Effects of structural variations on π-dimer formation: long-distance multicenter bonding of cation-radicals of tetrathiafulvalene analogues

2020 ◽  
Vol 22 (43) ◽  
pp. 25054-25065
Author(s):  
John T. Brown ◽  
Matthias Zeller ◽  
Sergiy V. Rosokha
Keyword(s):  
Structural Variations ◽  
Long Distance ◽  
Dimer Formation ◽  
Cation Radicals ◽  
Multicenter Bonding ◽  
The Stability

Replacement of sulfur with selenium or insertion of ethylenedithio-substituents into tetrathiafulvalene cation-radicals increases the stability of the π-bonded dimers.

scholarly journals Structural tuning of heterogeneous molecular catalysts for electrochemical energy conversion

2021 ◽  
Vol 7 (13) ◽  
pp. eabf3989
Author(s):  
Jiong Wang ◽  
Shuo Dou ◽  
Xin Wang
Keyword(s):  
Energy Conversion ◽  
Model Systems ◽  
Structural Variations ◽  
Metal Centers ◽  
Electrochemical Energy Conversion ◽  
Electronic Configurations ◽  
Coordination Spheres ◽  
The Stability ◽  
Molecular Catalysts ◽  
Electrochemical Energy

Heterogeneous molecular catalysts based on transition metal complexes have received increasing attention for their potential application in electrochemical energy conversion. The structural tuning of first and second coordination spheres of complexes provides versatile strategies for optimizing the activities of heterogeneous molecular catalysts and appropriate model systems for investigating the mechanism of structural variations on the activity. In this review, we first discuss the variation of first spheres by tuning ligated atoms; afterward, the structural tuning of second spheres by appending adjacent metal centers, pendant groups, electron withdrawing/donating, and conjugating moieties on the ligands is elaborated. Overall, these structural tuning resulted in different impacts on the geometric and electronic configurations of complexes, and the improved activity is achieved through tuning the stability of chemisorbed reactants and the redox behaviors of immobilized complexes.

scholarly journals Effect of Mixing Ratio of Oppositely Charged Block Copolymers on Polyion Complex Micelles for In Vivo Application

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Noriko Nakamura ◽  
Yuki Mochida ◽  
Kazuko Toh ◽  
Shigeto Fukushima ◽  
Horacio Cabral ◽  
...  
Keyword(s):  
Physicochemical Characteristics ◽  
Charge Ratio ◽  
Structural Variations ◽  
Polyion Complex ◽  
Functional Capabilities ◽  
The Stability ◽  
Biological Performance ◽  
Complex Micelles ◽  
Oppositely Charged

Self-assembled supramolecular structures based on polyion complex (PIC) formation between oppositely charged polymers are attracting much attention for developing drug delivery systems able to endure harsh in vivo environments. As controlling polymer complexation provides an opportunity for engineering the assemblies, an improved understanding of the PIC formation will allow constructing assemblies with enhanced structural and functional capabilities. Here, we focused on the influence of the mixing charge ratio between block aniomers and catiomers on the physicochemical characteristics and in vivo biological performance of the resulting PIC micelles (PIC/m). Our results showed that by changing the mixing charge ratio, the structural state of the core was altered despite the sizes of PIC/m remaining almost the same. These structural variations greatly affected the stability of the PIC/m in the bloodstream after intravenous injection and determined their biodistribution.

scholarly journals Different Benzendicarboxylate-Directed Structural Variations and Properties of Four New Porous Cd(II)-Pyridyl-Triazole Coordination Polymers

2020 ◽  
Vol 8 ◽  
Author(s):  
Ying Zhao ◽  
Jin Jing ◽  
Ning Yan ◽  
Min-Le Han ◽  
Guo-Ping Yang ◽  
...  
Keyword(s):  
Solid State ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Gas Sorption ◽  
Structural Variations ◽  
Benzenedicarboxylic Acid ◽  
Topological Framework ◽  
The Stability

