Polyimide(PI)is widely used in high-tech fields such as microelectronics,aerospace,and national defense because of its excellent optical properties,high-and low-temperature resistance,and good dimensional *** achieve ...
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Polyimide(PI)is widely used in high-tech fields such as microelectronics,aerospace,and national defense because of its excellent optical properties,high-and low-temperature resistance,and good dimensional *** achieve the desired properties of PI,the monomers 2,6-diaminopyrimidin-4-ol(DAPD)and 6-(2,3,5,6-tetrafluoro-4-vinylphenoxy)pyrimidin-2,4-diamine(DAFPD),which contains crosslinkable functional groups,were designed and synthesized successfully and copolymerized with 4,4'-oxydianiline(ODA)and 4,4-hexafluoroisopropylphthalic anhydride(6FDA).The prepared PI film(PI-3),with rigid backbones and loose packing had excellent heat resistance(Td5%=489℃)and optical properties(T450=82%).Furthermore,a crosslinked PI film(c-PI-3)with more heat-resistant(Td5%=524℃)and better mechanical properties(σ=125.46MPa),can be obtained through thermal crosslinking of *** addition,the changes in the properties caused by the proportion of DAFPD added during copolymerization are discussed *** study provides a promising candidate for heat-resistant PI materials.
The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH *** results showed that pH 8 was considered to be the most suitable condition for acid production,especially for the ...
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The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH *** results showed that pH 8 was considered to be the most suitable condition for acid production,especially for the formation of acetic acid and propionic *** average value of total volatile fatty acid at pH 8 was 8814 mg COD/L,1.5 times of that under blank *** average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L,*** activities of key functional enzymes such as phosphotransacetylase,acetokinase,oxaloacetate transcarboxylase and succinylcoA transferase were all *** further explore the regulatory mechanisms within the system,the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing,results indicating that the relative abundances of Clostridiales,Bacteroidales,Chloroflexi,Clostridium,Bacteroidetes and Propionibacteriales,which were great contributors for the hydrolysis and acidification,increased rapidly at pH 8 compared with the blank ***,the proportion of genes encoding key enzymes was generally increased,which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.
Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid *** satisfy the complex constraints inthe node cooperation of the flexible landing,a...
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Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid *** satisfy the complex constraints inthe node cooperation of the flexible landing,an intelligent cooperative guidance method is *** method consists of a double-layer cooperative guidance structure,a guidance parameterdetermination approach,and an action priority *** double-layer contains a basic guid-ance used to satisfy the terminal state constraints,and a compensatory guidance used to satisfythe lander's attitude *** the compensatory guidance,the parameters are determinedby multi-agent system,which are trained according to the performance index of flexible landing *** action priority strategy is used to reduce the detrimental effect of parameter inconsis-tency on the node *** simulation of flexible landing shows that the cooperativeguidance method is effective in improving the landing accuracy while satisfying the ***,the method is robust to the disturbance in the navigation and control.
Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor *** has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive con...
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Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor *** has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient *** being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor ***,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation *** on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa *** health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to *** the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.
Waveform generation and digitization play essential roles in numerous physics *** traditional distributed systems for large-scale experiments,each frontend node contains an FPGA for data preprocessing,which interfaces...
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Waveform generation and digitization play essential roles in numerous physics *** traditional distributed systems for large-scale experiments,each frontend node contains an FPGA for data preprocessing,which interfaces with various data converters and exchanges data with a backend central ***,the streaming readout architecture has become a new paradigm for several experiments benefiting from advancements in data transmission and computing *** paper proposes a scalable distributed waveform generation and digitization system that utilizes fiber optical connections for data transmission between frontend nodes and a central *** utilizing transparent transmission on top of the data link layer,the clock and data ports of the converters in the frontend nodes are directly mapped to the FPGA firmware at the *** streaming readout architecture reduces the complexity of frontend development and maintains the data conversion in proximity to the *** frontend node uses a local clock for waveform *** translate the timing information of events in each channel into the system clock domain within the backend central processing FPGA,a novel method is proposed and evaluated using a demonstrator system.
Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ***,there is a lack of data on the occurrence of OAPs in drinking water and t...
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Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ***,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health *** this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in china,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in *** findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in ***,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP *** analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.
Russula vinosa Lindblad(*** Lindblad)is a nutrient-rich wild edible fungus,abundant in *** this study,two polysaccharides(Russula polysaccharides extracted from 1%KOH(RP-1)and Russula polysaccharides extracted from 5%...
