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The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs 被引量:2
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作者 黄晓明 武辰飞 +3 位作者 陆海 任芳芳 朱洪波 王永进 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期171-174,共4页
The effect of oxygen partial pressure (Po2) during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) is investigated. As Po2 increases fr... The effect of oxygen partial pressure (Po2) during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) is investigated. As Po2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies (Or) within the a-IGZO layer is suppressed by increasing Po2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing Po2. Therefore, the improved interface quality with increasing Po2 during the channel layer deposition can be attributed to the reduction of interface Ov-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs. 展开更多
关键词 TFT The effect of Oxygen partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs
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Analysis of Partial Volume Effects on Accurate Measurement of the Hippocampus Volume
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作者 Maryam Hajiesmaeili Jamshid Dehmeshki Tim Ellis 《Journal of Electronic Science and Technology》 CAS 2014年第2期182-186,共5页
Hippocampal volume loss is an important biomarker in distinguishing subjects with Alzheimer's disease (AD) and its measurement in magnetic resonance images (MRI) is influenced by partial volume effects (PVE). T... Hippocampal volume loss is an important biomarker in distinguishing subjects with Alzheimer's disease (AD) and its measurement in magnetic resonance images (MRI) is influenced by partial volume effects (PVE). This paper describes a post-processing approach to quantify PVE for correction of the hippocampal volume by using a spatial fuzzyC-means (SFCM) method. The algorithm is evaluated on a dataset of 20 T1-weighted MRI scans sampled at two different resolutions. The corrected volumes for left and right hippocampus (HC) which are 23% and 18% for the low resolution and 6% and 5% for the high resolution datasets, respectively are lower than hippocampal volume results from manual segmentation. Results show the importance of applying this technique in AD detection with low resolution datasets. 展开更多
关键词 HIPPOCAMPUS magnetic resonance images partial volume effects spatial fuzzy C-means
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Effect of salt solutions on chain structure of partially hydrolyzed polyacrylamide 被引量:3
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作者 张青 周吉生 +2 位作者 翟永爱 刘凤岐 高歌 《Journal of Central South University》 SCIE EI CAS 2008年第S1期80-83,共4页
The effect of salt solutions(NaCl,Na2SO4 and CaCl2) on the conformational properties of partially hydrolyzed polyacrylamide(HPAM) was investigated by using static laser light scattering(SLLS).The special interaction b... The effect of salt solutions(NaCl,Na2SO4 and CaCl2) on the conformational properties of partially hydrolyzed polyacrylamide(HPAM) was investigated by using static laser light scattering(SLLS).The special interaction between CaCl2 solution and HPAM was also researched.Experimental results show that the chain structure of HPAM is interrelated with the charge density,the kind and the concentration of salt solutions.The mean-square radius of gyration(Rz) and the second virial coefficient(A2) of HPAM decrease with increasing concentration of salt solutions,and the salt effect tends towards the maximum when the concentration of salt solution is increased to some amount. 展开更多
关键词 partialLY hydrolyzed polyacrylamide(HPAM) SALT effect chain structure static laser light scattering(SLLS)
