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Clinical effects of phospholipase D2 in attenuating acute pancreatitis
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作者 Jin-Wei Niu Guo-Chao Zhang +3 位作者 Wu Ning Hai-Bin Liu Hua Yang Chao-Feng Li 《World Journal of Gastroenterology》 SCIE CAS 2025年第2期52-60,共9页
BACKGROUND The objective of the current study was to elucidate the clinical mechanism through which phospholipase D2(PLD2)exerted a regulatory effect on neutrophil migra-tion,thereby alleviating the progression of acu... BACKGROUND The objective of the current study was to elucidate the clinical mechanism through which phospholipase D2(PLD2)exerted a regulatory effect on neutrophil migra-tion,thereby alleviating the progression of acute pancreatitis.AIM To elucidate the clinical mechanism through which PLD2 exerted a regulatory effect on neutrophil migration,thereby alleviating the progression of acute pan-creatitis.METHODS The study involved 90 patients diagnosed with acute pancreatitis,admitted to our hospital between March 2020 and November 2022.A retrospective analysis was conducted,categorizing patients based on Ranson score severity into mild(n=25),moderate(n=30),and severe(n=35)groups.Relevant data was collected for each group.Western blot analysis assessed PLD2 protein expression in patient serum.Real-time reverse transcription polymerase chain reaction was used to evaluate the mRNA expression of chemokine receptors associated with neutrophil migration.Serum levels of inflammatory factors in patients were detected using enzyme-linked immunosorbent assay.Transwell migration tests were conducted to compare migration of neutrophils across groups and analyze the influence of PLD2 on neutrophil migration.RESULTS Overall data analysis did not find significant differences between patient groups(P>0.05).The expression of PLD2 protein in the severe group was lower than that in the moderate and mild groups(P<0.05).The expression level of PLD2 in the moderate group was also lower than that in the mild group(P<0.05).The severity of acute pancreatitis is negatively correlated with PLD2 expression(r=-0.75,P=0.002).The mRNA levels of C-X-C chemokine receptor type 1,C-X-C chemokine receptor type 2,C-C chemokine receptor type 2,and C-C chemokine receptor type 5 in the severe group are significantly higher than those in the moderate and mild groups(P<0.05),and the expression levels in the moderate group are also higher than those in the mild group(P<0.05).The levels of C-reactive protein,tumor necrosis factor-α,interleukin-1β,and interleukin-6 in the severe group were higher than those in the moderate and mild groups(P<0.05),and the levels in the moderate group were also higher than those in the mild group(P<0.05).The number of migrating neutrophils in the severe group was higher than that in the moderate and mild groups(P<0.05),and the moderate group was also higher than the mild group(P<0.05).In addition,the number of migrating neutrophils in the mild group combined with PLD2 inhibitor was higher than that in the mild group(P<0.05),and the number of migrating neutrophils in the moderate group combined with PLD2 inhibitor was higher than that in the moderate group(P<0.05).The number of migrating neutrophils in the severe group+PLD2 inhibitor group was significantly higher than that in the severe group(P<0.05),indicating that PLD2 inhibitors significantly stimulated neutrophil migration.CONCLUSION PLD2 exerted a crucial regulatory role in the pathological progression of acute pancreatitis.Its protein expression varied among patients based on the severity of the disease,and a negative correlation existed between PLD2 expression and disease severity.Additionally,PLD2 appeared to impede acute pancreatitis progression by limiting neutrophil migration. 展开更多
关键词 Phospholipase d2 Neutrophil migration Acute pancreatitis Retrospective analysis Inflammatory response
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列车作用下D型便梁加固体系的动力响应分析
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作者 黄三能 牟阳之星 +2 位作者 牛云彬 苏谦 王迅 《路基工程》 2025年第1期30-36,共7页
