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2022年四川泸定 M_(s)6.8地震强震动特性研究 被引量:1
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作者 张聪 周宝峰 +4 位作者 任叶飞 王晓敏 余桦 张亚军 吴华灯 《世界地震工程》 北大核心 2024年第1期13-24,共12页
北京时间2022年9月5日12时52分,四川省甘孜州泸定县发生M_(s)6.8级地震。国家强震动台网获得了133组三分量加速度记录,在对记录进行初步筛选和滤波后,研究了PGA和PGV衰减关系、竖向地震动特点、地震动速度脉冲,对比分析了反应谱和设计谱... 北京时间2022年9月5日12时52分,四川省甘孜州泸定县发生M_(s)6.8级地震。国家强震动台网获得了133组三分量加速度记录,在对记录进行初步筛选和滤波后,研究了PGA和PGV衰减关系、竖向地震动特点、地震动速度脉冲,对比分析了反应谱和设计谱,着重对石棉挖角台站附近震害与地震动的相关性进行了分析,结论如下:1)三种台站强震动记录的PGA和PGV拟合曲线都比较相近,PGA、PGV拟合曲线与霍俊荣的预测模型较为接近;2)竖向地震动偏大,约38.2%的强震动记录V/H大于2/3,可能是屋顶塌落、柱子扭转和天花板坠落等震害现象出现的主要原因;3)识别出具有速度脉冲特性的记录11条,该类记录对长周期结构影响较大;4)所选记录反应谱大多超过了罕遇地震设计谱水平段,具有速度脉冲特性的051SMW台站周围房屋破坏较严重,人员伤亡较重。 展开更多
关键词 泸定M_(s)6.8地震 地震动衰减 竖向地震动 速度脉冲 加速度反应谱
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Government's Responsibility for Control of Agricultural Environmental Pollution in China 被引量:1
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作者 Dongfang CHEN 《Asian Agricultural Research》 2016年第10期41-43,共3页
In this paper,the current situation of agricultural environmental pollution caused by the increase of chemicals input in agriculture in China was analyzed,and it is found that agricultural pollution is related to agri... In this paper,the current situation of agricultural environmental pollution caused by the increase of chemicals input in agriculture in China was analyzed,and it is found that agricultural pollution is related to agricultural industrial policies,urban-rural economic structure,funds input in pollution control,comprehensive environmental management,laws of pollution control,and so forth. To control agricultural pollution effectively,it is needed to implement integration of agricultural and environmental policies,establish environmentally friendly agricultural technology popularizing system,implement integrated planning and management of a basin,and set up and improve legislation to protect agricultural environment. 展开更多
关键词 China Agricultural environmental pollution Government’s responsibility
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Quantum Mechanics: Harmonic Wave-Packets, Localized by Resonant Response in Dispersion Dynamics
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作者 Antony J. Bourdillon 《Journal of Modern Physics》 CAS 2023年第2期171-182,共12页
From a combination of Maxwell’s electromagnetism with Planck’s law and the de Broglie hypothesis, we arrive at quantized photonic wave groups whose constant phase velocity is equal to the speed of light c = ω/k and... From a combination of Maxwell’s electromagnetism with Planck’s law and the de Broglie hypothesis, we arrive at quantized photonic wave groups whose constant phase velocity is equal to the speed of light c = ω/k and to their group velocity dω/dk. When we include special relativity expressed in simplest units, we find that, for particulate matter, the square of rest mass , i.e., angular frequency squared minus wave vector squared. This equation separates into a conservative part and a uniform responsive part. A wave function is derived in manifold rank 4, and from it are derived uncertainties and internal motion. The function solves four anomalies in quantum physics: the point particle with prescribed uncertainties;spooky action at a distance;time dependence that is consistent with the uncertainties;and resonant reduction of the wave packet by localization during measurement. A comparison between contradictory mathematical and physical theories leads to similar empirical conclusions because probability amplitudes express hidden variables. The comparison supplies orthodox postulates that are compared to physical principles that formalize the difference. The method is verified by dual harmonics found in quantized quasi-Bloch waves, where the quantum is physical;not axiomatic. 展开更多
关键词 Wave Packet Reduction Phase Velocity Hidden Variables Young’s slits Resonant response Dispersion Dynamics Quantum Physics
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Treat to target in Crohn’s disease:A practical guide for clinicians
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作者 Ashish R Srinivasan 《World Journal of Gastroenterology》 SCIE CAS 2024年第1期50-69,共20页
