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Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 251-255 doi: 10.1007/s11705-007-0045-1

摘要: A heterogeneous chiral catalyst Fe(III)-CS (chitosan) complex/mesoporous molecular sieve SBA-15 (Santa Barbara Amorphous) was prepared. The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor. Effects of Fe content in catalyst, reaction temperature, reaction time and promoter KOH concentration on the conversion of substrates and enantioselectivity were investigated. Fe-CS/SBA-15 with 2.2% mass fraction Fe exhibits considerable enantioselectivity and catalytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone. Under optimal reaction conditions: KOH concentration 0.03 mol/L, reaction temperature 70ºC and reaction time 4 h, enantiomer excess (ee) of ()-1-phenylethanol and conversion of acetophenone can reach 87.4% and 27.7%, respectively. Under the above KOH concentration and reaction temperature and reaction time of 8 h, the ee of ()-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2% and 25.5%, respectively.

关键词: asymmetric transfer     enantioselectivity     Fe-CS/SBA-15     aliphatic     aromatic    

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 203-211 doi: 10.1007/s11705-014-1420-3

摘要: ZSM-5/SBA-15 composite molecular sieves were synthesized using post-synthesis method and characterized by X-ray diffraction and N adsorption-desorption. The oxidative-extration desulfurization of model oil was investigated by using hydrogen peroxide as the oxidant, tetrabutyl ammonium bromide as phase transfer catalyst, dimethyl sulfoxide as extractant, and Zr-ZSM-5/SBA-15, Ag-ZSM-5/SBA-15, Ce-ZSM-5/SBA-15 as catalyst. Under the optimal conditions, the desulfurization rate decreases in the order: Zr-ZSM-5/SBA-15>Ce-ZSM-5/SBA-15>Ag-ZSM-5/SBA-15. The highest desulfurization rate is 84.53% under the catalysis of Zr-ZSM-5/SBA-15. Kinetics analysis shows that the reaction is pseudo-first-order with the activation energy of 44.23 kJ/mol.

关键词: composite molecular sieve     oxidation desulfuration     extraction     kinetic    

Enhanced desulfurization performance of hybrid membranes using embedded hierarchical porous SBA-15

Ye Zhang, Jian Song, Josue Quispe Mayta, Fusheng Pan, Xue Gao, Mei Li, Yimeng Song, Meidi Wang, Xingzhong Cao, Zhongyi Jiang

《化学科学与工程前沿(英文)》 2020年 第14卷 第4期   页码 661-672 doi: 10.1007/s11705-019-1830-3

摘要: The utilization of materials with a hierarchical porous structure as multi-functional additives is highly attractive in the preparation of hybrid membranes. In this study, novel hybrid membranes are designed by embedding hierarchical porous Santa Barbara Amorphous 15 (SBA-15) with a dual-pore architecture (micropores and mesopores) for pervaporation desulfurization. The SBA-15 with cylindrical mesopores provides molecular transport expressways to ensure improved permeability, while micropores on the wall have molecular sieving effects that are essential for the enhancement of permselectivity of thiophene molecules. Considering thiophene/ -octane mixture as a model system, the hybrid membrane with embedded 6 wt-% SBA-15 exhibits optimal pervaporation desulfurization performance with a permeation flux of 22.07 kg·m ·h and an enrichment factor of 6.76. Moreover, the detailed structure and properties of hybrid membranes are systematically characterized. This study demonstrates the immense potential of hierarchical porous materials as additives in membranes to simultaneously increase permeability and permselectivity.

关键词: hybrid membranes     hierarchical porous SBA-15     sieving effect     pervaporation     desulfurization    

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第3期   页码 397-404 doi: 10.1007/s11705-019-1884-2

摘要: Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.

关键词: photocatalysis     covalent triazine framework     aqueous medium     SBA-15     solid state    

A mini review on chemical fixation of CO 2 : Absorption and catalytic conversion into cyclic carbonates

Weili DAI, Chaktong AU, Shenglian LUO, Shuangfeng YIN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 163-171 doi: 10.1007/s11705-009-0235-0

摘要: In this article, we present our research results on chemical fixation of CO using organobismuth compounds. We fabricated bismuth biphenoate complex, Zn-Mg-Al composite oxides, and SBA-15 or Al-SBA-15 immobilized hydroxyl ionic liquid for CO cycloaddition onto epoxides. The hypervalent bismuth compounds show good ability for association and dissociation with CO. The bismuth biphenolate complexes are catalytically effective for the cycloaddition reaction. The heterogeneous catalysts, viz. Zn-Mg-Al oxides and SBA-15 or Al-SBA-15 immobilized ionic liquid, are efficient for the synthesis of cyclic carbonate from CO and epoxide. It is found that the presence of a trace amount of water can improve the catalytic activity of the immobilized ionic liquid.

