期刊文献+
共找到72,898篇文章
< 1 2 250 >
每页显示 20 50 100
Research Progress on Detection Techniques of Fungicide Residues in Chinese Chives
1
作者 Xiuying CHEN Zhe MENG +5 位作者 Chen DING Huihui LIU Yancheng ZHOU Jinlu LI Yanhua YAN Lei WANG 《Agricultural Biotechnology》 2024年第1期43-48,共6页
Chinese chive is a kind of medicinal and edible plant,with many diseases,and chemical fungicides are usually used for control.In order to find out the risk of pesticide residues in Chinese chives,this paper summarized... Chinese chive is a kind of medicinal and edible plant,with many diseases,and chemical fungicides are usually used for control.In order to find out the risk of pesticide residues in Chinese chives,this paper summarized relevant literatures published in recent years,and sorted out and analyzed the types of pesticides used and detection techniques of common diseases in Chinese chives. 展开更多
关键词 Chinese chive Pesticide residues FUNGICIDE Detection technique
下载PDF
Functional characterization and key residues engineering of a regiopromiscuity O-methyltransferase involved in benzylisoquinoline alkaloid biosynthesis in Nelumbo nucifera 被引量:3
2
作者 Yuetong Yu Yan Liu +6 位作者 Gangqiang Dong JinZhu Jiang Liang Leng XianJu Liu Jun Zhang An Liu Sha Chen 《Horticulture Research》 SCIE CSCD 2023年第2期241-251,共11页
Lotus(Nelumbo nucifera),an ancient aquatic plant,possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids(BIAs).However,only few genes and enzymes involved in BIA biosy... Lotus(Nelumbo nucifera),an ancient aquatic plant,possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids(BIAs).However,only few genes and enzymes involved in BIA biosynthesis in N.nucifera have been isolated and characterized.In the present study we identified the regiopromiscuity of an O-methyltransferase,designated NnOMT6,isolated from N.nucifera;NnOMT6 was found to catalyze the methylation of monobenzylisoquinoline 6-O/7-O,aporphine skeleton 6-O,phenylpropanoid 3-O,and protoberberine 2-O.We further probed the key residues affecting NnOMT6 activity via molecular docking and molecular dynamics simulation.Verification using site-directed mutagenesis revealed that residues D316,N130,L135,N176A,D269,and E328 were critical for BIA O-methyltransferase activities;furthermore,N323A,a mutant of NnOMT6,demonstrated a substantial increase in catalytic efficiency for BIAs and a broader acceptor scope compared with wild-type NnOMT6.To the best of our knowledge,this is the first study to report the O-methyltransferase activity of an aporphine skeleton without benzyl moiety substitutions in N.nucifera.The study findings provide biocatalysts for the semisynthesis of related medical compounds and give insights into protein engineering to strengthen O-methyltransferase activity in plants. 展开更多
关键词 BENZYL residues SKELETON
下载PDF
Rapid screening of 420 pesticide residues in fruits and vegetables using ultra high performance liquid chromatography combined with quadrupole-time of flight mass spectrometry 被引量:2
3
作者 Junmei Ma Sufang Fan +5 位作者 Liqiong Yang Liangna He Hongwen Zhai Xiaowei Ren Qiang Li Yan Zhang 《Food Science and Human Wellness》 SCIE CSCD 2023年第4期1064-1070,共7页
A new method for screening and identification 420 pesticide residues in fruits and vegetables by ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF/MS)were deve... A new method for screening and identification 420 pesticide residues in fruits and vegetables by ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF/MS)were developed.The samples were extracted with acetonitrile/acetic acid(99:1,V/V),and clean-up by SinChERS-Nano(single-step,cheap,effective,rugged,safe,nano)column,determined by UPLC-Q-TOF/MS.The accurate mass database and MS/MS database which contains 420 pesticides were established,the automatic retrieval of detection results was carried on according to the accurate mass,retention time,isotope ratio,ion fragment information,and so on.Method verification was performed on leeks samples.The results showed that 420 pesticides had good linearity in the range of 0.1-100μg/L,and the correlation coeffificients(R2)was greater than 0.990.The limits of detections(LODs)and limits of quantifications(LOQs)of 420 pesticides were in range of 0.05-2.0 and 0.1-5.0μg/L,respectively.The average spike recoveries at 3 levels were 70.1%to 119.7%,and the relative standard deviations(RSD)were lower than 20%(n=6).With this method,a survey of pesticide residues was conducted for 110 samples of 10 different fruits and vegetables,which provided scientific data for ensuring pesticide residue safety of the fruits and vegetables consumed daily by the public.This method was simple,sensitive and accurate,and could be used for rapid screening of 420 pesticide residues in fruits and vegetables. 展开更多
