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细粒层厚度与法向应力对砂土强度影响的试验研究 被引量:1
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作者 黄志全 张艳霞 +2 位作者 杨永香 李宣 王真 《华北水利水电大学学报(自然科学版)》 2014年第2期69-72,共4页
以河北磁县境内的砂土为研究对象,利用环剪仪对砂土的强度特性进行了研究.主要考虑细粒层厚度、法向应力对其峰值强度和残余强度的影响.结果表明:法向应力对砂土的峰值强度和残余强度及强度损失率均有影响,法向应力增大,峰值强度... 以河北磁县境内的砂土为研究对象,利用环剪仪对砂土的强度特性进行了研究.主要考虑细粒层厚度、法向应力对其峰值强度和残余强度的影响.结果表明:法向应力对砂土的峰值强度和残余强度及强度损失率均有影响,法向应力增大,峰值强度和残余强度均增大,强度损失率也越大,细粒层厚度对砂土强度的影响亦是如此;法向应力为50~200kPa,细粒层厚度为0.0—2.0mm的情况下,强度损失率由10.0%增大到28.0%;剪切面上土的性质决定了剪应力一剪切位移关系曲线的形状. 展开更多
关键词 砂土 环剪 细粒层厚度 法向应力 峰值强度 残余强度 强度损失率
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细粒层对浸矿表面形貌及钝化的影响
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作者 尹升华 王雷鸣 +1 位作者 潘晨阳 陈勋 《工程科学学报》 EI CSCD 北大核心 2018年第8期910-917,共8页
由于矿石粒径配比、表面粗糙度、密度等性质差异,筑堆过程中堆内极易出现矿石颗粒偏析现象.细粒层是导致矿石表面受侵蚀程度不均的关键因素,其严重制约了铜矿资源的高效浸取.为探究细粒层对矿石浸出效果、表面形貌及钝化现象的影响,选... 由于矿石粒径配比、表面粗糙度、密度等性质差异,筑堆过程中堆内极易出现矿石颗粒偏析现象.细粒层是导致矿石表面受侵蚀程度不均的关键因素,其严重制约了铜矿资源的高效浸取.为探究细粒层对矿石浸出效果、表面形貌及钝化现象的影响,选取粗颗粒矿石(4 mm〈d〈6mm)与细颗粒矿石(2mm〈d〈4mm),开展不同细粒层位置下次生硫化铜矿微生物浸出实验.结合CT扫描与冷场电镜扫描技术等分析手段,从宏、细、微观多层面,探究不同细粒层位置下矿石宏观浸出规律,细观矿石团聚结块,微观表面形貌特征与钝化.结果表明:细粒层导致铜浸出率普遍降低,均低于无细粒层、均匀粗颗粒介质的实验组;不同矿堆位置处细粒层对浸出效果影响不同,细粒层位于顶部的实验组铜浸出效果最优,浸矿60d铜浸出率达71.3%;同一细粒层不同位置处矿石表面孔裂结构演化程度不一;浸矿60d后,铜浸出率趋于峰值,矿石团聚结块与钝化现象显著,矿石表面形成以黄钾铁矾、多硫化物、胞外多聚物、硫膜为主的钝化物质层. 展开更多
关键词 次生硫化铜矿 生物浸出 细粒层 表面形貌 钝化现象
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湖相细粒岩二级指标划分法岩相分类及其应用实例 被引量:6
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作者 李增学 宋明水 +5 位作者 李莹 刘海燕 徐春华 王东东 孔凡飞 韩乔羽 《现代地质》 CAS CSCD 北大核心 2021年第2期365-377,共13页
采用细粒沉积岩宏观观察刻画与显微刻画的方法,探索基于湖相细粒沉积纹层类型及其结构特征作为关键指标的细粒岩岩相成因。提出了湖相细粒岩岩相的划分指标和原则,即以细粒沉积纹层作为细粒岩岩相划分的重要指标。用两级核心指标作为划... 采用细粒沉积岩宏观观察刻画与显微刻画的方法,探索基于湖相细粒沉积纹层类型及其结构特征作为关键指标的细粒岩岩相成因。提出了湖相细粒岩岩相的划分指标和原则,即以细粒沉积纹层作为细粒岩岩相划分的重要指标。用两级核心指标作为划分湖相细粒岩岩相及亚类的依据,分为一级指标和二级指标。一级指标为岩石组成类型,分为泥质岩类、灰岩类以及泥质—灰质细粒岩等9个指标类型。二级指标为细粒纹层类型,主要有有机质纹层、云质纹层、方解石纹层、粉砂质纹层、膏质纹层、炭质纹层等类型,将细粒岩划分为21种岩相和33个岩相亚类,并分析了各岩相及亚相发育的沉积环境特征。 展开更多
关键词 岩岩相与亚类 湖泊扩展与萎缩旋回 济阳坳陷
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Chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease:Correlations with blood eosinophil level
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作者 YANG Lu SHENG Yadan +7 位作者 YANG Kai HE Liyu GU Huihui SUN Guoqing CHEN Weiting ZHU Bingjie CHEN Yanrong JIN Chenwang 《中国医学影像技术》 CSCD 北大核心 2024年第8期1189-1193,共5页
Objective To observe the correlations of chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with blood eosinophil(EOS)level.Methods Chest CT data of 16... Objective To observe the correlations of chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with blood eosinophil(EOS)level.Methods Chest CT data of 162 AECOPD patients with elevated eosinophils were retrospectively analyzed.The patients were divided into low EOS group(n=105)and high EOS group(n=57)according to the absolute counting of blood EOS.The quantitative CT parameters,including the number of whole lung bronchi and the volume of blood vessels,low-attenuation area percentage(LAA%)of whole lung,of left/right lung and each lobe of lung,as well as the luminal diameter(LD),wall thickness(WT),wall area(WA)and WA percentage of total bronchial cross-section(WA%)of grade 3 to 8 bronchi were compared between groups.Spearman correlations were performed to analyze the correlations of quantitative CT parameters with blood EOS level.Results LAA%of the whole lung,of the left/right lung and each lobe of lung,as well as of the upper lobe of right lung LD grade 4,middle lobe of right lung WT grade 5,upper lobe of right lung WA grade 4,middle lobe of right lung WA grade 5 and lower lobe of left lung WA grade 3 in low EOS group were all higher than those in high EOS group(all P<0.05).Except for the upper lobe of right lung LD grade 4,the above quantitative CT indexes being significant different between groups were all weakly and negatively correlated with blood EOS level(r=-0.335 to-0.164,all P<0.05).Conclusion Chest CT quantitative parameters of AECOPD patients were correlated with blood EOS level,among which LAA%,a part of WT and WA were all weakly negatively correlated with blood EOS level. 展开更多
关键词 pulmonary disease chronic obstructive EOSINOPHILS tomography X-ray computed
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Malignant mesothelioma of the greater omentum mimicking omental infarction:A case report 被引量:6
