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Comparison of Starch Granule Size Distribution Between Hard and Soft Wheat Cultivars in Eastern China 被引量:9
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作者 LI Wen-yang YAN Su-hui YIN Yah-ping LIYong LIANG Tai-bo GU Feng DAI Zhong-min WANG Zhen-lin 《Agricultural Sciences in China》 CAS CSCD 2008年第8期907-914,共8页
Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai'an Ex... Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and functionality. Two types of wheat cultivars, the hard and soft wheat cultivars, grown at Tai'an Experimental Station of Shandong Agricultural University, Taian, Shandong, China, were examined in this study. The granule size distribution and amylose contents in wheat grains were studied and compared, and relationships between the properties were identified. A clear bimodal distribution of granule size was shown in all wheat cultivars. Volume distribution of starch granules shows the typical bimodal with peak values in the ranges of 5.6-6.1μm and 20.7-24.9μm, respectively. Also, granule surface area distribution was bimodal with peak values in the ranges of 2.4-3.2μm and 20.7-24.9μm, respectively. Number distribution of granules was a typical population with a peak value in the range of 0.54-1.05μm. Contributions from the granules 〈 2.8μm and 〈 9.9μm to the total volume were in the ranges of 94.2-95.1% and 99.7-99.9% of total number, respectively. Proportions of granules〈2.8μm, 2.8-9.9μm, 9.9-22.8μm, and 22.8-42.8μm were in the ranges of 12.9-14.3%, 28.4-31.1%, 33.5-35.6%, and 19.7-22.7% for hard wheat, and 10.3-13.9%, 26.6-28.1%, 32.7-34.6%, and 24.2-27% for soft wheat. Hard wheat had greater B-type granules ( 〈 9.9μm), and had fewer granules of 22.8-42.8μm than soft wheat. Amylose content was positively related to volume percentage of granules 22.8-42.8μm, and negatively related to volume percentage of granules 2.8-22.8μm. 展开更多
关键词 wheat (Triticum aestivum L.) starch granule size distribution AMYLOSE hard wheat soft wheat
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Magnetic Properties Hard-Soft SmCo<sub>5</sub>-FeNi and SmCo<sub>5</sub>-FeCo Composites Prepared by Electroless Coating Technique 被引量:3
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作者 M. Lamichanne B. K. Rai +2 位作者 S. R. Mishra V. V. Nguyen J. P. Liu 《Open Journal of Composite Materials》 2012年第4期119-124,共6页
Composites of SmCo5-FeNi and SmCo5-FeCo, hard-soft magnetic materials, have been synthesized via electroless plating of magnetically hard SmCo5 powder particles with magnetically soft FeNi and FeCo, respectively. The ... Composites of SmCo5-FeNi and SmCo5-FeCo, hard-soft magnetic materials, have been synthesized via electroless plating of magnetically hard SmCo5 powder particles with magnetically soft FeNi and FeCo, respectively. The influence of coating thickness of soft magnetic layers on the structure and magnetic properties of the composite has been studied. Overall FeNi coating was found to be less dense compared to FeCo for the same plating duration. Structurally the coat ing was found to be nodular in morphology. These coating have dramatic effect on the overall magnetic property of the composite. As compared to FeNi coated SmCo5 composite, two-fold increase in the saturation magnetization has been observed upon coating SmCo5 (Ms^28 emu/g) with FeCo to a value 56 emu/g. The coercivity of composite powder was found to decrease with increasing the coating layer thickness. The absence of exchange spring behavior in the hard-soft composite is attributed to magnetically soft layer thickness exceeding the theoretical length limit for exchange-spring coupling. 展开更多
