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Refinement and estimation of asphalt flow number using partial load history

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第1期9卷 120-133页

作者： M.A.Dalhat Khaleel Al-Adham Hamad I.Al-Abdul Wahhab Arshad Jamal Department of Transportation and Traffic Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityDammamSaudi Arabia Department of Civil and Environmental Engineering King Fahd University of Petroleum and MineralsDhahranSaudi Arabia

The effect of tertiary flow length on asphalt concrete(AC) flow number(FN) has been studied in this paper. The standard FN test(AASHTO T378) designated by American Association of State Highway and Transportation Officials(AASHTO) is currently among the widely adopted test for assessing the rutting performance of AC mixtures. The standard adopts the Fracken model(FM) for fitting the permanent deformation curve(PDC), prior to FN estimation. The FN was observed to vary as tertiary flow progresses. The FM, along with other PDC models(MFM-1 and MFM-2) obtained by modifying the FM, was utilized to analyze and minimized this variation. Variation of FN resulted because of mathematization of the PDC data. Instead of representing the actual initiating point of permanent shear deformation of the strain data, estimated values of FN were observed to indicate the inflection points of the fitted parent curve. As per standard FN range suggested by AASHTO T378, the observed variation in FN leads to the situation, where a single asphalt mix specimen can be regarded as appropriate for two different traffic levels, depending on the tertiary flow point at which the test is terminated. Supplementary steps in the FN estimation methods were proposed for refinement of FN values. For the refinement and further standardization of FN value and FN test respectively, FN:T(flow number to test duration ratio) has been recognized as the key and most simple solution. Two potential options for employing FN:T in the estimation of FN have also been highlighted. Several important correlations have been reported herein as well. Comparatively, MFM-1 was found to be more robust in FN:T curve utilization than MFM-2 and FM.

关键词： Road engineering hma Permanent deformation Flow number Francken model Tertiary flow

An efficient TILLING platform for cultivated tobacco

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Journal of Integrative Plant Biology 2020年第2期62卷 165-180页

作者： Yu-Long Gao Xue-Feng Yao Wen-Zheng Li Zhong-Bang Song Bing-Wu Wang Yu-Ping Wu Jun-Li Shi Guan-Shan Liu Yong-Ping Li Chun-Ming Liu Key Laboratory of Tobacco Biotechnological Breeding National Tobacco Genetic Engineering Research CenterYunnan Academy of Tobacco Agricultural SciencesKunming 650021China Key Laboratory of Plant Molecular Physiology Institute of Botanythe Chinese Academy of SciencesBeijing 100093China The University of Chinese Academy of Sciences Beijing 100049China Tobacco Research Institute the Chinese Agriculture Academy of SciencesQingdao 266101China Institute of Crop Sciences the Chinese Academy of Agricultural SciencesBeijing 100081China

Targeting-induced local lesions in genomes(TILLING)is a powerful reverse-genetics tool that enables high-throughput screening of genomic variations in plants.Although TILLING has been developed for many diploid plants,the technology has been used in very few polyploid species due to their genomic complexity.Here,we established an efficient capillary electrophoresis-based TILLING platform for allotetraploid cultivated tobacco(Nicotiana tabacum L.)using an ethyl methanesulfonate(EMS)-mutagenized population of 1,536 individuals.We optimized the procedures for endonuclease preparation,leaf tissue sampling,DNA extraction,normalization,pooling,PCR amplification,heteroduplex formation,and capillary electrophoresis.In a test screen using seven target genes with eight PCR fragments,we obtained 118 mutants.The mutation density was estimated to be approximately one mutation per 106kb on average.Phenotypic analyses showed that mutations in two heavy metal transporter genes,hma2S and hma4T,led to reduced accumulation of cadmium and zinc,which was confirmed independently using CRISPR/Cas9 to generate knockout mutants.Our results demonstrate that this powerful TILLING platform(available at http://***)can be used in tobacco to facilitate functional genomics applications.

关键词： An efficient TILLING platform cultivated tobacco hma

Comparative analysis on dynamic behavior of two hma railway substructures

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Journal of Modern Transportation 2011年第1期19卷 26-34页

作者： Mingjing FANG Yanjun QIU Jerry G. ROSE Randy C. WEST Changfa AI National Center for Asphalt Technology （NCAT） College of Engineering Auburn University Auburn AL 36830-5577 USA School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China College of Engineering Civil Engineering Department University of Kentucky Lexington KY40506-0281 USA

A numerical analysis using a finite element program was performed on three structures： hot mix asphalt （hma） reinforced trackbed （RACS-1）, hma directly supported trackbed （RACS-2）, and traditional Portland Cement Concrete （PCC） slab track （SlabTrack）. Although the comprehensive dynamic responses of RACS-1 were similar with SlabTrack, hma layer can positively affect the stress distributions. In particular, the horizontal stresses indicate that the resilience of RACS-1 was improved relative to SlabTrack. In addition, hma reinforced substructure has the capacity to recover the residual vertical deformation. The effective depth for weakening dynamic loadings is mainly from 0 to 2 m, this being especially true at 0.5 m. The results from the analysis show that hma is a suitable material for the railway substructure to enhance resilient performance, improve the stress distribution, weaken dynamic loading, and lower the vibration, especially at the effective depth of 2 m. The hma constructed at the top of the stone subbase layer allows the vertical modulus a smooth transition. In terms of the comprehensive dynamic behaviors, RACS-1 is better than SlabTrack, while the results for RACS-2 are inconclusive and require further research.