以六盘水钢城大道下穿沪昆铁路框架桥工程为依托,建立车-轨-梁耦合系统模型,对普速列车限速45 km/h通过D型便梁进行动力计算。结果表明:车体的最大垂向加速度值为0.276 m/s^(2),满足梁上运行车体垂向加速度允许限值;D型便梁的垂向加速... 以六盘水钢城大道下穿沪昆铁路框架桥工程为依托,建立车-轨-梁耦合系统模型,对普速列车限速45 km/h通过D型便梁进行动力计算。结果表明:车体的最大垂向加速度值为0.276 m/s^(2),满足梁上运行车体垂向加速度允许限值;D型便梁的垂向加速度在列车轮对作用时达到峰值,便梁跨中与梁端的最大垂向加速度分别为1.370、0.310 m/s^(2),最大垂向位移分别为6.69、2.59 mm,均满足梁身规范允许要求;轨道在梁端与跨中位置的垂向加速度最大值分别为4.120、4.610 m/s^(2),垂向动位移最大值分别为7.03、2.53 mm,均在规范要求范围之内,处于安全状态。 展开更多
关键词 下穿铁路 d型便梁施工 动力响应 数值计算 车-轨-梁耦合 安全性
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PDAP患者RDW D-D miR-216a-5p与SIRI的关系及对预后的预测价值分析
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作者 熊雯 刘丽 +2 位作者 吴杨 岳平 章丽 《河北医学》 2025年第1期84-91,共8页
目的:分析腹膜透析相关性腹膜炎(PDAP)患者红细胞分布宽度(RDW)、D-二聚体(D-D)、微小核糖核酸-216a-5(miR-216a-5p)与基线全身炎症反应指数(SIRI)的相关性及其对预后的预测价值。方法:选定本院2020年1月至2024年1月就诊的180例PDAP患者... 目的:分析腹膜透析相关性腹膜炎(PDAP)患者红细胞分布宽度(RDW)、D-二聚体(D-D)、微小核糖核酸-216a-5(miR-216a-5p)与基线全身炎症反应指数(SIRI)的相关性及其对预后的预测价值。方法:选定本院2020年1月至2024年1月就诊的180例PDAP患者,根据患者短期预后将其分为预后不良组(n=42)、预后良好组(n=138),比较两组外周血RDW、D-D、miR-216a-5p、SIRI,Pearson分析外周血RDW、D-D、miR-216a-5p与SIRI的相关性,采用Logistic回归法分析PDAP患者预后的影响因素,受试者工作曲线(ROC)分析外周血RDW、D-D、miR-216a-5p、SIRI对PDAP患者预后的预测效能。结果:与预后良好组比较,预后不良组外周血RDW、D-D、SIRI显著增高,差异有统计学意义(t=15.958、29.928、22.490,均P<0.05)。与预后良好组比较,预后不良组外周血miR-216a-5p显著降低,差异有统计学意义(t=22.041,P<0.05)。外周血RDW、D-D与SIRI均呈正相关性(r=0.498、0.481,均P<0.05),miR-216a-5p与SIRI呈负相关性(r=-0.507,P<0.05)。Logistic回归显示,RDW[OR(95%CI):2.125(1.045~4.392)]、D-D[OR(95%CI):1.984(1.134~3.584)]、miR-216a-5p[OR(95%CI):3.924(1.399~5.267)]、SIRI[OR(95%CI):2.684(1.284~3.569)]、ALB[OR(95%CI):1.813(1.064~3.284)]、CRP[OR(95%CI):2.007(1.052~4.006)]是PDAP患者预后不良的危险因素(均P<0.05)。外周血RDW、D-D、miR-216a-5p、SIRI联合检测预测PDAP患者预后不良的曲线下面积(AUC)是0.870,95%CI可信区间是0.819~0.937,外周血RDW、D-D、miR-216a-5p、SIRI四项联合检测的AUC高于单项检测,差异有统计学意义(Z/P=2.812/0.008、2.605/0.014、2.411/0.010、2.701/0.017)。结论:PDAP患者外周血RDW、D-D、miR-216a-5p与SIRI存在一定的相关性,外周血RDW、D-D增高、miR-216a-5p降低与患者预后关系密切,联合检测外周血RDW、D-D、miR-216a-5p、SIRI对PDAP患者预后具有较高的预测效能。 展开更多
关键词 腹膜透析 腹膜炎 红细胞分布宽度 d-二聚体 微小核糖核酸-216a-5p 基线全身炎症反应指数 预后
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维生素D通过抑制NLRP3炎症小体的活化改善肾脏缺血再灌注损伤
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作者 王平 李辉 +1 位作者 谢枫 苑晓姣 《中国免疫学杂志》 CAS CSCD 北大核心 2024年第7期1381-1386,共6页
目的:探讨维生素D(VD)在肾脏缺血再灌注(I/R)损伤中的作用及相关机制。方法:将48只雄性C57BL/6J小鼠分为4组:假手术组(Sham组)、活性VD类似物阿法骨化醇处理组(VD组)、肾缺血再灌注损伤组(I/R组)、阿法骨化醇处理的I/R组(I/R+VD组)。I/... 目的:探讨维生素D(VD)在肾脏缺血再灌注(I/R)损伤中的作用及相关机制。方法:将48只雄性C57BL/6J小鼠分为4组:假手术组(Sham组)、活性VD类似物阿法骨化醇处理组(VD组)、肾缺血再灌注损伤组(I/R组)、阿法骨化醇处理的I/R组(I/R+VD组)。I/R损伤造模24 h后处死各组小鼠,收集外周血,检测血尿素氮(BUN)、血清肌酐(SCr)和炎症因子IL-1β、IL-18、肿瘤坏死因子-α(TNF-α)含量;收集各组小鼠肾组织,TUNEL染色法检测各组小鼠肾组织细胞凋亡水平,免疫组织化学检测肾组织中NOD样受体蛋白3(NLRP3)的表达阳性率;Western blot检测各组小鼠肾组织中NLRP3炎症小体相关因子NLRP3、GSDMD-N、cleaved Caspase-1及NF-κB p65、IκBα的蛋白表达水平。结果:与Sham组比较,VD组血清中BUN、SCr和IL-1β、IL-18及TNF-α水平差异无统计学意义(P>0.05),I/R组与I/R+VD组明显升高(P<0.05);与I/R组比较,I/R+VD组BUN、SCr和IL-1β、IL-18及TNF-α水平显著降低(P<0.05);与Sham组比较,VD组小鼠肾组织中TUNEL阳性率与NLRP3表达差异无统计学意义(P>0.05),I/R组与I/R+VD组明显升高(P<0.01),与I/R组比较,I/R+VD组的TUNEL阳性率与NLRP3表达均显著降低(P<0.05);Western blot检测结果显示,与Sham组相比,VD组小鼠肾组织中NLRP3、GSDMD-N、cleaved Caspase-1、IL-1β和NF-κB p65、IκBα的蛋白表达水平差异无统计学意义(P>0.05),I/R组与I/R+VD组除IκBα蛋白表达明显降低外(P<0.05),其他蛋白表达水平均明显升高(P<0.05);与I/R组比较,I/R+VD组中NLRP3、GSDMD-N、cleaved Caspase-1和IL-1β和NF-κB p65蛋白表达水平均明显降低(P<0.05),IκBα蛋白表达水平明显降低(P<0.05)。结论:VD可通过抑制NF-κB途径介导的NLRP3炎症小体激活,减轻I/R损伤的炎症反应,发挥肾脏保护作用。 展开更多
关键词 维生素d NLRP3炎症小体 肾脏缺血再灌注损伤 NF-ΚB信号通路 炎症反应
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一种高速A/D转换器时域重构技术研究
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作者 崔庆林 杨松 《微电子学》 CAS 北大核心 2024年第2期317-322,共6页
A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该... A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该方法对于示波器采样速度要求比较高。文章提出一种高速A/D转换器时域重构技术,可以通过计算机数字信号处理方法来实现高速A/D转换器时间参数测试,同时避免对示波器采样速度的依赖。同时,在研究高速A/D转换器时域重构技术方法及其应用的基础上,通过了相关试验验证。 展开更多
关键词 高速A/d转换器 时域重构 瞬态响应 过压恢复 缺陷分析 单粒子闭锁和翻转
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Vitamin D supplementation improves sustained virologic response in chronic hepatitis C (genotype 1)-nave patients 被引量:31
