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改进CNN的风力机叶片故障诊断方法
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作者 黄灿冰 熊妮 +3 位作者 吴伟 刘诗剑 张巧 杨锡运 《风机技术》 2024年第2期67-73,共7页
针对图像分辨率低的风力机叶片图像会导致故障诊断过程中精度和速度降低等问题,提出了一种基于小波变换、深度可分离卷积和卷积块注意力机制模块的轻量级改进VGG-19模型;使用DB4小波和基于形态学的增强技术来提高风力机叶片图像的质量,... 针对图像分辨率低的风力机叶片图像会导致故障诊断过程中精度和速度降低等问题,提出了一种基于小波变换、深度可分离卷积和卷积块注意力机制模块的轻量级改进VGG-19模型;使用DB4小波和基于形态学的增强技术来提高风力机叶片图像的质量,然后将VGG-19中的传统卷积层替换为深度可分离卷积层,以减少网络参数的数量并提高训练效率,最后引入卷积注意力机制模块(Convolutional Block Attention Module, CBAM)来提高风力机叶片故障诊断的准确性;研究结果表明:所提模型的准确率为93.91%,与其他传统卷积神经网络(Convolutional Neural Networks,CNN)模型LeNet、AlexNet、GoogleNet、ResNet-50和VGG-19相比分别提高了15.06%、8.57%、3.10%、-1.13%和7.13%;测试时间为每幅图像0.046秒,较传统CNN模型每幅图像分别减少了-0.004秒、-0.002秒、0.006秒、0.015秒和0.010秒的检测时间;该模型结构轻巧,相比于其他传统CNN具有更高的准确性和更快的检测速度。 展开更多
关键词 故障检测 风力机叶片 模糊图像检测 深度学习 VGG-19 注意力机制
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The photo-decomposition and self-restructuring dynamic equilibrium mechanism of Cu_(2)(OH)_(2)CO_(3)for stable photocatalytic CO_(2)reduction
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作者 Yaqing Zhi Haoning Mao +5 位作者 Guangxing Yang qiao zhang Zhiting Liu Yonghai Cao Siyuan Yang Feng Peng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期104-112,共9页
Developing suitable photocatalysts and understanding their intrinsic catalytic mechanism remain key challenges in the pursuit of highly active,good selective,and long-term stable photocatalytic CO_(2)reduction(PCO_(2)... Developing suitable photocatalysts and understanding their intrinsic catalytic mechanism remain key challenges in the pursuit of highly active,good selective,and long-term stable photocatalytic CO_(2)reduction(PCO_(2)R)systems.Herein,monoclinic Cu_(2)(OH)_(2)CO_(3)is firstly proven to be a new class of photocatalyst,which has excellent catalytic stability and selectivity for PCO_(2)R in the absence of any sacrificial agent and cocatalysts.Based on a Cu_(2)(OH)_(2)^(13)CO_(3)photocatalyst and 13CO_(2)two-sided^(13)C isotopic tracer strategy,and combined with in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS)analysis and density functional theory(DFT)calculations,two main CO_(2)transformation routes,and the photo-decomposition and self-restructuring dynamic equilibrium mechanism of Cu_(2)(OH)_(2)CO_(3)are definitely revealed.The PCO_(2)R activity of Cu_(2)(OH)_(2)CO_(3)is comparable to some of state-of-the-art novel photocatalysts.Significantly,the PCO_(2)R properties can be further greatly enhanced by simply combining Cu_(2)(OH)_(2)CO_(3)with typical TiO_(2)to construct composites photocatalyst.The highest CO_(2)and CH_(4)production rates by 7.5 wt%Cu_(2)(OH)_(2)CO_(3)-TiO_(2)reach 16.4μmol g^(-1)h^(-1)and 116.0μmol g^(-1)h^(-1),respectively,which are even higher than that of some of PCO_(2)R systems containing sacrificial agents or precious metals modified photocatalysts.This work provides a better understanding for the PCO_(2)R mechanism at the atomic levels,and also indicates that basic carbonate photocatalysts have broad application potential in the future. 展开更多
关键词 CO_(2)photocatalytic reduction PHOTOCATALYSIS Basic copper carbonate SELF-RECONSTRUCTION PHOTOCATALYST
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高效光热催化废旧聚酯塑料升级回收
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作者 娄向西 高璇 +8 位作者 刘钰 褚名宇 张丛洋 邱盈华 杨文秀 曹暮寒 王贵领 张桥 陈金星 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第6期113-122,共10页
