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基于AMESim的多液缸合流式压裂泵流量脉动特性研究
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作者 晁宇 杨波 +4 位作者 戚伟 李伟 赵敏 吕春光 杨睿 《机电工程》 CAS 北大核心 2024年第2期253-261,共9页
传统的机械式压裂泵存在冲次高、冲程短、曲轴易于失效等问题,为此,提出了一种多液缸合流式液压驱动压裂泵,并对其产生流量脉动的机理进行了研究。首先,详细阐述了多液缸合流式压裂泵的工作原理,基于液压流体力学等理论,建立了多液缸合... 传统的机械式压裂泵存在冲次高、冲程短、曲轴易于失效等问题,为此,提出了一种多液缸合流式液压驱动压裂泵,并对其产生流量脉动的机理进行了研究。首先,详细阐述了多液缸合流式压裂泵的工作原理,基于液压流体力学等理论,建立了多液缸合流式压裂泵的数学模型,并进行了理论分析;其次,采用AMESim仿真软件搭建了多液缸合流式压裂泵工作仿真模型,选择了合理的仿真参数设置,进行了变负载压力下的仿真研究;最后,对液压动力传递链中的活塞-柱塞运动特性、泵腔流量特性、输出流量和压力脉动特性进行了研究,并对仿真结果进行了分析。研究结果表明:在25 MPa工况下,多液缸合流式压裂泵的输出压力和流量脉动率分别为36.8%和20.61%,冲次只有42次/min,符合实际工况;多液缸合流式压裂泵输出流量脉动的主要原因是各组液缸的频繁换向、泵送行程和吸入行程的切换,导致活塞-柱塞做减速停止运动和加速启动运动。 展开更多
关键词 往复泵 仿真模型 压力脉动特性 振动噪声 活塞-柱塞运动特性 泵腔流量特性 输出流量
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紫草素对激素诱导骨质疏松大鼠骨代谢的治疗机制研究
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作者 钞愈 李文高 +1 位作者 王文斌 郭书章 《安徽医药》 CAS 2024年第8期1518-1523,共6页
目的探讨紫草素(SKN)对骨质疏松大鼠骨代谢的治疗机制。方法2022年1―6月通过糖皮质激素诱导大鼠骨质疏松症,采取腹腔注射紫草素对大鼠进行治疗,通过腹腔注射shRNA-前蛋白转化酶枯草溶菌素(PCSK5)敲低大鼠体内PCSK5水平。骨密度仪测量... 目的探讨紫草素(SKN)对骨质疏松大鼠骨代谢的治疗机制。方法2022年1―6月通过糖皮质激素诱导大鼠骨质疏松症,采取腹腔注射紫草素对大鼠进行治疗,通过腹腔注射shRNA-前蛋白转化酶枯草溶菌素(PCSK5)敲低大鼠体内PCSK5水平。骨密度仪测量大鼠股骨骨密度(BMD),酶联免疫吸附测定(ELISA)大鼠血清骨钙素(BGP)及Ⅰ型胶原羧基末端肽(CTX),实时荧光定量PCR(qRT-PCR)检测大鼠股骨组织PCSK5信使RNA(mRNA)水平,免疫共沉淀验证PCSK5与生长分化因子11(GDF11)蛋白相互作用,蛋白质印迹法检测大鼠股骨组织GDF11蛋白水平。结果与磷酸缓冲盐溶液(PBS)组(0.23±0.01)g/cm2比较,糖皮质激素使得糖皮质激素性骨质疏松症(GIOP)组(0.12±0.01)g/cm2 BMD值降低(P<0.05),GIOP+二甲亚砜(DMSO)组(0.11±0.01)g/cm2较GIOP+SKN组(0.18±0.01)g/cm2相比BMD值降低(P<0.05);PBS组PCSK5 mRNA表达水平量显著低于GIOP组(1.01±0.01比0.23±0.02,P<0.05),GIOP+DMSO显著低于GIOP+SKN组(0.24±0.01比0.81±0.16,P<0.05),GIOP+DMSO+si-NC组显著高于GIOP+DMSO+si-PCSK5组(0.82±0.06比0.38±0.03,P<0.05);PBS组GDF11表达量显著低于GIOP组(0.30±0.01比1.22±0.11,P<0.05),GIOP+DMSO组显著高于GIOP+SKN组(1.28±0.11比0.52±0.04,P<0.05),GIOP+DMSO+si-NC组显著低于GIOP+DMSO+si-PCSK5组(0.49±0.04比0.87±0.16,P<0.05)。结论紫草素调控PCSK5/GDF11通路促进骨质疏松大鼠骨代谢。 展开更多
关键词 骨质疏松 紫草素 骨代谢 骨钙素 前蛋白转化酶枯草溶菌素 生长分化因子11
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Metabolic reprogramming: a new option for the treatment of spinal cord injury
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作者 Jiangjie Chen Jinyang Chen +11 位作者 chao yu Kaishun Xia Biao Yang Ronghao Wang Yi Li Kesi Shi yuang Zhang Haibin Xu Xuesong Zhang Jingkai Wang Qixin Chen Chengzhen Liang 《Neural Regeneration Research》 SCIE CAS 2025年第4期1042-1057,共16页
Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness ... Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they cause.Despite the ongoing development of various therapies for spinal cord injuries,their effectiveness remains unsatisfactory.However,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming.In this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic reprogramming.Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling.However,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial dysfunction.These metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of microglia.To rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell fate.The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury.To further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions. 展开更多
关键词 AXONS GLYCOLYSIS metabolic reprogramming metabolism mitochondria neural regeneration NEUROPROTECTION oxidative phosphorylation spinal cord injury therapy
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What factors control plant height?