Four new different porous crystalline Cd(II)-based coordination polymers (CPs), i. e., [Cd(mdpt)2]·2H2O (1), [Cd2(mdpt)2(m-bdc)(H2O)2] (2), [Cd(Hmdpt)(p-bdc)]·2H2O (3), and [Cd3(mdpt)2(bpdc)2]·2.5NMP (4), were obtained successfully by the assembly of Cd(II) ions and bitopic 3-(3-methyl-2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (Hmdpt) in the presence of various benzendicarboxylate ligands, i.e., 1,3/1,4-benzenedicarboxylic acid (m-H2bdc, p-H2bdc) and biphenyl-4,4′-bicarboxylate (H2bpdc). Herein, complex 1 is a porous 2-fold interpenetrated four-connected 3D NbO topological framework based on the mdpt− ligand; 2 reveals a two-dimensional (2D) hcb network. Interestingly, 3 presents a three-dimensional (3D) rare interpenetrated double-insertion supramolecular net via 2D ···ABAB··· layers and can be viewed as an fsh topological net, while complex 4 displays a 3D sqc117 framework. Then, the different gas sorption performances were carried out carefully for complexes 1 and 4, the results of which showed 4 has preferable sorption than that of 1 and can be the potential CO2 storage and separation material. Furthermore, the stability and luminescence of four complexes were performed carefully in the solid state.

Chemical repair of protein carbon-centred radicals: long-distance dynamic factors

2016 ◽  
Vol 94 (12) ◽  
pp. 1119-1126 ◽  
Author(s):  
Romina Castañeda-Arriaga ◽  
Adrián Domínguez-Castro ◽  
JinGyu Lee ◽  
J. Raul Alvarez-Idaboy ◽  
Nelaine Mora-Diez
Keyword(s):  
Hydrogen Transfer ◽  
Transfer Reaction ◽  
Alpha Helix ◽  
Diffusion Control ◽  
Long Distance ◽  
Dihydrolipoic Acid ◽  
Dynamic Factors ◽  
Additional Stability ◽  
The Stability ◽  
Protein Models

The thermodynamic and kinetic study of the repair reactions of three damaged aliphatic amino acids (alanine, valine, and leucine) with dihydrolipoic acid (DHLA) in a polar and a nonpolar solvent is presented in this work. Two simplified protein models were explored in the most common conformations (alpha helix and beta sheet). Calculations are performed at the M06-2X-SMD/6-31++G(d,p) level of theory. DHLA has shown to be an excellent antioxidant repair agent through hydrogen-transfer reaction involving the thiol groups, with rate constants close to diffusion control in most cases. The stability of the initial protein radical is not the most important factor determining the rate of the repair reaction because stabilizing intermolecular interactions involving the protein and the antioxidant can provide additional stability to some transition states accelerating the repair of sites that would otherwise not be so quickly repaired.

scholarly journals Monitoring of train-induced vibrations on rock slopes

2017 ◽  
Vol 13 (1) ◽  
pp. 155014771668755 ◽  
Author(s):  
Jiangbo Xu ◽  
Changgen Yan ◽  
Xu Zhao ◽  
Ke Du ◽  
Heng Li ◽  
...  
Keyword(s):  
Particle Velocity ◽  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Test System ◽  
Peak Particle Velocity ◽  
Vibration Test ◽  
Long Distance ◽  
Stability Of Slopes ◽  
The Stability

Train-induced vibrations will undoubtedly influence the stability of slopes near railway lines. To monitor the effects of such vibrations on slope stability, a wirelessly networked vibration test system was established, which included wirelessly networked vibration meters, high-precision and high-speed three-dimensional sensors and a remote wirelessly networked data server system. This system represents the first attempt to monitor the effects of train-induced vibrations on the stability of slopes in China. It enables real-time and long-distance monitoring by means of remote transmission with a low cost and high efficiency. The duration, frequency, amplitude, peak acceleration and peak particle velocity were adopted as measures for evaluating the influence of train vibrations. Simultaneously, we used additional monitoring technologies to verify the conclusions of the wirelessly networked vibration test system. The monitoring results indicated that the peak particle velocity was much higher near the track and gradually decreased with increasing distance. When the distance between the measurement point and the road axis was 12 m ( H = 0 m), the maximal peak particle velocity was 0.4 mm/s, which remained below the maximum safe value.