关键词： high-speed railway hma railway substructure FEM analysis

基于全基因组的三七hma基因家族鉴定与生物信息学分析

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分子植物育种 2023年第17期21卷 5642-5653页

作者：早浩龙刘春兰黄珍华徐瑞施辉能龙光强罗瑜范伟云南农业大学西南中药材种质创新与利用国家地方联合工程研究中心云南省药用植物生物学重点实验室昆明650201 云南农业大学资源与环境学院昆明650201 云南农业大学食品科学技术学院昆明650201

三七[Panax notoginseng (Burk.) F.H.Chen]作为中国重要的药用植物,具有较强的金属元素吸收富集特性,重金属ATP酶(heavy metal transporting ATPase,hma)家族已被证明参与了众多二价金属离子的吸收转运,然而目前在三七中还没有关于金... 详细信息

三七[Panax notoginseng (Burk.) F.H.Chen]作为中国重要的药用植物,具有较强的金属元素吸收富集特性,重金属ATP酶(heavy metal transporting ATPase,hma)家族已被证明参与了众多二价金属离子的吸收转运,然而目前在三七中还没有关于金属元素吸收转运相关研究。本研究从三七全基因组中鉴定了10个hmas基因家族成员(Pnhmas),Pnhma1~Pnhma3属于铜(Cu)/银(Ag)亚组,Pnhma4~Pnhma10属于锌(Zn)/钴(Co)/镉(Cd)/铅(Pb)亚组;Pnhmas均被预测定位于质膜或叶绿体上,Pnhma10与其他成员间蛋白理化性质差异较大;不同亚组成员间基因结构、蛋白结构域和保守基序模式与系统发育的多样性密切相关,它们均具有不同的金属离子转运相关功能,但具体转运的离子存在差异;片段复制和串联重复可能是Pnhmas家族基因在三七基因组中扩增和进化的主要原因之一;组织表达特异性表明,Pnhma6和Pnhma10在芦头中高表达,Pnhma7在主根中高表达,Pnhma3和Pnhma5在茎中高表达,Pnhma1、Pnhma2和Pnhma9在叶中高表达,Pnhma3、Pnhma4和Pnhma8在花中高表达;Cd胁迫下,Pnhmas在三七根部上调表达。密码子偏好性和异源表达适配受体分析发现,Pnhmas基因家族偏好使用以A/T结尾的密码子,且自然选择是其密码子偏好性的主要影响因素,酿酒酵母可作为其异源表达适配受体。本研究为今后三七金属元素候选基因的筛选和功能研究提供了前期生物信息学基础。

关键词：三七重金属转运ATP酶 hma 密码子偏好性生物信息学

THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-p-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION

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Chinese Journal of Polymer Science 1992年第3期10卷 250-257页

作者：丘坤元张璋华冯新德 Department of Chemistry Peking University Beijing 100871

The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.

关键词： HMT THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-p-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION BPO hma MMA DMT LPO

SSCP和hma方法在马MHC-I类分子基因多态性研究中的应用

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遗传 2008年第12期30卷 1635-1639页

作者：项伟马建王雪峰赵玉军周建华沈阳农业大学畜牧兽医学院沈阳110161 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室哈尔滨150001 东北林业大学野生动物资源学院哈尔滨150040 内蒙古农业大学动物科学与医学学院呼和浩特010018

文章使用SSCP和hma两种基于聚丙烯酰胺凝胶电泳的方法对马MHC-I类分子基因多态性进行了分析。在应用SSCP法进行分析时,尽管经过实验条件优化,仍未得到对MHC-I基因理想的分离效果,提示该方法对分离多态性较高的基因有一定局限性。在对HM... 详细信息

文章使用SSCP和hma两种基于聚丙烯酰胺凝胶电泳的方法对马MHC-I类分子基因多态性进行了分析。在应用SSCP法进行分析时,尽管经过实验条件优化,仍未得到对MHC-I基因理想的分离效果,提示该方法对分离多态性较高的基因有一定局限性。在对hma法用参考标准DNA对影响DNA分子构象的温度和变性剂浓度等实验条件进行优化后,获得了对马MHC-I类分子基因较好的分离效果。6、7、8、9和10号马的样本在相对应泳道上分别出现了6、5、6、5和7个条带。从凝胶中进行DNA条带回收后克隆测序的结果表明,这一方法可以有效地分离高度多态性的MHC-I类分子基因。

关键词： SSCP hma 基因多态性 MHC-I类分子基因

苎麻重金属ATP酶Bnhma1基因的克隆及表达分析

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植物生理学报 2020年第7期56卷 1531-1540页