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Effects of terlipressin versus splenectomy on liver regeneration after partial hepatectomy in rats: What we know so far? 被引量:6
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作者 antonios athanasiou eleftherios spartalis +4 位作者 mairead hennessy michael spartalis demetrios moris christos damaskos emmanouil pikoulis 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2018年第1期91-92,共2页
To the editor:We read with great interest the article entitled "Comparative study of the effects of terlipressin versus splenectomy on liver regeneration after partial hepatectomy in rats" by Ulmer et al.[1]... To the editor:We read with great interest the article entitled "Comparative study of the effects of terlipressin versus splenectomy on liver regeneration after partial hepatectomy in rats" by Ulmer et al.[1].The aim of this study was to analyse the impact of terlipressin ver- 展开更多
关键词 effects of terlipressin versus splenectomy on liver regeneration after partial hepatectomy in rats What we know so far
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Partial Volume Effect on MR Elastography
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作者 Daiki Ito Tomokazu Numano +3 位作者 Kazuyuki Mizuhara Toshikatsu Washio Masaki Misawa Naotaka Nitta 《Open Journal of Medical Imaging》 2017年第4期131-143,共13页
Magnetic resonance elastography (MRE) allows the quantitative assessment of the stiffness of tissues based on the tissue response to oscillatory shear stress. Shear wave displacements of the tissues are encoded as pha... Magnetic resonance elastography (MRE) allows the quantitative assessment of the stiffness of tissues based on the tissue response to oscillatory shear stress. Shear wave displacements of the tissues are encoded as phase shifts and converted to stiffness (elastogram). Generally, a partial volume effect occurs when different materials are encompassed on the same voxel. In MRE, however, the partial volume effect occurs even if the voxel is filled with the same materials because wave displacements due to vibrations are spatially distributed. The purpose of this study was to investigate how the partial volume effect can affect the phase shift and the elastogram in MRE. We assumed that the partial volume effect appears only in the slice thickness direction and performed a simulation and MRE experiment with various slice thicknesses (1 - 19 mm), two types of imaging plane (coronal and axial) and two types of vibration frequency (100 and 200 Hz). The results of the simulation and the MRE experiment were similar, and indicated that the phase shift and the elastogram changed variously depending on the slice thickness, the wave pattern and the vibration frequency, even if the voxel was filled with the same material. To reduce the partial volume effect, it is necessary to perform the MRE under the following conditions: Use a wave pattern which barely causes this artefact, a smaller voxel size and a lower vibration frequency. 展开更多
关键词 Magnetic RESONANCE ELASTOGRAPHY partial Volume effect ARTEFACT ELASTICITY VISCOELASTICITY
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Effect of the Partial Substitution of V for Nb on the Magnetic Properties of Fe-based Nanocrystalline Alloy
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作者 Guiqin ZHOU, Fazeng LIAN and Guozhen LI (Institute of Materials and Metallurgy, Northeastern University, Shenyang 110006,China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第6期643-644,共2页