关键词: SBA-15     CO cycloaddition     Al-SBA-15 immobilized     CO     dissociation    

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 150-154 doi: 10.1007/s11705-008-0036-x

摘要: CuO/SBA-16 catalysts were prepared by two different routes – the conventional impregnation method and the modified impregnation method with pH adjustment. These catalysts were characterized by X-ray diffraction (XRD), atomic absorption spectrometry (AAS), N physisorption and hydrogen temperature programmed reduction (H-TPR) measurements which reveal that the cubic cage-like () pore structure of the parent SBA-16 molecule sieves was well maintained throughout the synthesis. After introduction of Cu, a different CuO dispersion exists on these catalysts. The CuO/SBA-16 prepared by modified impregnation method has a single highly dispersed CuO which is considered as a highly efficient species for hydroxylation of phenol with HO. CuO/SBA-16 prepared by the conventional impregnation method shows the presence of bulk CuO species which is undesirable for this reaction.

关键词: different     CuO/SBA-16     temperature     physisorption     introduction    

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

《医学前沿(英文)》 2023年 第17卷 第1期   页码 119-131 doi: 10.1007/s11684-022-0949-7

摘要: Treating patients with esophageal squamous cell carcinoma (ESCC) is challenging due to the high chemoresistance. Growth differentiation factor 15 (GDF15) is crucial in the development of various types of tumors and negatively related to the prognosis of ESCC patients according to our previous research. In this study, the link between GDF15 and chemotherapy resistance in ESCC was further explored. The relationship between GDF15 and the chemotherapy response was investigated through in vitro and in vivo studies. ESCC patients with high levels of GDF15 expression showed an inferior chemotherapeutic response. GDF15 improved the tolerance of ESCC cell lines to low-dose cisplatin by regulating AKT phosphorylation via TGFBR2. Through an in vivo study, we further validated that the anti-GDF15 antibody improved the tumor inhibition effect of cisplatin. Metabolomics showed that GDF15 could alter cellular metabolism and enhance the expression of UGT1A. AKT and TGFBR2 inhibition resulted in the reversal of the GDF15-induced expression of UGT1A, indicating that TGFBR2-AKT pathway-dependent metabolic pathways were involved in the resistance of ESCC cells to cisplatin. The present investigation suggests that a high level of GDF15 expression leads to ESCC chemoresistance and that GDF15 can be targeted during chemotherapy, resulting in beneficial therapeutic outcomes.

关键词: GDF15     esophageal squamous cell carcinoma     chemoresistance     cellular metabolism     TGFBR2     AKT    

Beneficial metabolic activities of inflammatory cytokine interleukin 15 in obesity and type 2 diabetes

null

《医学前沿(英文)》 2015年 第9卷 第2期   页码 139-145 doi: 10.1007/s11684-015-0377-z

摘要:

In obesity, chronic inflammation is believed to induce insulin resistance and impairs adipose tissue function. Although this view is supported by a large body of literature, it has been challenged by growing evidence that pro-inflammatory cytokines may favor insulin sensitivity through induction of energy expenditure. In this review article, interleukin 15 (IL-15) is used as a new example to explain the beneficial effects of the pro-inflammatory cytokines. IL-15 is secreted by multiple types of cells including macrophages, neutrophils and skeletal muscle cells. IL-15 expression is induced in immune cells by endotoxin and in muscle cells by physical exercise. Its transcription is induced by transcription factor NF-κB. IL-15 binds to its receptor that contains three different subunits (α, β and γ) to activate JAK/STAT, PI3K/Akt, IKK/NF-κB and JNK/AP1 pathways in cells. In the regulation of metabolism, IL-15 reduces weight gain without inhibiting food intake in rodents. IL-15 suppresses lipogenesis, stimulates brown fat function, improves insulin sensitivity through weight loss and energy expenditure. In human, circulating IL-15 is negatively associated with body weight. In the immune system, IL-15 stimulates proliferation and differentiation of T cells, NK cells, monocytes and neutrophils. In the anti-obesity effects of IL-15, T cells and NK cells are not required, but leptin receptor is required. In summary, evidence from human and rodents supports that the pro-inflammatory cytokine IL-15 may enhance energy expenditure to protect the body from obesity and type 2 diabetes. The mechanism of IL-15 action remains to be fully uncovered in the regulation of energy expenditure.