关键词 ELECTROLESS Plating hard-soft COMPOSITES Exchange Spring
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Constitutive model for methane desorption and diffusion based on pore structure differences between soft and hard coal 被引量:9
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作者 Liu Yanwei Wang Dandan +2 位作者 Hao Fuchang Liu Mingju Mitri Hani S. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第6期937-944,共8页
This paper aims to improve the accuracy and applicability of gas diffusion mathematical models from coal particles. Firstly, a new constitutive model for gas diffusion from coal particles with tri-disperse pore struct... This paper aims to improve the accuracy and applicability of gas diffusion mathematical models from coal particles. Firstly, a new constitutive model for gas diffusion from coal particles with tri-disperse pore structure is constructed by considering the difference in characteristics between soft coal and hard coal.The analytical solution is then derived, that is, the quantitative relationship between gas diffusion rate(Qt/Q_∞) and diffusion time(t), The pore structure parameters of soft coal and hard coal from Juji coal mine are determined. Gas diffusion rules are numerically calculated and investigated by physical simulation methods. Lastly, the applicability of this model is verified. The results show that the homogeneous model only applies to the gas diffusion process of hard coal during the initial 10 min. The calculation results from this model and the physical experimental results of soft coal and hard coal are nearly identical during the initial 30 min. 展开更多
关键词 soft and hard coal Gas diffusion PORE structure CONSTITUTIVE models Physical simulation
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Influence of confining stress on fracture characteristics and cutting efficiency of TBM cutters conducted on soft and hard rock 被引量:2
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作者 刘京铄 曹平 +1 位作者 刘杰 蒋喆 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1947-1955,共9页
Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine(TRW-3000)... Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine(TRW-3000) designed and manufactured in Central South University(China). Results are obtained by performing analysis on the fracture scopes of cement and granite plates,the characteristics of cutting force in cutting processes and the cutting efficiency. Firstly, the increase of latitude fracture scope and the decrease of longitude fracture scope are both more notable in the tests conducted on cement plates subjected to the increasing confining stresses; secondly, the increase tendency of peak penetration forces obtained from tests conducted on granite plates is more obvious, however, the increase tendencies of average penetration forces achieved from cement and granite plates are close to each other; thirdly, the cutting efficiency could be improved by increasing the spacing between cutters when the confining stress which acts on soft and hard rock increases in a certain degree, and the cutting efficiency of soft rock is more sensitive to the varying confining stresses. 展开更多