scholarly journals Whole Genome Detection of Sequence and Structural Polymorphism in Six Diverse Horses

2019 ◽  
Author(s):  
Mohammed Ali Al Abri ◽  
Heather Marie Holl ◽  
Sara E Kalla ◽  
Nate Sutter ◽  
Samantha Brooks
Keyword(s):  
Copy Number ◽  
Copy Number Gain ◽  
Copy Number Variations ◽  
Nucleotide Polymorphisms ◽  
Structural Variations ◽  
Long Distance ◽  
Single Nucleotide ◽  
Evolutionary Selection ◽  
Climatic Environment ◽  
Physiological Adaptations

AbstractThe domesticated horse has played a unique role in human history, serving not just as a source of animal protein, but also as a catalyst for long-distance migration and military conquest. As a result, the horse developed unique physiological adaptations to meet the demands of both their climatic environment and their relationship with man. Completed in 2009, the first domesticated horse reference genome assembly (EquCab 2.0) produced most of the publicly available genetic variations annotations in this species. Yet, there are around 400 geographically and physiologically diverse breeds of horse. To enrich the current collection of genetic variants in the horse, we sequenced whole genomes from six horses of six different breeds: an American Miniature, a Percheron, an Arabian, a Mangalarga Marchador, a Native Mongolian Chakouyi, and a Tennessee Walking Horse. Aside from extreme contrasts in body size, these breeds originate from diverse global locations and each possess unique adaptive physiology. A total of 1.3 billion reads were generated for the six horses with coverage between 15x to 24x per horse. After applying rigorous filtration, we identified and functionally annotated 8,128,658 Single Nucleotide Polymorphisms (SNPs), and 830,370 Insertions/Deletions (INDELs), as well as novel Copy Number Variations (CNVs) and Structural Variations (SVs). Our results revealed putatively functional variants including genes associated with size variation like ANKRD1 and HMGA1 in the very large Percheron and the ZFAT gene in the American Miniature horse. We detected a copy number gain in the Latherin gene that may be the result of evolutionary selection for thermoregulation by sweating, an important component of athleticism and heat tolerance. The newly discovered variants were formatted into user-friendly browser tracks and will provide a foundational database for future studies of the genetic underpinnings of diverse phenotypes within the horse.Author SummaryThe domesticated horse played a unique role in human history, serving not just as a source of dietary animal protein, but also as a catalyst for long-distance migration and military conquest. As a result, the horse developed unique physiological adaptations to meet the demands of both their climatic environment and their relationship with man. Although the completion of the horse reference genome yielded the discovery of many genetic variants, the remarkable diversity across breeds of horse calls for additional effort in quantification of the breadth of genetic polymorphism within this unique species. Here, we present genome re-sequencing and variant detection analysis for six horses belonging to geographically and physiologically diverse breeds. We identified and annotated not just single nucleotide polymorphisms (SNPs), but also large insertions and deletions (INDELs), copy number variations (CNVs) and structural variations (SVs). Our results illustrate novel sources of polymorphism and highlight potentially impactful variations for phenotypes of body size and conformation. We also detected a copy number gain in the Latherin gene that could be the result of an evolutionary selection for thermoregulation through sweating. Our newly discovered variants were formatted into easy-to-use tracks that can be easily accessed by researchers around the globe.

Shotgun Weddings in Control Engineering and Postwar Economics, 1940–72

2020 ◽  
Vol 52 (S1) ◽  
pp. 115-142
Author(s):  
Judy L. Klein
Keyword(s):  
World War Ii ◽  
Rational Expectations ◽  
Optimization Theory ◽  
Feedback Loops ◽  
Fire Control ◽  
Long Distance ◽  
Control Engineering ◽  
Negative Feedback Loops ◽  
Useful Signal ◽  
The Stability