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Russula vinosa Lindblad(*** Lindblad)is a nutrient-rich wild edible fungus,abundant in *** this study,two polysaccharides(Russula polysaccharides extracted from 1%KOH(RP-1)and Russula polysaccharides extracted from 5%KOH(RP-5))were extracted from Russula fruit bodies using KOH-graded extraction *** molecular weights of RP-1 and RP-5 were 187000 and 97300 u,*** glycosyl compositions(galactose꞉glucose꞉xylose꞉mannose,i.e.,Gal꞉Glu꞉Xyl꞉Man)were 0.27:1.00:0.01:0.16 for RP-1 and 0.12:1.00:0.03:0.19 for *** magnetic resonance(NMR)analysis revealed that the main structural component of RP-1 was→3,6)-β-d-Glu p-(1→,with a→6)-β-d-Glu p-(1→residue linked at sites 1 and 6,and a→3)-β-d-Glu p-(1→residue linked at sites *** RP-5 shared this structure with an additional→4)-β-d-Man p-(1→residue attached to the→3)-β-d-Glu p-(1→.Phagocytosis assay demonstrated that RP-5,with a lower molecular weight,lower galactose content,and higher xylose and man-nose content,enhanced RAW 264.7 cell phagocytic activity by 121.04%,outperforming RP-1,which showed a 42.15%increase at the same concentration of 600𝜇g/***,both RP-1 and RP-5 reduced the release of inflammatory factors and induced the nuclear translocation of the nuclear transcription factor-𝜅B(NF-𝜅B)pathway in RAW 264.7 *** study provided insights into the structural characteristics and immunomodulatory properties of Russula polysac-charides,offering potential for further applications in bioactive compound development.
Machine learning-assisted retrosynthesis planning aims to utilize machine learning(ML)algorithms to find synthetic pathways for target *** recent years,with the development of artificial intelligence(AI),especially ML...
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Machine learning-assisted retrosynthesis planning aims to utilize machine learning(ML)algorithms to find synthetic pathways for target *** recent years,with the development of artificial intelligence(AI),especially ML,researchers’interest in ML-assisted retrosynthesis planning has rapidly increased,bringing development and opportunities to the *** this review,we aim to provide a comprehensive understanding of ML-assisted retrosynthesis *** first discuss the formal definition and the objective of retrosynthesis planning,and organize a modular framework which includes four modules:data preparation,data preprocessing,pathway generation and evaluation,and pathway ***,we sequentially review the current status of the first three modules(except pathway verification)in the ML-assisted retrosynthesis planning framework,including ideas,methods,and latest *** that,we specifically discuss large language models in retrosynthesis ***,we summarize the extant challenges that are faced by current ML-assisted retrosynthesis planning research and offer a perspective on future research directions and development.
Morphine and morphine-6-glucuronide(M6G)produce central nervous system(CNS)effects by activating mu-opioid receptors,while naloxone is used mainly for the reversal of opioid overdose,specifically for the fatal complic...
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Morphine and morphine-6-glucuronide(M6G)produce central nervous system(CNS)effects by activating mu-opioid receptors,while naloxone is used mainly for the reversal of opioid overdose,specifically for the fatal complication of respiratory depression,but also for alleviating opioid-induced side *** this study we developed a physiologically-based pharmacokinetic-pharmacodynamic(PBPK-PD)model to simultaneously predict pharmacokinetics and CNS effects(miosis,respiratory depression and analgesia)of morphine as well as antagonistic effects of naloxone against *** pharmacokinetic and pharmacodynamic parameters were obtained from in vitro data,in silico,or *** and pharmacodynamic simulations were conducted using 39 and 36 clinical reports,*** pharmacokinetics of morphine and M6G following oral or intravenous administration were simulated,and the PBPK-PD model was validated using clinical *** Emax model correlated CNS effects with free concentrations of morphine and M6G in brain *** predicted CNS effects were compared with *** clinical observations fell within the 5th-95th percentiles of simulations based on 1000 virtual *** of the simulated area under the concentration-time curve or peak concentrations also fell within 0.5-2-fold of *** contribution of morphine to CNS effects following intravenous or oral administration was larger than that of *** and antagonistic effects of naloxone on CNS effects were also successfully predicted using the developed PBPK-PD *** conclusion,the pharmacokinetics and pharmacodynamics of morphine and M6G,antagonistic effects of naloxone against morphine-induced CNS effects may be successfully predicted using the developed PBPK-PD model based on the parameters derived from in vitro,in silico,or animal studies.
The two-sided correlation transformation (TCT) algorithm is widely used to estimate the direction of arrival (DOA) for broadband signals. However, the traditional TCT algorithm requires DOA pre-estimation, which resul...
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The two-sided correlation transformation (TCT) algorithm is widely used to estimate the direction of arrival (DOA) for broadband signals. However, the traditional TCT algorithm requires DOA pre-estimation, which results in a high computational complexity and poor performance under low signal-to-noise ratio (SNR) conditions. To address these challenges, an improved TCT algorithm based on array manifold interpolation (AMI) is proposed in this paper, which utilised the AMI method to decompose the array manifold matrix and reconstruct the signal covariance matrix. It aims to obtain a DOA-independent focusing transformation matrix, thereby avoiding DOA pre-estimation. The simulation and lake experiment results are compared with the traditional TCT algorithms. It shows that the proposed algorithm can achieve higher DOA estimation accuracy and better angular resolution even in low SNR environments by fully utilising the information within the whole bandwidth of the target while reducing computational complexity.
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