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Correlation of gut microorganisms and non-volatile flavor substances provides new insights for breeding Scylla paramamosain
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作者 Gao GAO Xing LI +7 位作者 Kangxiang QIN Yun HU Xiaosong JIANG Chenxi CHE Yuntao LI Changkao MU Chunlin WANG Huan WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1336-1347,共12页
The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environmen... The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environment is one of the important ways to source gut microorganisms in the organism.In this study,the levels of dominant taxa in the gut flora of S.paramamosain from Mong Cai,Vietnam(VN),Taishan City,Guangdong Province(TS)of China,and Ninghai County,Ningbo City(NB)Zhejiang Province of China converged with those of S.paramamosain from Sanmen County,Ningbo City(CK 1,CK 2,and CK 3)at 28 d of domestication.The top 15 genera with the highest abundance of VN,TS,and NB gut flora were the same as CK 1,CK 2,and CK 3,but with different percentages,and gradually converged to CK 1,CK 2,and CK 3,respectively,at 28 d of domestication.Correlation between intestinal flora and non-volatile flavor substances in the hepatopancreas at the percentage level of relative abundance of bacterial genera found that above 28 d of domestication,Muribaculaceae,Psychrilyobacter,Clostridia_vadinBB 60_group,Halarcobacter Carboxylicivirga,Sediminispirochaeta may be the most important genera affecting flavor amino acids of VN.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Psychrilyobacter,and Pseudomonas may be the most important genera affecting flavor amino acids of NB.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Vibrio,and Sphingomonas may be the most important genera affecting flavor amino acids of TS.These results show that the intestinal flora structure of crabs from different areas were domesticated in the same area for at least 28 d before they converged to that of the domesticated crab,and the most important genera affecting the flavor amino acids of TS,VN,and NB were also identified.The results of this study provide a reference and basis for the technique of directional cultivation of the flavor quality of the crab. 展开更多
关键词 survival environment Scylla paramamosain intestinal flora structure non-volatile flavor substance directional breeding
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Occurrence,Spatial Distribution,Sources and Risk Assessment of Per-and Polyfluoroalkyl Substances in Surface Sediments of the Yellow River Delta Wetland
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作者 SUN Yu SHEN Nan +5 位作者 ZHANG Dahai CHEN Junhui HE Xiuping JI Yinli WANG Haiyang LI Xianguo 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1263-1274,共12页
Per-and polyfluoroalkyl substances(PFASs)are emerging persistent organic pollutants(POPs).In this study,47 surface sediment samples were collected from the Yellow River Delta wetland(YRDW)to investigate the occurrence... Per-and polyfluoroalkyl substances(PFASs)are emerging persistent organic pollutants(POPs).In this study,47 surface sediment samples were collected from the Yellow River Delta wetland(YRDW)to investigate the occurrence,spatial distribution,potential sources,and ecological risks of PFASs.Twenty-three out of 26 targeted PFASs were detected in surface sediment samples from the YRDW,with totalΣ23PFASs concentrations ranging from 0.23 to 16.30 ng g^(-1) dw and a median value of 2.27 ng g^(-1) dw.Perfluorooctanoic acid(PFOA),perfluorobutanoic acid(PFBA)and perfluorooctanesulfonic acid(PFOS)were the main contaminants.The detection frequency and concentration of perfluoroalkyl carboxylic acids(PFCAs)were higher than those of perfluoroal-kanesulfonic acids(PFSAs),while those of long-chain PFASs were higher than those of short-chain PFASs.The emerging PFASs substitutes were dominated by 6:2 chlorinated polyfluoroalkyl ether sulfonic acid(6:2 Cl-PFESA).The distribution of PFASs is significantly influenced by the total organic carbon content in the sediments.The concentration of PFASs seems to be related to human activities,with high concentration levels of PFASs near locations such as beaches and villages.By using a positive matrix factorization model,the potential sources of PFASs in the region were identified as metal plating mist inhibitor and fluoropolymer manufacturing sources,metal plating industry and firefighting foam and textile treatment sources,and food packaging material sources.The risk assessment indicated that PFASs in YRDW sediments do not pose a significant ecological risk to benthic organisms in the region overall,but PFOA and PFOS exert a low to moderate risk at individual stations. 展开更多