太阳能是一种绿色、清洁的能源.将可再生太阳能转化为热能驱动聚酯醇解反应,即发展光热催化聚酯醇解方法,实现废弃塑料转化为高纯度、高附加值单体,有望解决传统热催化体系效率低、能耗高的问题,实现废弃塑料的高效增值回收利用.一方面... 太阳能是一种绿色、清洁的能源.将可再生太阳能转化为热能驱动聚酯醇解反应,即发展光热催化聚酯醇解方法,实现废弃塑料转化为高纯度、高附加值单体,有望解决传统热催化体系效率低、能耗高的问题,实现废弃塑料的高效增值回收利用.一方面,光热催化体系可满足传统热催化所需的反应温度,同时光热催化过程中存在的局域热效应,可进一步提升聚酯回收的催化活性,保障聚酯的高效醇解.另一方面,利用太阳能驱动光热催化聚酯醇解反应,不仅降低能耗,减少CO_(2)排放,还可以充分利用清洁能源,实现太阳能到化学能的高效转化.然而,催化剂的光热转化效率低、局域热效应弱以及催化活性低是限制其发展的挑战问题.本文采用模板法合成了ZIF-8纳米粒子,在ZIF-8表面包覆一层SiO_(2),经高温处理后得到一体化光热催化剂.内部碳材料在吸收太阳光后产生热能,而外层SiO_(2)可以阻止内部热的辐射损失,从而提高局域温度.此外,SiO_(2)包覆层可以抑制c-ZIF-8在高温热解过程中的聚集,使催化剂在催化反应过程中具有更好的分散性.优化后的光热催化剂(c-ZIF-8@25SiO_(2))在0.78 Wcm-2模拟太阳光照射30 min下的PET转化率为84.97%,是热催化反应性能的3.4倍.当反应时间延长至45 min时,PET转化率达到100%.动力学分析表明,光热催化PET醇解的活化能为59.35 k Jmol-1,低于大多文献报道值(通常>70 k J mol-1),更重要的是,其活化能也与热催化PET醇解的活化能(61.04 k Jmol-1)相近反应.上述结果表明,c-ZIF-8@25SiO_(2)纳米颗粒光热催化PET醇解和热催化PET醇解的反应路径可能是相同的,因此排除了光化学活化在光热催化中的贡献.此外,这种SiO_(2)包覆层也使内部催化剂具有较高的稳定性,其中PET转化率和对苯二甲酸乙二醇酯产率在5次循环后分别保持在初始值的98%和95%.在室外太阳光照射下进行PET醇解实验以及从混合塑料中选择性回收PET,进一步证明了c-ZIF-8@25SiO_(2)在光热催化PET醇解方面具有较好的用前景.技术经济分析表明,每回收1万吨PET,选择光热催化可节电6390000 k W·h,减少3089.59吨CO_(2)排放.综上,本文策略为增强光热催化中的局部加热效应提供了一种普适性方法,为构筑高效塑料回收提供理论指导及实验参考. 展开更多
关键词 光热催化 局域热效应 聚酯升级回收 聚酯醇解 金属有机框架
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Statics, vibration, and buckling of sandwich plates with metamaterial cores characterized by negative thermal expansion and negative Poisson's ratio
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作者 qiao zhang Yuxin SUN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第9期1457-1486,共30页
This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relatio... This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relations between the mechanical responses of sandwich composites and the NPR or NTE of the metamaterial.First,the NPR and NTE of the metamaterial are derived analytically based on energy conservation.The effective elastic modulus and mass density of the 3D metamaterial are obtained and validated by the finite element method(FEM).Subsequently,the general governing equation of the 3D sandwich plate under thermal environments is established based on Hamilton’s principle with the consideration of the von Kármán nonlinearity.The differential quadrature(DQ)FEM(DQFEM)is utilized to obtain the numerical solutions.It is shown that NPR and NTE can enhance the global stiffness of sandwich structures.The geometric parameters of the Maltese cross metamaterial significantly affect the responses of the thermal stress,natural frequency,and critical buckling load. 展开更多
关键词 negative Poisson's ratio(NPR) negative thermal expansion(NTE) sand-wich plate VIBRATION BUCKLING
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Discovery of bauxite-type helium source rock in Jinzhong basin, central North China and its resource potential evaluation
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作者 qiao zhang Jun-lin Zhou +6 位作者 Yu-hong Li Ya-zhuo Niu Wang Guo Shang-wei Ma Yun-peng zhang Shao-hua Hu Yu Ding 《China Geology》 CAS CSCD 2023年第4期753-755,共3页
1. Objective Among globally known industrial helium-enriched natural gas reservoirs, associated helium is dominantly crust-derived helium(4He), which is generated by the radioactive decay of uranium(U) and thorium(Th)... 1. Objective Among globally known industrial helium-enriched natural gas reservoirs, associated helium is dominantly crust-derived helium(4He), which is generated by the radioactive decay of uranium(U) and thorium(Th) in crustal rocks. These rocks with old ages are also defined as helium source rocks.Published accumulation models for helium have revealed that granite is the main and effective helium source rock in the crust(Li YH et al., 2018). 展开更多
关键词 globally DECAY source
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人乳头瘤病毒16型DNA整合对宫颈癌变的影响 被引量:10
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作者 刘霞 张乔 张慧杰 《中国现代医学杂志》 CAS 2020年第9期28-33,共6页