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作者 Li Miao Xiangyu Wang +3 位作者 chao yu Chengyang Ye Yanyan Yan Huasen Wang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期1803-1824,共22页
Plant height(PH)is one of the most important components of the plant ideotype,and it affects plant biomass,yield,lodging resistance,and the ability to use mechanized harvesting.Since many complex pathways controlling ... Plant height(PH)is one of the most important components of the plant ideotype,and it affects plant biomass,yield,lodging resistance,and the ability to use mechanized harvesting.Since many complex pathways controlling plant growth and development remain poorly understood,we are still unable to obtain the most ideal plants solely through breeding efforts.PH can be influenced by genotype,plant hormonal regulation,environmental conditions,and interactions with other plants.Here,we comprehensively review the factors influencing PH,including the regulation of PH-related developmental processes,the genetics and QTLs contributing to PH,and the hormone-regulated molecular mechanisms for PH.Additionally,the symbiotic influence of grafting on PH is discussed,focusing on the molecular regulation of gene expression and genetics.Finally,we propose strategies for applying recent findings to breeding for better PH,highlight some knowledge gaps,and suggest potential directions for future studies. 展开更多
关键词 DWARFISM plant hormones interaction GRAFTING QTLS PHENOTYPING
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Experimental observations on the nonproportional multiaxial ratchetting of cast AZ91 magnesium alloy at room temperature
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作者 Binghui Hu yu Lei +3 位作者 Hang Li Ziyi Wang chao yu Guozheng Kang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1115-1125,共11页
The nonproportional multiaxial ratchetting of cast AZ91 magnesium (Mg) alloy was examined by performing a sequence of axial-torsional cyclic tests controlled by stress with various loading paths at room temperature (R... The nonproportional multiaxial ratchetting of cast AZ91 magnesium (Mg) alloy was examined by performing a sequence of axial-torsional cyclic tests controlled by stress with various loading paths at room temperature (RT).The evolutionary characteristics and path dependence of multiaxial ratchetting were discussed.Results illustrate that the cast AZ91 Mg alloy exhibits considerable nonproportional additional softening during cyclic loading with multiple nonproportional multiaxial loading paths;multiaxial ratchetting presents strong path dependence,and axial ratchetting strains are larger under nonproportional loading paths than under uniaxial and proportional45°linear loading paths;multiaxial ratchetting becomes increasingly pronounced as the applied stress amplitude and axial mean stress increase.Moreover,stress-strain curves show a convex and symmetrical shape in axial/torsional directions.Multiaxial ratchetting exhibits quasi-shakedown after certain loading cycles.The abundant experimental data obtained in this work can be used to develop a cyclic plasticity model of cast Mg alloys. 展开更多
关键词 cast magnesium alloy RATCHETTING multiaxial loading loading path stress level
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River width and depth as key factors of diurnal activity energy expenditure allocation for wintering Spot-billed Ducks in the Xin'an River Basin
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作者 chao yu Xuying Lu +3 位作者 Deli Sun Mengnan Chu Xueyun Li Qun Li 《Avian Research》 SCIE CSCD 2024年第1期116-122,共7页
Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and en... Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and energy expenditure allocation of diurnal behavior.The compensatory foraging hypothesis predicts that increased energy expenditure leads to longer foraging time,which in turn increases food intake and helps maintain a constant energy balance.However,it is unclear whether human-disturbed habitats result in increased energy expenditure related to safety or foraging.In this study,the scan sample method was used to observe the diurnal behavior of the wintering Spot-billed Duck(Anas poecilorhyncha) in two rivers in the Xin’an River Basin from October 2021 to March 2022.The allocation of time and energy expenditure for activity in both normal and disturbed environments was calculated.The results showed that foraging accounted for the highest percentage of time and energy expenditure.Additionally,foraging decreased in the disturbed environment than that in the normal environment.Resting behavior showed the opposite trend,while other behaviors were similar in both environments.The total diurnal energy expenditure of ducks in the disturbed environment was greater than that in the normal environment,with decreased foraging and resting time percentage and increased behaviors related to immediate safety(swimming and alert) and comfort.These results oppose the compensatory foraging hypothesis in favor of increased security.The optimal diurnal energy expenditure model included river width and water depth,which had a positive relationship;an increase in either of these two factors resulted in an increase in energy expenditure.This study provides a better understanding of energy allocation strategies underlying the superficial time allocation of wintering waterbirds according to environmental conditions.Exploring these changes can help understand the maximum fitness of wintering waterbirds in response to nature and human influences. 展开更多
关键词 Diurnal behavior activities River factors Time and energy expenditure allocation Wintering Spot-billed Duck Xin’an River Basin
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Tunable dispersion relations manipulated by strain in skyrmion-based magnonic crystals
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作者 金兆年 何宣霖 +3 位作者 于超 方贺男 陈琳 陶志阔 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期692-696,共5页
We theoretically investigate the propagation characteristics of spin waves in skyrmion-based magnonic crystals. It is found that the dispersion relation can be manipulated by strains through magneto-elastic coupling. ... We theoretically investigate the propagation characteristics of spin waves in skyrmion-based magnonic crystals. It is found that the dispersion relation can be manipulated by strains through magneto-elastic coupling. Especially, the allowed bands and forbidden bands in dispersion relations shift to higher frequency with strain changing from compressive to tensile,while shifting to lower frequency with strain changing from tensile to compressive. We also confirm that the spin wave with specific frequency can pass the magnonic crystal or be blocked by tuning the strains. The result provides an advanced platform for studying the tunable skyrmion-based spin wave devices. 展开更多
关键词 SKYRMION magnonic crystal spin wave dispersion relation
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Hemoglobin loss method calculates blood loss during pancreaticoduodenectomy and predicts bleeding-related risk factors
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作者 chao yu Yi-Min Lin Guo-Zhe Xian 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第2期419-428,共10页