A treat-to-target(T2T)approach applies the principles of early intervention and tight disease control to optimise long-term outcomes in Crohn's disease.The Selecting Therapeutic Targets in Inflammatory Bowel Disea... A treat-to-target(T2T)approach applies the principles of early intervention and tight disease control to optimise long-term outcomes in Crohn's disease.The Selecting Therapeutic Targets in Inflammatory Bowel Disease(STRIDE)-II guidelines specify short,intermediate,and long-term treatment goals,documenting specific treatment targets to be achieved at each of these timepoints.Scheduled appraisal of Crohn’s disease activity against pre-defined treatment targets at these timepoints remains central to determining whether current therapy should be continued or modified.Consensus treatment targets in Crohn’s disease comprise combination clinical and patient-reported outcome remission,in conjunction with biomarker normalisation and endoscopic healing.Although the STRIDE-II guidelines endorse the pursuit of endoscopic healing,clinicians must consider that this may not always be appropriate,acceptable,or achievable in all patients.This underscores the need to engage patients at the outset in an effort to personalise care and individualise treatment targets.The use of non-invasive biomarkers such as faecal calprotectin in conjunction with cross-sectional imaging techniques,particularly intestinal ultrasound,holds great promise;as do emerging treatment targets such as transmural healing.Two randomised clinical trials,namely,CALM and STARDUST,have evaluated the efficacy of a T2T approach in achieving endoscopic endpoints in patients with Crohn’s disease.Findings from these studies reflect that patient subgroups and Crohn’s disease characteristics likely to benefit most from a T2T approach,remain to be clarified.Moreover,outside of clinical trials,data pertaining to the real-world effectiveness of a T2T approach remains scare,highlighting the need for pragmatic real-world studies.Despite the obvious promise of a T2T approach,a lack of guidance to support its integration into real-world clinical practice has the potential to limit its uptake.This highlights the need to describe strategies,processes,and models of care capable of supporting the integration and execution of a T2T approach in real-world clinical practice.Hence,this review seeks to examine the current and emerging literature to provide clinicians with practical guidance on how to incorporate the principles of T2T into routine clinical practice for the management of Crohn’s disease. 展开更多
关键词 Treat to target Inflammatory bowel disease Crohn’s disease Treatment targets Endoscopic remission Transmural healing Time to response Intestinal ultrasound
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Bruton’s tyrosine kinase inhibitors in primary central nervous system lymphoma:New hopes on the horizon
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作者 Leonardo S Lino-Silva Sabrina B Martínez-Villavicencio Luisa Fernanda Rivera-Moncada 《World Journal of Clinical Oncology》 2024年第5期587-590,共4页
In this editorial,we comment on the article by Wang et al.This manuscript explores the potential synergistic effects of combining zanubrutinib,a novel oral inhibitor of Bruton’s tyrosine kinase,with high-dose methotr... In this editorial,we comment on the article by Wang et al.This manuscript explores the potential synergistic effects of combining zanubrutinib,a novel oral inhibitor of Bruton’s tyrosine kinase,with high-dose methotrexate(HD-MTX)as a therapeutic intervention for primary central nervous system lymphoma(PCNSL).The study involves a retrospective analysis of 19 PCNSL patients,highlighting clinicopathological characteristics,treatment outcomes,and genomic biomarkers.The results indicate the combination’s good tolerance and strong antitumor activity,with an 84.2%overall response rate.The authors emphasize the potential of zanubrutinib to modulate key genomic features of PCNSL,particularly mutations in myeloid differentiation primary response 88 and cluster of differentiation 79B.Furthermore,the study investigates the role of circulating tumor DNA in cerebrospinal fluid for disease surveillance and treatment response monitoring.In essence,the study provides valuable insights into the potential of combining zanubrutinib with HD-MTX as a frontline therapeutic regimen for PCNSL.The findings underscore the importance of exploring alternative treatment modalities and monitoring genomic and liquid biopsy markers to optimize patient outcomes.While the findings suggest promise,the study’s limitations should be considered,and further research is needed to establish the clinical relevance of this therapeutic approach for PCNSL. 展开更多
