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A novel approach to visual image encryption:2D hyperchaos,variable Josephus,and 3D diffusion 被引量:1
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作者 Yan Hong Xinyan Duan +2 位作者 Jingming Su Zhaopan Wang Shihui Fang 《Chinese Physics B》 2025年第4期335-352,共18页
With the development of the Internet,image encryption technology has become critical for network security.Traditional methods often suffer from issues such as insufficient chaos,low randomness in key generation,and po... With the development of the Internet,image encryption technology has become critical for network security.Traditional methods often suffer from issues such as insufficient chaos,low randomness in key generation,and poor encryption efficiency.To enhance performance,this paper proposes a new encryption algorithm designed to optimize parallel processing and adapt to images of varying sizes and colors.The method begins by using SHA-384 to extract the hash value of the plaintext image,which is then processed to determine the chaotic system’s initial value and block size.The image is padded and divided into blocks for further processing.A novel two-dimensional infinite collapses hyperchaotic map(2DICHM)is employed to generate the intra-block scrambling sequence,while an improved variable Joseph traversal sequence is used for inter-block scrambling.After removing the padding,3D forward and backward shift diffusions,controlled by the 2D-ICHM sequences,are applied to the scrambled image,producing the ciphertext.Simulation results demonstrate that the proposed algorithm outperforms others in terms of entropy,anti-noise resilience,correlation coefficient,robustness,and encryption efficiency. 展开更多
关键词 SHA-384 two-dimensional infinite collapses hyperchaotic map(2D-ICHM) variable Joseph traversal 3D forward shift diffusion
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Neural network analysis for prediction of heat transfer of aqueous hybrid nanofluid flow in a variable porous space with varying film thickness over a stretched surface
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作者 Abeer S Alnahdi Taza Gul 《Chinese Physics B》 2025年第2期316-326,共11页
The high thermal conductivity of the nanoparticles in hybrid nanofluids results in enhanced thermal conductivity associated with their base fluids.Enhanced heat transfer is a result of this high thermal conductivity,w... The high thermal conductivity of the nanoparticles in hybrid nanofluids results in enhanced thermal conductivity associated with their base fluids.Enhanced heat transfer is a result of this high thermal conductivity,which has significant applications in heat exchangers and engineering devices.To optimize heat transfer,a liquid film of Cu and TiO_(2)hybrid nanofluid behind a stretching sheet in a variable porous medium is being considered due to its importance.The nature of the fluid is considered time-dependent and the thickness of the liquid film is measured variable adjustable with the variable porous space and favorable for the uniform flow of the liquid film.The solution of the problem is acquired using the homotopy analysis method HAM,and the artificial neural network ANN is applied to obtain detailed information in the form of error estimation and validations using the fitting curve analysis.HAM data is utilized to train the ANN in this study,which uses Cu and TiO_(2)hybrid nanofluids in a variable porous space for unsteady thin film flow,and it is used to train the ANN.The results indicate that Cu and TiO_(2)play a greater role in boosting the rate. 展开更多
