Novel dendrimer-based nickel catalyst: synthesis, characterization and performance in ethylene oligomerization

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Jun Wang ◽  
Guang Yang ◽  
Cui-Qin Li ◽  
Wei-Guang Shi ◽  
Si-Han Wang
Keyword(s):  
Catalytic Activity ◽  
Nickel Complex ◽  
Nickel Chloride ◽  
Negative Influence ◽  
Ethylene Oligomerization ◽  
Ni Catalyst ◽  
Catalyst Precursor ◽  
Elemental Analyses ◽  
And Performance ◽  
Complexation Reactions

AbstractA novel nickel metallodendrimer was synthesized with poly(amidoamine), 3,5-di-tert-butyl-2-hydroxy-benzaldehyde and nickel chloride via the Schiff’s base and the complexation reactions. Structures of the dendritic ligand and its nickel complex were characterized by IR, NMR, UV, ESI-MS and elemental analyses. This new nickel metallodendrimer as a catalyst precursor, together with methylaluminoxane as an activator, was evaluated in the ethylene oligomerization. Under the conditions of 0.5 h, 0.5 MPa, 25°C and Al/Ni mole ratio 500: 1 employed for the nickel complex, the catalytic activity showed a maximum value of 4.93 × 105 grams per mole of Ni catalyst per hour. Substituents on the benzene ring seem to have a negative influence on the catalytic activity of the complex.

Concomitant Polymorphs: An Alternative to Modulate Oxygen Evolution Performance of Mononuclear Nickel Complex

2021 ◽  
Author(s):  
Chen Hu ◽  
Qing-Qing Huang ◽  
Haibing Xu ◽  
Yuexing Zhang ◽  
Xu Peng ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Evolution ◽  
Nickel Complex ◽  
Crystal Packing ◽  
The Relationship

The availability of polymorphs of metallic complexes provides an opportunity to reveal the relationship between crystal packing and catalytic activity. Herein, we immobilize two stable concomitant polymorphs (green NiL2-G and...

Perceiving Humor in Traditional Chinese Peking Opera

2018 ◽  
Vol 14 (3) ◽  
pp. 371-391
Author(s):  
Zhiyi Zhang ◽  
Xiaobing Jin
Keyword(s):  
Performing Arts ◽  
Negative Influence ◽  
Contributing Factors ◽  
Comprehension Difficulty ◽  
Inverse Proportion ◽  
Peking Opera ◽  
And Performance ◽  
Interview Analysis

Abstract Peking opera epitomizes the traditional Chinese performing arts, and all six factors concerning the story and performance of Peking opera, namely plot, role type, song, speech, acting, and combat, can produce humorous effects among the audience. The present paper is a tentative study on humor and sensing humor in Peking opera. The scale study testified that all six factors were able to produce humorous effects and that they had different degrees of comprehension difficulty and humor for different contributing factors. The degree of comprehension difficulty can assert negative influence upon the degree of humor. Different from the traditionally held nonmonotonic (inverted-U) correlation between the two, a monotonic inverse proportion between the two has been detected. The interview analyses revealed that the humorous effects had something to do with incongruity but that resolution might not necessarily be involved. The scale study and the interview analysis both support this finding.

scholarly journals COVID-19 fear and performance of workers: A moderated mediation role of organizational support and mental wellbeing

2022 ◽  
Vol 12 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Erasmus Keli Swanzy
Keyword(s):  
Regression Analysis ◽  
Organizational Support ◽  
Indirect Effect ◽  
Negative Influence ◽  
Self Report ◽  
Adverse Impact ◽  
Mental Wellbeing ◽  
Anxiety And Depression ◽  
And Performance

The paper aimed to examine the influence of employees’ COVID-19 fear on their performance through intervening mechanisms such as mental wellbeing and organizational support. A total of 446 workers from the bank completed a self-report survey. Findings from regression analysis conducted with SPSS PROCESS MACRO (Model 7) revealed that employees’ COVID-19 fear did not have any direct negative influence on their performance but instead had an indirect effect on their performance via mental wellbeing (anxiety and depression). The findings also revealed that organizational support was instrumental in buffering the adverse impact of employees’ COVID-19 fear via mental wellbeing (anxiety and depression). Therefore, organizations should increase employee-supportive measures throughout this era of the COVID-19 to help reduce the adverse impact of employees’ COVID-19 fear.

