Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

RNA解旋酶DEAD-box蛋白家族与肿瘤的相关性研究

RNA解旋酶DEAD-box蛋白家族是RNA解旋酶中最大的家族,是基因表达的重要调控因子,在RNA代谢的多个方面发挥作用。RNA解旋酶DEAD-box蛋白家族既在RNA代谢中具有重要作用,又与人类细胞中基因组的不稳定性直接相关。而基因组的不稳定性是癌症克隆进化的驱动因素,能够促进癌症的发生发展。该文对RNA解旋酶DEAD-box蛋白家族与肿瘤发生发展的相关性做一综述。

SEI/dead Li-turning capacity loss for high-performance anode-free solid-state lithium batteries

Anode-free solid-state lithium metal batteries(AF-SSLBs)have the potential to deliver higher energy density and improved safety beyond lithium-metal batteries.However,the unclear mechanism for the fast capacity decay in AF-SSLBs,either determined by dead Li or solid electrolyte interface(SEI),limits the proposal of effective strategies to prolong cycling life.To clarify the underlying mechanism,herein,the evolution of SEI and dead Li is quantitatively analyzed by a solid-state nuclear magnetic resonance(ss-NMR)technology in a typical LiPF6-based polymer electrolyte.The results show that the initial capacity loss is attributed to the formation of SEI,while the dead Li dominates the following capacity loss and the growth rate is 0.141 mA h cm^(−2)cycle−1.To reduce the active Li loss,the combination of inorganic-rich SEI and self-healing electrostatic shield effect is proposed to improve the reversibility of Li deposition/dissolution behavior,which reduces the capacity loss rate for the initial SEI and following dead Li generation by 2.3 and 20.1 folds,respectively.As a result,the initial Coulombic efficiency(ICE)and stable CE increase by 15.1%and 15.3%in Li-Cu cells,which guides the rational design of high-performance AF-SSLBs.

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

Research Background: The marketing of cosmetic products derived from Dead Sea (DS) mud has undergone significant evolution, transforming from simple souvenirs into a large-scale cosmetic industry offering a diverse array of products. DS mud is utilized both as pure mud for home spa treatments and as an active ingredient in cosmetic and cosmeceutical formulations. Its global appeal is largely due to its natural, health-oriented image, which aligns with consumer preferences and provides assurance regarding its use in skincare. Research Objectives: This review examines the published data related to the rationale for formulating DS mud in cosmetics, the biological and cosmetic effects of DS mud on the skin, and the speculated bio-mechanisms underlying these effects. Methods: We screened relevant literature on DS mud collected from the shores of the Dead Sea in Jordan and Israel. Publications on mineral muds excavated in different locations around the globe, as well as studies on the biological mechanisms of other DS minerals, were also reviewed as indications and supportive recommendations. Summarizing the vast collected data into a comprehensive review was undertaken to expose readers to the various aspects of DS mud in cosmetics. Results: The primary reason for formulating DS mud in skincare products is its deep cleansing and skin detoxification properties. Consequently, it is often incorporated into rinse-off masks, soaps, and scrubbing products. Additionally, DS mud is used in leave-on products and sheet masks. Cosmeceutical applications of DS mud, recommended for various skin conditions, offer complementary treatments to improve the quality of life for people with skin diseases. The physicochemical and biological effects of DS mud are driven by its rich mineral ion composition, including magnesium, calcium, sodium, potassium, zinc, and strontium—elements known to improve skin barrier function, enhance hydration, and reduce inflammation. The high salt concentration induces moderate ionic osmotic stress, stimulating cellular growth and hydration pathways. Moreover, DS mud’s anti-microbial properties further contribute to its therapeutic potential. Ongoing innovations in formulation techniques continue to expand the applications of DS mud, including blending it with other active ingredients, developing novel application methods, and refining manufacturing processes to improve product quality and efficacy. Conclusions: DS mud remains a valuable ingredient in modern skincare due to its rich mineral content and therapeutic properties. Ongoing research and technological advancements promise further innovations, reinforcing its status as a natural and effective component in the global cosmetics industry.

The “Dead Universe” Theory: Natural Separation of Galaxies Driven by the Remnants of a Supermassive Dead Universe

This article explores the dead universe theory as a novel interpretation for the origin and evolution of the universe, suggesting that our cosmos may have originated from the remnants of a preceding universe. This perspective challenges the conventional Big Bang theory, particularly concerning dark matter, the expansion of the universe, and the interpretation of phenomena such as gravitational waves.