目的研究人乳头瘤病毒(HPV)16型DNA在宫颈鳞状细胞癌(SCC)及其癌前病变中的整合状况,探讨其在宫颈癌变中的作用。方法采用多重聚合酶链反应技术检测428例HPV-16阳性并经组织学证实具有不同程度宫颈病变及正常宫颈上皮女性的宫颈脱落细胞... 目的研究人乳头瘤病毒(HPV)16型DNA在宫颈鳞状细胞癌(SCC)及其癌前病变中的整合状况,探讨其在宫颈癌变中的作用。方法采用多重聚合酶链反应技术检测428例HPV-16阳性并经组织学证实具有不同程度宫颈病变及正常宫颈上皮女性的宫颈脱落细胞中HPV-16 DNA的整合状况;采用E2/E6的比值作为整合的替代标志物。研究对象分为病例组(354例)包括经组织病理学证实的103例SCC及251例宫颈高级别鳞状上皮内病变(HSIL),对照组(74例)包括34例宫颈低级别鳞状上皮内病变(LSIL)及40例正常宫颈上皮细胞女性。不同程度宫颈病变中HPV-16 DNA整合率的变化采用χ2趋势分析;病毒整合与现患HSIL及SCC风险的优势比(O^R)采用非条件Logistic回归分析。结果HPV-16 DNA整合率随宫颈病变的加重逐渐升高,从对照组中的6.8%(5/74),升高至HSIL组的29.9%(75/251)及SCC组的68.0%(70/103),3组整合率比较差异有统计学意义(P<0.05)。经多因素分析调整吸烟状况及合并感染其他高危型HPV后,HPV-16基因组整合与现患HSIL及SCC风险的优势比为O^R=2.30(95%CI:1.62,3.18)。结论HPV-16 DNA整合发生在病毒感染自然史的早期,病毒整合在宫颈癌变过程中起促进作用。 展开更多
关键词 子宫肿瘤 子宫颈鳞状上皮内病变 人乳头瘤病毒 病毒整合
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Long noncoding RNA RP4 functions as a competing endogenous RNA through miR-7-5p sponge activity in colorectal cancer 被引量:16
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作者 Mu-Lin Liu qiao zhang +4 位作者 Xiao Yuan Long Jin Li-Li Wang Tao-Tao Fang Wen-Bin Wang 《World Journal of Gastroenterology》 SCIE CAS 2018年第9期1004-1012,共9页
AIM To investigate the role of long noncoding RNA(lnc RNA) RP4 in colorectal cancer.METHODS Lentivirus-mediated lnc RNA RP4 overexpression and knockdown were performed in the colorectal cancer cell line SW480. Cell pr... AIM To investigate the role of long noncoding RNA(lnc RNA) RP4 in colorectal cancer.METHODS Lentivirus-mediated lnc RNA RP4 overexpression and knockdown were performed in the colorectal cancer cell line SW480. Cell proliferation, tumor growth, and early apoptosis were evaluated by a cell counting kit-8 assay, an in vivo xenograft tumor model, and annexin V/propidium iodide staining, respectively. Analysis of the lnc RNA RP4 mechanism involved assessment of the association of its expression with mi R-7-5 p and the SH3 GLB1 gene. Western blot analysis was also performed to assess the effect of lnc RNA RP4 on the autophagy-mediated cell death pathway and phosphatidylinositol-3-kinase(PI3 K)/Akt signaling.RESULTS Cell proliferation, tumor growth, and early apoptosis in SW480 cells were negatively regulated by lnc RNA RP4. Functional experiments indicated that lnc RNA RP4 directly upregulated SH3 GLB1 expression by acting as a competing endogenous RNA(ce RNA) for mi R-7-5 p. This interaction led to activation of the autophagy-mediated cell death pathway and de-repression of PI3 K and Akt phosphorylation in colorectal cancer cells in vivo.CONCLUSION Our results demonstrated that lnc RNA RP4 is a ce RNA that plays an important role in the pathogenesis of colorectal cancer, and could be a potential therapeutic target for colorectal cancer treatment. 展开更多
关键词 COLORECTAL cancer LONG noncoding RNA RP4 SH3GLB1 miR-7-5p competing ENDOGENOUS RNA
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Increased Risk of Chronic Kidney Diseases in Patients with Metabolic Syndrome:A 3-year Prospective Cohort Study 被引量:10
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作者 Ying HU Li-xin SHI +1 位作者 qiao zhang Nian-chun PENG 《Current Medical Science》 SCIE CAS 2019年第2期204-210,共7页
The relationship of metabolic syndrome(MS)and its components with incident chronic kidney disease(CKD)and rapid decline of estimated glomerular filtration rate(eGFR)was investigated.A total of 10 140 patients particip... The relationship of metabolic syndrome(MS)and its components with incident chronic kidney disease(CKD)and rapid decline of estimated glomerular filtration rate(eGFR)was investigated.A total of 10 140 patients participating in the epidemiological study(Risk Evaluation of Cancers in Chinese Diabetic Individuals,REACTION)of risk factors of type 2 diabetes in China were followed up for 3 years,with MS being diagnosed by adult treatment panel IH(ATP IH)combined with waist circumference in Asian population and renal function being evaluated by eGFR<60 mL min^-1(1.73 m^2)^-1 and rapid decline of eGFR≤30%.The results showed that as