关键词 UPLC-Q-TOF/MS SinChERS-Nano column Pesticide residues Fruits and vegetables
下载PDF
Functional diversity of subgroup 5 R2R3-MYBs promoting proanthocyanidin biosynthesis and their key residues and motifs in tea plant 被引量:1
4
作者 Tianming Jiao Yipeng Huang +9 位作者 Ying-Ling Wu Ting Jiang Tongtong Li Yanzhuo Liu Yvchen Liu Yunyun Han Yajun Liu Xiaolan Jiang Liping Gao Tao Xia 《Horticulture Research》 SCIE CSCD 2023年第8期216-230,共15页
The tea plant(Camellia sinensis)is rich in polyphenolic compounds.Particularly,flavan-3-ols and proanthocyanidins(PAs)are essential for the flavor and disease-resistance property of tea leaves.The fifth subgroup of R2... The tea plant(Camellia sinensis)is rich in polyphenolic compounds.Particularly,flavan-3-ols and proanthocyanidins(PAs)are essential for the flavor and disease-resistance property of tea leaves.The fifth subgroup of R2R3-MYB transcription factors comprises the primary activators of PA biosynthesis.This study showed that subgroup 5 R2R3-MYBs in tea plants contained at least nine genes belonging to the TT2,MYB5,and MYBPA types.Tannin-rich plants showed an expansion in the number of subgroup 5 R2R3-MYB genes compared with other dicotyledonous and monocot plants.The MYBPA-type genes of tea plant were slightly expanded.qRT–PCR analysis and GUS staining analysis of promoter activity under a series of treatments revealed the differential responses of CsMYB5s to biotic and abiotic stresses.In particular,CsMYB5a,CsMYB5b,and CsMYB5e responded to high-intensity light,high temperature,MeJA,and mechanical wounding,whereas CsMYB5f and CsMYB5g were only induced by wounding.Three genetic transformation systems(C.sinensis,Nicotiana tabacum,and Arabidopsis thaliana)were used to verify the biological function of CsMYB5s.The results show that CsMYB5a,CsMYB5b,and CsMYB5e could promote the gene expression of CsLAR and CsANR.However,CsMYB5f and CsMYB5g could only upregulate the gene expression of CsLAR but not CsANR.A series of site-directed mutation and domain-swapping experiments were used to verify functional domains and key amino acids of CsMYB5s responsible for the regulation of PA biosynthesis.This study aimed to provide insight into the induced expression and functional diversity model of PA biosynthesis regulation in tea plants. 展开更多
关键词 plant WOUND residues
下载PDF
Determination of Veterinary Drug Residues in Animal-derived Foods by Liquid Chromatography-Mass Spectrometry 被引量:2
5
作者 Haowei CUI Kun XIN Guixia YANG 《Agricultural Biotechnology》 CAS 2023年第1期84-86,93,共4页
[Objectives]This study was conducted to establish a rapid and effective method for simultaneous extraction of 54 kinds of veterinary drug residues in animal-derived food, including sulfonamides, quinolones, tetracycli... [Objectives]This study was conducted to establish a rapid and effective method for simultaneous extraction of 54 kinds of veterinary drug residues in animal-derived food, including sulfonamides, quinolones, tetracyclines, malachite greens, penicillins, nitroimidazoles, tranquilizers and macrolides, by HPLC-MS. [Methods] The samples were extracted with 80% acetonitrile water(containing 0.1% formic acid), combined with QuEChERS extraction technology and C18 and PSA purification, analyzed by high performance liquid chromatography-mass spectrometry, and quantified by external standard method. The target substances were analyzed on ZORBAX Eclipse C18 chromatographic column using 0.2% formic acid water and 0.2% methanol as mobile phases. The gradient elution mode was used for chromatographic separation and multiple reaction detection. [Results] In the linear range of 0.5-50.0 ng/ml, the linear relationship of the 54 kinds of veterinary drug residues was good, with correlation coefficients(r~2) greater than 0.995, and the detection limits ranged from 0.30 to 1.00 μg/kg. The results showed that the recovery ranged from 75.4% to 118.2% when different matrixes were added for recovery. [Conclusions] This method is simple, efficient, accurate, stable, and highly operable. It is applicable to simultaneous batch screening of veterinary drug residues in animal-derived food, and has high practical application value. 展开更多