融合Dead-ends和离线监督Actor-Critic的动态治疗策略生成模型

强化学习对数学模型依赖性低,利用经验便于架构和优化模型,非常适合用于动态治疗策略学习。但现有研究仍存在以下问题:1)学习策略最优性的同时未考虑风险,导致学到的策略存在一定的风险;2)忽略了分布偏移问题,导致学到的策略与医生策略完全不同;3)忽略患者的历史观测数据和治疗史,从而不能很好地得到患者状态,进而导致不能学到最优策略。基于此,提出了融合Dead-ends和离线监督Actor-Critic的动态治疗策略生成模型DOSAC-DTR。首先,考虑学到的策略所推荐的治疗行动的风险性,在Actor-Critic框架中融入Dead-ends概念;其次,为缓解分布偏移问题,在Actor-Critic框架中融入医生监督,在最大化预期回报的同时,最小化所学策略与医生策略之间的差距;最后,为了得到包含患者关键历史信息的状态表示,使用基于LSTM的编码器解码器模型对患者的历史观测数据和治疗史进行建模。实验结果表明,DOSAC-DTR相比基线方法有更好的性能,可以得到更低的估计死亡率以及更高的Jaccard系数。

DEAD-box解旋酶21对猪传染性胃肠炎病毒复制的调控作用

旨在探究DEAD-box解旋酶21(DDX21)对猪传染性胃肠炎病毒(TGEV)复制的调控作用。首先通过蛋白免疫印迹(Western Blot)分析了TGEV感染对DDX21表达的影响;进一步构建了猪DDX21真核表达质粒以及建立稳定敲低DDX21的PK-15细胞系,运用荧光定量PCR(RT-qPCR)、蛋白免疫印迹、间接免疫荧光(IFA)和半数细胞培养物感染量(TCID 50)探究外源过表达DDX21及敲低DDX21对TGEV体外复制的调控作用;构建一系列DDX21截短突变体真核表达质粒,鉴定了DDX21调控TGEV增殖的关键功能域。Western Blot分析显示,在TGEV WH-1株感染早期,PK-15细胞内源性DDX21蛋白的表达水平显著上调;RT-qPCR、Western Blot、IFA和TCID 50试验显示,超表达DDX21可以显著提高TGEV N基因的mRNA水平、N蛋白的表达及病毒滴度,且呈剂量依赖性,其601-784 aa区域是其影响TGEV复制的关键;与阴性对照相比,在相应DDX21敲低细胞系中TGEV的增殖显著被抑制,而回补试验逆转了DDX21敲低细胞系中TGEV的滴度。该研究首次揭示了猪DDX21对TGEV增殖的促进作用并鉴定了其调控TGEV复制的关键结构域,为今后研究DDX21蛋白的功能及TGEV的致病机理提供了理论依据。

结直肠癌组织和细胞中DEAD盒解旋酶10和Bystin样蛋白的表达及其临床意义

目的:探讨结直肠癌(CRC)组织及结肠癌细胞DLD-1中DEAD盒解旋酶10(DDX10)与Bystin-like(BYSL)的关系及其临床意义。方法:收集2017年3月至2018年3月间福建医科大学附属第二医院手术切除的78例CRC组织和配对癌旁组织,采用免疫组织化学Envision法检测癌组织和癌旁组织中DDX10和BYSL的表达水平,采用卡方检验、Pearson相关性分析和Kaplan-Meier法分别分析CRC组织中DDX10、BYSL蛋白表达与其患者的临床病例特征的关系,两者表达的相关性,以及与患者PFS和OS的关系。利用瞬时转染技术在DLD-1细胞中分别转染siDDX10和siNC,用qPCR法检测DLD-1细胞中敲减DDX10的表达对BYSL表达的影响,用CCK-8及Transwell实验验证DDX10及BYSL表达对结肠癌细胞增殖迁移及侵袭的影响。结果:免疫组织化学Envision法检测显示,与癌旁组织相比,DDX10和BYSL在CRC组织中呈高表达(73.08%和74.36%)。CRC组织中DDX10与BY肿瘤分期、是否发生淋巴结转移及复发等临床病例特征均有关联(均P<0.05)。Pearson相关分析结果显示,DDX10与BYSL的表达呈正相关(r=0.636,P<0.001)。Kaplan-Meier生存分析结果显示,DDX10与BYSL的高表达与患者更差的预后相关。Logistic回归分析发现,DDX10与BYSL均是CRC复发的独立风险因素。CCK-8法及Transwell实验检测结果显示,敲降DDX10的表达可使BYSL表达降低,且可抑制DLD-1细胞的增殖、迁移、侵袭能力(均P<0.05)。结论:DDX10和BYSL在CRC组织中呈高表达,两者表达水平呈正相关,且与患者更差的预后相关,是CRC复发的独立风险因素。可调控结直肠癌DLD-1细胞的增殖、迁移、侵袭能力。