BACKGROUND The common clinical method to evaluate blood loss during pancreaticoduoden-ectomy(PD)is visual inspection,but most scholars believe that this method is extremely subjective and inaccurate.Currently,there is... BACKGROUND The common clinical method to evaluate blood loss during pancreaticoduoden-ectomy(PD)is visual inspection,but most scholars believe that this method is extremely subjective and inaccurate.Currently,there is no accurate,objective me-thod to evaluate the amount of blood loss in PD patients.We retrospectively analyzed the clinical data of 341 patients who underwent PD in Shandong Provincial Hospital from March 2017 to February 2019.According to different surgical methods,they were divided into an open PD(OPD)group and a laparoscopic PD(LPD)group.The differences and correlations between the in-traoperative estimation of blood loss(IEBL)obtained by visual inspection and the intraoperative calculation of blood loss(ICBL)obtained using the Hb loss method were analyzed.ICBL,IEBL and perioperative calculation of blood loss(PCBL)were compared between the two groups,and single-factor regression analysis was performed.RESULTS There was no statistically significant difference in the preoperative general patient information between the two groups(P>0.05).PD had an ICBL of 743.2(393.0,1173.1)mL and an IEBL of 100.0(50.0,300.0)mL(P<0.001).There was also a certain correlation between the two(r=0.312,P<0.001).Single-factor analysis of ICBL showed that a history of diabetes[95%confidence interval(CI):53.82-549.62;P=0.017]was an independent risk factor for ICBL.In addition,the single-factor analysis of PCBL showed that body mass index(BMI)(95%CI:0.62-76.75;P=0.046)and preoperative total bilirubin>200μmol/L(95%CI:7.09-644.26;P=0.045)were independent risk factors for PCBL.The ICBLs of the LPD group and OPD group were 767.7(435.4,1249.0)mL and 663.8(347.7,1138.2)mL,respectively(P>0.05).The IEBL of the LPD group 200.0(50.0,200.0)mL was slightly greater than that of the OPD group 100.0(50.0,300.0)mL(P>0.05).PCBL was greater in the LPD group than the OPD group[1061.6(612.3,1632.3)mL vs 806.1(375.9,1347.6)mL](P<0.05).CONCLUSION The ICBL in patients who underwent PD was greater than the IEBL,but there is a certain correlation between the two.The Hb loss method can be used to evaluate intraoperative blood loss.A history of diabetes,preoperative bilirubin>200μmol/L and high BMI increase the patient's risk of bleeding. 展开更多
关键词 PANCREATICODUODENECTOMY Hemoglobin loss Calculated blood loss Estimated blood loss
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高铁客站站区一体化建设策略研究与实践
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作者 杨斌 晁宇 张智允 《铁路技术创新》 2024年第4期24-28,共5页
高铁客站站区一体化强调站内与周边区域的整体协调,也为高铁客站的未来发展提供了广阔空间和无限可能。以黄山西站和九华山站站区为例,分析现有建设管理模式下,高铁客站站区规划和管理存在的难点,分析站区一体化管理模式相较于传统管理... 高铁客站站区一体化强调站内与周边区域的整体协调,也为高铁客站的未来发展提供了广阔空间和无限可能。以黄山西站和九华山站站区为例,分析现有建设管理模式下,高铁客站站区规划和管理存在的难点,分析站区一体化管理模式相较于传统管理模式,在土地资源、人力资源和效率提升方面的优势,从站区房屋功能整合、建筑形态一体化、景观设计一体化等方面提出站区一体化建设策略,提升高铁站房工程建设品质。研究成果可为高铁客站站区一体化工程建设提供参考。 展开更多
关键词 高铁客站 站区一体化 黄山西站 九华山站 建筑形态一体化 景观设计一体化
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亲代斑马鱼暴露于BPA及其类似物对子代胚胎发育毒性的研究
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作者 晁昱 刘昱辰 +2 位作者 曾丽雯 邵琪 宋肖垚 《环境卫生学杂志》 2024年第6期459-467,共9页
目的探讨亲代斑马鱼持续暴露于双酚A(bisphenol A,BPA)及其类似物,对子代斑马鱼发育情况、行为学特征和生物钟基因表达水平的影响。方法将70条4月龄雌性斑马鱼随机分为7组(对照组、BPA、BPS和BPF浓度分别设定为0.1以及10.0μg/L暴露组)... 目的探讨亲代斑马鱼持续暴露于双酚A(bisphenol A,BPA)及其类似物,对子代斑马鱼发育情况、行为学特征和生物钟基因表达水平的影响。方法将70条4月龄雌性斑马鱼随机分为7组(对照组、BPA、BPS和BPF浓度分别设定为0.1以及10.0μg/L暴露组),连续染毒28 d后,收集鱼卵,分析计算其子代幼鱼的死亡率、孵化率和畸形率的变化;利用体视显微镜拍摄并测量受精后72小时(hour post fertilization,hpf)幼鱼的眼睛尺寸、眼间距、体长、心率和相对血流量以及96 hpf活性氧水平;利用Zebrabox斑马鱼行为追踪分析仪记录斑马鱼幼鱼行为学活动;qPCR分析钟基因的表达水平。结果BPA、BPS和BPF暴露28 d后,与对照组相比,各染毒组的死亡率上升(P<0.05),孵化率、心率、相对血流量均降低(P<0.05),自发运动的振幅下降(P<0.05),活性氧含量及钟基因的表达水平都有所扰动。结论亲代斑马鱼暴露于BPA及其类似物可能通过钟基因的改变导致子代斑马鱼的发育异常。 展开更多
关键词 双酚A(BPA) 双酚A类似物 斑马鱼 生物钟 发育毒性
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Wide-field aurora imager onboard Fengyun satellite:Data products and validation 被引量:1
