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Effect of Reaction Temperature and Pressure on the Metathesis Reaction between Ethene and 2-Butene to Propene on the WO_3/Al_2O_3-HY Catalyst 被引量:2
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作者 Shengjun Huang Shenglin Liu +3 位作者 Wenjie Xin Sujuan Xie Qingxia Wang Longya Xu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第2期93-99,共7页
Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature an... Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature and reaches a plateau at 150-240 ℃. After that, the activity undergoes a remarkable decrement at too high temperature. The effect of temperature is elucidated by the oxidation state of tungsten species. The evaluation results also indicate that the stability is dependent on this reaction parameter. Medium pressure (0.5-0.8 MPa) is favorable for stability, while atmospheric pressure or too high pressure (〉1.0 MPa) deteriorates the stability. For explanation, UV Vis, FT-IR, O2-TPO, and TG techniques are used to characterize the spent catalysts. 展开更多
关键词 METATHESIS tungsten oxide catalyst temperature PRESSURE ETHENE 2-butene PROPENE
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Stereo-Selective Synthesis of 5-Norbornene-2-<i>exo</i>-carboxylic Acid—Rapid Isomerization and Kinetically Selective Hydrolysis 被引量:1
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作者 Miki Kanao Atsushi Otake +1 位作者 Kousuke Tsuchiya Kenji Ogino 《International Journal of Organic Chemistry》 2012年第1期26-30,共5页
Simple and efficient stereo-selective synthesis of exo-5-norbornene-2-carboxylic acid (NBCA) is reported. Preliminary studies on base promoted isomerization of methyl 5-norbornene-2-carboxylate (MNBC) revealed that ra... Simple and efficient stereo-selective synthesis of exo-5-norbornene-2-carboxylic acid (NBCA) is reported. Preliminary studies on base promoted isomerization of methyl 5-norbornene-2-carboxylate (MNBC) revealed that rapid isomerization was accomplished with sodium tert-butoxide (tBuONa), and the exo-content at the equilibrium was ca. 60%. The hydrolyses of endo-rich MNBC (endo/exo = 80/20) under various conditions were carried out. The exo selectivity for resulting NBCA was improved when the hydrolysis was conducted with equimolar water at room temperature in the presence of the stronger base (tBuONa) (endo/exo: 18/82). Whereas the use of excess amount of water led to rapid and non-selective hydrolysis affording high endo content of the product. The plausible reaction mechanism involving rapid equilibrium of thermodynamic isomerization and kinetically preferred hydrolysis of exo ester is proposed. 展开更多
关键词 Stereo-Selective Synthesis 2-Substituted NORBORNENE isomerization Kinetically SELECTIVE Hydrolysis
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A mild,efficient and selective iodination of aromatic compounds using iodine and 1,4-bis(triphenylphosphonium)-2-butene peroxodisulfate 被引量:1
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作者 Rashid Badri Maryam Gorjizadeh 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第12期1439-1443,共5页
A simple and efficient method for the iodination of aromatic compounds has been achieved in the presence of iodine and 1,4- bis(triphenylphosphonium)-2-butene peroxodisulfate.