关键词 thin film of Cu and TiO_(2)hybrid nanofluids variable porous space unsteady stretching sheet viscous dissipation heat transfer optimization artificial neural network
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Sentinel-2影像协同环境变量的土壤盐分估测研究
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作者 彭少聪 林楠 +1 位作者 麻玮玮 张中帅 《农业工程》 2026年第3期124-129,共6页
土壤盐渍化严重阻碍干旱地区的农业发展,威胁土地资源持续利用,有效开展土壤盐分变化监测对于实现农业可持续发展和维护生态环境稳定具有重要意义。以吉林省西部盐渍区土壤为研究对象,以2024年111个土壤实测数据和Sentinel-2遥感影像为... 土壤盐渍化严重阻碍干旱地区的农业发展,威胁土地资源持续利用,有效开展土壤盐分变化监测对于实现农业可持续发展和维护生态环境稳定具有重要意义。以吉林省西部盐渍区土壤为研究对象,以2024年111个土壤实测数据和Sentinel-2遥感影像为数据源,选取与土壤盐渍化密切相关的植被、地形、气候和地下水等因素作为环境变量。利用极端梯度提升决策树(XGBoost)评估光谱波段和环境变量的重要性并剔除冗余变量,采用高斯过程回归(GPR)、弹性网络回归(EN)和随机森林回归(RF)和XGBoost构建土壤盐分估测模型。结果表明,利用筛选后的光谱波段和环境变量(策略Ⅱ)构建的估测模型表现优异,决定系数(R^(2))0.80,均方根误差(RMSE)5.83 dS/m,相对分析误差(RPD)2.11。该研究结合环境变量与光谱信息,探讨其在土壤盐分累积过程中的作用,为土壤盐分预测提供依据。 展开更多
关键词 土壤盐渍化 环境变量 盐渍化制图 XGBoost Sentinel-2
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HRV与老年女性HFpEF合并T2DM患者MACE风险的相关性分析
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作者 刁振东 张利方 +3 位作者 耿凡琪 王燕 贾宏健 张雪娟 《中国动脉硬化杂志》 2026年第3期239-246,共8页
[目的]探讨心率变异性(HRV)与老年女性射血分数保留的心力衰竭(HFpEF)合并2型糖尿病(T2DM)患者主要不良心血管事件(MACE)发生风险之间的关系,评估HRV在该人群预后分层中的临床意义。[方法]采用回顾性队列研究。纳入2019年9月1日—2022年... [目的]探讨心率变异性(HRV)与老年女性射血分数保留的心力衰竭(HFpEF)合并2型糖尿病(T2DM)患者主要不良心血管事件(MACE)发生风险之间的关系,评估HRV在该人群预后分层中的临床意义。[方法]采用回顾性队列研究。纳入2019年9月1日—2022年9月1日在青岛大学附属医院住院的老年女性HFpEF合并T2DM患者103例。初诊时收集患者的临床资料,包括一般资料、实验室检查结果、超声心动图参数及24 h动态心电图HRV参数。随访1年,依据是否发生MACE,将患者分为观察组和对照组,比较两组的基线特征差异。将单因素分析中P<0.1的变量先采用LASSO回归筛选变量后进行多因素Cox回归分析,探讨MACE的独立影响因素;应用Kaplan-Meier法绘制生存函数曲线,并以Log-rank检验比较组间差异。[结果]与对照组相比,观察组的年龄较大,心房颤动史占比更高,N末端B型利钠肽原(NT-proBNP)、舒张早期二尖瓣口血流峰值速度/二尖瓣环舒张早期运动速度(E/e′)及左心房容积指数(LAVI)水平升高(均P<0.05),同时多项HRV指标[正常窦性心律R-R间期标准差(SDNN)、相邻窦性R-R间期差值的均方根(RMSSD)、相邻窦性R-R间期差值>50 ms的心搏数占总窦性心律的百分比(pNN50)、高频功率(HF)、低频功率(LF)及极低频功率(VLF)]均显著降低,且β受体拮抗剂、达格列净使用率较低(均P<0.05)。LASSO-Cox回归分析显示,NT-proBNP升高(HR=1.01,95%CI:1.00~1.01)、LAVI升高(HR=1.16,95%CI:1.04~1.30)及SDNN降低(HR=0.94,95%CI:0.91~0.98)与MACE风险增加相关,使用达格列净(HR=0.18,95%CI:0.07~0.45)为独立保护因素(均P<0.05)。根据SDNN中位数(82 ms)将患者分为低HRV组和高HRV组,Kaplan-Meier生存曲线分析表明,两组无MACE再入院生存率差异有统计学意义(P=0.0043)。[结论]HRV降低(尤其SDNN)与HFpEF合并T2DM患者MACE风险显著增加密切相关,可作为评估自主神经功能紊乱和预后风险的重要参考指标。 展开更多
关键词 心率变异性 射血分数保留的心力衰竭 2型糖尿病 主要不良心血管事件 自主神经功能
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Analysis of the Efficacy of Short-Term Intensive Continuous Subcutaneous Insulin Infusion (CSII) Combined with Ganagliflozin Proline Tablets in Elderly Patients with Type 2 Diabetes Mellitus
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作者 Hui Dai 《Journal of Clinical and Nursing Research》 2026年第2期286-291,共6页