compared with the non-MS group,the adjusted odds ratios(ORs)of CKD and rapid decline of eGFR were 1.64(OR:1.64;95%CI:1.20-2.25,P<0.05)and 1.23(OR:1.23;95%CI:1.05-1.43,P<0.05)respectively in MS group.With the increase in the number(0,1,2,3 and≥4)of MS components,the prevalence of CKD was 1.42%,1.44%,2.80%,3.42%,and 4.03%(P<0.001),respectively.The ORs of incident CKD were 1.67(OR:1.67;95%CI:1.22-2.27,P<0.05)for high TG,1.50(OR:1.50;95%CI:1.10-2.05,P<0.05)for low HDL-C,and 1.39(OR:1.39;95%CI:1.02-1.91,P<0.05)for hyperglycemia.The risk for developing incident CKD was higher in the group with the highest HOMA-IR than in the group with the lowest HOMA-IR(OR:1.83;95%CI:1.16-2.89,P<0.05).It is suggested that MS is an independent risk factor for incident CKD.The occurrence and development of CKD is closely related to insulin resistance. 展开更多
关键词 METABOLIC SYNDROME glomemlar FILTRATION rate INSULIN resistance
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Lignin derived multi-doped(N, S, Cl) carbon materials as excellent electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells 被引量:7
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作者 Yixing Shen Yuhang Li +3 位作者 Guangxing Yang qiao zhang Hong Liang Feng Peng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第5期106-114,共9页
Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy usi... Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells. 展开更多
关键词 ELECTROCATALYST Biocarbon Fuel cells Lignin-derived carbon Oxygen reduction reaction CHLORINE doping
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Peripheral nerve repair: a hot spot analysis on treatment methods from 2010 to 2014 被引量:6
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作者 Guang-yao Liu Yan Jin +1 位作者 qiao zhang Rui Li 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第6期996-1002,共7页
Therapeutic strategies for neurological deficits and for promoting nerve regeneration after peripheral nerve injuries have received much focus in clinical research. Advances in basic research in recent years have incr... Therapeutic strategies for neurological deficits and for promoting nerve regeneration after peripheral nerve injuries have received much focus in clinical research. Advances in basic research in recent years have increased our understanding of the anatomy of peripheral nerves and the importance of the microenvironment. Various new intervention methods have been developed, but with varying effectiveness. In the present study, we selected 911 papers on different repair methods for peripheral nerve injury from the Web of Science and indexed in the Science Citation Index from 2010 to 2014. We quantitatively examine new repair methods and strategies using bibliometrics, and we discuss the present state of knowledge and the problems and prospects of various repair methods, including nerve transfer, neural transplantation, tissue engineering and genetic engineering. Our findings should help in the study and development of repair methods for peripheral nerve injury. 展开更多
关键词 nerve regeneration peripheral nerve injury nerve repair neural transplantation nervetransfer tissue engineering genetic engineering BIBLIOMETRICS Web of Science neural regeneration
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Correlation Between the Clinical Severity, Bacterial Load, and Inflammatory Reaction in Children with Mycoplasma Pneumoniae Pneumonia 被引量:21
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作者 Chen zhang qiao zhang +7 位作者 Jie-lin DU Dan DENG Ye-lei GAO Cheng-lin WANG Hong-jie ZHAO Qian GUO Zhou FU Dai-yin TIAN 《Current Medical Science》 SCIE CAS 2020年第5期822-828,共7页