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作者 Min-Kee Shin Ok-Jae Lee +2 位作者 Chang-Yoon Ha Hyun-Joo Min Tae-Hyo Kim 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第38期4856-4859,共4页
Mesothelioma develops most commonly in the pleura, and less frequently in the peritoneum. Usually, it manifests as diffuse peritoneal thickening and multiple nodules, and rarely as a solitary mass. We report a rare ca... Mesothelioma develops most commonly in the pleura, and less frequently in the peritoneum. Usually, it manifests as diffuse peritoneal thickening and multiple nodules, and rarely as a solitary mass. We report a rare case of primary malignant mesothelioma of the greater omentum, which mimicked omental infarct. A 54-year-old Korean man was admitted because of severe abdominal pain of sudden onset. A tender mass with indistinct margins was palpated in the upper abdomen. Abdominal ultrasound and computed tomography showed an ill- def ined mass in the greater omentum and little ascites in the peri-hepatic space, and neutrophil-dominant exudates were documented on paracentesis. Intravenous antibiotics and analgesics were given for omental infarction with superimposed infection, which resulted in symptomatic improvement. The imaging studies after a week revealed a growing mass and ascites. Laparoscopic surgery was performed and an 8 cm×3.3 cm greater omental mass was found, with multiple small nodules on the peritoneum, diaphragm, and pelvic cavity wall. Histological examination showed proliferating malignant epithelioid cells that stained strongly for calretinin, which was compatible with malignant mesothelioma. We recommend that primary omental mesothelioma should be included in the differential diagnosis of patients with omental infarction, despite its rarity. 展开更多
关键词 INFARCTION Mesothelioma Omentum
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The Influence of an Acoustic Field on the Bed Expansion of Fine Particles
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作者 Akash M. Langde R.L.Sonolikar 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第4期649-655,共7页
Fine particles are difficult to fluidize due to strong interparticle attraction.An attempt has been made to study the bed expansion of silica gel(dp=25μm) powder in presence of an acoustic field.A 135 mm diameter flu... Fine particles are difficult to fluidize due to strong interparticle attraction.An attempt has been made to study the bed expansion of silica gel(dp=25μm) powder in presence of an acoustic field.A 135 mm diameter fluidized bed activated by an acoustic field with sound intensity up to 145 dB and frequency from 90 Hz to 170 Hz was studied.The effects of sound pressure level,sound frequency and particle loading on the bed expansion were investigated.Experimental results showed that,bed expansion was good in presence of acoustic field of particular frequency.In addition,it was observed that in presence of acoustic field the bed collapses slowly. 展开更多
关键词 acoustic field FREQUENCY VIBRATION fluidized bed fine powder EXPANSION
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The Study of the Anatomical Features of Wheat Grains in the Species T. dicoccum Schuebl,, Sort Mironovskaya-808 and AIIoplasmatic Lines (Their Interspecific Hybrids F9)
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作者 Nina Khailenko Nina Terletskaya Nazira Altayeva 《Journal of Agricultural Science and Technology(B)》 2013年第8期597-602,共6页
In cross sections by microscopic studies have examined the features of the shell thickness grains, cells, aleuronic layer and endosperm in the species T. dicoccum Schuebl., sorts Mironovskaya-808 and their interspecif... In cross sections by microscopic studies have examined the features of the shell thickness grains, cells, aleuronic layer and endosperm in the species T. dicoccum Schuebl., sorts Mironovskaya-808 and their interspecific hybrids F9 (alloplasmatic lines). The result of studies showed the specific and varietal differences, and differences in hybrid plants on linear parameters size grains, the degree of specificity of the shells grains of wheat and identified species and varietal differences as well as differences among hybrids in the linear dimensions of the cells of the aleuronic layer. It is shown that among the studied forms of wheat allocated species T. dicoccum Shuebl. and the lines D-N-05, D-F-05 and D-40-05-KhNA with relatively large grains, a well-developed endosperm, most of thin shells and large grain aleurone layer cells. They are of most interest for further breeding research in terms of nutritional value. 展开更多
