炎系统评价与试验序贯分析

目的:系统评价小青龙汤治疗过敏性鼻炎的临床疗效和安全性,分析证据质量,验证研究结果的可信度。方法:检索中国知网、万方数据库、维普中文期刊服务平台、中国生物医学文献数据库、PubMed、Web of Science、The Cochrane Library等数据库中从建库至2023年7月31日小青龙汤治疗过敏性鼻炎的文献。对所得文献进行筛选、资料提取和评估,使用RevMan5.3软件进行Meta分析,使用Stata 16.0软件进行敏感性分析,使用TSA V0.9软件进行试验序贯分析,使用GRADEpro软件对结局指标进行证据质量评级。结果:纳入20篇随机对照试验(Randomized Controlled Trial,RCT),患者1 723例。Meta分析结果显示,试验组比对照组有更好的临床疗效[相对危险度(RR)=1.19,95%置信区间(CI)(1.14,1.25),P <0.000 01]。试验组在降低半年复发率[RR=0.50, 95%CI (0.32,0.78),P=0.002],降低鼻塞[加权均数差(WMD)=-0.20,95%CI(-0.26,-0.13),P <0.000 01]、流涕[WMD=-0.09,95%CI(-0.15,-0.03),P=0.004]、喷嚏[WMD=-0.21,95%CI(-0.28,-0.13),P <0.000 01]等症状积分及体征积分[WMD=-0.25,95%CI(-0.37,-0.14),P <0.000 1]和血清白细胞介素-4水平[WMD=-4.23,95%CI(-7.22,-1.23),P=0.006]方面均优于对照组。试验序贯分析进一步肯定了小青龙汤治疗过敏性鼻炎的疗效。GRADE证据质量分级显示,临床有效率、不良反应发生率、鼻痒积分为低质量证据,其余均为极低质量证据。结论:小青龙汤治疗过敏性鼻炎安全有效,但需要纳入更高质量的临床研究进一步验证。

PTGD后择期腹腔镜胆囊切除治疗对GradeⅡ急性胆囊炎ACTH、MPO及Cor水平的影响

目的分析PTGD后择期LC治疗对GradeⅡ急性胆囊炎ACTH、MPO及Cor水平的影响。方法选取2021年12月至2023年5月安徽中科庚玖医院收治的急性胆囊炎患者121例,根据治疗方案分为三组,即甲组(急诊行LC治疗,未行PTGD)38例、乙组(PTGD引流管拔出后72 h后行LC,早期)43例和丙组(PTGD引流管拔出后14~30 d后行LC,晚期)40例。对比三组手术情况、炎症因子、肝功能、ACTH、MP、Cor水平及并发症发生率。结果甲组LC手术时长、术后卧床时长及住院天数均长于丙组、乙组,失血量、中转开腹率高于丙组、乙组,差异有统计学意义(P<0.05);丙组LC手术时长、术后卧床时长及住院天数均长于乙组,差异具有统计学意义(P<0.05)。LC术后1 d hs-CRP、PCT、IL-6、ST、ALT、ALP、ACTH、MPO及Cor:甲组>丙组>乙组,差异有统计学意义(P<0.05)。并发症发生率:甲组>丙组>乙组,差异有统计学意义(P<0.05)。结论PTGD后择期LC治疗对GradeⅡ急性胆囊炎ACTH、MPO及Cor水平影响小,且并发症低;而PTGD后早期行LC能有效改善肝功能、炎症因子,且术后应激反应更低,值得临床推广。

火针治疗神经性皮炎的Meta分析及GRADE证据质量评价

目的:运用Meta分析系统评价火针治疗神经性皮炎的临床疗效。方法:计算机检索中国期刊全文数据库(CNKI)、重庆维普(VIP)、万方数据库(WanFang)、中国生物医学文献数据库(CBM)及Pubmed、Cochrane library等中英文数据库,时限设定为建库-2023年2月28日,检索火针治疗神经性皮炎的随机对照试验(Randomized controlled,RCT)相关文献。运用Cochrane风险偏倚评估工具对纳入研究的文献质量评估,再运用Revman5.4软件进行Meta分析,运用TSA0.9.5.10软件进行试验序贯分析,使用GRADE软件对主要结局指标的证据进行证据质量评级。结果:①共纳入18篇研究,1 662例患者,火针组840例,对照组822例;②Meta分析结果显示:火针组的临床有效率[OR=3.99,95%CI(2.81,5.68),Z=7.71,P<0.00 001]、复发率[OR=0.27,95%CI(0.11,0.68),Z=2.79,P=0.005)]均优于对照组;症状积分[MD=-1.49,95%CI(-2.25,-0.73),Z=3.85,P=0.0 001]、TNF-α水平[MD=-4.26,95%CI(-7.01,-1.51),Z=3.03,P=0.002]、IL-6水平[MD=-7.39,95%CI(-14.36,-0.42),Z=2.08,P=0.04]、IL-4水平[MD=-1.50,95%CI(-1.94,-1.06),Z=6.69,P<0.00 001]方面火针组均低于对照组;③火针组不良反应率整体低于对照组;④试验序贯分析显示:累计Z值穿过了传统界值和TSA界值,表示虽然累计的信息量未达到期望值,但不需要更多的试验,提前得到肯定的结论,结果较为可靠。结论:火针治疗神经性皮炎的具有明确的疗效,在症状积分和TNF-α、IL-6、IL-4水平表达等方面效果均优于对照组,安全性也较高,可为中医外治法治疗神经性皮炎的有效性提供相关证据。但因GRADE证据质量评级显示证据质量不理想,建议后续医务工作者可减少开展火针治疗神经性皮炎相关低质量试验,开展一些多中心、高质量的研究对结果加以佐证,从而避免科研和医疗资源的浪费。