关键词 Primary central nervous system lymphoma Zanubrutinib Bruton’s tyrosine kinase PROGNOsIs Myeloid differentiation primary response 88 gene Cluster of differentiation 79B gene
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On the Government's Responsibility in China's Rural Land Transfer
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作者 Dongfang CHEN 《Asian Agricultural Research》 2016年第8期72-73,共2页
There is an urgent need for China's rural land transfer in order to develop modern agriculture,ensure food security,transfer rural population,and accelerate industrialization and urbanization.At present,there is s... There is an urgent need for China's rural land transfer in order to develop modern agriculture,ensure food security,transfer rural population,and accelerate industrialization and urbanization.At present,there is still disordered transfer of rural land in China,making the interests of the transferors and transferees difficult to be effectively guaranteed;there is inefficient transfer,leading to decline in actual agricultural production level after transfer;there is jobless transfer,leading to difficult placement for rural surplus labor after transfer,seriously restricting rural land transfer.Therefore,the Chinese government's legal responsibility,economic responsibility and social responsibility in rural land transfer should be further strengthened. 展开更多
关键词 China Rural land transfer Government’s responsibility
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2022年四川泸定M_(S)6.8地震强震动记录特征 被引量:1
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作者 江鹏 李萍萍 +4 位作者 李同林 曾均 王竞 苏金蓉 温瑞智 《地震研究》 CSCD 北大核心 2023年第4期593-602,共10页
对地震监测台网获取的2022年四川泸定M_(S)6.8地震的1799组强震动记录进行处理后计算地震动参数,利用克里金插值方法得到峰值加速度PGA、峰值速度PGV和加速度反应谱的空间分布图。结果表明:基准站、基本站和一般站记录到的地震动峰值依... 对地震监测台网获取的2022年四川泸定M_(S)6.8地震的1799组强震动记录进行处理后计算地震动参数,利用克里金插值方法得到峰值加速度PGA、峰值速度PGV和加速度反应谱的空间分布图。结果表明:基准站、基本站和一般站记录到的地震动峰值依次增大,反映出局部地形和场地条件对地震动的放大作用。高烈度区仪器地震烈度和调查地震烈度较为一致,Ⅵ度以下区域仪器地震烈度和调查地震烈度等值线方向差异较大,反映出在震害不显著情况下两种烈度的对应关系不太理想。初步震相分析发现,近断层台站垂直方向峰值较大,多个台站记录到水平向速度大脉冲现象。基于基岩地震动峰值统计了本次地震的衰减特性,PGV随距离衰减相比中国地震动参数区划图更慢,综合震相特征认为本次地震更符合浅源地震的特点。为进一步分析地震动与震害的关系,选取了2个震害较为严重乡镇的强震动记录计算5%阻尼比的拟加速度反应谱,在设计地震反应谱特征周期T g取值到1.5 s之间,台站记录反应谱值远超出设计地震反应谱,在部分周期区间还超出了罕遇地震设计反应谱值,体现出反应谱与震害较好的相关性。 展开更多
关键词 泸定地震 强震动记录 反应谱 衰减关系
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FT3、FT4、FT3/FT4、TSH与克罗恩病维得利珠单抗治疗后临床活动度变化关系的研究 被引量:1
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作者 王艳 陈延方 +3 位作者 陈璐 黄小莉 刘诗琦 陈洪 《东南大学学报(医学版)》 CAS 2023年第6期849-856,共8页
目的:探究血清游离三碘甲状腺原氨酸(FT3)、游离四碘甲状腺原氨酸(FT4)、FT3/FT4、促甲状腺激素(TSH)对克罗恩病(CD)患者维得利珠单抗(VDZ)治疗后临床应答的预测价值。方法:纳入2020年5月至2022年5月我院接受VDZ治疗且疗程超过3个月的C... 目的:探究血清游离三碘甲状腺原氨酸(FT3)、游离四碘甲状腺原氨酸(FT4)、FT3/FT4、促甲状腺激素(TSH)对克罗恩病(CD)患者维得利珠单抗(VDZ)治疗后临床应答的预测价值。方法:纳入2020年5月至2022年5月我院接受VDZ治疗且疗程超过3个月的CD患者54例,对照组89例。收集对照组及CD患者使用VDZ治疗前、治疗3个月后FT3、FT4、FT3/FT4、TSH等甲状腺功能指标数据,用CD活动指数(CDAI)评估CD疾病活动度。比较CD患者与对照组甲状腺功能指标差异。根据VDZ治疗前后CDAI差值(ΔCDAI)是否≥100分分为应答组及无应答组,比较两组患者VDZ治疗前后甲状腺功能指标变化及其差值(ΔFT3、ΔFT4、ΔFT3/FT4、ΔTSH)与ΔCDAI相关性;用受试者工作特征(ROC)曲线分析上述差值对VDZ临床应答的预测价值。结果:CD患者治疗前FT3、FT3/FT4低于对照组(P<0.05);VDZ治疗3个月后FT3、FT3/FT4较前提高,FT4降低(P<0.05)。应答组FT3、FT4、FT3/FT4、CDAI在VDZ治疗前后自身比较,差异均有统计学意义(P<0.05)。VDZ治疗前后ΔFT3、ΔFT3/FT4与ΔCDAI间呈负相关(P<0.05),ΔFT4、ΔTSH与ΔCDAI无直线相关关系(P>0.05)。ΔFT3、ΔFT3/FT4预测VDZ治疗临床应答潜能的ROC曲线下面积(AUC)分别为0.837、0.827,灵敏度为82.9%、80.5%,特异度均为81.8%。结论:血清游离甲状腺功能指标变化尤其是FT3、FT3/FT4变化与CD患者VDZ治疗后临床活动指数变化呈负相关,并对其临床应答有一定预测价值。 展开更多
关键词 克罗恩病 维得利珠单抗 临床应答 游离三碘甲状腺原氨酸 游离四碘甲状腺原氨酸 游离三碘甲状腺原氨酸/游离四碘甲状腺原氨酸
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基于IMO分级的MASS岸基操控人员法律地位探析 被引量:1
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作者 袁雪 姜爱华 《中国海洋大学学报(社会科学版)》 2023年第1期34-48,共15页
随着AI技术的发展,人工智能与传统设备的结合已深刻改变了人类的生产生活。MASS(Maritime Autonomous Surface Ships)全称为海上自主水面船舶,其作为人工智能的产物,代表着未来船舶的发展趋势,也推动MASS岸基操控人员这一新兴海事主体... 随着AI技术的发展,人工智能与传统设备的结合已深刻改变了人类的生产生活。MASS(Maritime Autonomous Surface Ships)全称为海上自主水面船舶,其作为人工智能的产物,代表着未来船舶的发展趋势,也推动MASS岸基操控人员这一新兴海事主体的产生。“自动化”并不意味着在MASS的操作过程中完全消除人员因素的干扰,在IMO所定义的MASS发展四阶段中,人在循环中的角色是不断变化的,其职能、责任、法律地位均有所不同,关于岸基操控人员法律地位的认定,具有基础性和高度优先性。L1级别MASS无需岸基操控人员;L2级别MASS岸基操控人员可视作L3级别岸基操控人员的实习或见习期;L3级别岸基操控人员可视为船长或“外部船长”;L4级别MASS系统的优先程度高于人,岸基操控人员仅具有“监督”与作出“降级”决定的职责,不排除其成为新兴海事主体的可能性。 展开更多