The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic pro... The variation of the magnetic properties of the nanocrystalline alloys for the partial substitution of V for Nb with crystallizing treatment temperature and time was investigated. The variation law of the magnetic properties with the annealing temperature and time is essentially the same. The magnetic properties of the Fe-based nanocrystalline alloys for the partial substitution of V for Nb reduce, and the crystallizing treatment temperature of the alloys increases. The optimum properties of Fe74Cu1Nb3Si13B9 nanocrystalline alloys crystallized at 550℃x60 min are μ0=9.2xl0^4, μm=54.8xl0^4, Hc=1.14 A/m and Bs=1.26 T. The best properties for Fe74Cu1Nb3Si13B9 alloys annealed at 560℃x60 min are μ0=8.79x10^4, μm=50.18xl0^4, Hc=1.26 A/m and Bs=1.24 T. 展开更多
关键词 Fe effect of the partial Substitution of V for Nb on the Magnetic Properties of Fe-based Nanocrystalline Alloy
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Effect of topiramate on partial excitatory amino acids in hippocampal dentate gyrus of rats after alcohol withdrawal
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作者 Qinghua Yang Guang Wu +2 位作者 Haiying Jiang Yuanzhe Jin Songbiao Cui 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第2期147-150,共4页
BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is o... BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE: To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN : A randomized control animal experiment SETTING : Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS: Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS: The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups: control group (n=10), alcohol group (n=10) and topiramate-treated group (n=10). Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol (10 mL/kg), once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy (HPLC) respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES : ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS: Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group (10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01). In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol (6.06±0.82, 3.50±0.92, P 〈 0.05), and the withdrawal scores at 48 and 72 hours were close to those in the control group (4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05).② Changes of the contents of glutamic acid in hippocampal dentate gyrus: In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [(143.32±11.42)%, (99.12±0.69)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(78.50±16.40)%, (99.12±0.69)%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.30±0.37)%, (118.91±10.40)%, (99.55±12.81)%, (99.08±11.42)%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus: In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [(126.60±8.67)%, (129.17±10.40)%, (99.25±0.87)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(89.87±9.93)%, (99.25±0.87)%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.27±0.32)%, (120.81 ±12.63)%, (98.91±7.83)%, (85.92±8.07)%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). CONCLUSION: ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats. 展开更多
关键词 effect of topiramate on partial excitatory amino acids in hippocampal dentate gyrus of rats after alcohol withdrawal
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Impact of back-gate bias on the hysteresis effect in partially depleted SOI MOSFETs
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作者 罗杰馨 陈静 +4 位作者 周建华 伍青青 柴展 余涛 王曦 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期473-478,共6页
