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1 – 10 of 574Yuzhen Zhao, Mingxu Zhao, Huimin Zhang, Xiangrong Zhao, Yang Zhao, Zhun Guo, Jianjing Gao, Cheng Ma and Yongming Zhang
This paper aims to prepare third-order nonlinear optical (NLO) organic materials with large nonlinear optimization value, high damage threshold and ultrafast response time.
Abstract
Purpose
This paper aims to prepare third-order nonlinear optical (NLO) organic materials with large nonlinear optimization value, high damage threshold and ultrafast response time.
Design/methodology/approach
A series of novel symmetric and asymmetric compounds possessing third-order NLO properties were synthesized using 1,3,5-tribromobenzene as the basis. The photophysical and electrochemical properties, as well as the click reactions, were characterized by means of UV–VIS–NIR absorption spectroscopy and cyclic voltammetry.
Findings
The donor–acceptor chromophores were inserted into compound, making the molecule to have a broader absorption in the near-infrared regions and a narrower optical and electrochemical band gap. It also formed an electron-delocalized organic system, which has larger effects on achieving a third-order NLO response. The third-order NLO phenomenon of benzene ring complexes was experimentally studied at 532 nm using Z-scan technology, and some compounds showed the expected NLO properties.
Originality/value
The click products exhibit more NLO phenomena by performing different click combinations to the side groups, opening new perspectives on using the system in a variety of photoelectric applications.
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Abstract
Purpose
The authors have prepared the triazole film on copper surface by click reaction and explored its inhibition mechanism.
Design/methodology/approach
The protective film is assembled by immersing bronze in solution containing p-toluenesulfonyl azide (TA) and propiolic acid (PA).
Findings
Fourier transform infrared spectroscopy (FT-IR) indicates that triazole (TTP) film was formed on bronze surface via click chemistry reaction between TA and PA. It shows TTP film has a good protection for bronze in the atmospheric environment simulation solution. Quantum chemical calculation (QC) and molecule dynamics simulation suggests TTP molecule adsorbs on bronze surface via N and O.
Originality/value
This is beneficial to develop the corrosion inhibitors for the corroded copper alloys.
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Libin Yang, Dong Wang, Hong Gao, Hui Cao, Yuzhen Zhao, Zongcheng Miao, Zhou Yang and Wanli He
This study aims to develop a new kind of functional low molecular weight organic dyes, which is highly efficient, meanwhile inexpensive and easily prepared and modified and can be…
Abstract
Purpose
This study aims to develop a new kind of functional low molecular weight organic dyes, which is highly efficient, meanwhile inexpensive and easily prepared and modified and can be used in photoacoustic (PA) imaging and photothermal therapy (PTT). To further realize the release of molecules under the biomedical condition, the releasing efficiency of micellar nanoparticles under different stimuli were represented.
Design/methodology/approach
A class of azo and Schiff base derivatives with different click reagents were characterized by PA imaging and photothermal (PT) experiments. The molecule with best PT effect was loaded into a temperature-stimuli-sensitive amphiphilic block copolymer which demonstrated the capability of releasing the polymers under the near-infrared (NIR) light of 650 nm.
Findings
The PA and PT effects of a series of azo and Schiff base derivatives with different click reagents were characterized. Introducing the click reagent F4-TCNQ can result in red shift of peaks of PA intensity. Stimulated with 650 nm laser irradiation, the polymer processed higher release rate than being stimulated by temperature stimuli.
Practical implications
This paper not only guides the design of NIR dyes with good PA intensity but also provides a method which has great potential for the application of NIR photothermal dyes in the field of biotechnology for controlled release.
Originality/value
This paper uses click reagents to modify azo and Schiff derivatives and an amphiphilic block copolymer under NIR light to realize controlled release.