关键词 triaxial testing machine numerical study tunnel boring machine(TBM) cutter confining stress soft and hard rock cutting efficiency
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Contrastive Study of Metadiscourse in the Conclusion of Academic Papers between Soft Science and Hard Science
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作者 徐伟伟 《海外英语》 2014年第3X期209-210,共2页
Academic paper as a genre is communicative.Interactional metadiscourse is one of the linguistic features that can significantly show the communicative feature of texts.With different research methodologies and charact... Academic paper as a genre is communicative.Interactional metadiscourse is one of the linguistic features that can significantly show the communicative feature of texts.With different research methodologies and characteristics,academic papers of hard and soft science present different degree of communicative features.The corpus of this study consists of 16 academic papers among which 8 are from hard science and 8 from soft science.This article aims to explore the different ways of scholars from soft and hard science to use metadiscourse in the conclusion part of their academic papers to exert lights to the pedagogical development of academic papers. 展开更多
关键词 academic papers BETWEEN soft SCIENCE and hard scie
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Proximal Femoral Cortical Thickness and Medullary Canal Diameter in Soft and Hard Water Regions
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作者 Ahmed Elmorsy Sarah Whitehouse +1 位作者 John Timperley Stephen Veitch 《Open Journal of Orthopedics》 2016年第3期58-62,共5页
This study compared proximal femoral morphology in patients living in soft and hard water regions. The proximal femoral morphology of two groups of 70 patients living in hard and soft water regions with a mean age of ... This study compared proximal femoral morphology in patients living in soft and hard water regions. The proximal femoral morphology of two groups of 70 patients living in hard and soft water regions with a mean age of 72.29 (range: 50 to 87 years) was measured using an antero-posterior radiograph of the non-operated hip with magnification adjusted. The medullary canal diameter at the level of the lesser trochanter (LT) was significantly wider in patients living in the hard water region (mean width: 1.9 mm wider;p = 0.003). No statistical significant difference was found in the medullary canal width at 10 cm below the level of LT, Dorr index, or Canal Bone Ratio (CBR). In conclusion, the proximal femoral morphology does differ in patients living in soft and hard water areas. These results may have an important clinical bearing in patients undergoing total hip replacement surgery. Further research is needed to determine whether implant survivorship is affected in patients living in hard and soft water regions. 展开更多
关键词 Hip hard Water soft Water Femoral Cortical Thickening Medullary Diameter