电影《Dead Poets Society》中对教育共情力的思考

共情力是个体在观察和理解他人情感的基础上,产生与观察对象相似的情感体验并表现出相应行为反应的一种能力。在教育过程中,家庭和学校对个体的教育最为直接,学生阶段是个体人生成长的重要时期,好的教育是需要共情力的。本文以美国影片《Dead Poets Society》为例,针对“共情教育”,启发家长、教师在教育过程中的共情能力对个体心理发展所具有的积极作用。提出加强教育者共情意识,家校合力,建立轻松和谐的交往氛围,促进教育者与受教育者之间关系融洽。

Evaluation of Nutritional Value and Safety of Black Soldier Flies Fed on Dead Pig Meat and Bone Meal

[Objectives]This study was conducted to evaluate the nutritional value and safety of black soldier flies fed with dead pig meat and bone meal(DPMBM)and to explore the resource utilization of DPMBM.[Methods]The general nutrient composition,amino acids,fatty acids and mineral elements of black soldier fly meal(BSLM)were detected and analyzed.[Results]The results showed that the contents of moisture,crude protein,crude fat and ash in BSLM were 3.42%,42.31%,34.04%and 5.40%,respectively.The contents of total amino acids(TAA),essential amino acids(∑EAA)and non-essential amino acids(∑NEAA)and umami amino acids(∑DAA),the EAA/TAA value and the EAA/NEAA value were 37.93%,13.08%,24.85%,13.43%,34.47%,52.61%,respectively.A total of eight kinds of saturated fatty acids and seven kinds of unsaturated fatty acids were detected,accounting for 63.65%and 32.67%of the total fatty acids.Among the major mineral elements,the content of Ca was the highest,followed by K,Mg and Na.Among the trace mineral elements,the content of Mn was the highest,followed by Fe,Zn,Cu,Ni,Cr,Cd,As,Pb,Se,Sn,Ti,Sb and Hg.The contents of heavy metal mineral elements in BSLM were far lower than the limits specified in Hygienical Standard for Feeds.[Conclusions]In conclusion,BSLM has high nutritional value and good safety of heavy metals,and thus great potential for development and utilization as a high quality dietary protein,fat and mineral elements source.

Chimeric ALT Perforator-Free Flap with Vastus Lateralis Muscle for the Obliteration of the Intrathoracic Dead Space Post-Pneumonectomy: A Case Report

Chest wall reconstruction is a surgical procedure aimed at restoring the integrity and function of the chest wall, which may be damaged due to trauma, cancer, infection, or congenital defects. The chest wall plays a vital role in protecting the thoracic organs, supporting the respiratory system, and maintaining the shape of the chest. Therefore, any defect or deformity of the chest wall can have significant functional and aesthetic consequences for the patient. The authors present a case report at Kenyatta National Hospital (KNH) of a dyspneic 47-year-old male patient with a right anterolateral chest wall defect post-pneumonectomy previously complicated by bronchopleural fistula. Past attempts at the chest wall reconstruction had utilized the ipsilateral latissimus dorsi muscle, pectoralis major muscle, and the omental pedicled flaps with limited success. A chimeric anterolateral thigh (ALT) perforator-free flap with vastus lateralis (VL) muscle was used to obliterate the post-pneumonectomy intrathoracic dead space and to provide a cutaneous paddle. This case report aims to show the versatility of the ALT flap for chest wall reconstruction to prevent the post-pneumonectomy syndrome associated with tracheal deviation, inspiratory stridor, and exertional dyspnea. In conclusion, chest wall reconstruction with obliteration of intrathoracic dead space post-pneumonectomy is challenging and needs careful planning and execution.