关键词 Iodoaromafic compounds Aromatic compounds IODINE 1 4-Bis(triphenylphosphonium)-2-butene peroxodisulfate
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Equilibrium Structures and Isomerization Reactions of the Unsaturated Germylenoid H_2C=GeLiF 被引量:1
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作者 LI Wen-Zuo CHENG Jian-Bo +1 位作者 bGONG Bao-An XIAO Cui-Ping 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第5期613-617,共5页
The unsaturated germylenoid H2C=GeLiF has been studied by using DFT method at the B3LYP/6-311+G (d, p) level. Geometry optimization calculations indicate that H2C=GeLiF has three equilibrium configurations, in whic... The unsaturated germylenoid H2C=GeLiF has been studied by using DFT method at the B3LYP/6-311+G (d, p) level. Geometry optimization calculations indicate that H2C=GeLiF has three equilibrium configurations, in which the p-complex is the lowest in energy and the most stable structure. Two transition states for isomerization reactions of H2C=GeLiF are located and the energy barriers are calculated. For the most stable one, vibrational frequencies and infrared intensities have been predicted. 展开更多
关键词 unsaturated germylenoid H2C=GeLiF DFT B3LYP isomerization
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γ-Al<sub>2</sub>O<sub>3</sub>Supported SO<sub>4</sub><sup>2&#45</sup>/ZrO<sub>2</sub>Solid Superacid Catalysts for n-Pentane Isomerization 被引量:1
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作者 Li Zhao Xiaoshuang Cheng +2 位作者 Ye Hu Shuqing Ma Yingjun Wang 《Modern Research in Catalysis》 2014年第3期89-93,共5页
A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solut... A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solution used in impregnation and Al2O3 concentration, were varied to investigate the effects on catalytic performance of Pt-SO42-/ZrO2-A12O3. The results showed that the PtSZA catalyst exhibited excellent catalytic performance for n-pentane isomerization. Under optimized preparation conditions of calcination temperature of 650°C, reaction time for 3 h, concentration of sulfuric acid solution for 0.5 mol/L, 30% of Al2O3 concentration and 0.3% of Pt concentration, the n-pentane conversion and isopentane selectivity of Pt-SO42-/ZrO2-A12O3 could reach up to 62.17% and 91.60%, respectively. 展开更多
关键词 SO42-/ZrO2 N-PENTANE isomerization γ-Al2O3 SUPPORTED SUPERACID Catalysts
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Investigation of Isomerization of 2-Seleno-1, 3, 2-diazaphospholidine Derivatives
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作者 ShengLouDENG RuYuCHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第5期398-401,共4页
For the first time the isomerization of 1, 3, 2-diazaphospholidine-2-selenide derivatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR,... For the first time the isomerization of 1, 3, 2-diazaphospholidine-2-selenide derivatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR, 1H NMR, 31P NMR, elemental analysis and X-ray crystallography. The mechanism of isomerization was also proposed. 展开更多
关键词 isomerization 2-seleno-1 3 2-diazaphospholidine derivatives crystal structure mechanism.
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A Novel Way to Prepareγ-A1_2O_3 Supported SO_4^(2-)/ZrO_2 Solid Superacid Catalysts for n-Butane Isomerization
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作者 Ting LEI Yi TANG +2 位作者 Wei Ming HUA Jin Suo XU Zi GAO (Department of Chemistry, Fudan University, Shanghai 200433) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第1期89-92,共4页
Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts wer... Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts were enhanced significantly j The activity of the most active sample. 60%SZ/Al_2O3-P, was even about 2 times more active than that of the SZ catalyst. 展开更多
关键词 SO_4^(2-)/ZrO_2 n-Butane isomerization γ-A1_2O_3 supported superacid catalysts.
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水溶液环境下手性配合物Phe·Ca^(2+)对映异构机理的DFT研究 被引量:3
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作者 赵丽红 彭国强 +3 位作者 郝成欣 苏丹 姜春旭 王佐成 《中山大学学报(自然科学版)(中英文)》 CAS CSCD 北大核心 2023年第6期50-60,共11页
采用DFT(density functional theory)的M06-2X、MN15方法和处理溶剂效应的SMD模型方法,研究了水溶液中S-苯丙氨酸(S-Phe)与二价钙(Ca^(2+))配合物(Phe·Ca^(2+))的对映异构。反应通道研究发现,S-Phe·Ca^(2+)的对映异构可在质子... 采用DFT(density functional theory)的M06-2X、MN15方法和处理溶剂效应的SMD模型方法,研究了水溶液中S-苯丙氨酸(S-Phe)与二价钙(Ca^(2+))配合物(Phe·Ca^(2+))的对映异构。反应通道研究发现,S-Phe·Ca^(2+)的对映异构可在质子以N和O分别为桥以及O和N联合为桥迁移的3个通道上实现。计算表明:最优势通道是质子以N为桥迁移,隐性水溶剂效应下决速步自由能垒是227.5 kJ/mol,显性水溶剂效应下该能垒降至108.0~117.6 kJ/mol。结果表明:水溶液中手性Phe·Ca^(2+)的消旋过程十分缓慢,将其用于生命体同补苯丙氨酸和钙元素可能比较安全。 展开更多
关键词 苯丙氨酸 二价钙 DFT(density functional theory) 对映异构 自由能垒
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Pt-CeO_(2)/ZSM-22催化正庚烷异构化反应性能研究 被引量:1
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作者 李子信 郗宏娟 +4 位作者 陈晓燕 马中义 贾丽涛 李德宝 侯博 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2023年第12期1805-1813,共9页
结合浸渍法和物理混合法调控金属活性中心Pt的位点,使其单独落位到ZSM-22分子筛或氧化铈载体上,从而分别得到金属-酸双中心位点的间距达到原子级接触的Pt-ZSM-22/CeO_(2)催化剂和保持纳米级间距的Pt-CeO_(2)/ZSM-22催化剂。利用球差电镜... 结合浸渍法和物理混合法调控金属活性中心Pt的位点,使其单独落位到ZSM-22分子筛或氧化铈载体上,从而分别得到金属-酸双中心位点的间距达到原子级接触的Pt-ZSM-22/CeO_(2)催化剂和保持纳米级间距的Pt-CeO_(2)/ZSM-22催化剂。利用球差电镜、XRD、BET、H2-TPR和XPS等手段,表征了两种催化剂的物化性质,并对其正庚烷异构化反应性能进行了研究。另外,考察了不同还原温度下Pt-CeO_(2)/ZSM-22催化剂的物化性质和反应性能变化。结果显示,金属-酸中心保持纳米级间距Pt-CeO_(2)/ZSM-22催化剂具有更高的正庚烷异构化活性和异构烃收率,这是由于Pt在CeO_(2)载体上呈原子级分散的原因。在Pt-CeO_(2)/ZSM-22催化剂还原过程中,CeO_(2)载体释放更多的氧空位有助于延缓金属Pt的聚集且有利于庚烷分子的吸附。当还原预处理温度为300℃时,庚烷转化率和庚烷异构烃收率分别为79.2%和75.4%,异构化选择性达到95.2%。 展开更多
关键词 正庚烷 异构化 双功能催化剂 亲密度 CeO_(2)
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The Synthesis of 7-[1-Aza-2-(dimethylamino)vinyl]-4-methylhydroquinolin-2-ones and their Isomerism in Different Solvents 被引量:3
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作者 Qian ZHANG Ying CHEN +4 位作者 Yun Hong ZHENG Wan Yun SHENG Peng XIAYi XIA Zheng Yu YANG Kuo Hsiung LEE 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第1期11-14,共4页
The reaction of 7-amino-4-methyl-2(1H)-quinolone 1 and its 6-methyl derivative 2 with Vilsmeier reagent (DMF and POCl3) afforded 7-[1-aza-2-(dimethylamino)vinyl]-4-methyl-hydroquinolin-2-one 3 and 7-[1-aza-2-(dimethyl... The reaction of 7-amino-4-methyl-2(1H)-quinolone 1 and its 6-methyl derivative 2 with Vilsmeier reagent (DMF and POCl3) afforded 7-[1-aza-2-(dimethylamino)vinyl]-4-methyl-hydroquinolin-2-one 3 and 7-[1-aza-2-(dimethylamino)vinyl]-4,6-dimethylhydroquinolin- 2-one 4, respec-tively. H-1-NMR analysis in different solvents indicated that isomerism occurred due to hindered rotation around the (CH3)(2)N-C:N o -bond. The rotational energy barrier of 3 was calculated. 展开更多
关键词 7-[1-aza-2-(dimethylamino)vinyl]-hydroquinolin-2-ones isomerISM H-1-NMR
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Improvement of Isomerization Process of Crude Isoamylene with Tertiary-amyl-alcohol Addition 被引量:1
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作者 徐泽辉 夏蓉晖 +2 位作者 郭世卓 范存良 房鼎业 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第5期761-766,共6页