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XPS STUDIES OF IRRADIATED HARD AND SOFT Si—SiO_2
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作者 刘昶时 赵元富 +3 位作者 王忠燕 陈萦 刘芬 赵汝权 《Nuclear Science and Techniques》 SCIE CAS CSCD 1993年第3期181-185,共5页
The interracial structure of hard and soft oxides grown by dry oxidation on<100> n-type silicon substrates is examined using high resolution mild X-ray photoelectron spectroscopy (XPS) before and after irradiati... The interracial structure of hard and soft oxides grown by dry oxidation on<100> n-type silicon substrates is examined using high resolution mild X-ray photoelectron spectroscopy (XPS) before and after irradiation. Substantial differences in silicon of silica state (B.E. 103.4 eV), silicon of transitional state (B.E. 101.5 eV), surplus oxygen (B.E. 529.6 eV) and negative two-valence oxygen (B.E. 531.4 eV) are observed between the two kinds of samples. The XPS spectra strongly depend on the conditions of irradiation for soft samples, but do not as remarkablely as soft samples for hard samples. The effects of irradiation doses on XPS are greater than that of irradiation bias fields. Some viewpoints of irradiation induced hole electron pair are proposed to explain the results. 展开更多
关键词 XPS Radiation hard Radiation soft Si-SiO_2 Bias field Radiation dose
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Proteomic analysis reveals the differential proteins of endosperm between soft and hard wheat varieties
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作者 Feng Jia Haicheng Yin +2 位作者 Qi Wang Yu Chen Jinshui Wang 《Grain & Oil Science and Technology》 2019年第2期27-32,共6页
In this study,we revealed the differential proteins from the wheat endosperms using proteomic analysis and investigated their surface properties.The pattern of the polypeptides obtained from the Yangmai-15 and Yangmai... In this study,we revealed the differential proteins from the wheat endosperms using proteomic analysis and investigated their surface properties.The pattern of the polypeptides obtained from the Yangmai-15 and Yangmai-16 wheat varieties were compared using two-dimensional polyacrylamide gels.In addition,we compared the characteristics of the grain such as grain hardness,protein content,wet gluten,dough development time,dough stability,gliadin and glutenin contents between Yangmai-15 and Yangmai-16,and the results were significantly different.Notably,216 and 197 protein spots were separated from Yangmai-15 and Yangmai-16,respectively.The isoelectric points of the identified proteins ranged from 4 to 10 and the molecular weights of proteins varied from 10 to 100 kDa.Further,21 and 8 specific differential protein spots were identified fromthe flour of Yangmai-15 and Yangmai-16,respectively.The surface properties of identified peptides consisted of hydrophobic or hydrophilic residues,as well as randomly scattered residues.The proteomic analysis of the wheat endosperms provides a novel insight into the biochemical basis for the differences in physicochemical properties between the soft and hard wheat varieties. 展开更多
关键词 soft and hard wheat PROTEOME PEPTIDES surfaces ENDOSPERM proteins
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High energy product of isotropic bulk Sm-Co/α-Fe(Co)nanocomposite magnet with multiple hard phases and nanoscale grains 被引量:6