关键词 Animal-derived food Multiple veterinary drug residues OPTIMIZATION Liquid chromatography-mass spectrometry
下载PDF
Detection and Analysis of Pesticide Residues in Chinese Chives and Risk Assessment of Dietary Intake 被引量:1
6
作者 Lei WANG Huihui LIU +9 位作者 Shuo YANG Ying WANG Shuai WANG Haitao ZHAO Huifang YAO Yajing WANG Liang ZHANG Yancheng ZHOU Sining TANG Yanhua YAN 《Agricultural Biotechnology》 CAS 2023年第1期87-93,共7页
[Objectives]This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive sa... [Objectives]This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive samples collected from Tangshan area were qualitatively and quantitatively determined by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) and gas chromatography(GC) in 2020. [Results] The results showed that 41 kinds of pesticide residues were detected in the 415 Chinese chive samples, and the detection rate was 69.4%(288/415), and there was a combination of pesticides in many samples. According to the National Food Safety Standard―Maximum Residue Limits of Pesticides in Food(GB 2763-2019), the residues of 12 pesticides exceeded the maximum residue limits(MRLs), and the unqualified rate was 38.07%(158/415). The highest detection rate of clothianidin was 41.20%(171/415), but there was no MRL in GB 2763-2019. The next was procymidone, the detection rate of which was 35.42%(147/415), and the over-standard rate was 30.12%(125/415). Forbidden and restricted pesticides were detected in some samples. According to the dietary exposure risk assessment, the NEDI/ADI values were all less than 1 and the intake risk was within acceptable range. In Tangshan area, the types of pesticides used in Chinese chive production are complex, and there are risks of multi-residue pollution and use of banned and restricted pesticides and unregistered pesticides. It is suggested that routine monitoring of pesticide residues and management of pesticide use should be strengthened to ensure the quality and safety of agricultural products. [Conclusions] This study provides a theoretical basis for the safe production of Chinese chive and the standardized and rational use of pesticides. 展开更多
关键词 Chinese chive Pesticide residues DETECTION Risk assessment
下载PDF
Structural properties of residual carbon in coal gasification fine slag and their influence on flotation separation and resource utilization:A review 被引量:2
7
作者 Rui Han Anning Zhou +4 位作者 Ningning Zhang Kaiqiang Guo Mengyan Cheng Heng Chen Cuicui Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期217-230,共14页
Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery a... Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery and the high-value utilization of residual carbon(RC)in FS are the keys to realizing the win-win situation of the coal chemical industry in terms of economic and environmental benefits.The structural properties,such as pore,surface functional group,and microcrystalline structures,of RC in FS(FS-RC)not only affect the flotation recovery efficiency of FS-RC but also form the basis for the high-value utilization of FS-RC.In this paper,the characteristics of FS-RC in terms of pore structure,surface functional groups,and microcrystalline structure are sorted out in accordance with gasification type and FS particle size.The reasons for the formation of the special structural properties of FS-RC are analyzed,and their influence on the flotation separation and high-value utilization of FS-RC is summarized.Separation methods based on the pore structural characterist-ics of FS-RC,such as ultrasonic pretreatment-pore-blocking flotation and pore breaking-flocculation flotation,are proposed to be the key development technologies for improving FS-RC recovery in the future.The design of low-cost,low-dose collectors containing polar bonds based on the surface and microcrystalline structures of FS-RC is proposed to be an important breakthrough point for strengthening the flotation efficiency of FS-RC in the future.The high-value utilization of FS should be based on the physicochemical structural proper-ties of FS-RC and should focus on the environmental impact of hazardous elements and the recyclability of chemical waste liquid to es-tablish an environmentally friendly utilization method.This review is of great theoretical importance for the comprehensive understand-ing of the unique structural properties of FS-RC,the breakthrough of the technological bottleneck in the efficient flotation separation of FS,and the expansion of the field of the high value-added utilization of FS-RC. 展开更多