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作者 Saif Abu-Mouch Zvi Fireman +3 位作者 Jacob Jarchovsky Abdel-Rauf Zeina Nimer Assy Liver Unit 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第47期5184-5190,共7页
AIM: To determine whether adding vitamin D, a potent immunomodulator, improves the hepatitis C virus (HCV) response to antiviral therapy. METHODS: Seventy-two consecutive patients with chronic HCV genotype 1 were rand... AIM: To determine whether adding vitamin D, a potent immunomodulator, improves the hepatitis C virus (HCV) response to antiviral therapy. METHODS: Seventy-two consecutive patients with chronic HCV genotype 1 were randomized into two groups: the treatment group (n = 36, 50% male, mean age 47 ± 11 years) received Peg-α-2b interferon (1.5 μg/kg per week) plus ribavirin (1000-1200 mg/d) together with vitamin D3 (2000 IU/d, target serum level > 32 ng/mL), and the control group (n = 36, 60% male, mean age 49 ± 7 years) received identical therapy without vitamin D. HCV-RNA was assessed by realtime polymerase chain reaction (sensitivity, 10 IU/mL). The sustained virologic response (SVR) was defined as undetectable HCV-RNA at 24 wk post-treatment. RESULTS: Clinical characteristics were similar in both groups. The treatment group had a higher mean bodymass index (27 ± 4 kg/m2 vs 24 ± 3 kg/m2, P < 0.01), viral load (50% vs 42%, P < 0.01), and fibrosis score (> F2: 42% vs 19%, P < 0.001) than the controls. At week 4, 16 (44%) treated patients and 6 (17%) controls were HCV-RNA negative (P < 0.001). At week 12, 34 (94%) treated patients and 17 (48%) controls were HCV-RNA negative (P < 0.001). At 24 wk post-treatment (SVR), 31 (86%) treated patients and 15 (42%) controls were HCV-RNA negative (P < 0.001). Viral load, advanced fibrosis and vitamin D supplementation were strongly and independently associated with SVR (multivariate analysis). Adverse events were mild and typical of Peg-α-2b/ribavirin. CONCLUSION: Adding vitamin D to conventional Peg-α-2b/ribavirin therapy for treatment-na■ve patients with chronic HCV genotype 1 infection significantly improves the viral response. 展开更多
关键词 Hepatitis C Vitamin d Sustained viral response Genotype 1 FIBROSIS
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Vitamin D status and viral response to therapy in hepatitis C infected children 被引量:3
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作者 Azza A Eltayeb Madleen Adel A Abdou +1 位作者 Amal M Abdel-aal Mostafa H Othman 《World Journal of Gastroenterology》 SCIE CAS 2015年第4期1284-1291,共8页
AIM: To study the frequency of vitamin D deficiency in patients with hepatitis C virus(HCV) infection and to evaluate the role of vitamin D supplementation in improving antiviral therapy.METHODS: Sixty-six children ag... AIM: To study the frequency of vitamin D deficiency in patients with hepatitis C virus(HCV) infection and to evaluate the role of vitamin D supplementation in improving antiviral therapy.METHODS: Sixty-six children aged from 7-14 years(mean ± SD, 11.17 ± 2.293) diagnosed with HCV infection were matched to 28 healthy controls. Serum levels of 25(OH) D3, calcium, phosphorus, alkaline phosphatase and plasma level of parathormone were measured. Quantitative PCR for HCV was performed Bone density was determined by dual energy X-ray absorptiometry. All cases received conventional therapy, and only 33 patients received vitamin D supplementation.RESULTS: Children with HCV showed significantly increased levels of HCV RNA(P < 0.001), parathormone(P < 0.01) and decreased vitamin D levels(P < 0.05)(33.3% deficient and 43.3% insufficient) compared with controls. Abnormal bone status(Z score-1.98 ± 0.75) was found in ribs, L-spine, pelvis and total body. Cases treated with vitamin D showed significant higher early(P < 0.04) and sustained(P < 0.05) virological response. There was a high frequency of vitamin D deficiency among the Egyptian HCV children, with significant decrease in bone density. The vitamin D level should be assessed before the start of antiviral treatment with the correction of any detected deficiency. CONCLUSION: Adding vitamin D to conventional Peg/RBV therapy significantly improved the virological response and helped to prevent the risk of emerging bone fragility. 展开更多