Comparisons of Wave Force Model Effects on the Structural Responses and Fatigue Loads of a Semi-Submersible Floating Wind Turbine

The selection of wave force models will significantly impact the structural responses of floating wind turbines.In this study,comparisons of wave force model effects on the structural responses and fatigue loads of a semi-submersible floating wind turbine(SFWT)were conducted.Simulations were performed by employing the Morison equation(ME)with linear or second-order wave kinematics and potential flow theory(PFT)with first-or second-order wave forces.A comparison of regular waves,irregular waves,and coupled wind/waves analyses with the experimental data showed that many of the simulation results and experimental data are relatively consistent.However,notable discrepancies are found in the response amplitude operators for platform heave,tower base bending moment,and tension in mooring lines.PFT models give more satisfactory results of heave but more significant discrepan-cies in tower base bending moment than the ME models.In irregular wave analyses,low-frequency resonances were captured by PFT models with second-order difference-frequency terms,and high-frequency resonances were captured by the ME models or PFT models with second-order sum-frequency terms.These force models capture the response frequencies but do not reasonably predict the response amplitudes.The coupled wind/waves analyses showed more satisfactory results than the wave-only analyses.However,an important detail to note is that this satisfactory result is based on the overprediction of wind-induced responses.

Quantitative analysis on resistant forces at oil-surfactant-rock interfaces with dynamic wettability characterization

Adhesion of oil at rock surface plays an important role in the liberation of oil from micro-/nano-pores,especially for heavy oil that has extremely high viscosity.Although molecular dynamics simulation is widely used to study the interfacial interaction for some specific oil-water-rock systems,experimental measurements provide more realistic and reliable evidence.In this work,we propose a dynamic wettability characterization method to indirectly measure resistant forces at oil-surfactant-rock interfaces,including frictional force,wettability hysteresis force,and viscous force,which are parallel with the oil-solid interface.The adhesive force,which is normal to the oil-solid interface is calculated through measurement of work of adhesion.The results show that work of adhesion instead of contact angle can better describe the adhesion of oil at solid surface.The effect of surfactant concentration on work of adhesion is different for water-wet and oil-wet surfaces.Moreover,average viscous forces are calculated through force analysis on oil drops moving along solid surface in different surfactant environments.It is found that viscous force has a magnitude comparable to the frictional force during the movement,while the wettability hysteresis force is negligible.On the other hand,the adhesive force calculated from the work of adhesion is also comparable to the viscous force.Therefore,both the resistant forces parallel with and normal to the oil-solid interface should be minimized for the liberation of oil from rock surface.This work proposes a simple method to evaluate the wetting capability of different surfactants and measure the adhesive force between heavy oil and rock surfaces indirectly,which provides insight into the adhesion of heavy oil at rock surface and would be valuable for the development of surfactant-based oil recovery methods.

Study of the Lift Force Induced by An Interceptor on A High-Speed Mono-Hull:The Affecting Factors and Estimation Formula

To find a better way to estimate the lift force induced by an interceptor on a high-speed mono-hull ship,a series of high-speed mono-hull ship models are designed and investigated under different conditions.Different lift forces are obtained by numerical calculations and validated by a model test in a towing tank.The factors that influence the force are the interceptor height,velocity,draft,and deadrise angle.The relationship between each factor and the induced lift force is investigated and obtained.We found that the induced lift mainly depends on the interceptor height and advancing velocity,and is proportional to the square of the interceptor height and velocity.The results also showed that the effects of the draft and deadrise angle are relatively less important,and the relationship between the induced lift and these two factors is generally linear.Based on the results,a formula including the combined effect of all factors used to estimate the lift force induced by the interceptor is developed based on systematic analysis.The proposed formula could be used to estimate the lift force induced by interceptors,especially under high-speed condition.

Culturally competent care across borders: Implementing culturally responsive teaching for nurses in diverse workforces

The migration of healthcare professionals,including nurses,is a global phenomenon.It is driven by various factors,including the pursuit of better opportunities,living conditions,and professional development,as well as political instability or conflict in their home countries.The World Health Organization(WHO)has noted that high-income countries often rely on foreign-trained nurses to fill gaps in their healthcare systems[1].For instance,as of 2021,over 40%(52 million)of all nurses in the United States(US)were expatriates[2].In the United Kingdom(UK),the percentage of expatriate nurses was even higher,reaching approximately 18%in 2021[3].Owing to globalization and migration,healthcare providers must possess cultural competence to deliver improved care[4,5].Culturally responsive teaching(CRT)is rooted in the idea that culture plays a vital role in shaping people’s behaviors,beliefs,values,and communication styles[6].Furthermore,these cultural factors influence patients’perspectives on health,illness,healing,and their preferences for care and communication[7].By recognizing and embracing these cultural differences,nurses can provide more effective and compassionate care to their diverse patient population[8].