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预硫化温度对煤直接液化催化剂组分转变及其催化性能的影响 被引量:5
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作者 陈晨 李海杰 +5 位作者 白杨 冯富祥 田磊 杨勇 刘源 郭强 《燃料化学学报》 EI CAS CSCD 北大核心 2022年第1期54-62,共9页
在5%H_(2)S/N_(2)气氛,不同预硫化温度下制备了系列硫铁催化剂,并在5 MPa的1%H_(2)S/H_(2)气氛、360℃下研究了其催化萘的加氢活性。借助MES、XRD和XPS等表征手段,探究了催化剂在不同预硫化温度及反应条件下组分转变规律。结果表明,预... 在5%H_(2)S/N_(2)气氛,不同预硫化温度下制备了系列硫铁催化剂,并在5 MPa的1%H_(2)S/H_(2)气氛、360℃下研究了其催化萘的加氢活性。借助MES、XRD和XPS等表征手段,探究了催化剂在不同预硫化温度及反应条件下组分转变规律。结果表明,预硫化过程是硫由表面向内部,依照FeS_(2)→FeS、Fe_(1−x)S→Fe_(3)S_(4)→Fe_(2)O_(3)顺序渗硫的过程,而升高温度有利于硫向体相内的传递;接触1%H_(2)S/H_(2)气氛后晶粒由外向内各组分均快速转化为Fe_(1–x)S的过程;调控预硫化条件可以实现活性组分Fe_(1–x)S的含量高、晶粒小,于是可获得最高活性。 展开更多
关键词 煤直接液化 γ-Fe_(2)O_(3) 硫化 组分转变 萘加氢反应
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相转变组分法制备缠结聚合物有机分散液研究进展与展望
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作者 曹文恺 王利鹏 +2 位作者 宿思琦 顾捷 白永平 《中国胶粘剂》 CAS 2024年第4期1-9,18,共10页
分别概述了高、低能乳化法的技术原理,并分析了不同乳化法的技术特点及应用现状。通过借鉴纳米乳液的制备方法,结合缠结聚合物的结构特性以及纳米乳液体系中有机相的分子量低、易变形特性,分析出高能乳化法制备缠结聚合物分散液的缺陷,... 分别概述了高、低能乳化法的技术原理,并分析了不同乳化法的技术特点及应用现状。通过借鉴纳米乳液的制备方法,结合缠结聚合物的结构特性以及纳米乳液体系中有机相的分子量低、易变形特性,分析出高能乳化法制备缠结聚合物分散液的缺陷,确定低能乳化法中的相转变法是实现缠结聚合物分散液制备的方法。结合相转变温度法(PIT)和相转变组分法(PIC)对乳化剂曲率变化的影响,确定了PIC法制备缠结聚合物有机分散液的技术可行性,并对缠结聚合物应用领域的拓展进行了技术展望。 展开更多
关键词 高能乳化 低能乳化 转变温度法 转变组分
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防冻型纳米乳化石蜡PF-EPF的研制与应用 被引量:11
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作者 赵春花 夏小春 +2 位作者 项涛 耿铁 苗海龙 《钻井液与完井液》 CAS 北大核心 2016年第5期9-14,共6页
为解决普通纳米石蜡乳液低温下易析出石蜡并凝结成固态,导致钻井现场无法正常应用的问题,选用液体石蜡作内相,多元醇水溶液为外相,在复合乳化剂的作用下,通过合适的乳化分散工艺(相转变组分法),制备了一种防冻型纳米乳化石蜡PF-EPF。... 为解决普通纳米石蜡乳液低温下易析出石蜡并凝结成固态,导致钻井现场无法正常应用的问题,选用液体石蜡作内相,多元醇水溶液为外相,在复合乳化剂的作用下,通过合适的乳化分散工艺(相转变组分法),制备了一种防冻型纳米乳化石蜡PF-EPF。通过室内实验,研究了水相、表面活性剂的HLB值、含量、乳化温度和油相含量等因素对PF-EPF性能的影响,得到了适宜的制备工艺,即多元醇溶液质量分数为50%~70%,体系的HLB值在10左右,油剂比为1∶1,乳化温度为80℃,体系的油相含量在30%左右,在此条件下制备的乳化石蜡PF-EPF平均粒径在160 nm左右,凝固点最低达到-30℃,防冻能力突出,并具有良好的稳定性。加入2%PF-EPF以后,海水基浆的PPT滤失量(砂盘孔径为5μm)从18.8 mL减少到10 mL左右,加入3%PE-EPF后使PEC钻井液的PPT滤失量从17.2 mL减少到6.4 mL。评价实验表明,PE-EPF能够明显提高钻井液的封堵性,起到防止井塌、提高钻速和保护油气层的作用。该剂在渤海区域CFD6-4-6D井也取得了很好的应用效果,应用前景广阔。 展开更多
关键词 封堵 纳米乳化石蜡 多元醇 复合乳化剂 转变组分
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水基纳米乳液润滑剂AF-Lube的研制与应用 被引量:3
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作者 丁玉 易勇 夏小春 《石油化工应用》 CAS 2018年第5期118-122,共5页
选用植物油酯为内相,多元醇水溶液为外相,单油酸甘油酯和十聚甘油单油酸酯为复合乳化剂,通过相转变组分法制备了一种水基纳米乳液润滑剂AF-Lube。通过室内实验研究确定了多元醇水溶液质量分数为30%~60%,植物油酯质量分数为35%~60%,复合... 选用植物油酯为内相,多元醇水溶液为外相,单油酸甘油酯和十聚甘油单油酸酯为复合乳化剂,通过相转变组分法制备了一种水基纳米乳液润滑剂AF-Lube。通过室内实验研究确定了多元醇水溶液质量分数为30%~60%,植物油酯质量分数为35%~60%,复合乳化剂HLB值为11~12。所制备的水基纳米乳液润滑剂AF-Lube凝固点低于-30℃且稳定性良好。在加入30 kg/m^3AF-Lube后,淡水基浆和模拟海水基浆扭矩均降低80%以上。在海上油田使用的PEM和PEC钻井液中加入30 kg/m^3AF-Lube后,润滑系数由0.24~0.26降至0.13~0.16且加入AF-Lube对PEM和PEC钻井液流变性能影响不大。 展开更多
关键词 水基润滑剂 纳米乳液 耐低温 转变组分 钻井液
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Expression and significance of homeodomain protein Cdx2 in gastric carcinoma and precancerous lesions 被引量:16
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作者 Rong Qin Na-Na Wang +1 位作者 Jing Chu Xian Wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第25期3296-3302,共7页