The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted(PD) silicon-on-insulator(SOI) MOSFETs at different back-gate biases.I D hystere... The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted(PD) silicon-on-insulator(SOI) MOSFETs at different back-gate biases.I D hysteresis has been developed to clarify the hysteresis characteristics.The fabricated devices show the positive and negative peaks in the I D hysteresis.The experimental results show that the I D hysteresis is sensitive to the back gate bias in 0.13-渭m PD SOI MOSFETs and does not vary monotonously with the back-gate bias.Based on the steady-state Shockley-Read-Hall(SRH) recombination theory,we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs. 展开更多
关键词 floating body effect hysteresis effect back gate bias partially depleted (PD) SOl
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Efficient Shrinkage Estimation about the Partially Linear Varying Coefficient Model with Random Effect for Longitudinal Data
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作者 Wanbin Li 《Open Journal of Statistics》 2016年第5期862-872,共12页
In this paper, an efficient shrinkage estimation procedure for the partially linear varying coefficient model (PLVC) with random effect is considered. By selecting the significant variable and estimating the nonzero c... In this paper, an efficient shrinkage estimation procedure for the partially linear varying coefficient model (PLVC) with random effect is considered. By selecting the significant variable and estimating the nonzero coefficient, the model structure specification is accomplished by introducing a novel penalized estimating equation. Under some mild conditions, the asymptotic properties for the proposed model selection and estimation results, such as the sparsity and oracle property, are established. Some numerical simulation studies and a real data analysis are presented to examine the finite sample performance of the procedure. 展开更多
关键词 partially Linear Varying Coefficient Model Mixed effect Penalized Estimating Equation
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Effect of doxazosin on rabbit bladder compliance after partial bladder outlet obstruction
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作者 皇甫雪军 《外科研究与新技术》 2011年第4期243-244,共2页
Objective To explore the effect of doxazosin on rabbit bladder compliance after partial bladder outlet ob- struction. Methods A total of 40 male New Zealand white rabbits were randomized into 4 groups,with 10 rabbits ... Objective To explore the effect of doxazosin on rabbit bladder compliance after partial bladder outlet ob- struction. Methods A total of 40 male New Zealand white rabbits were randomized into 4 groups,with 10 rabbits in each group. Partial bladder outlet 展开更多
关键词 effect of doxazosin on rabbit bladder compliance after partial bladder outlet obstruction der
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Open Partial Nephrectomy: One Night Length of Stay Is Safe and Cost Effective
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作者 Mohit Sirohi Kyrollis Attalla +1 位作者 Harris M. Nagler Erik T. Goluboff 《Open Journal of Urology》 2016年第9期139-146,共9页
Objective: To review our open partial nephrectomy (OPN) experience and compare to known robotic partial nephrectomy (RPN) data to determine whether length of stay (LOS) and morbidity are significant drivers in the sur... Objective: To review our open partial nephrectomy (OPN) experience and compare to known robotic partial nephrectomy (RPN) data to determine whether length of stay (LOS) and morbidity are significant drivers in the surgical approach employed for partial nephrectomy. Methods: We reviewed our OPN experience during the last 3 years examining age, tumor size, LOS, pathology, blood loss, complications, recurences, and deaths. Results: Seventy-five patients underwent OPN during this period. Mean age was 59 years, tumor size 2.8 cm, percent malignant 