关键词: inflammation     obesity     cytokine     energy expenditure     insulin resistance    

一种K自适应的广域网SDN控制器部署方法 Article

Peng XIAO,Zhi-yang LI,Song GUO,Heng QI,Wen-yu QU,Hai-sheng YU

《信息与电子工程前沿(英文)》 2016年 第17卷 第7期   页码 620-633 doi: 10.1631/FITEE.1500350

摘要: 软件定义网络(software-defined networking)作为一种新技术框架,正成为未来网络技术的核心。软件定义网络的核心思想就是控制平面和数据平面分离,方便管理和控制编程。虽然软件定义网络已在数据中心这样的局域网中得到了应用和部署,但在更大规模的广域网上部署依然面临着很多问题,如SDN域划分、控制器部署等问题。本文提出了一种基于谱聚类的SDN控制器部署方法,通过此方法能将较大的网络划分成小的SDN域并选择其控制器位置。通过分析模型的矩阵扰动和本征间隙,能够自动得到SDN域个数,以达到较好的划分效果和控制器部署方案。最后,为了验证算法的有效性,本文提出了一个新的实验框架,并基于广域网拓扑结构进行了实验。实验结果表明,该方法能很好的解决SDN域划分和控制器部署问题。

关键词: 软件定义网络;控制器部署;K自适应方法    

Experimental investigation on freeze−thaw durability of polymer concrete

《结构与土木工程前沿(英文)》 2021年 第15卷 第4期   页码 1038-1046 doi: 10.1007/s11709-021-0748-2

摘要: Assessing the durability of concrete is of prime importance to provide an adequate service life and reduce the repairing cost of structures. Freeze–thaw is one such test that indicates the ability of concrete to last a long time without a significant loss in its performance. In this study, the freeze–thaw resistance of polymer concrete containing different polymer contents was explored and compared to various conventional cement concretes. Concretes’ fresh and hardened properties were assessed for their workability, air content, and compressive strength. The mass loss, length change, dynamic modulus of elasticity, and residual compressive strength were determined for all types of concretes subjected to freeze–thaw cycles according to ASTM C666-procedure A. Results showed that polymer concrete (PC) specimens prepared with higher dosages of polymer contents possessed better freeze–thaw durability compared to other specimens. This high durability performance of PCs is mainly due to their impermeable microstructures, absence of water in their structure, and the high bond strength between aggregates and a polymer binder. It is also indicated that the performance of high-strength concrete containing air-entraining admixture is comparable with PC having optimum polymer content in terms of residual compressive strength, dynamic modulus of elasticity, mass loss, and length change.

关键词: durability test     freeze-thaw resistance     polymer concrete     residual compressive strength     ASTM C666-15    

思维的两重性及其向创造性思维的转化 纪念钱学森院士《关于思维科学》发表15周年

梁桂明

《中国工程科学》 2003年 第5卷 第2期   页码 26-34

摘要:

进入21世纪的新时代,带来与思维相关的两个特征:创新与共融。关于创新,如何激发创造性思维?成为热门的话题。从唯物辩证法的哲学的认识论和真理的相对性的高度来探索,发现任何一种思维形式(包括演绎法思维和定势-习惯思维)都具有两重性,即非创造性与创造性并存,在一定条件下,非创造性思维可以转化或激发为创造性思维,产生新知识,获得创新成果。关于共融,如何进行思维的界定和分类,有许多种说法。笔者把心理学与生理学的成果融合起来,形成两大类,即左半脑主导的理性思维和右半脑主导的悟性思维。其基本的思维形式的分类与思维的大类结合,成为两大类7种。把辩证法和共融结合,得到下列结论:理性思维与感性思维的统一,原有知识与新知识的统一,设想与验证的统一,发现与发明的统一,科学(真感)与艺术(美感)的统一。对最后一个结论,笔者以工业产品造型设计原理的探索为例加以说明。此原理在工业设计上属首次推出。

关键词: 创造性思维     转化条件     知识的相对性     融合    

Effects of ambient temperature on regulated gaseous and particulate emissions from gasoline-, E10- and M15

Rencheng Zhu, Jingnan Hu, Liqiang He, Lei Zu, Xiaofeng Bao, Yitu Lai, Sheng Su

《环境科学与工程前沿(英文)》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1306-1

摘要: Abstract • Emissions from two sedans were tested with gasoline, E10 and M15 at 30°C and -7°C. • As the temperature decreased, the PM, PN and BC emissions increased with all fuels. • Particulate emissions with E10 and M15 were more sensitive to the temperature. • The PN and BC generated during cold start-up dominated those over the WLTC. Ambient temperature has substantial impacts on vehicle emissions, but the impacts may differ between traditional and alcohol gasolines. The objective of this study was to investigate the effects of temperature on gaseous and particulate emissions with both traditional and alcohol gasoline. Regulated gaseous, particle mass (PM), particle number (PN) and black carbon (BC) emissions from typical passenger vehicles were separately quantified with gasoline, E10 (10% ethanol and 90% gasoline by volume) and M15 (15% methanol and 85% gasoline by volume) at both 30°C and -7°C. The particulate emissions with all fuels increased significantly with decreased temperature. The PM emissions with E10 were only 48.0%–50.7% of those with gasoline at 30°C but increased to 59.2%-79.4% at -7°C. The PM emissions with M15 were comparable to those with gasoline at 30°C, but at -7°C, the average PM emissions were higher than those with gasoline. The variation trend of PN emissions was similar to that of PM emissions with changes in the fuel and temperature. At 30°C, the BC emissions were lower with E10 and M15 than with gasoline in most cases, but E10 and M15 might emit more BC than gasoline at -7°C, especially M15. The results of the transient PN and BC emission rates show that particulate emissions were dominated mainly by those emitted during the cold-start moment. Overall, the particulate emissions with E10 and M15 were more easily affected by ambient temperature, and the advantages of E10 and M15 in controlling particulate emissions declined as the ambient temperature decreased.