关键词 per-and polyfluoroalkyl substances Yellow River Delta wetland sediment source identification risk assessment
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Research Progress of Volatile Substances Analysis and Sensory Evaluation of Soymilk
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作者 Xu Qiongyuan Li Ka +7 位作者 Huang Meina Liang Yuxin Tao Bingjie Zhang Tingting Song Nannan Ji Yazhou Zhang Huajiang Xia Ning 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期74-82,共9页
Soybean is one of the important crops in China. Soymilk, a traditional neutral plant-based protein drink, is rich in high quality proteins. Although soybean milk is rich in nutrients, its marketing among consumers, es... Soybean is one of the important crops in China. Soymilk, a traditional neutral plant-based protein drink, is rich in high quality proteins. Although soybean milk is rich in nutrients, its marketing among consumers, especially those in Western countries who are used to peaceful flavor, has been limited due to the adverse flavor impact brought by its special composition. In recent years, with the increasing attention to the nutritional value of soymilk, the flavor of soymilk has become a popular research object for scholars at home and abroad. The flavor components of soymilk are mainly volatile small molecular compounds produced by enzymatic reactions catalyzed by lipoxygenase(LOX). After formation, they interact with protein macromolecules to form the overall flavor of soymilk. At present, there are many methods to control the off-odor of soymilk at home and abroad, including physical heating methods, chemical methods, biological enzymatic digestion methods, mask methods, and a variety of breeding methods. These methods effectively reduce the off-odor of soymilk, but all of them have shortcomings. Currently, the sensory characteristics of the beany odor in soymilk are evaluated mainly by traditional human sensory scoring along with the assistance of modern instrument analysis of volatile flavor substances using headspace solid phase microextraction(SPME) gas chromatography coupled with-mass spectrometry(GC-MS). This paper summarized the research results of volatile flavor substances in soymilk in recent years and the sensory evaluation methods of soymilk at home and abroad, and looked forward to the future development direction, hoping to provide some theoretical bases and reference detection methods for solving the problem of soymilk flavor in the future. 展开更多
关键词 SOYMILK off-odor volatile substance FLAVOR sensory evaluation
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Evaluation of Rhizobium tropici-Derived Extracellular Polymeric Substances on Selected Soil Properties, Seed Germination, and Growth of Black-Eyed Peas (Vigna unguiculata)
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作者 Jonathan Alunge Metuge Erneste Havugimana +2 位作者 Jean Rugandirababisha Zachary N. Senwo Marie Chantal Mutimawurugo 《Agricultural Sciences》 2024年第5期548-564,共17页
Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility ... Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary. 展开更多
关键词 Rhizobium tropici Extracellular Polymeric substances Soil Respiration Soil Microbial Biomass Black-Eyed Peas
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Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances
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作者 Lan Lu Yuting Zhao +4 位作者 Mingxing Li Xiaobo Wang Jie Zhu Li Liao Jingya Wang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第4期506-524,共19页
Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing pr... Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing precise and effective antibiofilm approaches and strategies,tailored to the specific charac-teristics of EPS composition,can offer valuable insights for the creation of novel antimicrobial drugs.This,in turn,holds the potential to mitigate the alarming issue of bacterial drug resistance.Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias,which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds.Considering the pivotal role of EPS in biofilm functionality,it is imperative for EPS research to delve deeper into the analysis of intricate compositions,moving beyond the current focus on polymeric materials.This ne-cessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches.In this study,we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions.Additionally,novel strategies aimed at targeting EPS to enhance biofilm penetration were explored,with a specific focus on high-lighting the limitations associated with colorimetric methods.Furthermore,we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges.This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS,thereby inhibiting biofilm formation.This insight opens up a new avenue for exploration within this research domain. 展开更多
关键词 Analytic strategies and approaches Composition characterization Extracellular polymeric substances(EPS) Promoting biofilm penetration
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Prevalence and Factors Associated with Positivity of Antinuclear Antibodies (ANA) Patterns, Native Anti-DNA and Extractable Nuclear Antigens (ENA) Antibodies: Experience from a Laboratory in Dakar
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作者 Diop Abdou Diallo Thierno Abdoulaye +4 位作者 Ndiaye Babacar Mahou Chantal Diop Marième Gaye Dubrous Phillippe Seck Abdoulaye 《Open Journal of Rheumatology and Autoimmune Diseases》 2024年第1期26-36,共11页
Background: Diagnosis of autoimmune diseases (AID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA) are sensitive screening tests but anti-deoxyribonucleic aci... Background: Diagnosis of autoimmune diseases (AID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA) are sensitive screening tests but anti-deoxyribonucleic acid-antibody (anti-DNA), and anti-extractable nuclear antigens (anti-ENA) are specific for AIDs. We aimed to look at ANA patterns in our patients and correlated them with anti-ENA for proper interpretation and better patient management cost-effectively. Methods: A retrospective study was conducted over 1 year from January to December 2022 who were tested for ANA at biology medical laboratory of Pasteur Institute of Dakar. Anti-ENA and anti-DNA results were also analyzed for ANA-positive patients. Statistical analysis was performed using STATA 14.0, p Results: 216 patients were analyzed. Women predominated at 79.2% and mean age was 48 years [CI 95%, 46 - 50], with extremes of 10 and 89. Most represented age group was [41 - 60] with 38%. ANA was positive in 27 (12.5%) of patients, 59.2% of whom were strongly positive (titer of 1/1000, 1/3200 or 1/6400). The most common pattern was nuclear speckled, which was found in 77.8% of samples. Anti-ENA and anti-DNA positivity in ANA-positive patients was found respectively in 63% (17/27) and 1.4% (3/27) of the samples analyzed. Most commonly identified anti-ENA was anti-Sm 29.6%, anti-SSA 29.6%, anti-Ro-52 25.9%, anti-RNP 18.5% and anti-SSB 14.8% which was associated with speckled pattern. Association results indicated a significant relationship between both tests and between ANA titer in the anti-ENA- and ANA-positive patients (p 0.001). Conclusions: ANA, Anti-ENA and anti-DNA antibodies are essential for AIDS diagnosis. However, the testing repertoire should follow an algorithm comprising of clinical features, followed by ANA results with nuclear, mitotic, and cytoplasmic patterns, anti-ENA, and anti-DNA for a more meaningful, and cost-effective diagnostic approach. 展开更多
关键词 Antinuclear Antibodies extractable Nuclear antigen Autoimmune Disease Indirect Immunofluorescence
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Preserving the Ozone Layers: Battling Illegal Trade in Ozone-Depleting Substances
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作者 Ibrahim Badawi 《Atmospheric and Climate Sciences》 2024年第3期287-298,共12页