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作者 GuangXing Ding JiaWei Li +12 位作者 XiaoXin Zhang Fei He LingPing He KeFei Song Liang Sun Shuang Dai ShiJie Liu Bo Chen chao yu XiuQing Hu SongYan Gu ZhongDong Yang Peng Zhang 《Earth and Planetary Physics》 CSCD 2021年第1期73-78,共6页
New observations of auroras based on the wide-field aurora imager(WAI)onboard Fengyun-3D(FY-3D)satellite are exhibited in this paper.Validity of the WAI data is analyzed by comparing auroral boundaries derived from WA... New observations of auroras based on the wide-field aurora imager(WAI)onboard Fengyun-3D(FY-3D)satellite are exhibited in this paper.Validity of the WAI data is analyzed by comparing auroral boundaries derived from WAI observations with results obtained from data collected by the Special Sensor Ultraviolet Spectrographic Imager(SSUSI)aboard the Defense Meteorological Satellite Program(DMSP F18).Dynamic variations of the aurora with the solar wind,interplanetary magnetic field(IMF)parameters,and the SYM-H index are also investigated.The comparison of auroral boundaries indicates that the WAI data are morphologically valid and suitable to the study of auroral dynamics.Effective responses to solar wind parameters indicate that the WAI data can be useful to monitor and predict the Earth’s space weather.Since the configuration of aurora is a good indicator of the solar wind–magnetosphere–ionosphere(SW-M-I)coupling system,and can reflect the disturbance of the space environment,the WAI will provide important data to help us to study the physical processes in space. 展开更多
关键词 WAI FY-3D auroral dynamics SSUSI SW-M-I
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肩锁韧带三束重建技术在急性肩锁关节脱位肩关节镜手术中的应用效果 被引量:1
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作者 郭书章 李文高 +2 位作者 王文斌 钞愈 宋霞 《中国急救复苏与灾害医学杂志》 2023年第4期522-525,535,共5页
目的探讨肩锁韧带三束重建技术在急性肩锁关节脱位(ACJD)肩关节镜手术中的应用价值。方法回顾性分析2018年11月—2020年11月陕西省中医医院113例ACJD患者临床资料,根据手术方案分为钢板组(n=56)和重建组(n=57),分别行关节镜下锁骨钩钢... 目的探讨肩锁韧带三束重建技术在急性肩锁关节脱位(ACJD)肩关节镜手术中的应用价值。方法回顾性分析2018年11月—2020年11月陕西省中医医院113例ACJD患者临床资料,根据手术方案分为钢板组(n=56)和重建组(n=57),分别行关节镜下锁骨钩钢板固定术、关节镜下肩锁韧带三束重建技术。统计两组手术相关指标[手术时间、出血量、住院时间、喙突上平面与上锁骨下平面垂直距离(CC-Dist)值改善率]、并发症,比较手术前后创伤程度[皮质醇(COR)、促肾上腺皮质激素(ACTH)、去甲肾上腺素(NE)]、美国加州大学肩关节评分(UCLA)、喙突至锁骨距离(CCD)、肩峰至外侧锁骨距离(ACD)、视觉模拟评分法(VAS)。结果①两组手术时间、住院时间、CC-Dist值改善率比较,差异无统计学意义(P>0.05),重建组出血量少于钢板组(P<0.05);②术后3 d、5 d重建组COR、ACTH、NE水平低于钢板组(P<0.05);③术后3个月重建组UCLA评分高于钢板组,CCD、ACD小于钢板组(P<0.05);④术后1个月、3个月重建组VAS评分低于钢板组(P<0.05);⑤重建组并发症发生率5.26%与钢板组14.28%比较,差异无统计学意义(P>0.05);⑥术后3个月,重建组手术优良率91.23%高于钢板组(75.00%,P<0.05)。结论肩锁韧带三束重建技术应用于ACJD肩关节镜手术,有利于减少出血量,缓解疼痛,改善肩关节功能,提高手术效果,且创伤较小。 展开更多
关键词 急性肩锁关节脱位 肩关节镜手术 锁骨钩钢板 肩锁韧带三束重建技术 CC-Dist值改善率 关节功能
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Flexible nest site selection of the endangered Oriental Storks(Ciconia boyciana):Trade-off from adaptive strategies 被引量:2
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作者 Lei Cheng Lizhi Zhou +2 位作者 chao yu Zhenhua Wei Chunhua Li 《Avian Research》 SCIE CSCD 2023年第2期242-249,共8页
Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selectio... Nest site selection is a vital component of bird reproduction success,and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances.Understanding patterns of nest site selection can provide insights into how species adapt to changes in their habitat and has important conservation implications.In this study,we used microhabitat variables and multi-scale data with a field survey of nest occurrence to determine nest site selection patterns and adaptive strategies of the breeding Oriental Storks(Ciconia boyciana)in different nest areas.Results demonstrate that the nest site microhabitat characteristics of the breeding Oriental Storks significantly differed among the three nesting areas,and nest height was higher in the middle and lower Yangtze River floodplain than in the Northeast China and Bohai Bay nest areas.The food