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作者 Shuo Li Longfei Ma +5 位作者 Jinkui Fan Jianping Yang Qiang Zheng Baoru Bian Jian Zhang Juan Du 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第29期183-188,共6页
Nanocomposite magnets consisting of hard and soft magnetic phases have potential applications to be the next generation of permanent magnets with very high energy product and less expensive rare-earth elements.But it ... Nanocomposite magnets consisting of hard and soft magnetic phases have potential applications to be the next generation of permanent magnets with very high energy product and less expensive rare-earth elements.But it is still a big challenge to obtain bulk magnets with ideal microstructure and high performance.In this work,two-step warm processing at relative low temperatures had been adopted to obtain nearly theoretical density bulk nanocomposite magnets from amorphous/nanocrystalline powder precursors.Novel nanostructures consisting of multiple Sm-Co hard phases(SmCo_(5)as main phase,SmCO_(3),SmCo_(7),Sm_(2)Co_(17)as minor phases)and 25 wt%α-Fe(Co)soft phase,nanoscale grain size below 20 nm for both the hard phase and soft phase,and the diffusion of Fe and Co compositions had been obtained in bulk isotropic magnets.Besides the ideal nanostructures,a high coercivity of 5.9 kOe,M_(r)/M_(s)value of 0.78 and a high square degree of demagnetization curve S=0.47 were obtained.All of these factors together brought a new record-high energy product(BH)_(max)of 23.6 MGOe.These results make an important step toward fabricating novel nanostructure with high performance. 展开更多
关键词 hard/soft phase nanocomposite Isotropic bulk Magnetic properties Grain size Phase constitution
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用于输送带修补胶的室温固化聚氨酯的制备与性能研究
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作者 赵彤 冯桐伟 +3 位作者 孟阳 赵成哲 于冰 田明 《高分子学报》 北大核心 2026年第1期157-167,共11页
橡胶输送带常受到磨损而影响正常使用,通常使用浇注型聚氨酯等材料作为修补胶对磨损处进行现场修补,但现有聚氨酯修补胶对橡胶的粘接强度难以满足实际需求,且浇注型聚氨酯的结构组成与粘接强度间关系的研究尚不完善.基于此,本工作利用... 橡胶输送带常受到磨损而影响正常使用,通常使用浇注型聚氨酯等材料作为修补胶对磨损处进行现场修补,但现有聚氨酯修补胶对橡胶的粘接强度难以满足实际需求,且浇注型聚氨酯的结构组成与粘接强度间关系的研究尚不完善.基于此,本工作利用预聚体法成功制备了可室温固化的聚氨酯涂层,并同时从分子内聚力、润湿能力、粘接界面微观结构等角度对涂层与橡胶间的粘接性能展开研究.研究结果显示:硬段含量越高,分子内聚力越强,浇注型聚氨酯固化后形成的涂层对橡胶基体越容易形成更好的附着,T型剥离强度最高可达11.73 N/mm;低黏度浇注型聚氨酯有利于形成良好附着,适合的附着层厚度是良好粘接的关键.除此之外,本工作还研究了软硬段含量对浇注型聚氨酯涂层的拉伸性能、耐磨性能及硬度的影响,为浇注型聚氨酯涂层的制备与性能调控提供了理论支持.该聚氨酯涂层预期可作为橡胶修补胶,实现对橡胶输送带的室温快速修补. 展开更多
关键词 浇注型聚氨酯 室温固化 软硬段含量 黏度 内聚力
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“双碳”目标的法治化实现——法律的综合之治与协同共治
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作者 杨解君 李剑 《湖南工业大学学报(社会科学版)》 2026年第1期95-103,共9页
实现“双碳”目标,必须以法治化思维和方式推进。在法律规范层面,“硬法”规范和“软法”规范皆不可或缺,需要二者兼备。在部门法层面,需要多个法律部门的协同共治,尤其应发挥环境法、能源法、技术法、经济法、涉外法和行政法的综合治... 实现“双碳”目标,必须以法治化思维和方式推进。在法律规范层面,“硬法”规范和“软法”规范皆不可或缺,需要二者兼备。在部门法层面,需要多个法律部门的协同共治,尤其应发挥环境法、能源法、技术法、经济法、涉外法和行政法的综合治理作用。 展开更多
关键词 “双碳”目标 法治化 “硬法” “软法” 协同共治
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图书馆发展的软服务约束
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作者 魏辅轶 李媛 《四川图书馆学报》 2026年第1期74-79,共6页