关键词 VITAMIN d VIRAL response HEPATITIS C CHILdREN
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Vitamin D improves viral response in hepatitis C genotype 2-3 nave patients 被引量:25
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作者 Assy Nimer Abu Mouch 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第8期800-805,共6页
AIM: To examine whether vitamin D improved viral response and predicted treatment outcome in patients with hepatitis C virus (HCV) genotype 2-3. METHODS: Fifty patients with chronic HCV genotype 2-3 were randomized co... AIM: To examine whether vitamin D improved viral response and predicted treatment outcome in patients with hepatitis C virus (HCV) genotype 2-3. METHODS: Fifty patients with chronic HCV genotype 2-3 were randomized consecutively into two groups: Treatment group [20 subjects, age 48 ± 14 years, body mass index (BMI) 30 ± 6, 65% male], who received 180 μg pegylated α-interferon-2a plus oral ribavirin 800 mg/d (Peg/RBV), together with oral vitamin D3 (Vitamidyne D drops; 2000 IU/d, 10 drops/d, normal serum level > 32 ng/mL) for 24 wk; and control group (30 subjects, age 45 ± 10 years, BMI 26 ± 3, 60% male), who received identical therapy without vitamin D. HCV RNA was assessed by reverse transcription polymerase chain reaction. Undetectable HCV RNA at 4, 12 and 24 wk after treatment was considered as rapid virological response, complete early virological response, and sustained virological response (SVR), respectively. Biomarkers of in? ammation were measured. RESULTS: The treatment group with vitamin D hadhigher BMI (30 ± 6 vs 26 ± 3, P < 0.02), and high viral load (> 400 000 IU/mL, 65% vs 40%, P < 0.01) than controls. Ninety-fi ve percent of treated patients were HCV RNA negative at week 4 and 12. At 24 wk after treatment (SVR), 19/20 (95%) treated patients and 23/30 (77%) controls were HCV RNA negative (P < 0.001). Baseline serum vitamin D levels were lower at baseline (20 ± 8 ng/mL) and increased after 12 wk vitamin D treatment, to a mean level of (34 ± 11 ng/ mL). Logistic regression analysis identifi ed vitamin D supplement [odds ratio (OR) 3.0, 95% CI 2.0-4.9, P < 0.001], serum vitamin D levels (< 15 or > 15 ng/mL, OR 2.2, P < 0.01), and BMI (< 30 or > 30, OR 2.6, P < 0.01) as independent predictors of viral response. Adverse events were mild and typical of Peg/RBV. CONCLUSION: Low vitamin D levels predicts negative treatment outcome, and adding vitamin D to conventional Peg/RBV therapy for patients with HCV genotype 2-3 signifi cantly improves viral response. 展开更多
关键词 Hepatitis C Genotype 2-3 Vitamin d Sus-tained viral response Peg-interferon alpha 2a
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Blast response of continuous-density graded cellular material based on the 3D Voronoi model 被引量:5
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作者 Xu-ke Lan Shun-shan Feng +1 位作者 Qi Huang Tong Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第5期433-440,共8页
One-dimensional blast response of continuous-density graded cellular rods was investigated theoretically and numerically. Analytical model based on the rigid-plastic hardening(R-PH) model was used to predict the blast... One-dimensional blast response of continuous-density graded cellular rods was investigated theoretically and numerically. Analytical model based on the rigid-plastic hardening(R-PH) model was used to predict the blast response of density-graded cellular rods. Finite element(FE) analysis was performed using a new model based on the 3 D Voronoi technique. The FE results have a good agreement with the analytical predictions. The blast response and energy absorption of cellular rods with the same mass but different density distributions were examined under different blast loading. As a blast resistance structure, cellular materials with high energy absorption and low impulse transmit is attractive. However, high energy absorption and low impulse transmit cannot be achieved at the same time by changing the density distribution. The energy absorption capacity increases with the initial blast pressure and characteristic time of the exponentially decaying blast loading. By contract, when the blast loading exceeds the resistance capacity of cellular material, the transmitted stress will be enhanced which is detrimental to the structure being protected. 展开更多