The present work contributed to a new developed production method for enhancing the quality of isoamylene (IA) by adding a small amount of tertiary amyl alcohol (TAA) to the catalyst of strong acid cation exchange... The present work contributed to a new developed production method for enhancing the quality of isoamylene (IA) by adding a small amount of tertiary amyl alcohol (TAA) to the catalyst of strong acid cation exchange resin. TAA improved the selectivity of 2-methyl-2-butene (2M2B) at a high conversion level for the isomerization of IA. Compared with the other results from the current IA units, the conversion of 2-methyl- 1-butene (2M1B), the mass ratio of 2M2B to 2M1B and the selectivity of 2M2B were increased from 0.5474, 7.32 and 0.6864 to 0.72, 12 and 0.95, respectively, while the dimers content in the products decreased from 4.38% to below 1.0%. Optimized conditions for IA isomerization consisted of temperature between 28 and 33℃ and system pressure of 0.5 MPa, weight hourly space velocity of 8.0 h-1 with TAA mass fraction of 0.7%-0.9% in raw material. The results in lab supported bases for the developed process in industrial application which was later proved to be successful. In addition, a possible mechanism of the isomerization process was speculated to propose a key step of water formation in the TAA-added isomerization process and a verified experiment was conducted to support this speculation. 展开更多
关键词 isoamylene 2-methyl-1-butene 2-methyl-2-butene isomerization process tertiary amyl alcohol
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Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalysts 被引量:3
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作者 Huijuan Liu Ling Zhang +5 位作者 Xiujie Li Shengjun Huang Shenglin Liu Wenjie Xin Sujuan Xie Longya Xu 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2009年第3期331-336,共6页
A new propene production route from 1-butene metathesis has been developed on heterogeneous 10WO3/Al2O3-HY catalysts with different HY contents. It is found that the catalysts play bi-functionally first for the isomer... A new propene production route from 1-butene metathesis has been developed on heterogeneous 10WO3/Al2O3-HY catalysts with different HY contents. It is found that the catalysts play bi-functionally first for the isomerization of 1-butene to 2-butene and then for the cross-metathesis between 1-butene and 2-butene to propene and 2-pentene. The combination of HY zeolite and Al2O3 is prerequisite for the production of propene. The propene yield keeps increasing with the HY content in the range of 10-70 wt%, where 10WO3/Al2O3-70HY exhibits the highest propene yield. The MS-H2-TPR and MS-O2-TPO characterizations indicate that the increase of HY content in the catalysts weakens the interaction between W species and supports, whereas enhance the probability of coking on the metal species and acid sites. 展开更多
关键词 PROPENE 1-butene METATHESIS 10WO3/Al2O3-xHY bifunction
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A Promising MoO_x-based Catalyst for n-Heptane Isomerization 被引量:2
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作者 Song Hai CHAI Xin Ping WANG +1 位作者 Ying Jun WANG Tian Xi CAI 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第7期748-751,共4页
The SiO2 and g-Al2O3 supported MoOx catalyst and a MoOx-SiO2 catalyst have been studied in a conventional fixed-bed flow reactor for n-alkanes isomerization. It is shown that the MoOx-SiO2 catalyst with SiO2 framewor... The SiO2 and g-Al2O3 supported MoOx catalyst and a MoOx-SiO2 catalyst have been studied in a conventional fixed-bed flow reactor for n-alkanes isomerization. It is shown that the MoOx-SiO2 catalyst with SiO2 framework, in which the bulk MoOx phase is large enough to form typical mesoporous structure, is promising in terms of its advantages of both improved mechanical strength and high catalytic properties over the supported MoOx and bulk MoOx catalyst. 展开更多
关键词 n-Heptane isomerization molybdenum oxides SIO2 MESOPORE MoOx-based.