Given the lack of defining features in the clinical manifestations and radiographic findings for children with mycoplasma pneumoniae pneumonia(MPP),quantitative polymerase chain reaction(qPCR)has become a useful diagn... Given the lack of defining features in the clinical manifestations and radiographic findings for children with mycoplasma pneumoniae pneumonia(MPP),quantitative polymerase chain reaction(qPCR)has become a useful diagnostic method.This study was performed to explore the relationship between the qPCR findings,clinical symptoms,and inflammatory markers in children with MPP.Four hundred children with MPP have been enrolled in this retrospective analysis.All clinical and analytical information,including mycoplasma pneumoniae(MP)PCR results,has been collected.Based on the PCR results,the patients were divided into groups with load values(copy number)<105(54 cases),2105 and<106(71 cases),2106 and<107(112 cases),>107 and<108(114 cases),and>108(49 cases).The clinical features(including symptoms and signs)and inflammatory indicators were compared among the groups.The incidence of high fever(above 39℃),thermal peak during the entire hospitalization period,fever duration,days of hospitalization,and plasma lactate dehydrogenase(LDH)levels were statistically correlated with the MP PCR load value in children with MPP.The analysis of relevance degree showed the correlative order as a thermal peak of hospitalization>duration of fever>period of hospitalization>LDH value>C-reactive protein value.The host immune response was significantly greater in the complication group than in the non-complication group. 展开更多
关键词 mycoplasma pneumonia quantitative polymerase chain reaction bacterial load
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Strain and stress variations in the human amniotic membrane and fresh corpse autologous sciatic nerve anastomosis in a model of sciatic nerve injury 被引量:6
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作者 Chuangang Peng qiao zhang +1 位作者 Qi Yang Qingsan Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第23期1779-1785,共7页
A 10-mm long sciatic nerve injury model was established in fresh normal Chinese patient cadavers. Amniotic membrane was harvested from healthy maternal placentas and was prepared into multilayered,coiled,tubular speci... A 10-mm long sciatic nerve injury model was established in fresh normal Chinese patient cadavers. Amniotic membrane was harvested from healthy maternal placentas and was prepared into multilayered,coiled,tubular specimens.Sciatic nerve injury models were respectively anastomosed using the autologous cadaveric sciatic nerve and human amniotic membrane.Tensile test results showed that maximal loading,maximal displacement,maximal stress,and maximal strain of sciatic nerve injury models anastomosed with human amniotic membrane were greater than those in the autologous nerve anastomosis group.The strain-stress curves of the human amniotic membrane and sciatic nerves indicated exponential change at the first phase,which became elastic deformation curves at the second and third phases,and displayed plastic deformation curves at the fourth phase,at which point the specimens lost their bearing capacity.Experimental findings suggested that human amniotic membranes and autologous sciatic nerves exhibit similar stress-strain curves, good elastic properties,and certain strain and stress capabilities in anastomosis of the injured sciatic nerve. 展开更多
关键词 sciatic nerve injury model autologous nerve amniotic membrane ANASTOMOSIS tension mechanical properties neural regeneration
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Stress and strain analysis on the anastomosis site sutured with either epineurial or perineurial sutures after simulation of sciatic nerve injury 被引量:4