Objective:To investigate the effects of switching to either Prandilin 25R monotherapy or Prandilin 25R combined with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion du... Objective:To investigate the effects of switching to either Prandilin 25R monotherapy or Prandilin 25R combined with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion during hospitalization in elderly patients with type 2 diabetes mellitus on glycemic control,glycometabolic indicators,and cardiovascular risk factors,and to evaluate the safety of the two regimens.Methods:A total of 78 elderly patients with type 2 diabetes mellitus admitted to our hospital from January 2025 to September 2025 were selected and randomly divided into a control group and an observation group,with 39 cases in each group.The control group received monotherapy with insulin lispro protamine recombinant injection(Prandilin 25R)after intensive continuous subcutaneous insulin infusion,while the observation group received Prandilin 25R combined with ganagliflozin proline tablets.Continuous glucose monitoring(CGM)was performed for 14 days during the intensive continuous subcutaneous insulin infusion therapy phase in the hospital,followed by routine fingertip blood glucose monitoring after 14 days.Glycemic control indicators,glycometabolic indicators,and the incidence of adverse reactions were compared between the two groups.Results:After treatment,the mean amplitude of glycemic excursions and the 24-hour blood glucose standard deviation were significantly lower in the observation group than in the control group,while the time spent within the target blood glucose range was significantly higher(p<0.05).The levels of glycated hemoglobin,fasting blood glucose,and 2-hour postprandial blood glucose were better in the observation group than in the control group;moreover,the body mass index,systolic blood pressure,and blood lipid levels improved more significantly in the observation group than in the control group(p<0.05).There was no statistically significant difference in the incidence of hypoglycemia between the two groups.Conclusion:Combination therapy with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion therapy can effectively improve glycemic variability in elderly patients with type 2 diabetes mellitus,with good safety.This suggests that ganagliflozin proline tablets have a hypoglycemic advantage in the combination regimen and possess high clinical promotional value. 展开更多
关键词 Type 2 diabetes mellitus Continuous subcutaneous insulin infusion Ganagliflozin proline tablets Glycemic variability
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大型压裂船电力系统关键技术研究
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作者 阮红军 谢珉 +1 位作者 杨帷鑫 章爱群 《西南石油大学学报(自然科学版)》 北大核心 2026年第1期157-165,共9页
针对传统压裂船采用独立柴油机驱动方案存在能耗高、噪音大、环境污染等问题,依托“海洋石油623”大型压裂船,开展了压裂系统与船舶电力推进系统一体化驱动的关键技术研究。研究中采用公共电站一体化驱动架构,交流6600 V配电系统设计为... 针对传统压裂船采用独立柴油机驱动方案存在能耗高、噪音大、环境污染等问题,依托“海洋石油623”大型压裂船,开展了压裂系统与船舶电力推进系统一体化驱动的关键技术研究。研究中采用公共电站一体化驱动架构,交流6600 V配电系统设计为闭环结构,通过5个冗余组构建公共电站,配置主保护与后备保护双重故障隔离机制,集成高级发电机保护系统(AGP)与表决机制;压裂泵采用24脉冲二极管整流变频器(DFE)驱动方案,利用三绕组变压器隔离压裂系统与船舶400 V系统,并采用源滤波器治理谐波超标问题。使电站得以灵活运行,燃油消耗得以优化,缩小了最大单一故障影响范围,隐性故障潜在危害得以有效管控,电网稳定性与可靠性大幅提升。该一体化解决方案突破了传统驱动模式的技术瓶颈,显著降低了能耗与污染物排放,推动海上压裂作业向节能高效、绿色环保方向发展。 展开更多
关键词 变频驱动 DP-2闭环 隐性故障 主保护 后备保护
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结合功能预测值与Variable Threshold检验法研究非同义SNP 被引量:2
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作者 闫璐颖 华琳 闫岩 《中国组织工程研究》 CAS CSCD 2012年第37期6961-6966,共6页