AIM: To investigate the expression and significance of caudal-related homeobox transcription factor (Cdx2) in gastric carcinoma (GC) and precancerous lesions. METHODS: The expression of Cdx2 in GC, precancer- ou... AIM: To investigate the expression and significance of caudal-related homeobox transcription factor (Cdx2) in gastric carcinoma (GC) and precancerous lesions. METHODS: The expression of Cdx2 in GC, precancer- ous lesions and normal gastric mucosa were detected using immunohistochemical method. Hematoxylin and eosin staining, alcian blue/periodic acid-schiff and high iron diamine/alcian blue staining were used to classify intestinal metaplasia (IM) and GC. RESULTS: Cdx2 was not detected in normal gas- tric mucosa. Cdx2 expression was detected in 87.1% (101/116) of IM, 50% (36/72) of dysplasia and 48.2% (41/85) of GC. The Cdx2-expressing cells in IM were more prevalent than in dysplasia and carcinoma (P 〈 0.05). There was no relationship between Cdx2 ex- pression and the classification of IM or the degree of dysplasia. Expression of Cdx2 was significantly higher in intestinal-type carcinoma than in diffuse and mixed- type carcinoma (P 〈 0.05). Positive expression of Cdx2was mainly found in moderately to well differentiated GC. There was a negative association between nuclear Cdx2 expression and lymph node metastasis and tumor, nodes, metastasis stage of GC (P 〈 0.05). The patients with Cdx2-positive expression showed a higher survival rate than those with Cdx2-negative expression (P = 0.038). Multivariate analysis revealed that the expres- sion of Cdx2 and lymph node metastasis were indepen- dent prognostic indicators of GC (P 〈 0.05). 展开更多
关键词 Caudal-related homeobox transcription fac-tor Stomach neoplasm Intestinal metaplasia Dyspla-sia IMMUNOHISTOCHEMISTRY
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Undrained response of reconstituted clay to cyclic pure principal stress rotation 被引量:1
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作者 严佳佳 周建 +1 位作者 龚晓南 曹洋 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期280-289,共10页
A series of monotonic and rotational shearing tests are carried out on reconstituted clay using a hollow cylinder apparatus under undrained condition. In the rotational shearing tests, the principal stress axes rotate... A series of monotonic and rotational shearing tests are carried out on reconstituted clay using a hollow cylinder apparatus under undrained condition. In the rotational shearing tests, the principal stress axes rotate cyclically with the magnitudes of the principal stresses keeping constant. The anisotropy of the reconstituted clay is analyzed from the monotonic shearing tests. Obvious pore pressure is induced by the principal stress rotation alone even with shear stress q0=5 k Pa. Strain components also accumulate with increasing the number of cycles and increases suddenly at the onset of failure. The deviatoric shear strain of 7.5% can be taken as the failure criterion for clay subjected to the pure cyclic principal stress rotation. The intermediate principal stress parameter b plays a significant role in the development of pore pressure and strain. Specimens are weakened by cyclic rotational shearing as the shear modulus decreases with increasing the number of cycles, and the shear modulus reduces more quickly with larger b. Clear deviation between the directions of the principal plastic strain increment and the principal stress is observed during pure principal stress rotation. Both the coaxial and non-coaxial plastic mechanisms should be taken into consideration to simulate the deformation behavior of clay under pure principal stress rotation. The mechanism of the soil response to the pure principal stress rotation is discussed based on the experimental observations. 展开更多
关键词 clay principal stress rotation intermediate principal stress undrained behavior
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