关键词 GRAdIENT BLAST response Cellular material 3d VORONOI MOdEL
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Study on the gamma rays and neutrons energy response optimization of a scintillating fiber detector for EAST with Geant4 被引量:3
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作者 Wei-Kun Chen Li-Qun Hu +4 位作者 Guo-Qiang Zhong Rui-Jie Zhou Bing Hong Qiang Li Li Yang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第9期40-49,共10页
A new scintillating fiber detector inside magnetic shielding tube was designed and assembled for use in the next round of fusion experiments in the experimental advanced superconducting tokamak to provide D–T neutron... A new scintillating fiber detector inside magnetic shielding tube was designed and assembled for use in the next round of fusion experiments in the experimental advanced superconducting tokamak to provide D–T neutron yield with time resolution.In this study,Geant4 simulations were used to obtain the pulse height spectra for ideal signals produced when detecting neutrons and gamma rays of multiple energies.One of the main sources of interference was found to be low-energy neutrons below 10–5 MeV,which can generate numerous secondary particles in the detector components,such as the magnetic shielding tube,leading to high-amplitude output signals.To address this issue,a compact thermal neutron shield containing a 1-mm Cd layer outside the magnetic shielding tube and a 5-mm inner Pb layer was specifically designed.Adverse effects on the measurement of fast neutrons and the shielding effect on gamma rays were considered.This can suppress the height of the signals caused by thermal neutrons to a level below the height corresponding to neutrons above 4 MeV because the yield of the latter is used for detector calibration.In addition,the detector has relatively flat sensitivity curves in the fast neutron region,with the intrinsic detection efficiencies(IDEs)of approximately 40%.For gamma rays with energies that are not too high(<8 MeV),the IDEs of the detector are only approximately 20%,whereas for gamma rays below 1 MeV,the response curve cuts off earlier in the low-energy region,which is beneficial for avoiding counting saturation and signal accumulation. 展开更多
关键词 Sci-Fi detector d–T fusion neutron Thermal neutron shield Energy response GEANT4
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Multi dimensional Seismic Response Analysis of Base Isolated Frame Structure with 3D Isolator 被引量:1
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作者 XiongShishu HuangLiting ChenJinfeng SuJingsu 《Journal of China University of Geosciences》 SCIE CSCD 2005年第1期66-71,78,共7页
The three dimensional lead rubber dish spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish spring bearing (DSB) with damper in series. The 3DB put forward in t... The three dimensional lead rubber dish spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi dimensional seismic responses of 3D base isolated frame structures are established. Taking a five storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper. 展开更多
关键词 d base isolator multi earthquake seismic responses lead rubber bearing dish spring bearing.
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Time-dependent lateral response of pile embedded in elasto-plastic soil 被引量:2
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作者 J.M.ABBAS Z.H.CHIK +1 位作者 M.R.TAHA Q.S.M.SHAFIQU 《Journal of Central South University》 SCIE EI CAS 2010年第2期372-380,共9页