Bimetallic Alkoxides of Nickel(II) with Niobium(V) and Tantalum(V)

1985 ◽  
Vol 40 (10) ◽  
pp. 1371-1376 ◽  
Author(s):  
R. Jain ◽  
A. K. Rai ◽  
R. C. Mehrotra
Keyword(s):  
Molecular Weight ◽  
Nickel Chloride ◽  
Reflectance Spectroscopy ◽  
Octahedral Geometry ◽  
Molar Ratio ◽  
New Class ◽  
Elemental Analyses ◽  
Visible Reflectance ◽  
Bimetallic Alkoxides ◽  
Interchange Reactions

A new class of bimetallic isopropoxides of nickel(II) with niobium and tantalum with the general formula, Ni[M(OPri)6]2, (where M = Nb or Ta) have been synthesized by the reaction of nickel chloride isopropanolate, NiCl2·ϰPriOH, with potassium hexaisopropoxy metalates, KM(OPri)6, (M = Nb or Ta) in the molar ratio 1:2. These derivatives have been characterized by elemental analyses, molecular weight determinations, infrared and visible reflectance spectroscopy in addition to magnetic susceptibility measurements. Alcohol interchange reactions of these bimetallic alkoxides have also been studied. On the basis of above studies, an octahedral geometry has been assigned to Ni(II) in primary bimetallic alkoxides while in secondary derivatives, it appears that there exists an equilibrium between octahedral and tetrahedral forms.

A Study on the Design and Performance of Epicycloid Bevels of Pure-Rolling Contact

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Rulong Tan ◽  
Bingkui Chen ◽  
Dongyun Xiang ◽  
Dong Liang
Keyword(s):  
Negative Influence ◽  
Transmission Efficiency ◽  
Rolling Contact ◽  
Tooth Surface ◽  
Element Analysis ◽  
Surface Theory ◽  
Pure Rolling ◽  
Surface Models ◽  
And Performance ◽  
Mechanics Characteristics

To avoid the negative influence of sliding contact, this paper tries to investigate the spiral bevels of pure-rolling contact that can be manufactured by existing manufacture technology. In this process, spatial conjugate curve meshing theory and conjugate surface theory are both introduced to investigate the geometric principles and face hobbing process of the pure-rolling contact epicycloid bevel (PCEB for short in this paper). The tooth surface models of PCEBs by face hobbing process are obtained. Next, a sample is represented to show an application of this model. Then, finite element analysis (FEA) is applied to investigate the contact mechanics characteristics of these gears. Finally, the performance experiment of a prototype is completed to evaluate the deviations between theoretical expectations and practical results. From the FEA and experimental results, it is concluded that the PCEBs can mesh correctly and achieve a higher transmission efficiency.

scholarly journals N,N-Dimethylformamide-stabilized copper nanoparticles as a catalyst precursor for Sonogashira–Hagihara cross coupling

RSC Advances ◽  
2017 ◽  
Vol 7 (37) ◽  
pp. 22869-22874 ◽  
Author(s):  
Hideo Oka ◽  
Katsuya Kitai ◽  
Takeyuki Suzuki ◽  
Yasushi Obora
Keyword(s):  
Catalytic Activity ◽  
Copper Nanoparticles ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
High Catalytic Activity ◽  
Catalyst Precursor ◽  
Cross Coupling Reaction

We found that DMF-stabilized Cu NPs have high catalytic activity in the Sonogashira cross-coupling reaction at low catalyst loadings (0.2 mol%).

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