During World War II there was a “shotgun wedding” forged in the processes of designing feedback mechanisms used to control gunfire targeting fast-moving enemy aircraft. Hendrik Bode perceived the shotgun marriage as a union of the classic regulator approach and long-distance telephone communications engineering. Norbert Weiner took the wedding description a step further by nesting communication engineering into a statistical mechanics framework in which the information engineer had to filter the useful signal from the useless noise. A main goal in designing weapon-fire control systems was to use negative feedback loops to ensure the stability of a system that was always in a transient mode. In the 1950s, control engineers such as Arnold Tustin, Bill Phillips, and Charles Holt offered their new analytic tools of block diagrams of systems with feedback loops, stability criteria, and physical analogues to model the economy, realize the promise of stability of employment and prices, and avoid another depression similar to that of the 1930s. By the early 1970s Paul Samuelson and the rational expectations theorists were primed to be receptive to a second, Cold War shotgun wedding in control engineering. Richard Bellman described it as a marriage of classical optimization theory and the probabilistic theory of stochastic processes.

Real-time monitoring and early warning of transmission tower foundations under landslide disasters

2020 ◽  
Author(s):  
ChenChen Huang ◽  
Kunlong Yin ◽  
Xin Liang
Keyword(s):  
Transmission Lines ◽  
Early Warning ◽  
Early Warning System ◽  
Warning System ◽  
Economic Losses ◽  
Transmission Tower ◽  
Long Distance ◽  
Geological Disasters ◽  
Landslide Deformation ◽  
The Stability

<p>The Ultra High Voltage (UHV) power grids in China are playing an important role of large-region power supply, contain long-distance interconnected channels that have to span a variety of different geomorphic units. However, geological disasters around transmission lines can threaten the reliability of UHV system. Landslides, one of the most common geological disasters in China, can affect the stability of transmission towers by shearing their foundations or involving them to move overall. Once a power tower is destroyed catastrophically, it may lead to widespread power outages, which can result in serious social adverse effects and huge economic losses. This paper presents a multi-technology early warning system for monitoring landslide deformation and observing transmission tower stability. In this system, there are three categories of monitoring information, including landslide displacement, external hydrological conditions and the stability of tower, integrated that are critical to predicting slope stability. To implement this system, a variety of techniques are employed. Firstly, advanced aviation technologies, such as Interferometric Synthetic Aperture Rader (InSAR) and unmanned aerial vehicle (UAV) are used to monitor the overall deformation of the landslide. Absolute surface displacement, subsurface displacement and relative displacement of cracks are recorded by the Global Navigation Satellite System (GNSS), deep inclinometer cooperating with optical fiber sensors and surface crack meters respectively. Second, the two main factors influencing landslide deformation, rainfall and underground water level, are observed by rain gauge and pressure gauge respectively. Third, in order to evaluate the stability of tower, earth pressure sensors are installed on the four foots of the tower foundation and pylon inclinometer is installed on the tower body. This system has been applied to the Doupozi landslide, where a tower of 500KV Shen-wan UHV line is located. Compared with that of traditional methods, the recording process of the multi-technology system is automatic and continuous, which can save human resource cost. Besides, the integrated monitoring data obtained from this system can be used to analyze the interaction between geological disasters and power towers. The multi-technology early warning system is also suitable for risk mitigation of transmission lines, oil and gas pipelines, highways, railways and other linear projects in mountainous areas.</p>

Study on the Control Strategy of Wind Farms Connected to Power Grid by VSC-HVDC

2014 ◽  
Vol 687-691 ◽  
pp. 3446-3449
Author(s):  
Min Xue ◽  
Hui Ping Zheng ◽  
Shu Yong Song ◽  
Xin Jie Hao
Keyword(s):  
Power System ◽  
Wind Turbine ◽  
Wind Power ◽  
Control Strategy ◽  
Wind Farms ◽  
Long Distance ◽  
Voltage Level ◽  
Hvdc Transmission ◽  
The Stability ◽  
High Degree

The technology of VSC-HVDC transmission has a high degree of flexibility and controllability.This paper researches the control strategy of VSC-HVDC and the operating principle of the wind turbine, which can effectively enhance the stability of power system in the region of wind farms, improve the long-distance transmission capacity of wind power and stabilize the voltage level of public connection point.

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