文章从预算模式的角度解释图书馆服务发展迟滞的原因。通过引入经济学中软预算约束的概念,讨论图书馆预算的经济属性,指出图书馆属于软预算约束下的组织机构。进一步提出了“软服务约束”的概念来解释图书馆运行中出现的组织行为异化的... 文章从预算模式的角度解释图书馆服务发展迟滞的原因。通过引入经济学中软预算约束的概念,讨论图书馆预算的经济属性,指出图书馆属于软预算约束下的组织机构。进一步提出了“软服务约束”的概念来解释图书馆运行中出现的组织行为异化的五种特征,并提出图书馆服务发展的迟滞是在软服务约束下,读者、图书馆、馆员三者发展目标不能统一的结果。再进一步,解释了软服务约束不能完全消除的根本原因在于软预算约束的影响,但可以通过图书馆资本多元化和“馆人同评”的新评价体系来尽量消除软服务约束的影响。 展开更多
关键词 图书馆 软预算约束 硬预算约束 图书馆服务 服务评价
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某抽水蓄能电站软硬岩掺合料碾压试验
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作者 郭传科 李蒋金 高昱芃 《水电能源科学》 北大核心 2026年第1期99-103,共5页
近年来,抽水蓄能电站快速发展,建设过程中经常面临软硬岩混合利用的问题。软岩岩性较差,在施工过程中存在明显破碎现象,软硬岩混合料是否能满足筑坝强度和渗透特性的要求值得进一步探究。对安徽某拟建抽水蓄能电站的软硬岩筑坝料开展现... 近年来,抽水蓄能电站快速发展,建设过程中经常面临软硬岩混合利用的问题。软岩岩性较差,在施工过程中存在明显破碎现象,软硬岩混合料是否能满足筑坝强度和渗透特性的要求值得进一步探究。对安徽某拟建抽水蓄能电站的软硬岩筑坝料开展现场碾压试验,研究其在不同碾压参数条件下的物理力学和渗透特性。设计了全面的试验方案,比较了不同碾重(22、26 t)、加水量(5%、10%)、铺层厚度(0.6、0.8 m)和碾压遍数(6、8、10遍)组合条件下的碾压效果。采用新型张拉式直剪试验方法现场测定碾压后堆石料的抗剪强度指标,给出了满足设计要求的碾压参数,弥补了室内试验与现场工况的差异,为坝坡稳定性复核提供了直接依据。研究表明,相同碾压参数条件下,掺50%含碳质的绢云千枚岩混合料的干密度、渗透系数、抗剪强度均比绢云千枚岩混合料略小;混合料干密度随碾压遍数增加而增大,并呈现收敛趋势;提高碾重与减小铺层厚度均能显著提升压实质量。在颗粒破碎特性方面,碾压过程中颗粒破碎主要发生在铺层表层,而深层位置的堆石料由于细颗粒的包裹作用基本不发生破碎。绢云千枚岩混合料主要为大颗粒破碎,而含碳质绢云千枚岩混合料在碾压表层发生多次破碎,碾后呈粉质。在铺层厚度80 cm条件下,22 t振动碾碾压10遍得到的强度参数与26 t振动碾碾压8遍的强度参数基本相同。基于试验结果并综合考虑现场施工质量和效率,建议对绢云千枚岩混合料采用铺料层厚80 cm、加水量10%,各铺层采用22 t碾重振动碾压10遍,或采用26 t碾重振动碾压8遍的施工参数。 展开更多
关键词 软硬岩掺合料 碾压试验 碾压控制参数 抽水蓄能电站
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上软下硬地层大跨地铁车站初支拱盖法开挖力学特性研究
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作者 刘正 《国防交通工程与技术》 2026年第1期77-81,共5页
为研究上软下硬地层初支拱盖法力学特性,以锦江路站为例,选取车站中部典型断面作为分析对象,对不同施工阶段进行了初期支护、临时支护及大拱盖结构的应力分析和拱顶及地表沉降监测。研究结果表明:在各分析工况下,初期支护与临时支护的... 为研究上软下硬地层初支拱盖法力学特性,以锦江路站为例,选取车站中部典型断面作为分析对象,对不同施工阶段进行了初期支护、临时支护及大拱盖结构的应力分析和拱顶及地表沉降监测。研究结果表明:在各分析工况下,初期支护与临时支护的最大主拉应力和最大主压应力均远小于C25喷射混凝土的抗拉强度设计值和抗压强度设计值,支护结构整体处于安全状态。沉降监测显示:最大拱顶沉降、最大地表沉降,均满足规范控制要求;沉降主要发生在上部导坑开挖阶段,大拱盖施作后沉降趋于稳定,并有效减小了下部开挖引起的附加变形。采用初支拱盖法对保证施工安全、控制变形和加快施工进度起到了关键作用。 展开更多
关键词 上软下硬地层 初支拱盖法 地表沉降 结构受力 临时支护
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骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者正畸拔牙矫治前后软硬组织侧貌特征及牙根吸收情况对比
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作者 徐燕山 樊勤 贾德蛟 《中国美容医学》 2026年第1期96-100,共5页
目的:对比骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者正畸拔牙矫治前后软硬组织侧貌特征及牙根吸收情况。方法:回顾性选取11~15岁骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者104例,按照面角不同分为高角组(A组)、均角组(B组)及低角组(C... 目的:对比骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者正畸拔牙矫治前后软硬组织侧貌特征及牙根吸收情况。方法:回顾性选取11~15岁骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者104例,按照面角不同分为高角组(A组)、均角组(B组)及低角组(C组),对比三组患者正畸拔牙矫治前后软硬组织侧貌特征及牙根吸收情况。结果:矫治后,与三组患者矫治前软硬组织侧貌特征和牙根吸收情况比较。软硬组织侧貌特征:三组患者的∠U1-L1、Ptm-6、Z角、颏唇沟角增大(P<0.05),∠ANB、∠U1-SN、∠U1-NA、U1-NA、∠L1-NB、L1-NB、UL-Eline、LL-Eline减小(P<0.05),A组与B组∠L1-MP减小,鼻唇角增大(P<0.05),A组Co-Go、N-Me增大(P<0.05),C组Go-Me增大,Y轴角减小(P<0.05);牙根吸收情况:三组患者矫治牙根长度均减小(P<0.05),A组患者U1减小最大,依次为A组>B组>C组(P<0.05)。结论:骨性Ⅱ类错[牙合]不同垂直骨面型青少年患者正畸拔牙矫治前后软硬组织侧貌特征及牙根吸收存在差异性,在临床治疗中,不同垂直骨面型的骨性Ⅱ类错[牙合]畸形应根据其特点控制矫治效果。 展开更多
关键词 骨性Ⅱ类错[牙合] 不同垂直骨面型 青少年 正畸拔牙矫治 软硬组织侧貌特征 牙根吸收
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上软下硬地层超大矩形顶管施工沉降控制技术
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作者 阳斌 李文华 +2 位作者 艾浩泉 王亚 汪杰 《建筑机械》 2026年第1期97-102,共6页
为解决超大矩形顶管在上软下硬地层施工时的地面沉降问题,文章基于重庆两江新区N区C工程A匝道下穿快速路顶管隧道工程,介绍了矩形顶管机的施工原理和施工工艺,分析了超大矩形顶管在上软下硬地层中沉降控制的重难点。矩形顶管机采用3+3... 为解决超大矩形顶管在上软下硬地层施工时的地面沉降问题,文章基于重庆两江新区N区C工程A匝道下穿快速路顶管隧道工程,介绍了矩形顶管机的施工原理和施工工艺,分析了超大矩形顶管在上软下硬地层中沉降控制的重难点。矩形顶管机采用3+3复合刀盘、6滚筒设计,使用3螺旋输送机+2滚筒联合出渣技术,增加“帽檐”结构等针对性设计,通过对掘进参数、同步注浆进行优化调整,采用定点补浆措施,有效控制了地面沉降。结果表明:针对上软下硬地层、超浅覆土设计的矩形顶管机,能够满足复合地层的开挖,同时对地层的扰动小;对顶管机掘进参数优化调整后,大大降低了顶管机开挖后的滞后沉降;矩形顶管机贯通后,地面最大沉降为25.2 mm,满足设计和规范要求。 展开更多