The depletion of the ozone layer, a vital shield protecting the Earth from harmful ultraviolet (UV) radiation, is now a worldwide environmental concern. Human activities, particularly the release of ozone depleting su... The depletion of the ozone layer, a vital shield protecting the Earth from harmful ultraviolet (UV) radiation, is now a worldwide environmental concern. Human activities, particularly the release of ozone depleting substances (ODS), have led to the thinning of this protective layer over recent decades. Simultaneously, illegal trade has emerged as a global challenge, giving rise to economic issues, losses of tax revenue, heightened criminal activities, health risks, and environmental hazards. The depletion of the ozone layer, a critical shield protecting the Earth from harmful ultraviolet (UV) radiation, has become a global environmental concern. This paper delves into the legal dimensions surrounding ozone-depleting substances (ODS), their impact on the ozone layer, and the subsequent risk of skin cancer. As countries navigate international agreements, domestic regulations, and enforcement mechanisms, the intricate interplay between legal frameworks and the health implications of ozone layer depletion comes to the forefront. The paper highlights particular instances of illegal trade in ozone depleting substances, drawing from data reported by the parties to the Montreal Protocol. Notably, China stands out as a significant source of contraband ODS, with other countries such as Bulgaria, Lithuania, Poland, and France reporting numerous cases. Analyzing these case instances offers insights into the efficacy of legal frameworks and enforcement measures. The paper offers a comprehensive set of recommendations to strengthen global control and enforcement against the illegal trade of ozone depleting substances. These recommendations span diverse aspects such as production monitoring, customs collaboration, mutual verification, cross-border agreements, public-private partnerships, international cooperation, detection equipment, global regulatory standards, resource allocation, public awareness campaigns, alternative substance development, and controlling the trade at its source. By applying these recommendations and enhancing enforcement measures, we aim to protect the ozone layer and create a healthier and safer world for future generations and achieve sustainable development goals. 展开更多
关键词 Ozone-Depleting substances Illegal Trade Montreal Protocol Environmental Protection Ozone Layers Climate Change
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The Role of Jasmonates as Antibulbing Substances in the Bulb Formation of Onion
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作者 Noboru Takada Atsushi Saito +4 位作者 Yuuki Matsuzuka Tatsushi Mochiduki Eriko Wakita Meng WANG Yasunori Koda 《Agricultural Biotechnology》 2024年第1期1-4,8,共5页
Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extract... Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation. 展开更多
关键词 Onion(Allim cepa L.cv.Higuma) ISOLATION Bulb formation Antibulbing substance α-Linolenic acid Methyl jasmonate
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Analyzing the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells
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作者 Rui-Xue Chen Jing Li +3 位作者 Guo-Zhen Dong Sheng-Yan Qiao Xiao Hu Li-Guo Chen 《Clinical Research Communications》 2024年第1期3-10,共8页
Background:Xuefu Zhuyu decoction(XFZY)could significantly improve the function of hypertensive vascular endothelial cells,but the targets and mechanism are not clear.This study is to analyze the pharmacological substa... Background:Xuefu Zhuyu decoction(XFZY)could significantly improve the function of hypertensive vascular endothelial cells,but the targets and mechanism are not clear.This study is to analyze the pharmacological substances and targets of Xuefu Zhuyu decoction in hypertensive vascular endothelial cells.Methods:This study used Xuefu Zhuyu decoction to intervene human umbilical vein endothelial cells incubated by hypertensive patients’serum,then detected the function of vascular endothelial cells.The aqueous extract of XFZY was analyzed and validated by liquid chromatography-mass spectrometry technology;Finally,macromolecular docking technology was used to analyze the