Modelling the dead fuel moisture content in a grassland of Ergun City,China

The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression resources.In this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in 2021.We chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data collected.To ensure accuracy,we added time-lag variables of 3 d to the models.The results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three models.The accuracies of the models in spring and autumn were higher than those in the other two seasons.In addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time lags.Moreover,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the DFMC.This study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention.

甘肃舟曲江顶崖古滑坡复活变形特征与稳定性分析

为研究江顶崖古滑坡复活变形特征与稳定性,通过历史资料调研、现场踏勘与监测、卫星遥感和室内土工试验等方法,分析了主滑坡体、滑坡后壁及侧壁的变形特征与稳定性。结果表明:滑体前缘高陡边坡因降雨及河流冲刷导致坡脚失稳;中后部土体受地下水、连续强降雨影响,抗剪强度降低,下滑力增大,逐步向前推移;最终由于前缘土体的滑动,导致抗滑力减小,随之引发整体滑动,为缓慢滑动的牵引式滑坡。滑体后壁、两侧侧壁高陡,变形迹象明显,在强降雨或地震工况下易失稳滑动。江顶崖滑坡具有长期蠕滑变形、多次复活滑动等特点,是甘肃省近年来规模、范围最大的滑坡之一,在地震或暴雨作用下,滑坡有再次复活的可能,建议加强对滑坡区的变形监测,同时,对区域内不稳定斜坡进行加固治理,防止出现重大灾害。

基于简化有限集模型预测电流控制的五相PMSM统一容错控制

在五相永磁同步电机(permanent-magnet synchronous motor,PMSM)中,有限集模型预测容错控制(finite control set model predictive fault tolerant control,FCS-MPFTC)存在计算量大、电流谐波含量高等问题。因此,该文提出一种简化FCS-MPFTC来实现相开路和短路故障情况下的统一容错控制。首先,将模型预测电流控制的电流代价函数等效转化为电压代价函数,并采用无差拍方法通过电流模型计算出参考电压。然后,基于抑制三次谐波电流为0的原则合成虚拟电压矢量(virtual voltage vector,V^(3));通过重构V^(3)和扇区,以直接获得参考电压矢量对应的最优电压矢量。最后,对传统和简化FCS-MPFTC在开路和短路故障下进行对比实验。结果表明,所提策略能够有效减小故障后计算量、转矩脉动以及电流谐波含量。

钢筋混凝土拱桥加固施工次序方案及效果评价

为研究钢筋混凝土拱桥最优的加固施工次序,以一座在役4跨箱形拱桥的加固方案为背景,设计了3组针对性的加固方案,并对不同拆除加固施工次序下的主拱圈力学性能进行了分析;采用恒载应力变化率(αD)和荷载效应变化率(αN)评价了施工中拱圈的应力变化规律及加固后原拱圈的荷载效应。研究结果表明:拱上结构的拆建次序对加固后主拱圈的力学性能影响较小,但对加固过程中主拱圈的受力状态影响较大;拱顶对称拆除时αD<0,结构处于“卸载”状态,有利于拱桥施工中的受力;αN随着拱上结构恒载减小而增大,且增速减缓,故加固层材料利用率也随拱上结构恒载减小而增大,且增幅变缓;αN越大,则加固效果越好。

金沙江上游扎马古滑坡复活特征及堵河危险性分析

随着人类工程活动不断加剧和极端天气的频繁出现,古滑坡复活堵江问题日益突出,严重威胁着山区城镇安全。以金沙江上游巴曲右岸扎马特大古滑坡为例,采用无人机航测、现场精细调查和数值模拟分析等方法,查明了古滑坡复活特征,剖析了不同重现期降雨条件下滑坡的稳定性和失稳概率,模拟研究了不同工况下滑坡运动过程、堆积范围及堵河危险性。结果表明:(1)扎马古滑坡前缘局部复活主要表现为地表变形迹象清晰,呈现牵引式渐进破坏的特点,前缘复活区体积约185万m^(3),存在进一步失稳滑动可能;(2)滑坡前缘在天然状态下稳定,20年一遇的月极值降雨条件下处于不稳定状态,失稳概率为87.95%,50年、100年一遇的月极值降雨条件下前缘与后部整体处于不稳定状态,失稳概率分别为58.75%、68.60%;(3)前缘失稳或前缘与后部连续失稳后,滑坡体在沟口处达到的最大速度分别为9、11 m s,滑移距离最远可达480 m,在巴曲沟道形成高度约42~48 m的堰塞坝;(4)堵塞巴曲后形成的回水可能淹没滑坡上游德达乡段G318国道、居民建筑及场站等基础设施,涉及范围约0.81~1.02 km^(2),形成的堰塞湖可能在7天内发生漫坝,应引起重视。