关键词 Wheat grains shell thickness grains cells aleuronic layer ENDOSPERM SPECIES sorts alloplasmatic lines.
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Transfer of Ultrafine Particles and Air in Multi-storey Buildings
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作者 Amalie Gunner Siamak Rahimi Ardkapan Alireza Afshari Niels Christian Bergsoe 《Journal of Civil Engineering and Architecture》 2014年第4期389-394,共6页
An emerging issue in Denmark is passive smoking in residential buildings where non-smokers are exposed to smoke from their neighbours. There are various ways that smoke is transferred from one flat to another. The air... An emerging issue in Denmark is passive smoking in residential buildings where non-smokers are exposed to smoke from their neighbours. There are various ways that smoke is transferred from one flat to another. The air transfer rate between two flats in a multi-storey building depends on its construction, tightness and age. This paper presents results of a study on the transfer of ultrafine particles and tracer gas in an older multi-storey building in Copenhagen. The aim of the study was to quantify the transfer ofultrafine particles and gases from one flat to another fiat before and after sealing the floor. A new floor-sealing method was applied to seal the floor between the two flats. The sealing method was developed by a firm specialising in sealing. Indoor ultrafine particle concentrations and tracer gas were measured continuously in the two fiats during the measuring periods. In the unoccupied fiat, the gas source was N20 and the particle source was burning cigarettes. Reduction of the concentration of ultrafine particles and tracer gas by sealing the floor with polyethylene and joint filler made of bitumen was studied. It was evaluated how the sealing performed with regard to decreasing the amount of ultrafine particles and a tracer gas transferred between two fiats separated by a floor. When the floor between the flats was not sealed, the results showed that about 4% of the ultraflne particles and 14% of the tracer gas were transferred. After sealing, the amount transferred was reduced to 1.6% and 5%, respectively. 展开更多
关键词 PARTICLES air pollution ventilation full-scale experiments.
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Going Behind the Scenes: The Input Hypothesis Revisited
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作者 Shen Li 《Fudan Journal of the Humanities and Social Sciences》 2010年第1期90-112,共23页
Few studies have to date gone behind the scenes to unveil the hidden metaphor-metonymy structure underpinning the input hypothesis ( Krashen 1981 ) despite overt attention paid to it over the years. In an effort to ... Few studies have to date gone behind the scenes to unveil the hidden metaphor-metonymy structure underpinning the input hypothesis ( Krashen 1981 ) despite overt attention paid to it over the years. In an effort to use a fine-grained metaphor-analysis approach( e. g. , Lakoffand Johnson 1980, 1999) to revisit the input hypothesis, this study looks into its thrust--the causal effect of comprehensible input upon comprehension--in the hope of charting out its hidden organization. By discovering a theme of CAUSATION pivoted on space-based metaphors and metonyrnies, the present study brings to relief two fallacies committed in the input hypothesis. First, the heavy dependence on the prototypicaUy physical-spatial hierarchy leads to a red-herring fallacy, whose inconsistency defies rather than supports its statement about comprehensible input as the overriding cause. Second, although there is no denying that comprehensible input is a significant source of language gains, to enthrone it as the sole causal variable to the exclusion of all the other important variables, especially the agency of the 1.2 learner who should have been positioned in the spotlight in the first place, is another fallacy of immense magnitude. 展开更多
关键词 METAPHOR METONYMY the input hypothesis
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