关键词 coal gasification fine slag residual carbon pore structure surface functional groups microcrystalline structure flotation sep-aration resource utilization
下载PDF
Recycling and utilization of coal gasification residues for fabricating Fe/C composites as novel microwave absorbents
8
作者 Guomin Li Xiaojie Xue +7 位作者 Lutao Mao Yake Wang Lingxiao Li Guizhen Wang Kewei Zhang Rong Zhang Yuexiang Wang Liping Liang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第3期591-599,共9页
Under the background of a transformation of the global energy structure,coal gasification technology has a wide application prospect,but its by-product,the coal gasification residue(CGR),is still not being efficiently... Under the background of a transformation of the global energy structure,coal gasification technology has a wide application prospect,but its by-product,the coal gasification residue(CGR),is still not being efficiently utilized for recycling.The CGR contains abundant carbon components,which could be applied to the microwave absorption field as the carbon matrix.In this study,Fe/CGR composites are fabricated via a two-step method,including the impregnation of Fe^(3+)and the reduction process.The influence of the different loading capacities of the Fe component on the morphology and electromagnetic properties is studied.Moreover,the loading content of Fe and the surface morphology of the Fe/CGR can be reasonably controlled by adjusting the concentration of the ferric nitrate solution.Meanwhile,Fe particles are evenly inserted on the CGR framework,which expands the Fe/CGR interfaces to enhance interfacial polarization,thus further improving the microwave-absorbing(MA)properties of composites.Particularly,as the Fe^(3+)concentration is 1.0 mol/L,the Fe/CGR composite exhibits outstanding performance.The reflection loss reaches-39.3 dB at 2.5 mm,and the absorption bandwidth covers 4.1 GHz at 1.5 mm.In this study,facile processability,resource recycling,appropriately matched impedance,and excellent MA performance are achieved.Finally,the Fe/CGR composites not only enhance the recycling of the CGR but also pioneer a new path for the synthesis of excellent absorbents. 展开更多
关键词 coal gasification residue recycling utilization COMPOSITE microwave absorption
下载PDF
A Rapid Determination of 30 Prohibited Pesticide Residues in Lycii Fructus by UPLC-MS/MS
9
作者 Kesheng Lin Zhengqi Wang +6 位作者 Li Wang Jiawen Zhou Lijuan Han Jingjing Wen Tingxia Dong Ran Duan Ning Li 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第2期423-437,共15页
Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus,However,rarely studies focus on the rapid determination of these residues.Here,a total of 30 kinds of... Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus,However,rarely studies focus on the rapid determination of these residues.Here,a total of 30 kinds of prohibited pesticide residues were determined by ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry(UPLC-MS/MS)in five different process ways.Pretreatment methods,chromatographic separation and detection conditions in mass spectrometry were all optimized accordingly.Among the five different pretreatment methods,the first and third solid phase extraction failed to provide high recoveries of sulfosulfuron compounds(both lower than 60%).Recovery of chlorphenamidine by the Quick Easy Cheap Effective Rugged and Safe multiresidue method(QuEChERS)was lower than 60%,which did not meet the requirements of trace determination.The concentrations of 30 prohibited pesticides residues treated by straightforward and solid phase extraction showed good linearity in their corresponding ranges,with correlation coefficients over 0.99.The average recoveries of straightforward ranged from 78.13%to 110.9%,while RSD ranged from 1.3%to 16.9%,albeit poor purification was observed.The recovery yield from solid phase extraction was between 67.75%and 103.08%with RSD value from 0.8%to 14.0%,which met the requirements of trace determination,this method has good precision and stability.These results could be employed to other Traditional Chinese Medicines(TCMs)in detecting prohibited pesticide residues. 展开更多