关键词 岸基操控人员 MAss 法律地位 船员职责 船长
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基于B/S架构的医疗器械灭菌自动化控制系统
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作者 武卓 袁丽洁 +3 位作者 张旋 马良 于斌 高翔宇 《信息技术》 2023年第12期69-74,共6页
为提升医疗器械灭菌自动化控制的稳定性及输出值的精度,设计基于B/S架构的医疗器械灭菌自动化控制系统。通过器械设备层采集器械、包装器械、敷料包类、橡胶类和液体类五种医疗器械的器械信息;灭菌服务层设计了由不同灭菌温度及时间设... 为提升医疗器械灭菌自动化控制的稳定性及输出值的精度,设计基于B/S架构的医疗器械灭菌自动化控制系统。通过器械设备层采集器械、包装器械、敷料包类、橡胶类和液体类五种医疗器械的器械信息;灭菌服务层设计了由不同灭菌温度及时间设置成的五种灭菌模式;融合STC89C52单片机与模糊PID控制算法,中心服务层的服务器将灭菌服务层的灭菌控制结果存储并反馈到控制用户层,为用户查询、分析控制结果提供依据。实验结果显示,该系统的稳定性高,系统输出/执行值始终处于4%以内,输出值准确性较高,系统控制效果较好。 展开更多
关键词 B/s架构 医疗器械灭菌 自动化控制 模糊PID控制 控制响应
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Estimating peak response frequencies in a tidal band in the seas adjacent to China with a numerical model 被引量:2
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作者 CUI Xinmei FANG Guohong +1 位作者 TENG Fei WU Di 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第1期29-37,共9页
A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest p... A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China's adjacent seas shows that the Bohai Sea has a highest peak response frequency (PRF) of 1.52 d^-1; the northern Yellow Sea has a PRF of 1.69 d^-1; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d^-1; the Yellow Sea (includ- ing the Gyeonggi Bay), the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d^-1 and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d^-1 respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d^-1. The PRFs of the Bohal Sea, the northern Yellow Sea, the Bei- bu Gulf and the South China Sea can be explained by a classical quarter (half for the Bohai Sea) wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Talwan Strait, and the Gulf of Thailand. 展开更多
关键词 China's adjacent seas response to tidal forcing peak response frequency resonance numericalmodel
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Icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels in the hippocampus of the senescence-accelerated mouse 被引量:4
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作者 Zhanwei Zhang Ting Zhang Keli Dong 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第12期885-890,共6页
At 8 weeks after intragastric administration of icariin to senescence-accelerated mice (P8 strain), Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increa... At 8 weeks after intragastric administration of icariin to senescence-accelerated mice (P8 strain), Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse. 展开更多
关键词 ICARIIN Alzheimer's disease HIPPOCAMPUs phosphorylated cyclic adenosine monophosphate response element binding protein neural regeneration
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3-D DYNAMIC RESPONSE OF TRANSVERSELY ISOTROPIC SATURATED SOILS 被引量:3
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作者 王小岗 黄义 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第11期1409-1419,共11页
A study on dynamic response of transversely isotropic saturated poroelastic media under a circular non-axisymmetrical harmonic source has been presented by Huang Yi et al. using the technique of Fourier expansion and ... A study on dynamic response of transversely isotropic saturated poroelastic media under a circular non-axisymmetrical harmonic source has been presented by Huang Yi et al. using the technique of Fourier expansion and Hankel transform. However, the method may not always be valid. The work is extended to the general case being in the rectangular coordinate. The purpose is to study the 3-d dynamic response of transversely isotropic saturated soils under a general source distributing in arbitrary rectangular zoon on the medium surface. Based on Biot's theory for fluid- saturated porous media, the 3-d wave motion equations in rectangular coordinate for transversely isotropic saturated poroelastic media were transformed into the two uncoupling governing differential equations of 6-order and 2-order respectively by means of the displacement functions. Then, using the technique of double Fourier transform, the governing differential equations were easily solved. Integral solutions of soil skeleton displacements and pore pressure as well as the total stresses for poroelastic media were obtained. Furthermore, a systematic study on half-space problem in saturated soils was performed. Integral solutions for surface displacements under the general harmonic source distributing on arbitrary surface zone, considering both case of drained surface and undrained surface, were presented. 展开更多