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作者 Guangyao Liu qiao zhang +1 位作者 Yan Jin Zhongli Gao 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第29期2299-2304,共6页
The magnitude of tensile stress and tensile strain at an anastomosis site under physiological stress is an important factor for the success of anastomosis following suturing in peripheral nerve injury treatment. Sciat... The magnitude of tensile stress and tensile strain at an anastomosis site under physiological stress is an important factor for the success of anastomosis following suturing in peripheral nerve injury treatment. Sciatic nerves from fresh adult cadavers were used to create models of sciatic nerve injury. The denervated specimens underwent epineurial and perineurial suturing. The elastic modulus (40.96 + 2.59 MPa) and Poisson ratio (0.37 + 0.02) of the normal sciatic nerve were measured by strain electrical measurement. A resistance strain gauge was pasted on the front, back left, and right of the edge of the anastomosis site after suturing. Strain electrical measurement results showed that the stress and strain values of the sciatic nerve following perineurial suturing were lower than those following epineurial suturing. Scanning electron microscopy revealed that the sciatic nerve fibers were disordered following epineurial compared with perineurial suturing. These results indicate that the effect of perineurial suturing in sciatic nerve injury repair is better than that of epineurial suturing. 展开更多
关键词 sciatic nerve injury epineurial suture perineurial suture strain electrical measurement anastomosis site tensile stress tensile strain elastic modulus Poisson ratio BIOMECHANICS peripheral nerve injury neural regeneration
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Comparison of Two Novel MRAS Based Strategies for Identifying Parameters in Permanent Magnet Synchronous Motors 被引量:7
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作者 Kan Liu qiao zhang +3 位作者 Zi-Qiang Zhu Jing zhang An-Wen Shen Paul Stewart 《International Journal of Automation and computing》 EI 2010年第4期516-524,共9页
Two model reference adaptive system (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on the Lyapunov stability theorem and the Popov stability crit... Two model reference adaptive system (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function. 展开更多
关键词 Permanent magnet synchronous motors (PMSM) model reference adaptive system (MRAS) Lyapunov stability theorem Popov stability criterion parameter identification.
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Autologous nerve anastomosis versus human amniotic membrane anastomosisA rheological comparison following simulated sciatic nerve injury 被引量:4
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作者 Guangyao Liu qiao zhang +1 位作者 Yan Jin Zhongli Gao 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第31期2424-2428,共5页
The sciatic nerve is biological viscoelastic solid,with stress relaxation and creep characteristics.In this study,a comparative analysis of the stress relaxation and creep characteristics of the sciatic nerve was cond... The sciatic nerve is biological viscoelastic solid,with stress relaxation and creep characteristics.In this study,a comparative analysis of the stress relaxation and creep characteristics of the sciatic nerve was conducted after simulating sciatic nerve injury and anastomosing with autologous nerve or human amniotic membrane.The results demonstrate that,at the 7 200-second time point,both stress reduction and strain increase in the human amniotic membrane anastomosis group were significantly greater than in the autologous nerve anastomosis group.Our findings indicate that human amniotic membrane anastomosis for sciatic nerve injury has excellent rheological characteristics and is conducive to regeneration of the injured nerve. 展开更多