resources and intensity of human disturbance had the greatest effects on the nest site selection of the breeding Oriental Storks.The intensity of human disturbance was positively correlated with the nest height of the breeding Oriental Storks in Bohai Bay and the middle and lower Yangtze River floodplain;however,nest height decreased with the abundance of food resources in the Northeast China nest area.Our findings indicate that the nest site selection patterns of Oriental Storks showed flexible adaptive strategies.In safer environments,nests were lower and closer to food resources,which allows parent storks to invest more in the nestlings.However,in areas where human activity was intense,nests were higher to ensure the safety of their offspring.Some measures that could be taken to improve the breeding habitat of Oriental Storks include increasing the percentage of wetland areas in nesting areas to enhance food resources availability and setting artificial nests at suitable heights in potential nesting grounds to encourage nesting.Finally,the establishment of soft barriers around the nesting areas could increase the safety of nests. 展开更多
关键词 Adaptive strategies Breeding range expansion Habitat characteristics Nest site selection Oriental storks
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Generation and Evolution of Cavitation Bubbles in Volume Alternate Cavitation(VAC)
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作者 Shangshuang Chen yun Wang +4 位作者 Fuzhu Li Shenwei Xue Zhenying Xu chao yu Kun Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期241-251,共11页
Cavitation generation methods have been used in multifarious directions because of their diversity,and numerous studies and discussions have been conducted on cavitation generation methods.This study aims to explore t... Cavitation generation methods have been used in multifarious directions because of their diversity,and numerous studies and discussions have been conducted on cavitation generation methods.This study aims to explore the generating mechanism and evolution law of volume alternate cavitation(VAC).In the VAC,liquid water is placed in an airtight container with a variable volume.As the volume alternately changes,the liquid water inside the container continues to cavitate.Then,the mixture turbulence model and in-cylinder dynamic grid model are adopted to conduct computational fluid dynamics simulation of volume alternate cavitation.In the simulation,the cloud images at seven heights on the central axis are monitored,and the phenomenon and mechanism of height and eccentricity are analyzed in detail.By employing the cavitation flow visualization method,the generating mechanism and evolution law of cavitation are revealed.The synergistic effects of experiments and high-speed camera capturing confirm the correctness of the simulation results.In the experiment,the volume change stroke of the airtight container is set to 20 mm,the volume change frequency is 18 Hz,and the shooting frequency of the high-speed camera is set to 10000 FPS.The experimental results indicate that the position of the cavitation phenomenon has a reasonable law during the whole evolution cycle of the cavitation cloud.Also,the volume alternation cycle corresponds to the generation,development,and collapse stages of cavitation bubbles. 展开更多
关键词 Cavitation generation method Volume alternate cavitation(VAC) Generating mechanism Evolution law Computational fluid dynamics(CFD) Cavitation flow visualization(CFV)
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Combining unscented Kalman filter and wavelet neural network for anti-slug
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作者 Chuan Wang Long Chen +7 位作者 Lei Li Yong-Hong Yan Juan Sun chao yu Xin Deng Chun-Ping Liang Xue-Liang Zhang Wei-Ming Peng 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3752-3765,共14页