关键词 Lycii fructus prohibited pesticide residues UPLC-MS/MS
下载PDF
Rapid Screening of Pesticide Residues in Strawberry Based on HPLC-QTOF/MS SWATH Acquisition Mode
10
作者 Fang LI Yu ZOU +3 位作者 Xiangang LI Xuemei LI Sining LIU Ying WANG 《Plant Diseases and Pests》 CAS 2023年第3期10-13,共4页
[Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified ... [Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified with anhydrous magnesium sulfate,sodium chloride and primary secondary amine(PSA)powder,and then loaded on the machine.The full information spectrum was collected by positive ion mode and screened by comparing with the spectrum library,and 20 kinds of pesticide residues were quantitatively analyzed.[Results]The detection limits of 20 pesticide residues were 0.0002-0.0100 mg/kg,and they showed good linearity in the range of 0.0005-0.1000μg/mL(R 2≥0.995).The recoveries ranged from 62.8%to 106.3%.[Conclusions]This method is rapid,simple,sensitive and non-targeted,and can be used for rapid screening of multiple pesticide residues in strawberry. 展开更多
关键词 STRAWBERRY HPLC-QTOF/MS Non-targeted screening SWATH Pesticide residue
下载PDF
Multiple Pesticide Residues in Bananas Sold in Tangshan City and Dietary Risk Assessment
11
作者 Lin LI Huihui LIU +8 位作者 Hefeng ZHANG Yancheng ZHOU Yuping LIU Zhenguo ZHANG Qianqian CONG Liang ZHANG Yajing WANG Ling ZHENG Baiqin ZHENG 《Agricultural Biotechnology》 2023年第6期52-57,共6页
[Objectives]This study was conducted to investigate the pesticide residue status of bananas in Tangshan area and the dietary intake risk of consumers.[Methods]High-performance liquid chromatography-tandem mass spectro... [Objectives]This study was conducted to investigate the pesticide residue status of bananas in Tangshan area and the dietary intake risk of consumers.[Methods]High-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)was applied to detect 70 pesticide residues in 191 batches of banana samples extracted from Tangshan area,and chronic and acute risk assessments were conducted.[Results]Among the 191 batches of bananas,172 batches of samples were detected to contain agrochemicals,with a detection rate of 90.05%.Seventeen agrochemicals were detected,accounting for 24.29%of the total agrochemicals tested.There was a phenomenon of multiple pesticide residues in a single sample,and high detection rates were found in carbendazim(49.21%),prochloraz(41.88%),pyraclostrobin(34.03%)and imidacloprid(30.37%).According to GB 2763-2021 National Food Safety Standards—Maximum Residue Limits for Pesticides in Food,the over-standard rate of imidacloprid was 17.8%;and the chronic and acute dietary risks of the 17 pesticide residues were all less than 100%.[Conclusions]The pesticide residues in bananas consumed by consumers on a daily basis do not pose unacceptable dietary risks. 展开更多
关键词 Bananas Pesticide residues Dietary intake Risk assessment
下载PDF
Simultaneous Determination of 14 β-Receptor Agonists Residues in Mutton by High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS)
12
作者 Zhe MENG Jianhua WANG +5 位作者 Bo LIU Yuhang GUO Haoshuang DONG Pingyang SHAN Dawei WANG Yajuan SONG 《Agricultural Biotechnology》 CAS 2023年第5期55-58,共4页
[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-g... [Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-glucuronidase and extracted with 5%acetic acid-acetonitrile(1:99,V/V)solution.An Eclipse plus C 18 column was used for separation,and the MRM mode was used for qualitative analysis,and the external standard method was used for quantitative analysis of matrix standard solutions.[Results]Under the optimal conditions,the retention time of the 14 kinds ofβ-receptor agonists ranged from 1.0 to 9.5 min.When the mass concentration was in the range of 0.05-0.50μg/ml,the linear relationship ofβ-receptor agonists was good,with correlation coefficients(r)≥0.9992.The detection limits of the method were in the range of 0.04-0.87μg/kg,and the quantitative limits were in the range of 0.35-1.86μg/kg.The average recovery values were in the range of 82.8%-108.9%,with RSDs(n=6)in the range of 1.9%-6.7%.[Conclusions]The method is simple,sensitive,reproducible,accurate,and can be used for simultaneous determination of the 14 kinds ofβ-receptor agonist residues in mutton. 展开更多