关键词 sciatic nerve injury ANASTOMOSIS autologous nerve human amniotic membrane RHEOLOGY
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光诱导双助催化剂在半导体表面的自发形成(英文)
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作者 慕林超 张巧 +5 位作者 陶晓萍 赵越 王升扬 崔俊艳 范峰滔 李灿 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第11期1730-1735,共6页
半导体光催化体系的助催化剂在光生电荷分离和表面催化反应过程中扮演着重要的角色.然而,在反应条件下助催化剂的化学态是否发生改变尚不清楚.本文以钽酸钠为模型光催化剂,系统地研究了镍基助催化剂在光催化分解水反应中的化学态.结果发... 半导体光催化体系的助催化剂在光生电荷分离和表面催化反应过程中扮演着重要的角色.然而,在反应条件下助催化剂的化学态是否发生改变尚不清楚.本文以钽酸钠为模型光催化剂,系统地研究了镍基助催化剂在光催化分解水反应中的化学态.结果发现,在光诱导条件下半导体钽酸钠单晶表面自发形成了金属镍和氧化镍双助催化剂.首先用传统的水热法合成只暴露单一晶面的六面体钽酸钠半导体单晶光催化剂和暴露不等同晶面的二十六面体钽酸钠半导体单晶光催化剂.原位光沉积结果显示,暴露不同晶面的二十六面体钽酸钠半导体单晶光催化剂存在晶面间的电荷分离现象,进一步利用该现象可以确定不同催化活性位上镍基助催化剂的作用.XPS结果显示,半导体钽酸钠单晶表面的镍基助催化剂存在的不同价态.高分辨透射电镜结果表明,不同晶面上的镍基助催化剂具有不同的形貌,并且通过晶格衍射条纹的对比确认了不同镍基助催化剂物种的归属和作用.将表面浸渍氧化镍的二十六面体钽酸钠半导体光催化剂用于全分解水测试发现,反应开始阶段H_2:O_2比值小于2:1,说明部分光生电子被消耗掉,用于还原氧化镍,生成了金属镍.将表面还原的金属镍光催化剂进行全分解水测试发现,反应开始阶段H_2:O_2比值大于2:1,说明部分光生空穴被消耗掉,用于氧化金属镍,生成了氧化镍,金属镍和氧化镍最终在反应的过程中达到了平衡.金属镍担载在{001}晶面上,起着还原助催化剂的作用,参与质子还原,释放出H_2;氧化镍担载在其他晶面上,扮演着氧化助催化剂,参与水的氧化,释放出O_2;金属镍和氧化镍共同促进了光催化全分解水反应,使反应活性达到了最高.这种双助催化剂的自发形成现象不仅存在于二十六面体钽酸钠单晶半导体表面,在六面体钽酸钠单晶半导体表面也同样存在,是一个普适性的现象.在六面体钽酸钠半导体单晶光催化剂表面同样可以发现不同形貌的镍基助催化剂,分别归属于金属镍和氧化镍.本文说明了助催化剂的化学态在光催化反应的条件下是可以发生改变的,并且光生电荷可以在半导体表面诱导双助催化剂的自发形成. 展开更多
关键词 光催化 助催化剂 化学态 光生电荷 自发形成
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Effect of heat stress on the MDA, proline and soluble sugar content in leaf lettuce seedlings 被引量:7
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作者 Yingyan Han Shuangxi Fan +1 位作者 qiao zhang Yanan Wang 《Agricultural Sciences》 2013年第5期112-115,共4页
High temperature stress on different varieties of lettuce seedlings in MDA, proline and soluble sugar content were studied. The results were as follows : With the stress temperature, varieties of leaf lettuce seedling... High temperature stress on different varieties of lettuce seedlings in MDA, proline and soluble sugar content were studied. The results were as follows : With the stress temperature, varieties of leaf lettuce seedlings in the MDA, proline and soluble sugar content gradually increased;Different varieties had the most significant difference in 38/33℃(d/n). The increase of heat-resistant varieties on proline and soluble sugar content was quick and high, while its increase in MDA content was slow and small. 展开更多
关键词 LEAF LETTUCE High Temperature MDA PRALINE Soluble Sugar
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Incorporation of nano/micron-SiC particles in Ni-based composite coatings towards enhanced mechanical and anti-corrosion properties 被引量:2
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作者 Bowei zhang qiao zhang +5 位作者 Zhan zhang Kui Xiao Qiong Yao Guojia Ma Gang Sun Junsheng Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第1期153-160,共8页
Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The ... Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath,followed by the evaluation of their mechanical and anti-corrosion properties.The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate.X-ray diffraction(XRD)patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along(200)facet.In addition,it is found that the incorporated SiC particles with medium micron sizes(8 and 1.5μm)could significantly enhance the micro-hardness of the Ni composite coatings.Nevertheless,electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced.In contrast,the combined incorporation of nanosized(50 nm)SiC particles with medium micron(1.5μm)ones is capable of promoting the compactness of the composite coatings,which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss. 展开更多
关键词 Watts bath Ni coating SiC particles corrosion resistance ELECTRODEPOSITION