A two-dimensional (2D) finite element analysis was carried out to assess the time-dependent behavior of single vertical pile embedded in elasto-plastic soil. The finite element analyses were carried out using the li... A two-dimensional (2D) finite element analysis was carried out to assess the time-dependent behavior of single vertical pile embedded in elasto-plastic soil. The finite element analyses were carried out using the linear elastic model for the structure of the pile, while the Mohr-Coulomb model was used for representing the soil behavior surrounding the pile. The study includes cohesionless and cohesive soil to assess the lateral response of pile in the two types of soil. The whole geoteehnical model is suitable for problem of piles to determine the design quantities such as lateral deformation, lateral soil stress and its variation with time. The model is verified based on the results of published cases and there is good comparison between the results of published ease and the present simulation model. It is found that, the pile in cohesionless soil has more resistance in the rapid loading and less one in the long term loading. On the other hand, the pile in cohesive soil shows opposite behavior. 展开更多
关键词 single pile consolidation effect lateral response soil pressure 2d finite element method
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一种双控制模式的同步降压型DC/DC转换器
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作者 李新 佟宇航 高从勇 《微处理机》 2024年第4期12-16,共5页
为突破转换器在输出电容选型上的局限性,保证转换器快速的负载瞬态响应,基于自适应恒定导通时间控制的两种控制模式,提出一种可根据输出电容类型选择控制模式的同步降压型DC/DC转换器。在D-CAP模式下,支持具有适当等效串联电阻的电容等... 为突破转换器在输出电容选型上的局限性,保证转换器快速的负载瞬态响应,基于自适应恒定导通时间控制的两种控制模式,提出一种可根据输出电容类型选择控制模式的同步降压型DC/DC转换器。在D-CAP模式下,支持具有适当等效串联电阻的电容等作为输出电容;在电流模式下,支持等效串联电阻较低的陶瓷电容作为输出电容。基于0.35μm BCD工艺,使用Cadence软件对转换器进行瞬态仿真。结果表明,该设计在两种模式下都具有快速的瞬态响应。 展开更多
关键词 自适应恒定导通时间控制 直接电容感应控制 快速瞬态响应
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Tail Waving Speed Affects Territorial Response in the Toad-headed Agama Phrynocephalus vlangalii 被引量:1
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作者 Xia QIU Jinzhong FU Yin QI 《Asian Herpetological Research》 SCIE CSCD 2018年第3期182-187,共6页
Territorial response affects a resident's access to resources and mates, but the response level is likely flexible
关键词 tail display territorial response 3d animation PLAYBACK Phrynocephalus vlangalii
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Research on Rapid Response Schematic Design for Flexible Transfer Line CAPP-Based
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作者 GAO Ju-hong 1, XU Yan-shen 2 (1. Department of Industrial Engineering, School of Management, Tianjin University, 2. Department of Mechanical Engineering, School of Management, Tianjin Univers ity, Tianjin 300072, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期174-175,共2页
To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp on... To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp onse schematic design CAPP-based, one of the key techniques, are presented in t his paper. In order to achieve this purpose, an integrated system for integrated design of CAD/CAPP/FTL with box-type parts is realized. In this paper, firstly the theory of the conceptual design of FTL based on CAPP is established and the software architecture is developed. The global-domain pr oduct model is put forward to meet with data representation. After the manufactu ring feature is analyzed and decomposed for machining operations, the feature-b ased part unified data model object-oriented is built. Secondly the knowledge- based CAPP system data model is established. The process planning unit model is formed by work element (WE), which is tool-cell based function abstraction meth od, and has unified layers with respect to designing and manufacturing. With WEs through dynamic response and simultaneous structure in process planning, the pr inciple solution for CAPP function system can be implemented. Lastly the mapping from process domain to module design domain is built. The unidirectional select ion process based on fuzzy matching technology is easily dealt with computer. Th e algorithm of decision with fuzzy synthetic evaluation method and technology is applied to estimate the feasibility of the results in local working procedure o f modular NC machine tools and make decision of designs in overall FTL, which co nsists of many different factors. The example shows that the rapid response desi gn in bidding-based FTL scheme design is realized. 展开更多