关键词 MUTTON High performance liquid chromatography-tandem mass spectrometry β-receptor agonist residuE
下载PDF
Residual stress modeling of mitigated fused silica damage sites with CO_(2)laser annealing
13
作者 张传超 廖威 +3 位作者 张丽娟 蒋晓龙 方振华 蒋晓东 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期509-514,共6页
A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the resi... A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage sites.The proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient temperature.The residual stress fields of mitigated damage sites for the CO_(2)laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive equations.The simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal history.The calculated maximum hoop stress is in good agreement with the reported experimental result.The estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic measurements.These results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO_(2)laser annealing. 展开更多
关键词 fused silica damage mitigation residual stress laser annealing
下载PDF
A short overview of the lead iodide residue impact and regulation strategies in perovskite solar cells
14
作者 Eng Liang Lim Zhanhua Wei 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期504-510,I0012,共8页
Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other wor... Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other words,the PbI2 content in the precursor and as formed film will affect the efficiency and stability of the PSCs.With moderate residual PbI2,it passivates the bulk/surface defects of perovskite,reduces the interfacial recombination,promotes the perovskite stability,minimizes the device hysteresis,and so on.Deficient PbI2 residue will reduce the interfacial passivation effect and device performance.In addition to facilitating the non-radiative recombination,over PbI2 residue can also lead to electronic insulation in the grain boundary and deteriorate the device performance.However,the impact and regulation of PbI2 residue on the device performance and stability is still not fully understood.Herein,a comprehensive and detailed review is presented by discussing the PbI2 residue impact and its regulation strategies(i.e., elimination,facilitation and conversion of the residue PbI2) to manipulate the PbI2 content,distribution and forms.Finally,we also show future outlooks in this field,with an aim to help further the progression of high-efficiency and stable PSCs. 展开更多
关键词 Lead iodide residuE REGULATION Perovskite solar cells Efficiency Stability
下载PDF
Afforestation with an age-sequence of Mongolian pine plantation promotes soil microbial residue accumulation in the Horqin Sandy Land, China
15
作者 GUO Jingwen SONG Xueshu +2 位作者 WANG Xiao DU Zhangliu LU Sen 《Journal of Arid Land》 SCIE CSCD 2024年第4期567-579,共13页
Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue chan... Land use change affects the balance of organic carbon(C)reserves and the global C cycle.Microbial residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue changes over time following afforestation.In this study,16-,23-,52-,and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land,China.We analyzed changes in SOC,amino sugar content,and microbial parameters to assess how microbial communities influence soil C transformation and preservation.The results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27-1.29 kg/m2 after 52 a.Moreover,there were consistent increases in amino sugars and microbial residues with increasing stand age.As stand age increased from 16 to 62 a,soil pH decreased from 6.84 to 5.71,and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg.A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed,indicating that the effects of soil acidification promote amino sugar stabilization during afforestation.In contrast to the Mongolian pine plantation of the same age,the cropland accumulated more SOC and microbial residues because of fertilizer application.Across Mongolian pine plantation with different ages,there was no significant change in calculated contribution of bacterial or fungal residues to SOC,suggesting that fungi were consistently the dominant contributors to SOC with increasing time.Our results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence. 展开更多