75%, estimated blood loss 350 cc. With a median follow-up of 18 months, there was one urinoma managed by drain-age, one pseudo aneurysm that required embolization and one pulmonary embolism that required anticoagulation. There were no readmissions, no tumor recurences, and no deaths. Our major complication rate was 4% as compared to other trials that re-ported major complication rates between 1% - 9% for RPN and between 3% - 24% for OPN. In the first half of the experience (n = 37), median LOS was 57 hours. Using a pathway encouraging early ambulation and smaller incisions in the second half of the experience (n = 38), median LOS was 35 hours. This is much shorter than reported RPN LOS of 62 - 67 hours and OPN LOS of 108 - 142 hours. Conclusion: OPN can be performed safely and effectively with one night hospital stay. This provides a more cost-effective approach to partial nephrectomy with similar or better complication rates and calls into question the main value drivers of RPN. 展开更多
关键词 Cost effective Length of Stay Open partial Nephrectomy Robotic partial Nephrectomy
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部分强化效应驱动的大规模多目标优化问题求解算法
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作者 顾清华 王晗睿 +1 位作者 王倩 骆家乐 《计算机工程与应用》 北大核心 2026年第1期172-191,共20页
针对大规模多目标优化问题中决策空间维度高、收敛难及计算资源分配低效等挑战,提出部分强化效应驱动的大规模多目标优化问题求解算法DVA-PRO。该算法通过决策变量二元化重构原目标问题以降维,利用部分强化效应理论设计评估与正强化机制... 针对大规模多目标优化问题中决策空间维度高、收敛难及计算资源分配低效等挑战,提出部分强化效应驱动的大规模多目标优化问题求解算法DVA-PRO。该算法通过决策变量二元化重构原目标问题以降维,利用部分强化效应理论设计评估与正强化机制,动态分配计算资源——优化初期高倍率强化促进收敛,后期扩大强化范围维护多样性。DVA-PRO与6种对比算法在100例大规模多目标优化基准测试问题上进行对比实验,并在4类实际工程应用问题上进行仿真。实验结果表明,DVA-PRO在79例基准测试问题和所有实际工程应用问题上性能指标排名第一。在相同计算资源限制下,DVA-PRO能有效搜索并收敛至帕累托前沿,综合性能优于其他算法,并在不同类型的大规模多目标优化问题上兼具高效性与通用性。 展开更多
关键词 进化算法 大规模优化 多目标优化 部分强化效应 问题重构
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腹腔镜下肾部分切除术在局限性肾癌中的应用效果及术后发生DVT的风险分析
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作者 孙超群 林磊 +2 位作者 杨树立 郝阳 赵晓峰 《河南医学研究》 2026年第1期88-92,共5页
目的分析腹腔镜下肾部分切除术在局限性肾癌中的应用效果及术后发生深静脉血栓(DVT)的风险。方法选取2020年6月至2023年6月平顶山市第一人民医院收治的180例局限性肾癌患者为研究对象,均行腹腔镜肾部分切除术治疗,观察患者临床疗效及不... 目的分析腹腔镜下肾部分切除术在局限性肾癌中的应用效果及术后发生深静脉血栓(DVT)的风险。方法选取2020年6月至2023年6月平顶山市第一人民医院收治的180例局限性肾癌患者为研究对象,均行腹腔镜肾部分切除术治疗,观察患者临床疗效及不同时间点患者肾功能指标变化。同时根据患者术后是否出现DVT分为DVT组和非DVT组。收集受试者术前资料及术后资料,采用单因素和多因素分析影响局限性肾癌患者术后发生DVT的危险因素。同时构建局限性肾癌患者术后发生DVT风险模型。结果患者手术前后血肌酐(SCr)、血清尿素氮(BUN)、肾小球滤过率(GFR)水平比较,差异无统计学意义(P>0.05)。腹腔镜下肾部分切除术治疗局限性肾癌的临床总有效率为76.11%(137/180)。DVT组患者年龄、气腹压力、总胆固醇(TC)、尿微量白蛋白(UmAlb)、BUN、D-二聚体(D-D)水平高于非DVT组(P<0.05),手术时间、引流管留置时间长于非DVT组(P<0.05)。logistic回归分析结果显示年龄、手术时间、气腹压力、引流管留置时间、D-D均是影响局限性肾癌患者术后发生DVT的危险因素(P<0.05)。构建的预测模型对预测局限性肾癌患者术后发生DVT的曲线下面积(AUC)、灵敏度、特异度为0.853(95%CI:0.731~0.989)、94.70%、75.80%(P<0.05)。结论腹腔镜下肾部分切除术治疗局限性肾癌的效果确切,对肾功能的影响较小。高龄、手术时间、气腹压力、引流管留置时间、D-D均是影响局限性肾癌患者术后发生DVT的危险因素,基于上述危险因素构建的预测模型对局限性肾癌患者术后发生DVT的预测价值较高。 展开更多
关键词 局限性肾癌 腹腔镜下肾部分切除术 临床疗效 深静脉血栓
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天津市植被演变特征及其对水热效应的时滞分析
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作者 吴华 李佳潼 +4 位作者 徐悦 朱嘉琦 郭齐韵 张鑫 谢雪 《长江科学院院报》 北大核心 2026年第1期66-75,共10页
明确天津市植被活动的动态变化及其对水热条件响应的时滞性,可为区域生态环境治理和持续发展提供科学依据。以2000—2022年的天津市MODIS13数据集、气温和降雨数据集为研究对象,采用Hurst指数、Theil-Sen趋势分析、M-K检验、地理信息系... 明确天津市植被活动的动态变化及其对水热条件响应的时滞性,可为区域生态环境治理和持续发展提供科学依据。以2000—2022年的天津市MODIS13数据集、气温和降雨数据集为研究对象,采用Hurst指数、Theil-Sen趋势分析、M-K检验、地理信息系统(GIS)空间分析和时滞偏相关分析等方法,探究近23 a天津市植被动态变化特征及其水热效应。结果表明:(1)天津市年归一化植被指数(NDVI)均值为0.782,年内波动趋势与气温、降雨的变化存在一定的正向联系;(2)全市Hurst指数均值为0.493,59.62%的区域NDVI向恶性发展;(3)天津市分别有10.943%和61.408%的区域与气温和降雨存在时滞效应,植被对气温的平均滞后时长为2.737个月,对降雨的平均滞后时间为1.016个月;(4)不同植被类型对气温和降雨的响应有所不同,阔叶林对降雨的响应时间最短,草本植物覆盖的响应时间最长;稀疏植被对气温的响应最快,阔叶林对其响应最慢。近23 a天津地区植被整体覆盖水平较好,呈现过去退化但未来改善的趋势。降雨与植被相关性更高,气温的滞后时间更长。 展开更多
关键词 水热效应 归一化植被指数(NDVI) 偏相关分析 气温 降雨 时滞效应 天津市