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Serum Mac-2 binding protein glycosylation isomer level predicts hepatocellular carcinoma development in E-negative chronic hepatitis B patients 被引量:2
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作者 Lung-Yi Mak Wai-Pan To +5 位作者 Danny Ka-Ho Wong James Fung Fen Liu Wai-Kay Seto Ching-Lung Lai Man-Fung Yuen 《World Journal of Gastroenterology》 SCIE CAS 2019年第11期1398-1408,共11页
BACKGROUND Liver cirrhosis is a major risk factor for hepatocellular carcinoma(HCC)development in chronic hepatitis B(CHB). Serum Mac-2 binding protein glycosylation isomer(M2 BPGi) is a novel serological marker for f... BACKGROUND Liver cirrhosis is a major risk factor for hepatocellular carcinoma(HCC)development in chronic hepatitis B(CHB). Serum Mac-2 binding protein glycosylation isomer(M2 BPGi) is a novel serological marker for fibrosis. The role of M2 BPGi in prediction of HCC is unknown.AIM To examine the role of serum M2 BPGi in predicting HCC development in hepatitis B e antigen(HBeAg)-negative patients.METHODS Treatment-naive CHB patients with documented spontaneous HBeAg seroconversion were recruited. Serum M2 BPGi was measured at baseline(within3 years from HBeAg seroconversion), at 5 years and 10 years after HBeAg seroconversion and expressed as cut-off index(COI). Multivariate cox regression was performed to identify predictors for HCC development. ROC analysis was used to determine the cut-off value of M2 BPGi.RESULTS Among 207 patients(57% male, median age at HBeAg seroconversion 40 years old) with median follow-up of 13.1(11.8-15.5) years, the cumulative incidence of HCC at 15 years was 7%. Median M2 BPGi levels were significantly higher in patients with HCC compared to those without HCC(baseline: 1.39 COI vs 0.38 COI, P < 0.001; 5-year: 1.45 COI vs 0.47 COI, P < 0.001; 10-year: 1.20 COI vs 0.55 COI, P = 0.001). Multivariate analysis revealed age at HBeAg seroconversion[odds ratio(OR) = 1.196, 95% confidence interval(CI): 1.034-1.382, P = 0.016] and baseline M2 BPGi(OR = 4.666, 95%CI: 1.296-16.802, P = 0.018) were significant factors predictive of HCC. Using a cut-off value of 0.68 COI, baseline M2 BPGi yielded AUROC of 0.883 with 91.7% sensitivity and 80.8% specificity.CONCLUSION High serum M2 BPGi within 3 years after HBeAg seroconversion was a strong predictor for subsequent HCC development in treatment-naive HBeAg-negative CHB patients. 展开更多
关键词 HEPATOCELLULAR carcinoma HEPATITIS B Liver FIBROSIS Mac-2 binding protein GLYCOSYLATION isomer Biomarker
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Usefulness of Mac-2 binding protein glycosylation isomer in noninvasive probing liver disease in the Vietnamese population 被引量:1
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作者 Thuy Thi Thu Pham Dat Tan Ho Toan Nguyen 《World Journal of Hepatology》 CAS 2020年第5期220-229,共10页
BACKGROUND Early diagnosis is critical for successful intervention before liver disease progresses to cirrhosis and hepatocellular carcinoma.AIM To examine a novel biomarker for probing early liver disease quickly usi... BACKGROUND Early diagnosis is critical for successful intervention before liver disease progresses to cirrhosis and hepatocellular carcinoma.AIM To examine a novel biomarker for probing early liver disease quickly using an automated immunology system.METHODS This was a cross-sectional study.140 patients at various stages of liver disease were randomly selected.The cohort consisted of patients who were treatment naïve and currently undergoing therapy.We included patients with diverse liver disease etiologies.Mac-2 binding protein glycosylation isomer(M2BPGi)levels in addition to different clinical parameters,co-morbidities and transient elastography results were collected and compared.RESULTS M2BPGi levels were significantly correlated with transient elastography for liver fibrosis staging across all disease etiologies.Statistically significant differences were observed in patients with F0-1;F2 and>F3 liver fibrosis.Further examination showed that M2BPGi levels were two-fold higher in F4 than F3 hepatitis C(HCV)patients.M2BPGi was observed to be etiology-specific and HCV patients had higher mean M2BPGi levels.We also observed significant correlations with aspartate aminotransferase to platelet ratio index and fibrosis-4 index as well as HBV DNA levels.Mean M2BPGi levels for HBV patients with a viral load lower than 2000 IU/mL was 1.75-fold lower than those with a viral load greater than 2000 IU/mL.CONCLUSION M2BPGi was observed to be a good indicator of early liver disease in patients with different etiologies.Our results provide reference cut-offs for different causes of liver disease and demonstrated the utility of this marker for early disease monitoring.This is useful for remote regions in developing countries. 展开更多
关键词 Hepatitis B Hepatitis C Noninvasive fibrosis markers Mac-2 binding protein glycosylation isomer Liver disease
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Three Novel Isomers of FCH_2CP System
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作者 MingXiaLI HaiTaoYU +2 位作者 HongGangFU ZeShengLI JiaZhongSUN 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第2期250-252,共3页
Three new isomers of FCH2CP system, F(H)CCPH (1), F-cCPC-H(H) (2) and F-cCC(H)P-H (3), are predicted by means of B3LYP and CCSD(T) (single-point) methods with 6-311++G(d,p) and 6-311++G(2df,2p) basis sets, respectivel... Three new isomers of FCH2CP system, F(H)CCPH (1), F-cCPC-H(H) (2) and F-cCC(H)P-H (3), are predicted by means of B3LYP and CCSD(T) (single-point) methods with 6-311++G(d,p) and 6-311++G(2df,2p) basis sets, respectively. The three calculated isomers can isomerize into thermodynamically the most stable species F-cPC(H)C-H, which has been suggested in previous theoretical studies, with relatively higher reaction barriers. In view of their higher thermodynamic and kinetic stability, we believe that the three species can be detected in future experiments. 展开更多
关键词 FCH2CP system STABILITY isomer.