关键词 soil organic matter stand age biomarker amino sugars microbial residues
下载PDF
Residual alkali-evoked cross-linked polymer layer for anti-air-sensitivity LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)cathode
16
作者 Chao Zhao Xuebao Li +7 位作者 Yun Zhao Jingjing He Yuanpeng Cao Wei Luo Ding Wang Jianguo Duan Xianshu Wang Baohua Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期450-458,共9页
High-energy density lithium-ion batteries(LIBs)with layered high-nickel oxide cathodes(LiNi_(x)Co_(y)Mn_(1-x-y)O_(2),x≥0.8)show great promise in consumer electronics and vehicular applications.However,LiNi_(x)Co_(y)M... High-energy density lithium-ion batteries(LIBs)with layered high-nickel oxide cathodes(LiNi_(x)Co_(y)Mn_(1-x-y)O_(2),x≥0.8)show great promise in consumer electronics and vehicular applications.However,LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)faces challenges related to capacity decay caused by residual alkalis owing to high sensitivity to air.To address this issue,we propose a hazardous substances upcycling method that fundamentally mitigates alkali content and concurrently induces the emergence of an anti-air-sensitive layer on the cathode surface.Through the neutralization of polyacrylic acid(PAA)with residual alkalis and then coupling it with 3-aminopropyl triethoxysilane(KH550),a stable and ion-conductive cross-linked polymer layer is in situ integrated into the LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)(NCM)cathode.Our characterization and measurements demonstrate its effectiveness.The NCM material exhibits impressive cycling performance,retaining 88.4%of its capacity after 200 cycles at 5 C and achieving an extraordinary specific capacity of 170.0 mA h g^(-1) at 10 C.Importantly,this layer on the NCM efficiently suppresses unfavorable phase transitions,severe electrolyte degradation,and CO_(2)gas evolution,while maintaining commendable resistance to air exposure.This surface modification strategy shows widespread potential for creating air-stable LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)cathodes,thereby advancing high-performance LIBs. 展开更多
关键词 Lithium-ion batteries Nickel-rich layered cathode residual alkalis Cross-linked polyme rmodification Airsensitivity
下载PDF
Attention-Based Residual Dense Shrinkage Network for ECG Denoising
17
作者 Dengyong Zhang Minzhi Yuan +3 位作者 Feng Li Lebing Zhang Yanqiang Sun Yiming Ling 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2809-2824,共16页
Electrocardiogram(ECG)signal is one of the noninvasive physiological measurement techniques commonly usedin cardiac diagnosis.However,in real scenarios,the ECGsignal is susceptible to various noise erosion,which affec... Electrocardiogram(ECG)signal is one of the noninvasive physiological measurement techniques commonly usedin cardiac diagnosis.However,in real scenarios,the ECGsignal is susceptible to various noise erosion,which affectsthe subsequent pathological analysis.Therefore,the effective removal of the noise from ECG signals has becomea top priority in cardiac diagnostic research.Aiming at the problem of incomplete signal shape retention andlow signal-to-noise ratio(SNR)after denoising,a novel ECG denoising network,named attention-based residualdense shrinkage network(ARDSN),is proposed in this paper.Firstly,the shallow ECG characteristics are extractedby a shallow feature extraction network(SFEN).Then,the residual dense shrinkage attention block(RDSAB)isused for adaptive noise suppression.Finally,feature fusion representation(FFR)is performed on the hierarchicalfeatures extracted by a series of RDSABs to reconstruct the de-noised ECG signal.Experiments on the MIT-BIHarrhythmia database and MIT-BIH noise stress test database indicate that the proposed scheme can effectively resistthe interference of different sources of noise on the ECG signal. 展开更多
关键词 Electrocardiogram signal denoising signal-to-noise ratio attention-based residual dense shrinkage network MIT-BIH
下载PDF