关键词 超大矩形顶管 上软下硬地层 沉降控制 开挖技术 超浅覆土
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An experimental study on fractural features of concrete samples containing hard inclusion 被引量:2
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作者 许昭永 王彬 +2 位作者 赵晋明 胡毅力 梅世蓉 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第1期95-103,共9页
The final fractural forms and variation status of hard inclusion samples under biaxial compression have been primarily studied in this paper. The lateral fractural forms of samples are mainly compressive shear fractu... The final fractural forms and variation status of hard inclusion samples under biaxial compression have been primarily studied in this paper. The lateral fractural forms of samples are mainly compressive shear fracture, two kinds appear on surface: one is strike slip fault with reversed thrust, and another is thrust. Some hard inclusions rupture and some do not while hard contact serves between hard inclusions and sample; main fracture bypasses hard inclusion while soft contact serves. Finally, process of stress concentration, yield, softening until failure for hard inclusions have been analysed under a certain condition. 展开更多
关键词 hard inclusion fractural forms hard contact soft contact
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“三软”厚煤层开采覆岩多层位离层注浆减沉技术及应用 被引量:5
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作者 郭文兵 吴东涛 +3 位作者 郭明杰 胡玉杭 杨伟强 王比比 《煤炭科学技术》 北大核心 2025年第5期1-12,共12页
采动覆岩离层注浆中注浆层位精准识别及保护层厚度合理确定,对防治地表沉陷、保护地表建(构)筑物具有重要意义。为了实现覆岩多层位离层精准注浆减沉,基于组合梁理论改进了离层位置判别方法,确定了覆岩多层位离层注浆充填位置;通过弹性... 采动覆岩离层注浆中注浆层位精准识别及保护层厚度合理确定,对防治地表沉陷、保护地表建(构)筑物具有重要意义。为了实现覆岩多层位离层精准注浆减沉,基于组合梁理论改进了离层位置判别方法,确定了覆岩多层位离层注浆充填位置;通过弹性薄板理论,建立了覆岩离层注浆保护层采动岩体结构力学模型;构建了覆岩多层位离层注浆充填空间的等效模型,并根据注浆空间上位岩层和下位岩层破断规律,给出了充填空间的最小和最大总体积;采用概率积分法并结合地表实际监测结果,评价了“三软”厚煤层覆岩多层位离层注浆效果,并对郑州矿区裴沟煤矿22151工作面开展了实例分析。结果表明:钻孔窥视验证了多层位离层注浆位置的准确性,在距煤层152.6 m中粒砂岩底部和距煤层168.6 m处细粒砂岩下方之间成功实施覆岩多层位离层注浆;工作面在开采厚度为7.1 m时,保护层厚度为25.2 m能够实现覆岩离层注浆工作的安全实施;理论计算注浆量为9.5×10^(4)~14.7×10^(4)t,实际工程注浆量约为13.3×10^(4)t,注采比约为0.41;采用覆岩多层位离层注浆开采后,地表最大下沉量为649.8 mm,大部分民房处地表最大水平变形值处于Ⅰ级损害程度内;覆岩多层位离层注浆开采地表沉陷控制效果显著,减沉率约77.91%。 展开更多
关键词 “三软”厚煤层 软硬交互覆岩 覆岩离层 多层位注浆 保护层 沉陷控制
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黔西矿区软硬分层煤温度-压力耦合影响瓦斯解吸试验 被引量:1
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作者 黄良 李希建 +1 位作者 刘钰 陈守坤 《工矿自动化》 北大核心 2025年第1期156-162,170,共8页
煤层瓦斯解吸特性对矿井瓦斯涌出规律和煤层气开发有重要影响,煤层温度和压力变化对软硬分层煤瓦斯解吸有明显控制作用。贵州黔西矿区煤层大多属于高瓦斯近距离突出煤层群,软硬结合较多,且煤层透气性低。为进一步明确该地区煤层瓦斯解... 煤层瓦斯解吸特性对矿井瓦斯涌出规律和煤层气开发有重要影响,煤层温度和压力变化对软硬分层煤瓦斯解吸有明显控制作用。贵州黔西矿区煤层大多属于高瓦斯近距离突出煤层群,软硬结合较多,且煤层透气性低。为进一步明确该地区煤层瓦斯解吸特性,以贵州黔西典型矿区小屯煤矿和青龙煤矿软硬分层煤为研究对象,利用HCA型高压容量法吸附装置对软硬分层煤进行不同温度、压力下的瓦斯解吸特征试验研究,对比分析温度、压力耦合变化对软硬分层煤瓦斯解吸特征的影响。结果表明:同一煤样温度、压力越高,瓦斯解吸初速度越大,对于0~120 s内的初始瓦斯解吸,瓦斯压力不占主导作用;软分层煤初始瓦斯解吸速率大于硬分层煤,硬分层煤累计瓦斯解吸量大于软分层煤,硬分层煤累计瓦斯解吸量最快在540 s内超过软分层煤;煤体暴露后60 s内含煤瓦斯解吸量变化最剧烈,且软分层煤前60 s解吸量所占比例大于硬分层煤,解吸更“活跃”;瓦斯解吸速率随压力的增加而升高,解吸速率可划分为3个阶段,即0~60 s为“解吸爆炸期”,60~1500 s为“解吸跳跃期”,1500~7200 s为“解吸稳定期”;软分层煤中值解吸时间受温度、压力影响大于硬分层煤,软分层煤瓦斯解吸主要集中在煤炭暴露后1800 s内。 展开更多
关键词 构造煤 软硬分层 瓦斯解吸速率 瓦斯解吸量 温度-压力耦合影响
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