关键词 CAPP flexible transfer line product model rapi d response design
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Thre-dimensional topographic responses in MT using finite diference method
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作者 陈伯舫 候作中 范国华 《Acta Seismologica Sinica(English Edition)》 EI CSCD 1998年第5期111-115,共5页
In this paper, the magnetotelluric response to 3-D earth topography was studied using the finite difference method for rectangular cells. Three numerical modeling calculations were carried out; the results indicate th... In this paper, the magnetotelluric response to 3-D earth topography was studied using the finite difference method for rectangular cells. Three numerical modeling calculations were carried out; the results indicate that the finite difference method is applicable to the magnetotelluric problem in estimating the 3-D topographic responses. 展开更多
关键词 d finite difference method 3-d topographic response magnetotelluric method
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The Scaling Constant D in Item Response Theory
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作者 Gregory Camilli 《Open Journal of Statistics》 2017年第5期780-785,共6页
In item response theory (IRT), the scaling constant D = 1.7 is used to scale a discrimination coefficient a estimated with the logistic model to the normal metric. Empirical verification is provided that Savalei’s?[1... In item response theory (IRT), the scaling constant D = 1.7 is used to scale a discrimination coefficient a estimated with the logistic model to the normal metric. Empirical verification is provided that Savalei’s?[1] proposed a scaling constant of D = 1.749 based on Kullback-Leibler divergence appears to give the best empirical approximation. However, the understanding of this issue as one of the accuracy of the approximation is incorrect for two reasons. First, scaling does not affect the fit of the logistic model to the data. Second, the best scaling constant to the normal metric varies with item difficulty, and the constant D = 1.749 is best thought of as the average of scaling transformations across items. The reason why the traditional scaling with D = 1.7 is used is simply because it preserves historical interpretation of the metric of item discrimination parameters. 展开更多
关键词 ITEM response Theoru IRT SCALING CONSTANT d
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Application of D-Optimal Study Design with Contour Surface Response for Designing Sustained Release Gliclazide Matrix Tablets 被引量:1
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作者 Chien Nguyen John Mark Christensen Thuy Nguyen 《Pharmacology & Pharmacy》 2014年第7期620-635,共16页
An optimized formulation of a sustained release tablet of Gliclazide was developed. The use of Doptimal design with a polynomial statistical model to analyze dissolution data reduced the number of laboratory tests req... An optimized formulation of a sustained release tablet of Gliclazide was developed. The use of Doptimal design with a polynomial statistical model to analyze dissolution data reduced the number of laboratory tests required to obtain an optimal dosage form. The final formulation contained 22 mg of Methocel&regE15LV, 16.5 mg Methocel&regE15 and 10.0 mg of Dibasic Calcium Phosphate per 30 mg Gliclazide sustained release tablet. Dissolution studies performed on tablets from 5000 tablet test batches released greater than 90 percent of loaded drug in eight hours. Drug release from the optimized tablets followed a pattern more closely similar to zero-order than other mechanisms of drug release tested. Storage of tablets in accelerated and ambient conditions for 6 and 12 months respectively did not alter any of the physico-chemical properties, drug release or the drug release rate compared to initial observations and dissolution data of the prepared tablets. The addition of potassium phosphate and monosodium phosphate to the tablet reduced the effect pH has on Gliclazide dissolution compared to the commercially available product. 展开更多
