scholarly journals Recent Advances in Synthesis and Properties of Nitrated-Pyrazoles Based Energetic Compounds

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3475 ◽  
Author(s):  
Shijie Zhang ◽  
Zhenguo Gao ◽  
Di Lan ◽  
Qian Jia ◽  
Ning Liu ◽  
...  

Nitrated-pyrazole-based energetic compounds have attracted wide publicity in the field of energetic materials (EMs) due to their high heat of formation, high density, tailored thermal stability, and detonation performance. Many nitrated-pyrazole-based energetic compounds have been developed to meet the increasing demands of high power, low sensitivity, and eco-friendly environment, and they have good applications in explosives, propellants, and pyrotechnics. Continuous and growing efforts have been committed to promote the rapid development of nitrated-pyrazole-based EMs in the last decade, especially through large amounts of Chinese research. Some of the ultimate aims of nitrated-pyrazole-based materials are to develop potential candidates of castable explosives, explore novel insensitive high energy materials, search for low cost synthesis strategies, high efficiency, and green environmental protection, and further widen the applications of EMs. This review article aims to present the recent processes in the synthesis and physical and explosive performances of the nitrated-pyrazole-based Ems, including monopyrazoles with nitro, bispyrazoles with nitro, nitropyrazolo[4,3-c]pyrazoles, and their derivatives, and to comb the development trend of these compounds. This review intends to prompt fresh concepts for designing prominent high-performance nitropyrazole-based EMs.

2019 ◽  
Vol 13 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Saeed Ahmed ◽  
Muhammad Naeem Ashiq ◽  
Dianqing Li ◽  
Pinggui Tang ◽  
Fabrice Leroux ◽  
...  

Background: High concentration of phosphate has been threatening human health and the ecosystem. Adsorption is one of high-efficiency and low-cost techniques to reduce the concentration of phosphate. This mini review aims to summarize the recent development of adsorption materials for phosphate removal. Method: We conducted a detailed search of “adsorption of phosphate” in the published papers and the public patents on the adsorbents for phosphate based on Web of Science database in the period from January 1 2012 to December 31 2017. The corresponding literature was carefully evaluated and analyzed. Results: One hundred and forty one papers and twenty two recent patents were included in this review. An increased trend in scientific contributions was observed in the development of adsorption materials for phosphate removal. Three kinds of promising adsorbents: layered double hydroxides, natural materials, and metal oxides were paid special attention including removal mechanism, performance as well as the relationship between adsorption performance and structure. Both the chemical composition and the morphology play a key role in the removal capacity and rate. Conclusion: The findings of this review confirm the importance of phosphate removal, show the development trend of high-performance and low-cost adsorption materials for phosphate removal, and provide a helpful guide to design and fabricate high-efficiency adsorbents.


2016 ◽  
Vol 94 (9) ◽  
pp. 738-743 ◽  
Author(s):  
Alka Devi ◽  
Vikas D. Ghule

Based on the backbone of the nitrogen-rich triazole and tetrazole structure, their N–OH derivatives were designed to improve the properties of energetic materials. This work introduces five novel nitrogen-rich derivatives and their energetic salts as high-performance compounds. Reliable methods and correlations are used to predict the heat of formation, density, detonation, and combustion properties and explosive power. The predicted energetic properties are also compared with well-known explosives, TNT, TATB, RDX, and HMX, to evaluate the performance. A majority of the designed salts exhibited high positive heats of formation, good detonation properties, and high explosive power. Ammonium, hydrazinium, and hydroxylammonium salts (1–3), which have relatively high densities (over 1.86 g/cm3), resulted in good detonation velocities (above 9.0 km/s) and pressures (above 35 GPa), making them competitive energetic materials.


RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 13185-13195 ◽  
Author(s):  
Keyu Pu ◽  
Linyuan Wang ◽  
Jian Liu ◽  
Kai Zhong

Bis-azole derivatives are a new class of energetic materials with features that include high nitrogen content, high heat of formation (HOF), high detonation performance and insensitivity to external stimuli.


2019 ◽  
Vol 7 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Xiao Wang ◽  
Shuanghao Zheng ◽  
Feng Zhou ◽  
Jieqiong Qin ◽  
Xiaoyu Shi ◽  
...  

Abstract The rapid development of printed and microscale electronics imminently requires compatible micro-batteries (MBs) with high performance, applicable scalability, and exceptional safety, but faces great challenges from the ever-reported stacked geometry. Herein the first printed planar prototype of aqueous-based, high-safety Zn//MnO2 MBs, with outstanding performance, aesthetic diversity, flexibility and modularization, is demonstrated, based on interdigital patterns of Zn ink as anode and MnO2 ink as cathode, with high-conducting graphene ink as a metal-free current collector, fabricated by an industrially scalable screen-printing technique. The planar separator-free Zn//MnO2 MBs, tested in neutral aqueous electrolyte, deliver a high volumetric capacity of 19.3 mAh/cm3 (corresponding to 393 mAh/g) at 7.5 mA/cm3, and notable volumetric energy density of 17.3 mWh/cm3, outperforming lithium thin-film batteries (≤10 mWh/cm3). Furthermore, our Zn//MnO2 MBs present long-term cyclability having a high capacity retention of 83.9% after 1300 cycles at 5 C, which is superior to stacked Zn//MnO2 batteries previously reported. Also, Zn//MnO2 planar MBs exhibit exceptional flexibility without observable capacity decay under serious deformation, and remarkably serial and parallel integration of constructing bipolar cells with high voltage and capacity output. Therefore, low-cost, environmentally benign Zn//MnO2 MBs with in-plane geometry possess huge potential as high-energy, safe, scalable and flexible microscale power sources for direction integration with printed electronics.