potential active substances and targets of XFZY in the prevention and treatment of hypertension.Results:Compared with the model group,the XFZY group showed a significant increase in NO expression(P<0.01)and a significant decrease in ET-1 expression(P<0.001);and the expression of BIP,P-JNK,CHOP,and BAX in XFZY group cells was significantly decreased(P<0.001),while the expression of JNK and BCL2 was significantly increased(P<0.001).19 main compounds were identified in XFZY and there were 3 pairs of molecular complexes with high affinity for markers of the endoplasmic reticulum stress,including BIP-Hesperidin complex,BIP-HSYA complex and JNK-Naringin complex.Conclusion:This study analyzed the potential pharmacodynamic substance and targets of Xuefu Zhuyu decoction in improving the function of hypertensive vascular endothelial cells,which could provide a scientific basis for the future molecular mechanism of XFZY in treating hypertension. 展开更多
关键词 Xuefu Zhuyu decoction HYPERTENSION vascular endothelial cells pharmacological substances and targets
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Advances in Research Methods of Pharmacodynamic Substances in Traditional Chinese Medicines and Their Application in the Teaching of Traditional Chinese Medicine Analysi
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作者 Jiangwei Tian 《Journal of Contemporary Educational Research》 2024年第5期97-102,共6页
With the continuous progress of science and technology,the research methods of pharmacodynamic substances in traditional Chinese medicine are developing,and the application of these methods in teaching is becoming mor... With the continuous progress of science and technology,the research methods of pharmacodynamic substances in traditional Chinese medicine are developing,and the application of these methods in teaching is becoming more and more extensive.By introducing these research methods into the classroom,teachers can help students to deeply understand the nature and mechanism of action of pharmacodynamic substances in traditional Chinese medicine,and improve their interest in and knowledge of traditional Chinese medicine.This paper introduces the definition of pharmacodynamic substances in traditional Chinese medicine,research methods,and their application in the teaching of traditional Chinese medicine analysis. 展开更多
关键词 Traditional Chinese medicine Pharmacodynamic substances Teaching of traditional Chinese medicine analysis Teaching application
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基于知识图谱增强的恶意代码分类方法
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作者 夏冰 何取东 +2 位作者 刘文博 楚世豪 庞建民 《郑州大学学报(理学版)》 CAS 北大核心 2025年第2期61-68,共8页
针对应用程序接口(application programming interface,API)序列识别的恶意代码分类方法存在特征描述能力弱和调用关系缺失的问题,提出一种基于知识图谱增强的恶意代码分类方法。首先,基于函数调用图抽取恶意代码所含的API实体及其调用... 针对应用程序接口(application programming interface,API)序列识别的恶意代码分类方法存在特征描述能力弱和调用关系缺失的问题,提出一种基于知识图谱增强的恶意代码分类方法。首先,基于函数调用图抽取恶意代码所含的API实体及其调用关系,在此基础上构建恶意代码API知识图谱。其次,使用Word2Vec技术计算携带上下文调用语义的API序列向量,借助TransE技术捕获API知识图谱中的API实体向量,将这两个向量的融合结果作为API特征。最后,将恶意代码所含的API表示为特征矩阵,输入TextCNN进行分类模型训练。在恶意代码家族分类任务中,与基线模型相比,所提方法的准确率有较大提升,达到93.8%,表明知识图谱可以有效增强恶意代码家族分类效果。同时,通过可解释性实验证实了所提方法具有应用价值。 展开更多
关键词 恶意代码 API序列 语义抽取 知识图谱 可解释性
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Relationship and effect of redox potential,jarosites and extracellular polymeric substances in bioleaching chalcopyrite by acidithiobacillus ferrooxidans 被引量:13
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作者 余润兰 钟代立 +3 位作者 苗雷 吴发登 邱冠周 顾国华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1634-1640,共7页
The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2+ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different condition... The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2+ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe(III) to Fe(II) in the solutions containing synthetic extracellular polymeric substances (EPS).When the solution potential is lower than 650 mV (vs SHE),the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe(III) ions is up to 20 g/L but increases with increasing the concentration of Fe(III) ions;jarosites formed by bio-oxidized Fe3+ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2+ ions inside and outside EPS space into Fe^3+ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly. 展开更多