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Al_(2)O_(3)晶型对Pt/Al_(2)O_(3)-Cl催化剂物化性质及其催化C_(5)/C_(6)异构化性能的影响 被引量:5
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作者 唐俊 于中伟 刘洪全 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2023年第1期88-96,共9页
以拟薄水铝石粉和湃水铝石粉为前驱体,通过挤条成型和焙烧制备了3种不同晶型(γ、θ、η)Al_(2)O_(3)载体,并分别经负载Pt和氯化制备了3种Pt/Al_(2)O_(3)-Cl催化剂(Pt/γ-Al_(2)O_(3)-Cl、Pt/θ-Al_(2)O_(3)-Cl和Pt/η-Al_(2)O_(3)-Cl)... 以拟薄水铝石粉和湃水铝石粉为前驱体,通过挤条成型和焙烧制备了3种不同晶型(γ、θ、η)Al_(2)O_(3)载体,并分别经负载Pt和氯化制备了3种Pt/Al_(2)O_(3)-Cl催化剂(Pt/γ-Al_(2)O_(3)-Cl、Pt/θ-Al_(2)O_(3)-Cl和Pt/η-Al_(2)O_(3)-Cl);采用X射线衍射(XRD)、N_(2)吸附-脱附(BET)、吡啶红外(Py-IR)、透射电镜(TEM)、NH_(3)程序升温脱附(NH_(3)-TPD)等手段表征了3种Al_(2)O_(3)载体及Pt/Al_(2)O_(3)-Cl催化剂,并通过固定床微反装置考察了Pt/Al_(2)O_(3)-Cl催化剂的C_(5)/C_(6)异构化性能。结果表明:γ、θ、η型Al_(2)O_(3)载体经负载Pt和氯化后,晶型不发生改变,Cl含量和酸量均大幅度提高,Lewis酸酸性显著增强,比表面积和孔体积明显下降;Pt/η-Al_(2)O_(3)-Cl催化剂的比表面积和酸量最大,C_(5)/C_(6)异构化活性最高,Pt/γ-Al_(2)O_(3)-Cl次之,Pt/θ-Al_(2)O_(3)-Cl最低;在温度为150℃、压力为3.2 MPa、进料质量空速为1.5 h^(-1)、氢/烃摩尔比为1.0的条件下,Pt/η-Al_(2)O_(3)-Cl催化剂作用下,C_(5)异构化率、C_(6)异构化率和C_(6)选择性分别为77.13%、88.68%和31.87%。 展开更多
关键词 Pt/Al_(2)O_(3)-Cl催化剂 异构化 氧化铝 晶型 酸量
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Synthesis and Structure of a Novel Supramolecular Compound [Co(2,2′-bipy)(H_2O)_4 ][trans-1,4-chdc] and Separation of Isomer of 1,4-Cyclohexanedicarboxylic Acid
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作者 YU Miao LIU Shu-xia ZHANG Chun-dan GAO Bo SUN Chun-yan XIE Lin-hua WANG Chun-ling CHENG Hai-yan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第4期415-418,共4页
A supramolecular compound, [ Co(2,2'-bipy) ( H2O)4 ] [ trans-1,4-chdc ] ( compound 1 ) ( 2,2'-bipy = 2,2'- bipyridine, 1,4-chdcH2 = 1,4-cyclohexanedicarboxylic acid), was synthesized and characterized by si... A supramolecular compound, [ Co(2,2'-bipy) ( H2O)4 ] [ trans-1,4-chdc ] ( compound 1 ) ( 2,2'-bipy = 2,2'- bipyridine, 1,4-chdcH2 = 1,4-cyclohexanedicarboxylic acid), was synthesized and characterized by single-crystal Xray diffraction analysis, IR spectrometry, TG analysis, and elemental analyses. Single-crystal X-ray diffraction analysis revealed that [ Co( 2,2'-bipy) ( H2O)4 ]^2+ units and adjacent 1,4-chdc^2- formed a single layer by hydrogen bonding and electrostatic interactions along the ac-plane, and two symmetry-related single layers interacted with each other by hydrogen bonding, resulting in a double layer, which further formed a 3-D structure by π-π stacking. The most attractive structural feature of compound 1 is that 1,4-chdc2- possesses only tram-conformation although there are both c/s- and tram-conformations in the raw material. 展开更多
关键词 isomer separation 1 4-chdcH2 Supramolecular compound Hydrogen bonding
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Low-Lying Isomers of(TiO_(2))_(n)(n=2-8)Clusters
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作者 Binli Wang Abubakar Sadiq Abdullahi +1 位作者 Yahui Wang Hong-Jun Fan 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第2期311-321,I0002,共12页