关键词: Particle mass     Particle number     Black carbon     Alcohol gasoline     Low temperature    

15届亚洲纺织会议The 15th Asian Textile Conference

会议日期: 2019年09月23日

会议地点: 中国/浙江/杭州

主办单位: 中国纺织工程学会

Symbiotic performance, shoot biomass and water-use efficiency of three groundnut (

Sofiya K. MUHABA, Felix D. DAKORA

《农业科学与工程前沿(英文)》 2020年 第7卷 第4期   页码 455-466 doi: 10.15302/J-FASE-2020354

摘要:

Phosphorus is a key nutrient element involved in energy transfer for cellular metabolism, respiration and photosynthesis and its supply at low levels can affect legume nodulation, N fixation, and C assimilation. A two-year field study was conducted in Ethiopia in 2012 and 2013 to evaluate the effects of P supply on growth, symbiotic N nutrition, grain yield and water-use efficiency of three groundnut genotypes. Supplying P to the genotypes significantly increased their shoot biomass, symbiotic performance, grain yield, and C accumulation. There was, however, no effect on shoot δ C values in either year. Compared to the zero-P control, supplying 40 kg·ha P markedly increased shoot biomass by 77% and 66% in 2012 and 2013, respectively. In both years, groundnut grain yields were much higher at 20 and 30 kg·ha P. Phosphorus supply markedly reduced shoot δ N values and increased the %Ndfa and amount of N-fixed, indicating the direct involvement of P in promoting N fixation in nodulated groundnut. The three genotypes differed significantly in δ N, %Ndfa, N-fixed, grain yield, C concentration, and δ C. The phosphorus × genotype interaction was also significant for shoot DM, N content, N-fixed and soil N uptake.

关键词: shoot yield     N-fixed     %Ndfa     δ15N     δ13C     water-use efficiency    

15万吨规模燃煤电厂燃烧后二氧化碳捕集示范工程

崔青汝, 赵瑞, 王天堃, 张帅, 黄艳, 顾永正, 徐冬

《工程(英文)》 2022年 第14卷 第7期   页码 22-26 doi: 10.1016/j.eng.2022.04.006

关键词: 工程成就    

标题 作者 时间 类型 操作

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

期刊论文

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

期刊论文

Enhanced desulfurization performance of hybrid membranes using embedded hierarchical porous SBA-15

Ye Zhang, Jian Song, Josue Quispe Mayta, Fusheng Pan, Xue Gao, Mei Li, Yimeng Song, Meidi Wang, Xingzhong Cao, Zhongyi Jiang

期刊论文

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

期刊论文

A mini review on chemical fixation of CO 2 : Absorption and catalytic conversion into cyclic carbonates

Weili DAI, Chaktong AU, Shenglian LUO, Shuangfeng YIN,

期刊论文

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

期刊论文

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

期刊论文

Beneficial metabolic activities of inflammatory cytokine interleukin 15 in obesity and type 2 diabetes

null

期刊论文

一种K自适应的广域网SDN控制器部署方法

Peng XIAO,Zhi-yang LI,Song GUO,Heng QI,Wen-yu QU,Hai-sheng YU

期刊论文

Experimental investigation on freeze−thaw durability of polymer concrete

期刊论文

思维的两重性及其向创造性思维的转化 纪念钱学森院士《关于思维科学》发表15周年

梁桂明

期刊论文

Effects of ambient temperature on regulated gaseous and particulate emissions from gasoline-, E10- and M15

Rencheng Zhu, Jingnan Hu, Liqiang He, Lei Zu, Xiaofeng Bao, Yitu Lai, Sheng Su

期刊论文

15届亚洲纺织会议The 15th Asian Textile Conference

2019年09月23日

会议信息

Symbiotic performance, shoot biomass and water-use efficiency of three groundnut (

Sofiya K. MUHABA, Felix D. DAKORA

期刊论文

15万吨规模燃煤电厂燃烧后二氧化碳捕集示范工程

崔青汝, 赵瑞, 王天堃, 张帅, 黄艳, 顾永正, 徐冬

期刊论文