背景:目前,随着全基因组关联分析的开展,成千上万的SNP基因型测序已经使遗传流行病学的研究进入一个新的阶段。通常,识别疾病相关的遗传位点依赖于DNA序列的单个碱基改变,而其中的一些改变可能影响蛋白质的结构和功能。因此出现在编码... 背景:目前,随着全基因组关联分析的开展,成千上万的SNP基因型测序已经使遗传流行病学的研究进入一个新的阶段。通常,识别疾病相关的遗传位点依赖于DNA序列的单个碱基改变,而其中的一些改变可能影响蛋白质的结构和功能。因此出现在编码区域并导致氨基酸替代或插入的非同义SNP由于改变了氨基酸序列,更倾向于影响与复杂疾病易感性相关的蛋白质功能。目的:结合非同义SNP的功能预测分数和Variable Threshold(VT)检验提高复杂疾病易感基因识别的准确率。方法:文中首先对非同义SNP,计算它们的SIFT分数值和Polyphen-2分数值。然后筛选了35个疾病基因,对这些基因采用加权的VT检验进行分析,并与传统的关联分析进行了比较。结果与结论:结果显示结合了SNP功能预测分数的VT检验,检验效能要高于传统的关联分析,提高了风险基因识别的准确率。 展开更多
关键词 功能预测 variable THRESHOLD SNP SIFT分数 Polyphe-2分数
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经皮穴位电刺激降低腹腔镜胆囊切除术围术期心律失常风险并改善苏醒质量:基于抑制CO_(2)气腹复极异常的作用
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作者 田明德 高鸿 +5 位作者 种朋贵 宋庆迎 张乃心 丁瑜 杨波 杨家康 《针刺研究》 北大核心 2026年第3期374-380,共7页
目的:观察经皮穴位电刺激(TEAS)辅助麻醉对腹腔镜胆囊切除术(LC)围术期体表心电图复极指标及苏醒质量的影响。方法:将60例择期行LC的患者随机分为TEAS组(30例,剔除2例)和对照组(30例,剔除2例)。TEAS组在麻醉前开始刺激双侧内关和外关,... 目的:观察经皮穴位电刺激(TEAS)辅助麻醉对腹腔镜胆囊切除术(LC)围术期体表心电图复极指标及苏醒质量的影响。方法:将60例择期行LC的患者随机分为TEAS组(30例,剔除2例)和对照组(30例,剔除2例)。TEAS组在麻醉前开始刺激双侧内关和外关,疏密波,频率2 Hz/10 Hz,电流强度4~10 mA,持续至手术结束。分别于术前(t0)、麻醉后1 min(t1)、二氧化碳(CO_(2))气腹后1 min(t2)、CO_(2)气腹后30 min(t3),术后10 min(t4),使用心电工作站测定患者的QT间期离散度(QTD)、校正QT间期离散度(QTcD)、QT间期(QT)、校正QT间期(QTc)、低频归一化值[LF(norm)]、高频归一化值[HF(norm)]和低频/高频比值(LF/HF);监测患者平均动脉压(MAP)、心率(HR);记录患者苏醒时间和苏醒后1、6、24 h的视觉模拟量尺(VAS)评分。结果:与t0相比,对照组t2、t3、t4和TEAS组t2 QTD均增大(P<0.001,P<0.01,P<0.05),对照组t2、t3、t4 QTcD均增大(P<0.001,P<0.01,P<0.05)。与对照组相比,TEAS组t2、t3、t4 QTD和QTcD均降低(P<0.001,P<0.05,P<0.01);TEAS组t2、t3 HR均降低(P<0.05);TEAS组的术后苏醒时间显著降低(P<0.01);TEAS组苏醒后1 h VAS评分降低(P<0.05)。结论:TEAS辅助麻醉可有效降低LC患者CO_(2)气腹期间心律失常发生的风险。此外,TEAS辅助麻醉还可显著缩短LC患者的术后苏醒时间,降低苏醒早期的疼痛,具有潜在的临床应用价值。 展开更多
关键词 经皮穴位电刺激 腹腔镜胆囊切除术 CO_(2)气腹 QT间期离散度 心率变异性
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西格列汀联合硝苯地平与二甲双胍治疗对2型糖尿病合并高血压患者左心室质量指数、血管内皮功能及血压变异性的影响
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作者 程远 丁文凤 李园园 《中国合理用药探索》 2026年第1期84-90,共7页
目的:探讨2型糖尿病(T2DM)合并高血压患者应用西格列汀联合硝苯地平与二甲双胍治疗的临床效果。方法:前瞻性选取2023年4月~2024年7月某院接诊的90例T2DM合并高血压患者作为研究对象,采用随机数字表法分为对照组(硝苯地平控释片+盐酸二... 目的:探讨2型糖尿病(T2DM)合并高血压患者应用西格列汀联合硝苯地平与二甲双胍治疗的临床效果。方法:前瞻性选取2023年4月~2024年7月某院接诊的90例T2DM合并高血压患者作为研究对象,采用随机数字表法分为对照组(硝苯地平控释片+盐酸二甲双胍片)和观察组(磷酸西格列汀片联合硝苯地平控释片与盐酸二甲双胍片),每组45例。持续用药3个月后,对比两组患者24 h/日间/夜间血压变异性指标[舒张压变异性(DBPV)、收缩压变异性(SBPV)]、血管内皮功能指标[可溶性内皮糖蛋白(sEng)、内皮素(ET)]、左心室质量指数、胰岛素敏感性指标[空腹胰岛素(FINS)、空腹血糖(FPG)、稳态模型评估胰岛素抵抗指数(HOMA-IR)]、临床疗效以及不良反应发生情况。结果:治疗后,两组24 h DBPV、日间DBPV、夜间DBPV、24 h SBPV、日间SBPV、夜间SBPV、FINS、FPG、HOMA-IR、sEng及ET较治疗前均降低(P<0.05),且观察组24 h DBPV、24 h SBPV、日间SBPV、FINS、FPG及HOMA-IR均低于对照组(P<0.05);两组日间DBPV、夜间DBPV、夜间SBPV、sEng、ET及左心室质量指数比较均无统计学差异(P>0.05);观察组临床治疗总有效率(91.11%)高于对照组(75.56%,P<0.05);两组患者不良反应总发生率比较无统计学差异(P>0.05)。结论:西格列汀联合硝苯地平与二甲双胍治疗T2DM合并高血压患者有一定的疗效,能改善患者的血压变异性及胰岛素敏感性指标、血管内皮功能,且不会增加不良反应发生风险。 展开更多
关键词 2型糖尿病 高血压 西格列汀 硝苯地平 血压变异性
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高血压合并2型糖尿病患者心血管事件风险与血糖变异性关联的回顾性队列研究
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作者 徐廉 邓昭美 《糖尿病新世界》 2026年第1期51-54,68,共5页
目的探讨高血压合并2型糖尿病患者血糖变异性与心血管事件发生风险之间的关系。方法采用回顾性队列研究设计,选取2023年1月—2025年1月在贵州中医药大学第一附属医院就诊的120例高血压合并2型糖尿病患者的临床资料进行分析,随访时间为2... 目的探讨高血压合并2型糖尿病患者血糖变异性与心血管事件发生风险之间的关系。方法采用回顾性队列研究设计,选取2023年1月—2025年1月在贵州中医药大学第一附属医院就诊的120例高血压合并2型糖尿病患者的临床资料进行分析,随访时间为24个月。根据随访期间是否发生主要心血管不良事件(major adverse cardiovascular events,MACE)分为MACE组(32例)和非MACE组(88例)。比较两组血糖变异性指标[空腹血糖标准差(fasting plasma glucose-standard deviation,FPG-SD)和变异系数(fasting plasma glucose-coefficient variation,FPG-CV)],并采用多因素Cox回归分析心血管事件的危险因素。结果MACE组的FPG-SD和FPG-CV均高于非MACE组,差异均有统计学意义(P均<0.001)。Kaplan-Meier分析显示,高变异组无MACE生存率更低,差异有统计学意义(Log-rank P=0.004)。血糖变异性(FPG-CV≥17.45%)是高血压合并2型糖尿病患者发生MACE的独立危险因素(HR=1.821,95%CI:1.198~2.769,P=0.005)。结论在高血压合并2型糖尿病患者中,血糖变异性与心血管事件风险增加为独立危险因素,提示血糖变异性可能作为心血管预后的预测指标之一。临床管理中需同时关注血糖平均水平与波动控制。 展开更多