关键词 Blot's wave equation transversely isotropic saturated poroelastic medium HALF-sPACE harmonic response double Fourier transform
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Induced Th2 dominant immune response in APPswe, PSEN1dE9 transgenic mice after nasal immunization with an adenoviral vector encoding 10 tandem repeats of beta-amyloid 3-10 被引量:2
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作者 Rong Guo Kui Huang +4 位作者 Tongzi Jiang Jian Li Yu Li Xiaona Xing Yunpeng Cao 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第26期2005-2012,共8页
Immunotherapy for Alzheimer's disease (AD) is effective in improving cognitive function in transgenic mouse models of AD. Because the AN1792 [beta-amyloid (Aβ) 1-42] vaccine was halted because of T cell mediated... Immunotherapy for Alzheimer's disease (AD) is effective in improving cognitive function in transgenic mouse models of AD. Because the AN1792 [beta-amyloid (Aβ) 1-42] vaccine was halted because of T cell mediated meningoencephalitis, many scientists are searching for a nove) vaccine to avoid the T cell mediated immune response caused by the Aβ1-42. Importantly, the time when the immunization is begun can influence the immune effect. In this study, an adenovirus vaccine was constructed containing 10 x Aβ3-10 repeats and gene adjuvant CpG DNA. Transgenic AD mice were immunized intranasally for 3 months. After 10 × Aβ3-10 vaccine immunization, high titers of anti-Aβ42 IgG1 predominant antibodies were induced. In spatial learning ability and probe tests, the 10 × Aβ3-10 immunized mice showed significantly improved memories compared to control mice. The 10 × Aβ3-10 vaccine resulted in a robust Th2 dominant humoral immune response and reduced learning deficits in AD mice. In addition, the 10 × Aβ3-10 vaccine might be more efficient if administered before Aβ aggregation at an early stage in the AD mouse brain. Thus, the adenovirus vector encoding 10 × Aβ-10 is a promising vaccine for AD. 展开更多
关键词 Alzheimer's disease IMMUNOTHERAPY gene vaccine amyloid plaque T cell immunity response neural regeneration
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Determination of the Response Amplitude Operator(s) of an FPSO 被引量:1
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作者 Imabibo Ibinabo Daniel T. Tamunodukobipi 《Engineering(科研)》 2019年第9期541-556,共16页
The driving necessities of cost reduction and the need to develop fields at ever increasing water depths have led to the use of floating structures. Among these structures are the Floating Production Storage and Offlo... The driving necessities of cost reduction and the need to develop fields at ever increasing water depths have led to the use of floating structures. Among these structures are the Floating Production Storage and Offloading (FPSO) units whose motion analysis is considered in this paper. In actual environmental condition, it is required to accurately determine or predict large amplitude motion of the FPSO before any offshore operation. This paper seeks to present a detailed method of computing the Response Amplitude Operator(s) (RAOs) for the six (6) degrees of freedom using ANSYS AQWA. The results indicate for Heave motion a tendency for the heave peak value to move slightly higher dimensionless encounter-frequency as the wave moves from Head sea to Beam sea direction. A MATLAB source code was developed to validate the result for heave motion at head sea. Although a small difference in predicted heave motion occurred, it is pertinent to note that the comparisons between results generated in the MATLAB program and ANSYS AQWA demonstrate generally good agreement, and the roll response of the FPSO is noted to be critical. 展开更多
关键词 responsE AMPLITUDE Operator(s) FLOATING Production storage and OFFLOADING Unit ANsYs AQWA MATLAB simplified Method
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Approximate analytical solutions and experimental analysis for transient response of constrained damping cantilever beam 被引量:1