关键词 extracellular polymeric substances CHALCOPYRITE BIOLEACHING jarosites redox potential
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Interaction mechanism of Cu^(2+),Fe^(3+) ions and extracellular polymeric substances during bioleaching chalcopyrite by Acidithiobacillus ferrooxidans ATCC2370 被引量:11
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作者 余润兰 刘晶 +5 位作者 陈安 钟代立 李乾 覃文庆 邱冠周 顾帼华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期231-236,共6页
The extracellular polymeric substances(EPS) of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction ... The extracellular polymeric substances(EPS) of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction mechanism of Cu2+,Fe3+ and EPS during bioleaching chalcopyrite.Generally,Cu2+ ions can stimulate bacteria to produce more EPS than Fe3+ ions.The mass ratio of Fe3+/Cu2+ enclosed in EPS decreased gradually from about 4:1 to about 2:1 when the concentration of Cu2+ ions increased from 0.01 to 0.04 mol/L.The amount of iron and copper bound together by EPS in ferrous-free 9K medium containing 1% chalcopyrite was about 2 times of that in 9K medium containing 0.04 mol/L Cu2+ ions.It was inferred that the EPS with jarosites on the surface of chalcopyrite gradually acted as a weak diffusion barrier for Cu2+,Fe3+ ions transference during bioleaching chalcopyrite. 展开更多
关键词 extracellular polymeric substances iron ions copper ions BIOLEACHING CHALCOPYRITE
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Study on the Effect of Osmosis-regulating Substances and Organic Appendices on Somatic Embryogenesis in Wheat 被引量:4
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作者 孙朝霞 侯思宇 王玉国 《Agricultural Science & Technology》 CAS 2008年第3期46-48,共3页
[Objective] The study aimed to reveal the effect of osmosis-regulating substances and organic appendices on somatic embryogenesis in wheat. [Method] The suitable concentration combination of appendices was optimized b... [Objective] The study aimed to reveal the effect of osmosis-regulating substances and organic appendices on somatic embryogenesis in wheat. [Method] The suitable concentration combination of appendices was optimized by adding different concentrations of osmosis-regulating substances including mannitol, sorbitol and organic appendices such as Gln, CH and LH, into the somatic embryogenesis in wheat. [Result] The mannitol or sorbitol lower than 40 g/L was helpful for improving somatic embryogenesis; there was no significant difference in the induction rate of somatic embryogenesis when 300-500 mg/L Gln、CH or LH was respectively added into the induced medium, while somatic embryogenesis could be enhanced dramatically in the presence of 500 mg/L Gln together with 300 mg/L CH. [Conclusion] Somatic embryogenesis could be improved to some extent by different concentrations of osmosis-regulating substances and organic appendices, which laid foundation for establishing a more perfect system of somatic embryogenesis in wheat. 展开更多
关键词 WHEAT SOMATIC EMBRYOGENESIS ORGANIC appendix Osmosis-regulating substance
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基于音频特征的拖拉机发动机状况识别系统设计
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作者 余建华 《农机化研究》 北大核心 2025年第2期228-233,238,共7页
拖拉机发动机是保证拖拉机正常运行的关键部件,目前主要采用振动信号开展发动机故障预测与状况识别。为此,提出了一种基于GRU的循环神经网络模型,通过对拖拉机发动机在不同作业条件下产生的音频信号进行分析,提取Mel作为主要特征,构建... 拖拉机发动机是保证拖拉机正常运行的关键部件,目前主要采用振动信号开展发动机故障预测与状况识别。为此,提出了一种基于GRU的循环神经网络模型,通过对拖拉机发动机在不同作业条件下产生的音频信号进行分析,提取Mel作为主要特征,构建基于音频特征的拖拉机发动机状况识别系统。预测结果表明:系统能够准确地识别发动机的正常运行状态和不同类型的故障状况,对拖拉机发动机异常的识别率可以达到97.15%。研究结果可以提高拖拉机的运行安全性和可靠性,减少故障停机时间,提高农业生产效率。 展开更多
关键词 拖拉机发动机 音频信号 特征提取 模态分解
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自动引线系统中旋转偏心检测与补偿方法
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作者 王跃宗 曲道多 王盛逸 《北京工业大学学报》 CAS 北大核心 2025年第1期1-12,共12页
在空心杯转子线圈的自动引线微操作系统中,线圈的几何中心很难与旋转台的回转中心重合,因此在旋转过程中产生偏心现象,进而导致线圈引线失败。为此,提出了一种检测和补偿线圈偏差的方法。从分析线圈偏心源出发,建立偏心数学模型,设计了... 在空心杯转子线圈的自动引线微操作系统中,线圈的几何中心很难与旋转台的回转中心重合,因此在旋转过程中产生偏心现象,进而导致线圈引线失败。为此,提出了一种检测和补偿线圈偏差的方法。从分析线圈偏心源出发,建立偏心数学模型,设计了一种偏心模型与图像特征提取算法结合的偏差测量方法,并提出基于自动控制与补偿模型的校正方法。通过实验验证了模型的精确性以及偏心补偿的有效性,基于均方根误差的评价,模型对于偏差预测以及特征提取算法均具有较高的精度,补偿后的最大残余误差小于4μm,平均补偿幅度约为98.6%,引线实验展示了所提方法的优良性能。提出的偏心检测补偿方法具有精度高、复杂度低、效率高、实时性,以及嵌入式等优点,且在微操作以及微装配领域具有更合适、更广泛的应用。 展开更多