双有源桥无回流功率控制的死区影响与补偿

针对三重移相协同控制(CTPS)加入桥臂死区后,会导致双有源桥(DAB)变换器回流功率发生及软开关失效的问题,提出针对CTPS控制的死区补偿策略.通过分析CTPS控制不同模式下桥臂死区引起的变压器原副边电压及漏感电流的变化,基于回流功率产生的原理,更正了不同模式移相比之间的耦合关系,对功率传输模型及CTPS控制模式的切换条件进行修正,实现了死区对CTPS控制影响的有效控制.利用所提的补偿方案,抑制了由死区引起的回流功率,恢复了CTPS控制的软开关性能,具有较补偿前更优的电流应力.分别开展死区补偿前、后的实验,对死区影响的分析和所提出的补偿策略进行验证.

绒毛皂荚特定森林环境育苗技术组合与常规育苗对比试验

[目的]提高绒毛皂荚场地发芽率,加速种群回归。[方法]在特定的森林环境进行育苗技术组合试验,并以苗圃常规育苗为对照,研究不破坏林地环境的小铲破土和地表播种+死地被物多种覆盖方式技术组合对发芽率与苗木生长的影响。[结果]小铲破土播种或地表播种加4种不同死地被物覆盖方式技术组合的场地发芽率分别为(A_(1))61.67%、(A_(2))55.56%、(A_(3))61.11%、(A_(4))57.22%,均高于常规育苗(CK)的35.03%;A_(1)小铲破土播种后,盖1 cm厚表层有机土+3 cm厚粗腐殖质+未分解的枯枝落叶组合和A_(3)种子直播土壤地表后,盖3 cm厚的粗腐殖质+未分解枯枝落叶同为最佳组合;常规育苗的苗木成苗率(成苗数与发芽数之比×100%)与苗木生长量略高于其他处理;但从成苗数的绝对数比较,CK小于A_(1)、A_(2)、A_(3)、A_(4)处理的106、85、95和88株。[结论]特定的森林环境母树下小铲破土或地表播种后+林地死地被物覆盖组合育苗是提高场地发芽率和成苗数的有效方法。

抑制采样白噪声干扰的PWM整流器无差拍控制

无差拍控制(DBC)是一种应用于整流器电流内环的预测控制,但该算法对系统参数敏感,当采样受到持续噪声干扰时波形畸变严重。为此,此处提出了一种基于DBC的白噪声抑制算法,实验结果表明,该算法在较大电感参数偏差下能保持稳定,在白噪声干扰下能够显著降低电流畸变率。

基于SBAS-InSAR技术的雅鲁藏布江色东普沟地质灾害发育特征与复活趋势分析

随着全球气候不断变暖,青藏高原发生地质灾害的频率和危害强度大幅增加,对川藏铁路沿线的滑坡泥石流进行及时有效的监测和防治具有重要意义。文章选取了2016年7月至2020年1月之间的Senti⁃nel-1A数据,解译和分析了区域内地物发生的变化情况,采用SBAS-InSAR技术对雅鲁藏布江沿岸的色东普沟发生高位冰崩地质灾害链致灾过程和复活趋势进行了研究。结果表明:依据区域内时序相关性的变化情况推断出的灾害事件与SBAS-InSAR的灾害探测结果具有高度一致性,SBAS-InSAR对冰崩-岩崩-滑坡泥石流等灾害链进行监测是一种有效的手段;色东普沟自2018年致灾以来,新增5处变形体,累计形变量均已超过40 mm,存在复活迹象。随着气候变暖、降雨量增加、冰川消融,色东普沟在今后相当长的时期内仍会保持此类灾害事件的高发频发态势,应进一步加强该区域地灾监测,提前开展防治工作。