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部分抗剪连接钢-混凝土组合梁负弯矩区剪力滞后效应研究
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作者 罗达 谭菁 +2 位作者 邢国华 李亚坤 苗鹏勇 《东南大学学报(自然科学版)》 北大核心 2026年第1期70-79,共10页
为研究部分抗剪连接钢-混凝土组合梁(简称组合梁)负弯矩区剪力滞后效应,基于桁架类比理论并结合界面剪力均匀分布假设,建立了理论计算模型,阐明了其力学形成机理。通过DIANA软件建立数值模型,并利用既有试验数据验证模型合理性,进一步... 为研究部分抗剪连接钢-混凝土组合梁(简称组合梁)负弯矩区剪力滞后效应,基于桁架类比理论并结合界面剪力均匀分布假设,建立了理论计算模型,阐明了其力学形成机理。通过DIANA软件建立数值模型,并利用既有试验数据验证模型合理性,进一步分析主要参数对剪力滞后效应的影响规律,并对理论模型进行了校核。结果表明,混凝土板开裂后,剪力滞后效应随荷载增加而增强,直至钢筋屈服,随后迅速减弱,但在峰值荷载下依然明显。钢筋屈服前,剪力滞后效应随剪力连接程度的提升而愈发显著,峰值荷载下趋势相反。除板厚外,其余参数在不同剪力连接程度下的影响规律基本一致。此外,剪力滞后效应随距零弯矩点距离增加而增强。所建理论模型可有效预测开裂后各参数对剪力滞后效应的影响规律,且在屈服荷载下计算最为准确。当实际板宽接近我国现行规范规定的翼板有效宽度时,组合梁负弯矩区剪力滞后效应被普遍低估。 展开更多
关键词 组合结构 部分抗剪连接组合梁 剪力滞后效应 负弯矩区 数值模型 计算模型
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基于谱-效关系的青刺尖抗氧化活性成分分析
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作者 桂鹏燕 杨秀霞 +1 位作者 杨兆祥 曲丽萍 《食品工业科技》 北大核心 2026年第4期348-359,共12页
为探究青刺尖(Prinsepia utilis Royle)主要抗氧化活性成分,阐明其药效物质基础,本研究以1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picryl-hydrazyl radical,DPPH·)清除率为指标,采用高效液相色谱(high performance liquid c... 为探究青刺尖(Prinsepia utilis Royle)主要抗氧化活性成分,阐明其药效物质基础,本研究以1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picryl-hydrazyl radical,DPPH·)清除率为指标,采用高效液相色谱(high performance liquid chromatography,HPLC)建立11批青刺尖提取物指纹图谱,并结合皮尔逊、斯皮尔曼和偏最小二乘回归分析探讨了指纹图谱共有峰与抗氧化作用间的谱-效关系,筛选出对抗氧化活性贡献较大的组分进行质谱定性和高效液相色谱定量分析,进一步通过体外DPPH·、ABTS^(+)·、·OH清除能力和人皮肤成纤维细胞(human foreskin fibroblasts,HFF)抗衰活性检测,评价其抗氧化及抗衰活性。结果从11批青刺尖提取物指纹图谱中标定13个色谱峰,并识别出其中6个化学成分,其中芦丁、水仙苷、碟豆素、夏佛塔苷和香蒲新苷等化合物为青刺尖发挥抗氧化功效的潜在物质成分,定量分析结果表明各化学成分的含量存在一定差异,碟豆素含量最高(738.123μg/mL),其次是芦丁(538.612μg/mL)、水仙苷(385.881μg/mL)和香蒲新苷(337.168μg/mL),且各单体化合物均表现出较好的自由基清除活性和良好的抗衰效果,其中芦丁和水仙苷能有效清除DPPH·、ABTS^(+)·及·OH,其中芦丁对DPPH·和ABTS^(+)·的清除率分别为92.84%和92.44%,对·OH清除作用的IC_(50)值为0.45 mg/mL;水仙苷对DPPH·和ABTS^(+)·的清除率为37.71%和82.01%,·OH清除作用的IC_(50)值为1.01 mg/mL。夏佛塔苷、香蒲新苷(P<0.01)及芦丁(P<0.05)可显著抑制SA-β-gal活性,降低衰老相关β-半乳糖苷酶阳性细胞比例,显示出良好的抗衰效果;细胞氧化应激模型中,香蒲新苷、蝶豆素、水仙苷及夏佛塔苷、芦丁能显著下调MMP-1、MMP-3和MMP-9的表达(P<0.001),促进皮肤胶原蛋白合成并抑制其降解,具有潜在的抗衰老能力。综上表明青刺尖的抗氧化功效可能是由夏佛塔苷、香蒲新苷、芦丁、水仙苷及碟豆素等多种化学成分共同作用产生的结果。 展开更多
关键词 青刺尖 抗氧化 谱-效关系 Pearson 相关性 偏最小二乘回归
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多级膜提氢在合成氨放空气处理中的应用及回收率推导
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作者 袁强强 《山东化工》 2026年第2期165-167,172,共4页
某传统合成氨企业“3652”项目配备一套PSA变压吸附装置与一套膜提氢装置,PSA变压吸附装置用于对液氨储罐驰放气的分离回收,膜提氢用于合成放空气的分离回收。实际运行中,膜提氢渗透气1.65 MPa送压缩四段,氢气体积含量92%,氢气回收率在... 某传统合成氨企业“3652”项目配备一套PSA变压吸附装置与一套膜提氢装置,PSA变压吸附装置用于对液氨储罐驰放气的分离回收,膜提氢用于合成放空气的分离回收。实际运行中,膜提氢渗透气1.65 MPa送压缩四段,氢气体积含量92%,氢气回收率在80%左右,氢气回收率不足导致氢气损耗较大。为提升氢气回收率,该公司在原膜提氢装置基础上串联新增一组渗透膜,新增膜渗透气压力0.25 MPa送压缩机二段。通过增大膜两侧浓度梯度,提升氢气穿透率,改造后氢气回收率提升至95%以上。本文对多级膜提氢在合成氨装置中的应用情况阐述,突出提高氢气回收率的重要性,对合成氨放空尾气回收提供借鉴。同时本文完成多级膜提氢回收率的公式推导,填补行业内多级回收装置回收率精确计算的空白。 展开更多
关键词 多级膜提氢 溶解扩散机理 渗透分压 回收率推导 经济效应
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Configuration model of partial repairable spares under batch ordering policy based on inventory state 被引量:21
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作者 Ruan Minzhi Luo Yi Li Hua 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第3期558-567,共10页
Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost (LCC). With an analysis of various impacts on support system, the spares... Rational planning of spares configuration project is an effective approach to improve equipment availability as well as reduce life cycle cost (LCC). With an analysis of various impacts on support system, the spares demand rate forecast model is constructed. According to systemic analysis method, spares support effectiveness evaluation indicators system is built, and then, initial spares configuration and optimization method is researched. To the issue of discarding and