关键词 高血压 2型糖尿病 血糖变异性 心血管事件
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二甲双胍联合度拉糖肽对肥胖2型糖尿病患者血糖变异、胰岛素抵抗及三酰甘油-葡萄糖指数、内脏脂肪指数的影响
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作者 于鸿悦 周淑娟 +2 位作者 高芳娟 周亚君 金进 《西北药学杂志》 2026年第1期265-270,共6页
目的探讨二甲双胍联合度拉糖肽对肥胖2型糖尿病(type 2 diabetes mellitus,T2DM)患者血糖变异、胰岛素抵抗及三酰甘油-葡萄糖指数(triglyceride-glucose index,TyG)、内脏脂肪指数(visceral adiposity index,VAI)的影响。方法选取2021年... 目的探讨二甲双胍联合度拉糖肽对肥胖2型糖尿病(type 2 diabetes mellitus,T2DM)患者血糖变异、胰岛素抵抗及三酰甘油-葡萄糖指数(triglyceride-glucose index,TyG)、内脏脂肪指数(visceral adiposity index,VAI)的影响。方法选取2021年5月—2024年5月收治的肥胖T2DM患者110例作为研究对象,根据随机数字表法分为2组,每组55例。对照组采用盐酸二甲双胍片治疗,观察组在对照组治疗的基础上联合度拉糖肽治疗,2组均连续治疗3个月。比较2组治疗前、治疗后的血糖变异性[平均血糖波动幅度(mean amplitude of glucose excursion,MAGE)、日间血糖平均绝对差(absolute means of daily differences,MODD)、血糖变异系数(glucose variability expressed as coefficient of variation,CV)]、胰岛素抵抗、空腹血糖(fasting blood glucose,FBG)、三酰甘油(triglyceride,TG)、TyG、内脏脂肪(内脏脂肪面积、VAI)水平以及不良反应发生率。结果治疗后观察组的MAGE、MODD、CV水平均低于对照组(P<0.05);治疗后观察组的空腹血浆胰岛素、胰岛素抵抗指数水平均低于对照组,胰岛β细胞指数水平高于对照组(P<0.05);治疗后观察组的FBG、TG、TyG水平均低于对照组(P<0.05);治疗后观察组的内脏脂肪面积、VAI水平均低于对照组(P<0.05);2组不良反应发生率比较差异无统计学意义(P>0.05)。结论度拉糖肽对肥胖T2DM患者的临床应用价值较高,可降低患者的血糖水平,减少机体的血糖波动,同时改善患者的胰岛素抵抗情况,并可促进患者内脏脂肪水平的降低,且安全性较高,值得临床推广和应用。 展开更多
关键词 肥胖2型糖尿病 度拉糖肽 二甲双胍 血糖变异 胰岛素抵抗 三酰甘油-葡萄糖指数 内脏脂肪指数
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Interaction Between Charge Characteristics and Cu^(2+) Adsorption-Desorption of Soils with Variable or Permanent Charge 被引量:12
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作者 LI XUEYUAN, LING WANTING and HE JIZHENGKey Laboratory of Subtropical Soil Resources and Environment, Chinese Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070 (China) 《Pedosphere》 SCIE CAS CSCD 2002年第4期321-328,共8页
Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption ... Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption equilibrium respectively. The amount of variable negative charge was much less in variable-charge soil than in permanent-charge soil and increased with the pH in the system, but the opposite trend occurred in the points of zero charge (PZCs). The amount of Cu2+ ions sorbed by permanent-charge soil was more than that by variable-charge soil and increased with the increase of Cu2+ concentration within a certain range in the equilibrium solution. The amount of Cu2+ ions desorbed with KC1 from permanent-charge soil was more than that from variable-charge soil, but the amount of Cu2+ ions desorbed with de-ionized water from permanent-charge soil was extremely low whereas there was still a certain amount of desorption from variable-charge soil. The increase of PZC of soils with variable or permanent charge varied with the increment of Cu2+ ions added. When the same amount of Cu2+ ions was added, the increments of PZC and variable negative surface charge of permanent-charge soil were different from those of variable-charge soil. 展开更多
关键词 ADSORPTION-DESORPTION Cu2+ ion permanent-charge soil variable-charge soil variable negat surface charge