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Shuchen Tian, Hui Cao, Zhou Yang, Yuzhen Zhao, Wanli He and Hong Gao
Currently, conjugated nonlinear optical (NLO) materials suffer from the drawbacks of complex manufacturing process and high cost. To further study the NLO materials with…
Abstract
Purpose
Currently, conjugated nonlinear optical (NLO) materials suffer from the drawbacks of complex manufacturing process and high cost. To further study the NLO materials with cost-effective, it is necessary to prepare new NLO materials with satisfactory performance.
Design/methodology/approach
Pyrene derivatives with good third-order NLO properties were synthesized by combining pyrene compounds with TCNE, TCNQ, F4-TCNQ and other molecular systems by clicking chemical method.
Findings
The pyrene derivatives were characterized by ultraviolet spectrum and Z-scan. The charge-transfer of the D-p-A structures plays a key role in the absorption peak shifts. And the third-order nonlinear absorption of the products revealed good third-order NLO susceptibilities.
Research limitations/implications
The synthesis technology of pyrene derivatives is not mature enough and is in the preliminary exploration stage. So, the authors produced a relatively small number of samples and did not conduct a very comprehensive test.
Practical implications
This novel pyrene derivative is suggestive and can promote the exploration and development of the third-order nonlinear materials.
Originality/value
Four new pyrene derivatives were synthesized by selecting new molecular systems. Because of its good chemical properties and stable properties, it can be a reference for the development of third-order nonlinear materials in the future.
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Aziz Boutouil, My Rachid Laamari, Ilham Elazhary, Hafid Anane, Abdeslem Ben Tama and Salah-Eddine Stiriba
This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely…
Abstract
Purpose
This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4.
Design/methodology/approach
The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques.
Findings
It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system.
Originality/value
This work is original with the aim of finding new acid corrosion inhibitors.
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Yvette Taminiau and Stefan Heusinkveld
Tenders are generally considered important in auditing research and practice, and are associated with significant difficulties for the auditing profession, as well as for…
Abstract
Purpose
Tenders are generally considered important in auditing research and practice, and are associated with significant difficulties for the auditing profession, as well as for individual auditors in the context of client relationships. The purpose of this paper is to explore the way auditors respond to complex client expectations related to the audit tendering process.
Design/methodology/approach
Using a role-theory perspective, the authors analyzed 75 client evaluations of auditors, along with in-depth interviews with high-level auditors.
Findings
The authors present a theoretical framework of audit tenders that identifies different formal and informal practices auditors may employ in response to evolving client expectations that arise throughout different phases of the tendering process, and elucidate relevant conditions that may enable or impede these practices.
Research limitations/implications
First, the study reveals that, in the context of auditor-client relationships, expectations cannot be considered stable, but may vary significantly throughout the tendering process. Second, the study indicates that auditors are not only determined by the formal tendering procedures, but are also influenced by their level of agency.
Practical implications
The framework has practical value by providing individual auditors guidance in managing their client relationships and, further, top management guidance for creating favorable conditions for auditors to meet client needs.
Originality/value
The findings provide a deeper and more nuanced understanding of the autonomy auditors have in responding to the contemporary pressures exerted on them.
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Greta Miezinyte, Jolita Ostrauskaite, Egidija Rainosalo, Edvinas Skliutas and Mangirdas Malinauskas
The purpose of this paper is the design and investigation of novel acrylated epoxidized soybean oil-based photocurable systems as candidate materials for optical 3D printing.
Abstract
Purpose
The purpose of this paper is the design and investigation of novel acrylated epoxidized soybean oil-based photocurable systems as candidate materials for optical 3D printing.
Design/methodology/approach
Aromatic dithiols, benzene-1,3-dithiol or benzene-1,4-dithiol, were used as cross-linking agents of acrylated epoxidized soybean oil in these systems. Kinetics of photocross-linking was investigated by real-time photorheometry using two different photoinitiators, 2, 2-dimethoxy-2-phenylacetophenone or 2-hydroxy-2-methylpropiophenone, in different quantities. The effect of the initial composition on the rate of photocross-linking, mechanical, thermal properties and swelling of obtained polymers was investigated.