2021 ◽  
Vol 11 (15) ◽  
pp. 6831
Author(s):  
Yue Chen ◽  
Jian Lu

With the rapid development of road traffic, real-time vehicle counting is very important in the construction of intelligent transportation systems (ITSs). Compared with traditional technologies, the video-based method for vehicle counting shows great importance and huge advantages in its low cost, high efficiency, and flexibility. However, many methods find difficulty in balancing the accuracy and complexity of the algorithm. For example, compared with traditional and simple methods, deep learning methods may achieve higher precision, but they also greatly increase the complexity of the algorithm. In addition to that, most of the methods only work under one mode of color, which is a waste of available information. Considering the above, a multi-loop vehicle-counting method under gray mode and RGB mode was proposed in this paper. Under gray and RGB modes, the moving vehicle can be detected more completely; with the help of multiple loops, vehicle counting could better deal with different influencing factors, such as driving behavior, traffic environment, shooting angle, etc. The experimental results show that the proposed method is able to count vehicles with more than 98.5% accuracy while dealing with different road scenes.


Nanoscale ◽  
2021 ◽  
Author(s):  
Chenxi Gao ◽  
Jiawei Wang ◽  
Yuan Huang ◽  
Zixuan Li ◽  
Jiyan Zhang ◽  
...  

Zinc-ion batteries (ZIBs) have attracted significant attention owing to their high safety, high energy density, and low cost. ZIBs have been studied as a potential energy device for portable and...


Author(s):  
Zhengwei Lin ◽  
Qinghong Zhang ◽  
Gongliang Wang ◽  
Jie Mao ◽  
Martin Hoch ◽  
...  

ABSTRACT Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Na Wang ◽  
Yuanyuan Cai ◽  
Junsong Fu ◽  
Jie Xu

The rapid development of Internet of Medical Things (IoMT) is remarkable. However, IoMT faces many problems including privacy disclosure, long delay of service orders, low retrieval efficiency of medical data, and high energy cost of fog computing. For these, this paper proposes a data privacy protection and efficient retrieval scheme for IoMT based on low-cost fog computing. First, a fog computing system is located between a cloud server and medical workers, for processing data retrieval requests of medical workers and orders for controlling medical devices. Simultaneously, it preprocesses physiological data of patients uploaded by IoMT, collates them into various data sets, and transmits them to medical institutions in this way. It makes the entire execution process of low latency and efficient. Second, multidimensional physiological data are of great value, and we use ciphertext retrieval to protect privacy of patient data in this paper. In addition, this paper uses range tree to build an index for storing physiological data vectors, and meanwhile a range retrieval method is also proposed to improve data search efficiency. Finally, bat algorithm (BA) is designed to allocate cost on a fog server group for significant energy cost reduction. Extensive experiments are conducted to demonstrate the efficiency of the proposed scheme.


2021 ◽  
Vol 9 ◽  
Author(s):  
Zhuolin Tang ◽  
Mengming Yuan ◽  
Huali Zhu ◽  
Guang Zeng ◽  
Jun Liu ◽  
...  

Nowadays, Li–CO2 batteries have attracted enormous interests due to their high energy density for integrated energy storage and conversion devices, superiorities of capturing and converting CO2. Nevertheless, the actual application of Li–CO2 batteries is hindered attributed to excessive overpotential and poor lifespan. In the past decades, catalysts have been employed in the Li–CO2 batteries and been demonstrated to reduce the decomposition potential of the as-formed Li2CO3 during charge process with high efficiency. However, as a representative of promising catalysts, the high costs of noble metals limit the further development, which gives rise to the exploration of catalysts with high efficiency and low cost. In this work, we prepared a K+ doped MnO2 nanowires networks with three-dimensional interconnections (3D KMO NWs) catalyst through a simple hydrothermal method. The interconnected 3D nanowires network catalysts could accelerate the Li ions diffusion, CO2 transfer and the decomposition of discharge products Li2CO3. It is found that high content of K+ doping can promote the diffusion of ions, electrons and CO2 in the MnO2 air cathode, and promote the octahedral effect of MnO6, stabilize the structure of MnO2 hosts, and improve the catalytic activity of CO2. Therefore, it shows a high total discharge capacity of 9,043 mAh g−1, a low overpotential of 1.25 V, and a longer cycle performance.


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