27 research outputs found

    Corrigendum to: The TianQin project: current progress on science and technology

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    In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article

    Clustering rooting for the high heat resistance of some CHNO energetic materials

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    Highly thermostable energetic materials (EMs) are highly desired for deep underground and space exploration, and therefore have attracted much attention. This work employs four typical traditional EMs composed of C, H, N and O atoms as example to clarify the origin of high heat resistance, by means of molecular dynamics simulations with the molecular reactive forcefield of ReaxFF. These EMs include 3,5-dinitro-N,N´-bis(2,4,6-trinitrophenyl)pyridine-2,6-diamine (PYX), 1,3,5-diamino-2,4,6-trinitrobenzene (TATB) and 2,2´,4,4´,6,6´-hexanitrostilbene (HNS), which are highly thermostable with decomposition temperature peaks > 600 K, and a less one of pentaerythritol tetranitrate (PETN) for comparison. It is found that the clustering in the decomposition of PYX, TATB and HNS retards the extraction of small product molecules from clusters, as well as heat release, and thereby roots for their high heat resistance; while, the clustering in the PETN decay is negligible and heat release and fragmentation proceed rapidly, facilitating to fast decomposition. Combining this finding with the well-known molecular stability, this work presents a perspective on the high heat resistance of traditional EMs. Based on it, a highly negative oxygen balance, a high C content and a high molecular stability are proposed as a strategy for designing and constructing new highly heat-resistant EMs

    Detection and Risk Assessments of Multi-Pesticides in Traditional Chinese Medicine Chuanxiong Rhizoma by LC/MS-MS and GC/MS-MS

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    With the internationalization of traditional Chinese medicines (TCMs) and the increasing use of herbal medicines around the world, there are concerns over their safety. In recent years, there have been some sporadic reports of pesticide residues in Chuanxiong Rhizoma (CX), although the lack of systematic and comprehensive analyses of pesticide residues and evaluations of toxicological risks in human health has increased the uncertainty of the potential effects of pesticides exposure in humans. This study aimed to clarify the status of pesticide residues and to determine the health risks of pesticide residues in CX. The findings of this study revealed that 99 batches of CX samples contained pesticide residues ranging from 0.05 to 3013.17 μg/kg. Here, 6–22 kinds of pesticides were detected in each sample. Prometryn, carbendazim, dimethomorph, chlorpyrifos, chlorantraniliprole, pyraclostrobin, and paclobutrazol were the most frequently detected pesticides, with detection rates of 68.69–100%. Insecticides and fungicides accounted for 43.23% and 37.84% of the total pesticides detected, respectively. Here, 86.87% of the pesticide content levels were lower than 50 μg/kg, and a small number of samples contained carbofuran, dimethoate, and isofenphos-methyl exceeding the maximum residue levels (MRLs). A risk assessment based on the hazard quotient/hazard index (HQ/HI) approach revealed that the short-term, long-term, and cumulative risks of pesticide residues in CX are well below the levels that may pose a health risk. Worryingly, six banned pesticides (carbofuran, phorate sulfone, phorate-sulfoxide, isofenphos-methyl, terbufos-sulfone, and terbufoxon sulfoxide) were detected. This study has improved our understanding of the potential exposure risk of pesticide multi-residues in CX. The results of the study will have a positive impact on improving the quality and safety of CX and the development of MRLs for pesticide residues

    A Two-Stage Planning Optimization Study of an Integrated Energy System Considering Uncertainty

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    In the context of a rapidly evolving integrated energy system (IES), taking into account the uncertainty of the renewable energy output can make integrated energy system planning more realistic. In view of this, this paper proposes an integrated energy system planning approach that takes uncertainty into account. Firstly, in order to accurately describe the renewable energy output scenarios, this paper describes the IES model and introduces the scenario analysis methods used. Secondly, an integrated energy system equipment output model is constructed, the corresponding constraints and objective functions are set, an improved particle swarm-ant colony optimization algorithm is used for the solution, and a planning solution strategy considering uncertainty is proposed. Finally, the above conclusions are verified by the actual case data of a park, and the results show that the method proposed in this paper is economical and reasonable

    Progress on the use of satellite technology for gravity exploration

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    In this paper, the technological progress on Chinese gravity exploration satellites is presented. Novel features such as ultra-stable structure, high accurate thermal control, drag-free and attitude control, micro-thrusters, aerodynamic configuration, the ability to perform micro-vibration analyses, microwave ranging system and mass center trimmer are described. Keywords: Ultra-stable structure, Precision thermal control, Drag-free, Micro-thruster, K-band ranging, Aerodynamics, Micro-vibration, Gravity satellit
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