Findings
The rate of photocross-linking was higher, more cross-links and shorter polymer chains between cross-linking points of the network were formed when benzene-1,4-dithiol and 2, 2-dimethoxy-2-phenylacetophenone were used in compositions. The higher yield of insoluble fraction, glass transition temperatures and values of compressive modulus were obtained when benzene-1,3-dithiol and 2, 2-dimethoxy-2-phenylacetophenone were used in compositions.
Originality/value
This is the first study of acrylated epoxidized soybean oil-based thiol-ene system by real-time photorheometry. The designed novel photocurable systems based on acrylated epoxidized soybean oil and benzenedithiols are promising renewable photoresins for rapid optical 3D printing on demand.
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While one's route on the World Wide Web (WWW) may not be “straight on 'til morning,” it can be nearly as exciting. Sometimes the promise of a WWW file is not fulfilled, or…
Abstract
While one's route on the World Wide Web (WWW) may not be “straight on 'til morning,” it can be nearly as exciting. Sometimes the promise of a WWW file is not fulfilled, or different titles yield the same file, or one receives a message claiming that a server is not accessible; however, there are many good resources for the deaf that are under construction on the Web. Creative, responsible people are trying to arrange information to make it accessible for everyone. In spite of current limitations, the World Wide Web is an excellent platform on which everyone can share information and compare almost instantly the information and knowledge found.
Xingxing Li, Shixi You, Zengchang Fan, Guangjun Li and Li Fu
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health…
Abstract
Purpose
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health care. The purpose of this paper is to summarize the current state of the field, identify challenges and limitations and discuss future prospects for the development of saliva-based electrochemical sensors.
Design/methodology/approach
The paper reviews relevant literature and research articles to examine the latest developments in electrochemical sensing technologies for saliva analysis. It explores the use of various electrode materials, including carbon nanomaterial, metal nanoparticles and conducting polymers, as well as the integration of microfluidics, lab-on-a-chip (LOC) devices and wearable/implantable technologies. The design and fabrication methodologies used in these sensors are discussed, along with sample preparation techniques and biorecognition elements for enhancing sensor performance.
Findings
Electrochemical sensors for salivary analyte detection have demonstrated excellent potential for noninvasive, rapid and cost-effective diagnostics. Recent advancements have resulted in improved sensor selectivity, stability, sensitivity and compatibility with complex saliva samples. Integration with microfluidics and LOC technologies has shown promise in enhancing sensor efficiency and accuracy. In addition, wearable and implantable sensors enable continuous, real-time monitoring of salivary analytes, opening new avenues for personalized health care and disease management.
Originality/value
This review presents an up-to-date overview of electrochemical sensors for analyte detection in saliva, offering insights into their design, fabrication and performance. It highlights the originality and value of integrating electrochemical sensing with microfluidics, wearable/implantable technologies and point-of-care testing platforms. The review also identifies challenges and limitations, such as interference from other saliva components and the need for improved stability and reproducibility. Future prospects include the development of novel microfluidic devices, advanced materials and user-friendly diagnostic devices to unlock the full potential of saliva-based electrochemical sensing in clinical practice.
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Listening with spirit is the key skill which teams need to attain andsustain creative dialogue. This is especially true for organizationallearning. Building on the distinction…
Abstract
Listening with spirit is the key skill which teams need to attain and sustain creative dialogue. This is especially true for organizational learning. Building on the distinction between dialogue and discussion, poses the question: “What makes dialogue dialogue?” and also offers tools for dialogue. The core of team dialogue is collectively listening with spirit, that is: in a group, people listen (individually) with selfless receptivity to each others′ ideas, thereby emptying themselves to create a common vessel which – shaped by and sustained by the power of the group′s collective listening – receives and contains a collective spirit. Draws on multiple disciplines including ethnography and the spiritual science of Austrian philosopher and founder of Waldorf Education, Rudolph Steiner. Provides examples of how this approach has improved the creativity of work teams. Also offers an explanation of how future search conferences work using the idea of creating a container via collective listening.
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