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作者 胡明勇 王安稳 章向明 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第11期1359-1370,共12页
Vibration mode of the constrained damping cantilever is built up according to the mode superposition of the elastic cantilever beam. The control equation of the constrained damping cantilever beam is then derived usin... Vibration mode of the constrained damping cantilever is built up according to the mode superposition of the elastic cantilever beam. The control equation of the constrained damping cantilever beam is then derived using Lagrange's equation. Dynamic response of the constrained damping cantilever beam is obtained according to the principle of virtual work, when the concentrated force is suddenly unloaded. Frequencies and transient response of a series of constrained damping cantilever beams are calculated and tested. Influence of parameters of the damping layer on the response time is analyzed. Analyitcal and experimental approaches are used for verification. The results show that the method is reliable. 展开更多
关键词 constrained damping cantilever beam transient response Lagrange's equation mode superposition
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Dynamic response of electromagnetic launcher's rail subjected to harmonic magnetic pressure 被引量:1
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作者 刘文 张立功 +1 位作者 白象忠 张忠建 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第6期120-126,共7页
In order to extend the rail life and improve the firing accuracy,the electromagnetic launcher's rail can be modeled as a beam on elastic foundation with simply supported beam with moving load.Euler beam theory is ... In order to extend the rail life and improve the firing accuracy,the electromagnetic launcher's rail can be modeled as a beam on elastic foundation with simply supported beam with moving load.Euler beam theory is applied to build the mechanical model and the analytical solution of the equation subjected to harmonic magnetic pressure is derived in details,which has successfully avoided the errors caused by using the uniform pressure to approximately replace the variable force.Numerical analysis of the dynamic response on rail by using the MATLAB software shows that the peak values of maximal deflection and vibration velocity increase gradually as the exciting frequency increases.Taking the same speed of load into account,the dynamic response of rail is obviously smaller than that under constant force.Therefore the reliable theory basis is provided for the design and control of rail to promote the practical application of electromagnetic launcher. 展开更多
关键词 electromagnetic launcher’s rail harmonic pressure analytical solutions exciting frequency dynamic response
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Hydroelastic Response of VLFS with An Attached Submerged Horizontal Solid/Porous Plate Under Wave Action 被引量:1
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作者 FENG Ming-wei SUN Zhao-chen +1 位作者 LIANG Shu-xiu LIU Bi-jin 《China Ocean Engineering》 SCIE EI CSCD 2020年第4期451-462,共12页
The hydroelastic responses of a submerged horizontal solid/porous plate attached at the front of a very large rectangular floating structure(VLFS)under wave action has been investigated in the context of linear water ... The hydroelastic responses of a submerged horizontal solid/porous plate attached at the front of a very large rectangular floating structure(VLFS)under wave action has been investigated in the context of linear water wave theory.Darcy’s law is adopted to represent energy dissipation in pores.It is assumed that the porous plates are made of material with very fine pores so that the normal velocity across the perforated porous is linearly associated with the pressure drop.In the analytic method,the eigenfunction expansion-matching method(EEMM)for multiple domains is applied to solve the hydrodynamic problem and the elastic equation of motion is solved by the modal expansion method.The performance of the proposed submerged horizontal solid/porous plate can be significantly enhanced by selecting optimal design parameters,such as plate length,horizontal position,submerged depth and porosity.It is concluded that good damping effect can be achieved through installation of solid and porous plate.Porous plate has better damping effect at low frequencies,while solid plate has better damping effect at high frequencies.The optimal ratio of plate length to water depth is 0.25-0.375,and the optimal ratio of submerged depth to water depth is 0.09-0.181. 展开更多