The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the com... The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the complexity of production makes it difficult to measure the pressure of subsea pipelines, and measured values are not always accessible in real-time. The research introduces a technique for integrating Unscented Kalman Filter (UKF) and Wavelet Neural Network (WNN) to estimate the state of subsea pipeline pressure using historical data and a state model. The proposed method treats multiphase flow transport as a nonlinear model, with a dynamic WNN serving as the state observer. To achieve real-time state estimation, the WNN is included into the UKF algorithm to create a WNN-based UKF state equation. Integrate WNN and UKF in a novel way to predict system state accurately. The simulated results show that the approach can efficiently predict the inlet pressure and manage the slug flow in real-time using the riser's top pressure, outlet flow and valve opening. This method of estimate can significantly increase the control effect. 展开更多
关键词 State estimation Stable control Method fusion Wavelet neural network Unscented Kalman filter
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Fourier neural operator with boundary conditions for efficient prediction of steady airfoil flows
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作者 yuanjun DAI Yiran AN +2 位作者 Zhi LI Jihua ZHANG chao yu 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第11期2019-2038,共20页
An efficient data-driven approach for predicting steady airfoil flows is proposed based on the Fourier neural operator(FNO),which is a new framework of neural networks.Theoretical reasons and experimental results are ... An efficient data-driven approach for predicting steady airfoil flows is proposed based on the Fourier neural operator(FNO),which is a new framework of neural networks.Theoretical reasons and experimental results are provided to support the necessity and effectiveness of the improvements made to the FNO,which involve using an additional branch neural operator to approximate the contribution of boundary conditions to steady solutions.The proposed approach runs several orders of magnitude faster than the traditional numerical methods.The predictions for flows around airfoils and ellipses demonstrate the superior accuracy and impressive speed of this novel approach.Furthermore,the property of zero-shot super-resolution enables the proposed approach to overcome the limitations of predicting airfoil flows with Cartesian grids,thereby improving the accuracy in the near-wall region.There is no doubt that the unprecedented speed and accuracy in forecasting steady airfoil flows have massive benefits for airfoil design and optimization. 展开更多
关键词 deep learning(DL) Fourier neural operator(FNO) steady airfoil flow
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Chinese herbal medicine combined with cognitive–behavioural therapy for avoidant paruresis:a controlled trial
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作者 Shijie Liang Ying Zhou +10 位作者 chao yu Xiang Gao Fangbin Ji Qianyuan Fang Zhihang Zhang Libin Yang Youkang Zhao yuhui Zhao Renwu Yin Kaimin Chen Zheng Lu 《General Psychiatry》 CSCD 2023年第5期402-409,共8页