作者：苏小惠佘玮杨瑞芳崔丹丹刘婕仪王继龙王昕慧刘婉慧崔国贤湖南农业大学农学院长沙410128

植物重金属ATP酶(heavy metal transporting ATPase, hma)涉及植物对重金属的吸收、转运、解毒和富集等过程。根据苎麻(Boehmeria nivea)转录组测序结果中hma基因的保守序列设计特异性引物,采用RACE (rapid-amplification of cDNA ends... 详细信息

植物重金属ATP酶(heavy metal transporting ATPase, hma)涉及植物对重金属的吸收、转运、解毒和富集等过程。根据苎麻(Boehmeria nivea)转录组测序结果中hma基因的保守序列设计特异性引物,采用RACE (rapid-amplification of cDNA ends)技术从苎麻中获得了hma全长cDNA序列(Genbank:2209492)。该基因cDNA全长为2 811 bp,含有一个2 487 bp的开放阅读框,编码蛋白含828个氨基酸,分子量为90.70 kDa,等电点(p I)为8.84,属于P-type ATPase家族成员。与川桑(Morus notabilis)、白梨(Pyrus bretschneideri)的相似性高达80%以上。亚细胞定位预测Bnhma1定位在叶绿体, qRT-PCR分析表明Bnhma1在苎麻中的相对表达量依次为叶片>茎皮>根部>茎秆。镉(Cadmium)胁迫前后镉敏感品种‘湘苎3号’叶片、茎秆和根中Bnhma1表达量高于其他两个品种,基因表达的差异化可能是苎麻品种耐镉能力不同的原因之一。

关键词：苎麻 hma 基因克隆序列分析

Impact of Intrinsic Properties of Aggregate and Volumetric Properties of Hot Mixture Asphalt (hma) in the Influence of the Resistance to Rutting

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Open Journal of Civil Engineering 2020年第3期10卷 187-194页

作者： Mouhamed Lamine Chérif Aidara Makhaly Ba Alan Carter UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal Ecole de Technologie Supérieure (ETS) Director of Pavement Bituminous Materials Laboratory (LCMB) Montréal Canada

Several studies show that properties of Hot Mixture Asphalt (hma) mix design materials, aggregate gradation and volumetric properties had an influence on their resistance to rutting. However, these properties do not i... 详细信息

Several studies show that properties of Hot Mixture Asphalt (HMA) mix design materials, aggregate gradation and volumetric properties had an influence on their resistance to rutting. However, these properties do not impact in the same way this performance. For a given aggregate type, an infinity aggregate gradation type can be observed, and for each type of HMA several types of bituminous binder can be used. This article aims to measure the evolution of resistance to rutting according to the three main classes of National Cooperative Highway Research Program (NCHRP) aggregate gradation (dense-graded, fine-graded and coarse-graded). To this end, a study was conducted on the measurement of rutting resistance for eight bituminous mixtures manufactured with two bitumen types and two types of manufacturing aggregates. The results showed that there is a priority order of these different parameters on the influence of the resistance to rutting. This highlights a competition between the properties of aggregate and type of granular skeleton. Indeed, for the same type of aggregate, asphalt binder type first impacts resistance to rutting of the HMA followed by aggregate gradation, volumetric properties of the mix and finally by the angularity of the aggregates. However, this order cannot be fixed and can depend of the intensity of each parameter.

关键词： Aggregate Gradation hma Rutting Basalt Quartzite

Rutting Resistance of hma Rehabilitated with Micro-Surfacing

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Open Journal of Civil Engineering 2018年第2期8卷 245-255页

作者： Arbia Garfa Alan Carter Anne Dony école de Technologie Supérieure ETS Montréal Canada Ecole Spécial des travaux publics ESTP Paris France

The work presented here is a study on the measurement and prediction of the rutting resistance of previously rutted asphalt mixes rehabilitated with a layer of micro-surfacing manufactured with virgin and recycled aggregates at different stages of aging. The experimental procedure consisted of rutting tests on hot mix asphalt slabs already degraded and repaired with virgin and recycled micro-surfacing. Then, the evolution of the behavior of micro-surfacing cast on the hot mix asphalt slabs is observed according to loading cycles of the pavement rutting tester MLPC. Before rutting tests, slabs are subjected to 24 hours at 50°C and aged for 2 days and 5 days at 85°C in the oven. The results showed rutting percentages of 6.3% for hot mix asphalt slabs aged for 2 days and 7.2% for 5 days. These hot mix slabs repaired with virgin micro-surfacing have rutting percentage of about 9.2 % for 2 days of aging and 6.5% for 5 days of aging. While, the hma slabs repaired with recycled micro-surfacing have rutting percentage of about 8.1% for 2 days of aging and 5.9% for 5 days of aging. These results allowed the development of a prediction model based essentially on three predictor variables including cycle number, rutting state and percentage of water in the micro-surfacing material. The developed model shows a strong correlation between the predicted rutting values and the rutting values measured with the MLPC rut tester. Thermal aging in oven has a positive impact on the resistance to permanent deformation of new asphalt mixes and those rehabilitated with micro-surfacing. The parameters of rutting state and contribution water are significant in the rutting prediction model, while the cycle number remains a non-significant parameter in the model but determinant.

关键词： hma RAP Micro-Surfacing Rutting Aging