关键词 VLFs hydroelastic response Darcy’s law eigenfunction expansion-matching method submerged horizontal solid/porous plate
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The Planet’s Response to Human Activity. Thermodynamic Approach 被引量:1
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作者 Vladimir Kh. Dobruskin 《Open Journal of Ecology》 2021年第2期126-135,共10页
The applicability of the laws of thermodynamics to processes on Earth is discussed and it is shown that the chemical thermodynamics provides the reasonable basis for predicting probable changes. The historical evoluti... The applicability of the laws of thermodynamics to processes on Earth is discussed and it is shown that the chemical thermodynamics provides the reasonable basis for predicting probable changes. The historical evolution of the planet is considered in the framework of the Harari approach;a civilization’s level is estimated by the Kardashev scale based on the amount of energy it is able to use. During a short historical interval (≈500 years), when the effect of biological evolution is imperceptible and the main changes on the planet are caused by human activity, two systems are considered: 1) a nonequilibrium inhabited planet and 2) a quasi-equilibrium hypothetical planet without people, which is accepted as a comparison system. It is shown that in response to the energy impact, the equilibrium of the hypothetical system with the primordial nature is disturbed and processes are initiated aimed to prevent further growth of energy production. In the case of a real planet, this implements changes preventing the uncontrolled activities of humans—the energy producers. Climate change, an increase in the number of natural disasters and epidemics can be recognized as a direct response of the planet, while changes in socio-economic relations, morality, demographic situation, new threats etc. can be considered as an indirect reaction to changing conditions of human beings. The latter results from the mutual correlation between the progress of society, on the one hand, and humanitarian and political processes, on the other. The role of renewable and non-renewable energy sources in evolution is taken into account. Obviously, it is better to take meaningful measures to achieve an acceptable balance now than to wait for the blind and extremely painful action of the laws of nature, which would lead to a reduction in the population. 展开更多
关键词 Planet’s response Human Activity EVOLUTION
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Stability and Hopf Bifurcation of a Virus Infection Model with a Delayed CTL Immune Response 被引量:1
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作者 LI Xiao-tong TIAN Xiao-hong XU Rui 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第3期426-437,共12页
In this paper, a virus infection model with standard incidence rate and delayed CTL immune response is investigated. By analyzing corresponding characteristic equations,the local stability of each of feasible equilibr... In this paper, a virus infection model with standard incidence rate and delayed CTL immune response is investigated. By analyzing corresponding characteristic equations,the local stability of each of feasible equilibria and the existence of Hopf bifurcations at the CTL-activated infection equilibrium are established, respectively. By means of comparison arguments, it is verified that the infection-free equilibrium is globally asymptotically stable if the basic reproduction ratio is less than unity. By using suitable Lyapunov functional and LaSalle's invariance principle, it is shown that the CTL-inactivated infection equilibrium of the system is globally asymptotically stable if the immune response reproduction ratio is less than unity and the basic reproduction ratio is greater than unity. Numerical simulations are carried out to illustrate the theoretical result. 展开更多
关键词 virus infection CTL immune response time delay Hopf bifurcation Lasalle’s invariance principle global stability
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