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A Variable Separation Approach to Solve the Integrable and Nonintegrable Models:Coherent Structures of the (2 + 1)-Dimensional KdV Eqnation 被引量:8
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作者 TANG Xiao-Yan LOU Sen-Yue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第7期1-8,共8页
We study the localized coherent structures ofa generally nonintegrable (2+ 1 )-dimensional KdV equation via a variable separation approach. In a special integrable case, the entrance of some arbitrary functions leads ... We study the localized coherent structures ofa generally nonintegrable (2+ 1 )-dimensional KdV equation via a variable separation approach. In a special integrable case, the entrance of some arbitrary functions leads to abundant coherent structures. However, in the general nonintegrable case, an additional condition has to be introduced for these arbitrary functions. Although the additional condition has been introduced into the solutions of the nonintegrable KdV equation, there still exist many interesting solitary wave structures. Especially, the nonintegrable KdV equation possesses the breather-like localized excitations, and the similar static ring soliton solutions as in the integrable case. Furthermor,in the integrable case, the interaction between two travelling ring solitons is elastic, while in the nonintegrable case we cannot find even the single travelling ring soliton solution. 展开更多
关键词 variable SEPARATION approach INTEGRABLE and nonintegrable models (2+1)-dimensional SOLITONS
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Aerodynamic optimization and mechanism design of flexible variable camber trailing-edge flap 被引量:13
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作者 Weishuang LU Yun TIAN Peiqing LIU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第3期988-1003,共16页
Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camb... Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camber trailing-edge flap is introduced,capable of changing its shape smoothly from 50% flap chord to the rear of the flap.Using a numerical simulation method for the case of the GA(W)-2 airfoil,the multi-objective optimization of the overlap,gap,deflection angle,and bending angle of the flap under takeoff and landing configurations is studied.The optimization results show that under takeoff configuration,the variable camber trailing-edge flap can increase lift coefficient by about 8% and lift-to-drag ratio by about 7% compared with the traditional flap at a takeoff angle of 8°.Under landing configuration,the flap can improve the lift coefficient at a stall angle of attack about 1.3%.Under cruise state,the flap helps to improve the lift-todrag ratio over a wide range of lift coefficients,and the maximum increment is about 30%.Finally,a corrugated structure–eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam. 展开更多
关键词 Aerodynamic optimization GA(W)-2 airfoil Mechanism design Trailing-edge flap variable camber
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Adsorption Kinetics of Pb^(2+) and Cu^(2+) on Variable Charge Soils and Minerals:Ⅰ.Technique 被引量:2
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作者 HU GUO-SONGInstitute of Soil Science, Academia Sinica, P. O. Box 821, Nanjing 210008 (China) 《Pedosphere》 SCIE CAS CSCD 1993年第1期57-66,共10页