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Near-infrared chemical imaging for quantitative analysis of chlorpheniramine maleate and distribution homogeneity assessment in pharmaceutical formulations 被引量:2
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作者 Manfei Xu Luwei Zhou +3 位作者 qiao zhang Zhisheng Wu Xinyuan Shi Yanjiang qiao 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2016年第6期12-20,共9页
Near infrared chemical imaging(NIR-CI)combines conventional near infrared(NIR)spectros-copy with chemical imaging,thus provides spectral and spatial information simult aneously.It could be utilized to visualize the sp... Near infrared chemical imaging(NIR-CI)combines conventional near infrared(NIR)spectros-copy with chemical imaging,thus provides spectral and spatial information simult aneously.It could be utilized to visualize the spatial distribution of the ingredients in a sample.The data acquired using NIR CI instrument are hyperspectral data cube(hypercube)containing thousands of spectra.Chemometric methodologies are necessary to transform spectral information into chemical information.Partial least squares(PLS)method was performed to extract chemical information of chlorpheniramine maleate in pharmaceutical formulations.A series of samples which consisted of different CPM concentrations(w/w)were compressed and hypercube data were measured.The spectra extracted from the hypercube were used to establish the PLS model of CPM.The results of the model were R^(2)_(val)0.981,RMSEC 0.384%,RMSECV 0.483%,RMSEP 0.631%,indicating that this model was reliable. 展开更多
关键词 Near infrared chemical imaging partial least squares regression assessment of distributional homogeneity chlorpheniramine maleate
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Identification of berbamine dihydrochloride from barberry as an anti-adipogenic agent by high-content imaging assay 被引量:2
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作者 Shifeng Wang qiao zhang +4 位作者 Yuxin zhang Yanling zhang Qinghua Wu Shiyou Li Yanjiang qiao 《Journal of Traditional Chinese Medical Sciences》 2016年第2期91-99,共9页
Objective:Lipid droplet(LD)deposition in adipose tissue is a critical factor leading to metabolic dysfunction.Various herbal medicines in traditional Chinese medicine(TCM)are used to treat hyperlipidemia,type 2 diabet... Objective:Lipid droplet(LD)deposition in adipose tissue is a critical factor leading to metabolic dysfunction.Various herbal medicines in traditional Chinese medicine(TCM)are used to treat hyperlipidemia,type 2 diabetes,obesity,and other diseases.The objective of this study was to identify potential anti-adipogenic agents from TCM herbal compounds.Methods:One hundred and twenty compounds were evaluated in terms of their effect on adipocyte differentiation through image-based high content screening.Anti-adipogenic effects of identified hits were further confirmed at various concentrations.In addition,drug-induced liver injury assay was performed with HepG2 cells to test the hepatotoxicity of hit compounds.Results:Berbamine(BBM),a chemical isolated from barberry,and a derivative of BBM,berbamine dihydrochloride(BBMD),reduced LDs formation by more than 50%.Dose-dependent effects were observed and the IC50 values of the two hits,BBM and BBMD,were determined as 1.88 mM and 0.95 mM,respectively.Moreover,BBM induced mild HepG2 cell injury,while its dihydrochloridedBBMD did not exhibit hepatotoxicity within 40 mM.Conclusion:This study demonstrates that BBMD may be a potential therapeutic candidate for disorders associated with elevated LDs accumulation. 展开更多
关键词 3T3-L1 adipocyte Berbamine dihydrochloride HEPATOTOXICITY High content screening Lipid droplet
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