Comprehensive reutilization of herbal waste:Coproduction of magnolol,honokiol,and β-amyrin from Magnolia officinalis residue
18
作者 Lukun Xiao Anyi Zhao +12 位作者 Jie Qiu An Liu Sha Chen Jinzhu Jiang Jun Zhang Cong Guo Jipeng Di Jintang Cheng Chang Chen Kangxin Hou Aiping Zhang Yan Liu Caixia Wang 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第2期403-412,共10页
Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia off... Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia officinalis residues(MOR)as an example.The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients(magnolol and honokiol)originally remaining in MOR and to make MOR more accessible for hydrolysis.A metal–organic frame material MIL-101(Cr)with a maximum absorption capacity of 255.64 mg g^(-1)was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions,and 40 g L^(-1)reducing sugars were obtained with 81.8%enzymatic hydrolysis rate at 10%MOR solid loading.Finally,382 mg L-1β-amyrin was produced from MOR hydrolysates by an engineered yeast strain.In total,1 kg honokiol,8 kg magnolol,and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB. 展开更多
关键词 Magnolia officinalis residues(MOR) Comprehensive utilization Metal-organic frame material BIOSYNTHESIS
下载PDF
Radar Signal Intra-Pulse Modulation Recognition Based on Deep Residual Network
19
作者 Fuyuan Xu Guangqing Shao +3 位作者 Jiazhan Lu Zhiyin Wang Zhipeng Wu Shuhang Xia 《Journal of Beijing Institute of Technology》 EI CAS 2024年第2期155-162,共8页
In view of low recognition rate of complex radar intra-pulse modulation signal type by traditional methods under low signal-to-noise ratio(SNR),the paper proposes an automatic recog-nition method of complex radar intr... In view of low recognition rate of complex radar intra-pulse modulation signal type by traditional methods under low signal-to-noise ratio(SNR),the paper proposes an automatic recog-nition method of complex radar intra-pulse modulation signal type based on deep residual network.The basic principle of the recognition method is to obtain the transformation relationship between the time and frequency of complex radar intra-pulse modulation signal through short-time Fourier transform(STFT),and then design an appropriate deep residual network to extract the features of the time-frequency map and complete a variety of complex intra-pulse modulation signal type recognition.In addition,in order to improve the generalization ability of the proposed method,label smoothing and L2 regularization are introduced.The simulation results show that the proposed method has a recognition accuracy of more than 95%for complex radar intra-pulse modulation sig-nal types under low SNR(2 dB). 展开更多
关键词 intra-pulse modulation low signal-to-noise deep residual network automatic recognition
下载PDF
A method for establishing a bearing residual life prediction model for process enhancement equipment based on rotor imbalance response analysis
20
作者 Feng Wang Haoran Li +3 位作者 Zhenghui Zhang Yan Bai Hong Yin Jing Bian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期203-215,共13页
A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adh... A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adhere to the wire mesh packing in the rotor,thus resulting in an imbalance in the vibration of the rotor,which may cause serious damage to the bearing and material leakage.This study proposes a model prediction for estimating the bearing residual life of a rotating packed bed based on rotor imbalance response analysis.This method is used to determine the influence of the mass on the imbalance in the vibration of the rotor on bearing damage.The major influence on rotor vibration was found to be exerted by the imbalanced mass and its distribution radius,as revealed by the results of orthogonal experiments.Through implementing finite element analysis,the imbalance response curve for the rotating packed bed rotor was obtained,and a correlation among rotor imbalance mass,distribution radius of imbalance mass,and bearing residue life was established via data fitting.The predicted value of the bearing life can be used as the reference basis for an early safety warning of a rotating packed bed to effectively avoid accidents. 展开更多
关键词 Rotating packed bed Mass imbalance Harmonic response analysis residual life Prediction model
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部