Background Avoidant paruresis is a common clinical condition in urology and psychosomatic medicine.However,it has limited treatment options that are safe and effective with few side effects.Aims Our study aimed to inv... Background Avoidant paruresis is a common clinical condition in urology and psychosomatic medicine.However,it has limited treatment options that are safe and effective with few side effects.Aims Our study aimed to investigate the effectiveness and safety of the Chinese herbal Yangxin Tongquan decoction combined with cognitive-behavioural therapy(CBT)for avoidant paruresis.Methods Sixty-eight patients with avoidant paruresis were divided into a treatment group(33 patients)and a control group(35 patients).The control group was assigned 10 weeks of CBT and systematic desensitisation.In addition to CBT and systematic desensitisation,the treatment group was given the Chinese herbal Yangxin Tongquan decoction during the 10-week study.The Shy Bladder Syndrome Scale(SBS)and the Self-rating Anxiety Scale(SAS)were administered before and after treatment to measure any change.Results The overall efficacy in the treatment group(n=30)was 80.0%vs 62.5%in the control group(n=33).Comparing pretreatment and post-treatment measures,both groups showed improvement in SBS scores and SAS scores(treatment group:t_((SBS))=8.397,p_((SBS))<0.001,t_((SAS))=8.216,p_((SAS))<0.001;control group:t_((SBS))=6.802,p_((SBS))<0.001,t_((SAS))=5.171,p_((SAS))<0.001).Moreover,both groups’SBS and SAS scores changed significantly over time(SBS scores:F_(time)=118.299,p<0.001;SAS scores:F_(time)=92.114,p<0.001).However,the treatment group performed better than the control group(SBS scores:F_(time*group)=5.709,p=0.020;SAS scores:F_(time*group)=7.235,p=0.009).Conclusions The Chinese herbal Yangxin Tongquan decoction combined with cognitive-behavioural psychotherapy positively affects the treatment of avoidant paruresis without significant adverse effects. 展开更多
关键词 HERBAL DECOCTION BEHAVIOUR
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液压系统脉动主动控制研究现状及展望
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作者 晁宇 杨波 +1 位作者 戚伟 李永涛 《机床与液压》 北大核心 2023年第12期188-194,共7页
液压系统的流量脉动会引起压力脉动,脉动过大会产生管道振动、辐射噪声、发热、元器件寿命缩短等不利影响,抑制流体脉动对液压系统的稳定性有着重要作用。相比于液压系统脉动的被动抑制,主动抑制能更好地在非线性变工况和定工况系统中... 液压系统的流量脉动会引起压力脉动,脉动过大会产生管道振动、辐射噪声、发热、元器件寿命缩短等不利影响,抑制流体脉动对液压系统的稳定性有着重要作用。相比于液压系统脉动的被动抑制,主动抑制能更好地在非线性变工况和定工况系统中抑制脉动。介绍液压系统流体脉动机制及危害,将主动抑制策略分为伺服作动筒控制、特制液压管路控制和液压阀控制三大类,分析其工作原理、控制特点及优缺点。总结和分析国内外液压系统脉动主动抑制方法的研究现状,最后对液压系统流体脉动主动抑制技术的发展前景和方向进行展望。 展开更多
关键词 液压系统 主动抑制 流体脉动 振动噪声 控制策略
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经内镜逆行胰胆管造影术与腹腔镜胆道手术在肝内外胆管结石治疗中的疗效评价 被引量:47
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作者 谷化剑 郭宇廷 +4 位作者 韩民 喻超 陈自力 潘耀振 孙诚谊 《中国内镜杂志》 北大核心 2017年第8期32-37,共6页
目的探讨经内镜逆行胰胆管造影术(ERCP)与腹腔镜胆道手术在肝内外胆管结石治疗中的疗效。方法对110例肝内胆管结石位于Ⅰ和Ⅱ级肝管与378例单纯胆总管结石患者行ERCP+内镜下十二指肠乳头括约肌切开术(EST)+经内镜鼻胆管引流术(ENBD),或... 目的探讨经内镜逆行胰胆管造影术(ERCP)与腹腔镜胆道手术在肝内外胆管结石治疗中的疗效。方法对110例肝内胆管结石位于Ⅰ和Ⅱ级肝管与378例单纯胆总管结石患者行ERCP+内镜下十二指肠乳头括约肌切开术(EST)+经内镜鼻胆管引流术(ENBD),或腹腔镜胆道探查取石术(LBDEL)联合激光碎石术,术中胆管一期缝合或放置T管,比较两种术式的围手术期并发症及术后恢复情况。结果 110例肝内胆管结石患者结石残余率为31.82%,其中ERCP组(51.06%)残余结石率高于LBDEL组(17.46%)(P<0.05),术后恢复LBDEL组优于ERCP组。378例单纯胆总管结石患者结石残余率为8.20%,其中ERCP组(3.68%)残余结石率低于LBDEL组(11.63%)(P<0.05);术后恢复情况两组差异无统计学意义(P>0.05)。术后并发症中LBDEL组胆漏与肺部感染发生率高于ERCP组;腹腔感染、急性胰腺炎、消化道出血及消化道穿孔方面ERCP组发生率高于LBDEL组。单纯胆总管结石患者ERCP治疗时出现2例消化道穿孔导致死亡。结论 LBDEL和ERCP治疗胆总管结石具有相同的临床疗效,但在肝内胆管结石治疗中ERCP优势不明显,术后并发症发生率高。LBDEL治疗肝内外胆管结石疗效显著,可保持Oddi括约肌的完整性,该项技术易于普及到基层医院,令广大患者受益。 展开更多
关键词 肝内胆管结石 胆总管结石 经内镜逆行胰胆管造影术(ERCP) 十二指肠乳头括约肌切开术(EST) 腹腔镜胆道探查取石术
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大鲵皮胶原蛋白制备工艺优化及其抗氧化活性研究 被引量:10
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作者 杨碧仙 曹宇 +2 位作者 范琴芳 袁敏 李灿 《食品工业科技》 CAS 北大核心 2020年第5期195-200,共6页
选择大鲵皮中胶原蛋白得率为指标,研究适宜的有机酸浸提液种类和提取温度,并考察酸浓度、料液比和提取时间三个因素对胶原蛋白提取得率的影响。在单因素基础上,通过正交试验优化了大鲵皮胶原蛋白的提取工艺。并采用DPPH法与水杨酸法对... 选择大鲵皮中胶原蛋白得率为指标,研究适宜的有机酸浸提液种类和提取温度,并考察酸浓度、料液比和提取时间三个因素对胶原蛋白提取得率的影响。在单因素基础上,通过正交试验优化了大鲵皮胶原蛋白的提取工艺。并采用DPPH法与水杨酸法对大鲵皮中胶原蛋白进行抗氧化活性研究。结果表明,大鲵皮胶原蛋白的最佳提取条件为:盐酸浸提液浓度为0.4 mol/L、提取温度为35℃、料液比为1∶15 (g∶mL)、提取时间为24 h,在该条件下,大鲵皮胶原蛋白得率为40.2%。该条件下得到的胶原蛋白对DPPH自由基、羟基自由基的IC50值分别为9.96和7.79 mg/mL。研究显示,酸法浸提大鲵皮中胶原蛋白得率较高,且具有较好抗氧化活性,为大鲵皮的开发应用提供了理论依据。 展开更多
关键词 大鲵皮 胶原蛋白 正交试验 抗氧化活性
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