A new technique for studying the adsorption kinetics of heavy metals,Pb^2+ and Cu^2+,on variable charge surfaces was established with two selective electrodes and microcomputer control system.Feasibility of the techni... A new technique for studying the adsorption kinetics of heavy metals,Pb^2+ and Cu^2+,on variable charge surfaces was established with two selective electrodes and microcomputer control system.Feasibility of the technique,including interference of other ions (mainly Fe^3+ and Al^3+),response time of electrodes,and the pH range of testing,was studied.Comparision with the most widely used miscible displacement technique,which was considered insufficient in studying 30-minute rapid reactions,at present time showed that the new technique was more advantageous in testing in situ,easy to operate,and economic. 展开更多
关键词 CU2+ kinetics PB2+ two-ion-selective-electrode technique variable charge soils
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Multi-attribute group decision making method under 2-dimension uncertain linguistic variables 被引量:4
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作者 JIANG Kexin ZHANG Quan YAN Manting 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第6期1254-1261,共8页
A method is proposed to deal with the uncertain multiple attribute group decision making problems,where 2-dimension uncertain linguistic variables(2DULVs)are used as the reliable way for the experts to express their f... A method is proposed to deal with the uncertain multiple attribute group decision making problems,where 2-dimension uncertain linguistic variables(2DULVs)are used as the reliable way for the experts to express their fuzzy subjective evaluation information.Firstly,in order to measure the 2DULVs more accurately,a new method is proposed to compare two 2DULVs,called a score function,while a new function is defined to measure the distance between two 2DULVs.Secondly,two optimization models are established to determine the weight of experts and attributes based on the new distance formula and a weighted average operator is used to determine the comprehensive evaluation value of each alternative.Then,a score function is used to determine the ranking of the alternatives.Finally,the effectiveness of the proposed method is proved by an illustrated example. 展开更多
关键词 2-dimension uncertain linguistic variables(2DULVs) multi-attribute group decision making problem score function distance formula
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Adsorption Kinetics of Pb^(2+) and Cu^(2+) on Variable Charge Soils and Minerals: Ⅲ. Adsorption Kinetics of Pb^(2+) Within 30 Minutes 被引量:2
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作者 HUGUO-SONG YUMING-FENG 《Pedosphere》 SCIE CAS CSCD 1993年第4期349-359,共11页
The adsorption kinetics of Pb^2+ on different soils and minerals with variable charges was studied by the two ion-selective electrode technique at different pH and concentrations.The results showed that more than 95% ... The adsorption kinetics of Pb^2+ on different soils and minerals with variable charges was studied by the two ion-selective electrode technique at different pH and concentrations.The results showed that more than 95% of adsorption on all the samples occurred during the first 5 minutes.All adsorption