Although there are diverse bond features of Ti and O atoms,so far only several isomers have been reported for each(TiO_(2))n cluster.Instead of the widely used global optimization,in this work,we search for the low-ly... Although there are diverse bond features of Ti and O atoms,so far only several isomers have been reported for each(TiO_(2))n cluster.Instead of the widely used global optimization,in this work,we search for the low-lying isomers of(TiO_(2))_(n)(n=2-8)clusters with up to 10000 random sampling initial structures.These structures were optimized by the PM6 method,followed by density functional theory calculations.With this strategy,we have located many more low-lying isomers than thosereported previously.The number of isomers increases dramatically with the size of the cluster,and about 50 isomers were found for(TiO_(2))_(7) and(TiO_(2))_(8) with the energy within 30 kcal/mol.Furthermore,new lowest isomers have been located for(TiO_(2))_(5) and(TiO_(2))_(8),and isomers with three terminal oxygen atoms,five coordinated oxygen atoms as well as six coordinated titanium atoms have been located.Our work highlights the diverse structural features and a large number of isomers of small TiO_(2) clusters. 展开更多
关键词 TiO_(2) Cluster Low-lying isomer Density functional theory Geometric structure
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Measurement of^(134)Xe(n,2n)^(133m),gXe reaction cross sections in 14‑MeV region with detailed uncertainty quantification 被引量:2
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作者 Jun‑Hua Luo Jun‑Cheng Liang +3 位作者 Li Jiang Fei Tuo Liang Zhou Long He 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第1期33-42,共10页
A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(1... A lead-shielded HPGe detector and offlineγ-ray spectra of the residual product were used to measure the cross section(CS)and ratios of isomeric CS(σm/σg)in^(134)Xe(n,2n)^(133m),gXe reactions at different energies(13.5 MeV,13.8 MeV,14.1 MeV,14.4 MeV,14.8 MeV)relative to the^(93)Nb(n,2n)^(92)mNb reaction CS.The target was high-purity natural Xe gas under high pressure.The T(d,n)4He reaction produces neutrons.TALYS code(version 1.95)for nuclear reactions was used for calculations,with default parameters and nuclear level density models.The uncertainties in the measured CS data were thoroughly analyzed using the covariance analysis method.The results were compared with theoretical values,evaluation data,and previous experimental findings.CS data of the 134Xe(n,2n)133mXe and 134Xe(n,2n)133gXe reactions and the corresponding isomeric CS ratios at 13.5 MeV,13.8 MeV,and 14.1 MeV neutron energies are reported for the first time.This research advances our knowledge of pre-equilibrium emission in the(n,2n)reaction channel by resolving inconsistencies in the Xe data. 展开更多
关键词 ^(134)Xe(n 2n)reactions 14-MeV neutrons Cross sections(CSs) isomeric ratios(IRs) Covariance analysis
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