关键词 GLICLAZIdE SUSTAINEd RELEASE d-Optimal Zero-Order response Surface Modified RELEASE
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Dynamic response analysis of liquefiable ground due to sinusoidal waves of different frequencies of shield construction
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作者 Wang Jingyue Ge Xinsheng +4 位作者 Sun Jingyuan Liu Yasheng Shang Zhuo Wang Zhiqiang Tian Maoguo 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期637-646,共10页
Vibration induced by shield construction can lead to liquefaction of saturated sand.Based on FLAC3D software,a numerical model of tunnel excavation is established and sinusoidal velocity loads with different frequenci... Vibration induced by shield construction can lead to liquefaction of saturated sand.Based on FLAC3D software,a numerical model of tunnel excavation is established and sinusoidal velocity loads with different frequencies are applied to the excavation face.The pattern of the excess pore pressure ratio with frequency,as well as the dynamic response of soil mass under different frequency loads before excavation,is analyzed.When the velocity sinusoidal wave acts on the excavation surface of the shield tunnel with a single sand layer,soil liquefaction occurs.However,the ranges and locations of soil liquefaction are different at different frequencies,which proves that the vibration frequency influences the liquefaction location of the stratum.For sand-clay composite strata with liquefiable layers,the influence of frequency on the liquefaction range is different from that of a single stratum.In the frequency range of 5-30 Hz,the liquefaction area and surface subsidence decrease with an increase in vibration frequency.The research results in this study can be used as a reference in engineering practice for tunneling liquefiable strata with a shield tunneling machine. 展开更多
关键词 shield tunnel liquefiable formation FLAC3d numerical simulation excess pore pressure ratio dynamic response analysis
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Hydrodynamic Response of A Fully Coupled TLP Hull-TTR System with Detailed Modeling of A Hydraulic Pneumatic Tensioner and Riser Joints
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作者 HAO Shuai YU Yang +2 位作者 YU Jian-xing YUAN Zhi-ming XU Li-xin 《China Ocean Engineering》 SCIE EI CSCD 2022年第3期451-463,共13页
Tension Leg Platform(TLP)in deepwater oil and gas field development usually consists of a hull,tendons,and top tension risers(TTRs).To maintain its top tension,each TTR is connected with a tensioner system to the hull... Tension Leg Platform(TLP)in deepwater oil and gas field development usually consists of a hull,tendons,and top tension risers(TTRs).To maintain its top tension,each TTR is connected with a tensioner system to the hull.Owing to the complicated configuration of the tensioners,the hull and TTRs form a strong coupled system.Traditionally,some simplified tensioner models are applied to analyze the TLP structures.There is a large discrepancy between their analysis results and the actual mechanism behaviors of a tensioner.It is very necessary to develop a more detailed tensioner model to consider the coupling effects between TLP and TTRs.In the present study,a fully coupled TLP hull-TTR system for hydrodynamic numerical simulation is established.A specific hydraulic pneumatic tensioner is modeled by considering 4 cylinders.The production TTR model is stacked up by specific riser joints.The simulation is also extended to analyze an array of TTRs.Different regular and irregular waves are considered.The behaviors of different cylinders are presented.The results show that it is important to consider the specific configurations of the tensioner and TTRs,which may lead to obviously different response behaviors,compared with those from a simplified model. 展开更多
关键词 top tension riser(TTR) fully coupled hull-tendon-TTR-tensioner model hydraulic pneumatic tensioner hydrodynamic response 3d potential flow theory
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