time-dependent data could fit the surface second-order equation very well.The values of Xm were goethite>kaolinite,and latosol>red soil at the same initial reaction concentration.The values of k were kaolinite>>goethite,and latosol>red soil at the same reaction pH and initial concentration.The higher the suspension pH,the faster the adsorption occurred.The meaning of Xm got by the two ion-selective electrode technique(one kind of batch technique) was different from that by the miscible displacement technique in that the former was only the equilibrium adsorption amount at a definite concentration and pH,but the latter was almost equal to the adsorption capacity at a definite pH with much less influence of concentration.One Pb^2+ was supposed to occupy two adsorption sites as the adsorption mechanism is concerned. 展开更多
关键词 ADSORPTION KINETICS PB2+ two ion-selective electrode technique variable charge surfaces
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Direct Reduction and Exact Solutions for Generalized Variable Coefficients 2D KdV Equation under Some Integrability Conditions 被引量:2
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作者 M.H.M.Moussa RehabM.El-Shiekh 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期551-554,共4页
Based on the closed connections among the homogeneous balance (HB) method and Clarkson-KruSkal (CK) method, we study the similarity reductions of the generalized variable coefficients 2D KdV equation. In the meant... Based on the closed connections among the homogeneous balance (HB) method and Clarkson-KruSkal (CK) method, we study the similarity reductions of the generalized variable coefficients 2D KdV equation. In the meantime it is shown that this leads to a direct reduction in the form of ordinary differential equation under some integrability conditions between the variable coefficients. Two different cases have been discussed, the search for solutions of those ordinary differential equations yielded many exact travelling and solitonic wave solutions in the form of hyperbolic and trigonometric functions under some constraints between the variable coefficients. 展开更多
关键词 direct reduction method the generalized variable coefficients 2D KdV equation exact solutions
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Solving (2+1)-dimensional sine-Poisson equation by a modified variable separated ordinary differential equation method 被引量:1
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作者 苏卡林 谢元喜 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第10期40-48,共9页
By introducing a more general auxiliary ordinary differential equation (ODE), a modified variable separated ordinary differential equation method is presented for solving the (2 + 1)-dimensional sine-Poisson equa... By introducing a more general auxiliary ordinary differential equation (ODE), a modified variable separated ordinary differential equation method is presented for solving the (2 + 1)-dimensional sine-Poisson equation. As a result, many explicit and exact solutions of the (2 + 1)-dimensional sine-Poisson equation are derived in a simple manner by this technique. 展开更多
关键词 modified variable separated ODE method (2 1)-dimensional sine-Poisson equation explicit and exact solution
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