con-sumption for incomplete repairable items, its expected backorders function is approximated by Laplace demand distribution. Combining the (s-1, s) and (R, Q) inventory policy, the spares resup-ply model is established under the batch ordering policy based on inventory state, and the optimi-zation analysis flow for spares configuration is proposed. Through application on shipborne equipment spares configuration, the given scenarios are analyzed under two constraint targets:one is the support effectiveness, and the other is the spares cost. Analysis reveals that the result is consistent with practical regulation;therefore, the model's correctness, method's validity as well as optimization project's rationality are proved to a certain extent. 展开更多
关键词 Batch ordering Inventory state Operations research partial repairable spares Support effectiveness evaluation
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A new structure and its analytical model for the vertical interface electric field of a partial-SOI high voltage device 被引量:2
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作者 胡盛东 张波 +1 位作者 李肇基 罗小蓉 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期496-502,共7页
A new partial-SOI (PSOI) high voltage device structure called a CI PSOI (charge island PSOI) is proposed for the first time in this paper. The device is characterized by a charge island layer on the interface of t... A new partial-SOI (PSOI) high voltage device structure called a CI PSOI (charge island PSOI) is proposed for the first time in this paper. The device is characterized by a charge island layer on the interface of the top silicon layer and the dielectric buried layer in which a series of equidistant high concentration n+-regions is inserted. Inversion holes resulting from the vertical electric field are located in the spacing between two neighbouring n+-regions on the interface by the force with ionized donors in the undepleted n+-regions, and therefore effectively enhance the electric field of the dielectric buried layer (Ei) and increase the breakdown voltage (BV), thereby alleviating the self-heating effect (SHE) by the silicon window under the source. An analytical model of the vertical interface electric field for the CI PSOI is presented and the analytical results are in good agreement with the 2D simulation results. The BV and El of the CI PSOI LDMOS increase to 631 V and 584 V/μm from 246 V and 85.8 V/μm for the conventional PSOI with a lower SHE, respectively. The effects of the structure parameters on the device characteristics are analysed for the proposed device in detail. 展开更多
关键词 interface charges breakdown voltage partial-SOI self-heating effect
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EFFECTIVE DYNAMICS OF A COUPLED MICROSCOPIC-MACROSCOPIC STOCHASTIC SYSTEM 被引量:2
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作者 任剑 付红波 +1 位作者 曹道民 段金桥 《Acta Mathematica Scientia》 SCIE CSCD 2010年第6期2064-2076,共13页
A conceptual model for microscopic-macroscopic slow-fast stochastic systems is considered. A dynamical reduction procedure is presented in order to extract effective dynamics for this kind of systems. Under appropriat... A conceptual model for microscopic-macroscopic slow-fast stochastic systems is considered. A dynamical reduction procedure is presented in order to extract effective dynamics for this kind of systems. Under appropriate assumptions, the effective system is shown to approximate the original system, in the sense of a probabilistic convergence. 展开更多
关键词 microscopic-macroscopic system stochastic partial differential equations averaging principle effective dynamics slow-fast scales
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