关键词 空心杯转子线圈 旋转偏心 模型 特征提取 微操作 微装配
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Effects of Drought Stress on Osmotic Regulation Substances of Five Catalpa bungei Clones 被引量:3
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作者 董蕾 李吉跃 +2 位作者 王军辉 谢堃 苏艳 《Agricultural Science & Technology》 CAS 2013年第9期1335-1343,共9页
[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to d... [Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances(free proline,soluble sugar and soluble protein) in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level(CK, with soil water content of 97.49% and leaf water potential of-0.54MPa), light drought(LD with soil water content of 59.96% and leaf water potential of-1.28 MPa), mediate drought(MD with soil water content of 34.19% and leaf water potential of-2.32 MPa) and severe drought(SD with soil water content of 14.52%and leaf water potential of-2.99 MPa). The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3(P0.001). The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress(P 0.001). To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level(P0.001); the free proline content of Catalpa bungei clone 1-3 rapidly increased to(855.46±227.52) μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached(1.644 ±0.137)mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress. 展开更多
关键词 Drought stress Catalpa bungei clones Osmotic regulation substances
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基于细节增强和多颜色空间学习的联合监督水下图像增强算法
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作者 胡锐 程家亮 胡伏原 《现代电子技术》 北大核心 2025年第1期23-28,共6页
由于水下特殊的成像环境,水下图像往往具有严重的色偏雾化等现象。因此文中根据水下光学成像模型设计了一种新的增强算法,即基于细节增强和多颜色空间学习的无监督水下图像增强算法(UUIE-DEMCSL)。该算法设计了一种基于多颜色空间的增... 由于水下特殊的成像环境,水下图像往往具有严重的色偏雾化等现象。因此文中根据水下光学成像模型设计了一种新的增强算法,即基于细节增强和多颜色空间学习的无监督水下图像增强算法(UUIE-DEMCSL)。该算法设计了一种基于多颜色空间的增强网络,将输入转换为多个颜色空间(HSV、RGB、LAB)进行特征提取,并将提取到的特征融合,使得网络能学习到更多的图像特征信息,从而对输入图像进行更为精确的增强。最后,UUIE-DEMCSL根据水下光学成像模型和联合监督学习框架进行设计,使其更适合水下图像增强任务的应用场景。在不同数据集上大量的实验结果表明,文中提出的UUIE-DEMCSL算法能生成视觉质量良好的水下增强图像,且各项指标具有显著的优势。 展开更多
关键词 水下图像增强 多颜色空间学习 无监督学习 细节增强 特征提取 特征融合
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Development and Validation of Liquid Chromatographic Method for the Determination of the Related Substances of Rifampicin 被引量:2
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作者 朱斌 胡昌勤 《Journal of Chinese Pharmaceutical Sciences》 CAS 2002年第1期19-23,共5页
A number of HPLC methods have been approved for the determination of rifampicin, but no references involved the assay of related substances of rifampicin. In the present paper, a reversed-phase liquid chromatographic ... A number of HPLC methods have been approved for the determination of rifampicin, but no references involved the assay of related substances of rifampicin. In the present paper, a reversed-phase liquid chromatographic method for the determination of related substances of rifampicin is developed and validated. Rifampicin and its related substances, including rifamycin SV, rifampicin N-oxide and 3-formylrifamycin SV were separated using a Zorbax Eclipse C8, 250×4.6 mm(i.d), 5 μm column by isocratic elution at a flow rate of 1 mL·min -1. The detector was set at 254 nm. The mobile phase is a mixture of methanol-acetonitrile -0.075 mol·L -1 monopotassium phosphate -1.0 mol·L -1 citric acid (31:31:35:3, v/v). The method validation included accuracy, precision, linearity, sensitivity and stability. All results are shown to be acceptable. 展开更多
关键词 RIFAMPICIN Related substances HPLC
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基于双目立体视觉的多分辨率图像匹配方法研究
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作者 刘华春 吴广文 闫静莉 《现代电子技术》 北大核心 2025年第1期29-32,共4页
在双目立体视觉系统中,面对复杂场景时噪声会损害图像特征,增加提取难度,导致匹配精度和鲁棒性下降。因此,文中提出基于双目立体视觉的多分辨率图像匹配方法,旨在从不同尺度图像中有效获取信息并实现高精度匹配。该方法利用双目立体视... 在双目立体视觉系统中,面对复杂场景时噪声会损害图像特征,增加提取难度,导致匹配精度和鲁棒性下降。因此,文中提出基于双目立体视觉的多分辨率图像匹配方法,旨在从不同尺度图像中有效获取信息并实现高精度匹配。该方法利用双目立体视觉模型的双目旋转相机扫描目标并进行成像,根据内、外空间标定提升双目旋转相机的位置精度,保证目标的多分辨率成像效果;将其输入金字塔立体匹配网络中,通过网络中的类金字塔多空洞卷积操作提取双目图像特征,在此基础上,基于可变卷积增强其纹理特征细节;结合细粒度特征和互注意力机制完成双目图像匹配。测试结果显示,空间标定后,左、右两个相机的成像误差最小值分别为0.6 Pixel和0.4 Pixel;匹配点坐标偏差均值和坐标偏差方差值分别低于0.012和0.011,匹配效果良好。 展开更多
关键词 双目立体视觉 多分辨率 图像匹配 空间标定 双目旋转相机 特征提取 特征增强 细粒度
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