期刊文献+
共找到14,670篇文章
< 1 2 250 >
每页显示 20 50 100
Reduction of Aromatic α-Keto Esters by Commercially Available Zinc Dust and Ammonium Formate: Formation of Aromatic α-Hydroxy Esters
1
作者 CHEN Gang YAO Guo-xin SONG Guang-wei ZHU Jin-tao 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第5期784-786,共3页
Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens, ... Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens, methoxy and esters. 展开更多
关键词 Aromatic aoketo ester Zinc dust Ammonium formate Aromatic a-hydroxy ester
下载PDF
Pathogenic contribution of cholesteryl ester accumulation in the brain to neurodegenerative disorders
2
作者 Michiko Shirane 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第10期2099-2100,共2页
Cholesteryl esters(CEs) have been increasingly implicated in neurodegenerative disorders such as Alzheimer's disease(AD).Alois Alzheimer noted three prominent neuropathologic features in his original analysis of t... Cholesteryl esters(CEs) have been increasingly implicated in neurodegenerative disorders such as Alzheimer's disease(AD).Alois Alzheimer noted three prominent neuropathologic features in his original analysis of the AD brain:senile plaques,neurofibrillary tangles,and lipid granule accumulation.Senile plaques,which are aggregates of amyloid-beta(Aβ),and neurofibrillary tangles,which are aggregates of phosphorylated tau,have been regarded as more consistent characteristics of the AD brain compared with lipid granule accumulation and thus have been studied more intensively(Foley,2010). 展开更多
关键词 esterS ester cholesteryl
下载PDF
Exploring Ester Prodrugs: A Comprehensive Review of Approaches, Applications, and Methods
3
作者 Guangyang Zhou 《Pharmacology & Pharmacy》 2024年第8期269-284,共16页
The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformat... The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformation within the body, which offers advantages concerning the solubility, stability, and targeted delivery of the active drug. Several approaches of ester prodrugs have been reviewed in this review, including simple ester prodrugs, amino acid ester prodrugs, sugar ester prodrugs, lipid ester prodrugs, and polymeric ester prodrugs. This review incorporates in vitro and in vivo methods as well as the characterization of physical and chemical properties for ester prodrugs, cell culture systems, enzymatic assays, and animal models—all of these having a very important bearing on the evaluation of stability, bioavailability, and efficacy for ester prodrugs. While the benefits of using ester prodrugs are significant, there are also disadvantages like instability, poor or variable enzymatic hydrolysis, and toxicity from released promoieties or by-products. This review discusses solutions to the various limitations that include enhancing stability with ionizable promoieties and using physiologically-based pharmacokinetic modeling. The review also highlights the application of ester prodrugs in neurological disorders, such as Parkinson’s disease, and the ongoing efforts to address the critical limitations in treatment efficacy. Future prodrug strategies are poised to advance significantly by harnessing diverse transport mechanisms across the blood-brain barrier and integrating nanotechnology. 展开更多
关键词 ester Prodrugs Solubility BIOAVAILABILITY Stability ester Prodrug Approaches Simple ester Prodrugs Amino Acid ester Prodrugs Sugar ester Prodrugs Lipid ester Prodrugs Polymeric ester Prodrugs esterase-Responsive Nanoparticles Hydrolysis Cancer Treatment Cardiovascular Diseases Neurological Disorders
下载PDF
Structural characteristics of phenylboronic acid-modified astaxanthin ester and its effect on DSS-induced ulcerative colitis by blocking reactive oxygen species and maintaining intestinal homeostasis
4
作者 Xing Qiao Hongyan Li +4 位作者 Qun Gao Zhigao Wang Jie Xu Lu Yang Changhu Xue 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2754-2764,共11页
A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical struc... A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical structure and physicochemical property were identified.AstaD-PBA could effectively improve the ROS quenching ability in the lipopolysaccharide(LPS)-induced RAW264.7 cell inflammation model.Then,the bioactivity of AstaD-PBA was studied by 4 zebrafish ROS-responsive infl ammatory models induced by LPS,copper(Cu^(2+)),high-fat diet,and dextran sodium sulfate(DSS).The results suggest that AstaD-PBA might have high biosafety and the best effect on ulcerative colitis(UC)induced by DSS.Furtherly,AstaDPBA significantly alleviated and treated weight loss and colonic shrinkage,inhibited infl ammatory cytokines,and maintained microbiota homeostasis to improve UC in C57BL/6J mice.Alistipes and Oscillibacter were expected to be considered UC marker fl ora according to the Metastats analysis and Pearson correlation Mantel test(P<0.01)of 16S rRNA gene sequencing data.In conclusion,AstaD-PBA has been promised to be a functional compound to improve UC and maintain intestinal microbiota homeostasis. 展开更多
关键词 Astaxanthin ester Reactive oxygen species-responsive Ulcerative colitis Intestinal microbiota Inflammatory cytokines
下载PDF
Carboxyl Ester Lipase Protects Against Metabolic Dysfunction-Associated Steatohepatitis by Binding to Fatty Acid Synthase
5
作者 Yang Song Wei Zhong +9 位作者 Harry Cheuk-Hay Lau Yating Zhang Huayu Guan Mingxu Xie Suki Ha Diwen Shou Yongjian Zhou Hongzhi Xu Jun Yu Xiang Zhang 《Engineering》 SCIE EI CAS CSCD 2024年第10期204-215,共12页
Carboxyl ester lipase(CEL),a pivotal enzyme involved in lipid metabolism,is recurrently mutated in obese mice.Here,we aimed to elucidate the functional significance,molecular mechanism,and therapeutic potential of CEL... Carboxyl ester lipase(CEL),a pivotal enzyme involved in lipid metabolism,is recurrently mutated in obese mice.Here,we aimed to elucidate the functional significance,molecular mechanism,and therapeutic potential of CEL in metabolic dysfunction-associated steatohepatitis(MASH).Hepatocyte-specific carboxyl ester lipase gene(Cel)knockout(Cel^(DHEP))and wildtype(WT)littermates were fed with cholinedeficient high-fat diet(CD-HFD)for 16 weeks,or methionine-and choline-deficient diet(MCD)for three weeks to induce MASH.Liquid chromatography–mass spectrometry and co-immunoprecipitation were employed to identify the downstream targets of CEL.CD-HFD/MCD-fed WT mice received intravenous injections of CEL-adeno-associated viral,serotype 8(AAV8)to induce specific overexpression of CEL in the liver.We observed a decrease in CEL protein levels in MASH induced by CD-HFD or MCD in mice.Cel^(DHEP) mice fed with CD-HFD or MCD exhibited pronounced hepatic steatosis,inflammation,lipid peroxidation,and liver injury compared to WT littermates,accompanied by increased hepatic nuclear factor kappa-light-chain-enhancer of activated B cell(NF-jB)activation.Consistently,Cel knockdown in mouse primary hepatocytes and AML12 cells aggravated lipid accumulation and inflammation,whereas CEL overexpression exerted the opposite effect.Mechanistically,CEL directly bound to fatty acid synthase(FASN),resulting in reduced FASN SUMOylation,which in turn promoted FASN degradation through the proteasome pathway.Furthermore,inhibition of FASN ameliorated hepatocyte lipid accumulation and inflammation induced by Cel knockdown in vivo and in vitro.Hepatocyte-specific CEL overexpression using AAV8-Cel significantly mitigated steatohepatitis in mice fed with CD-HFD or MCD.CEL protects against steatohepatitis development by directly interacting with FASN and suppressing its expression for de novo lipogenesis.CEL overexpression confers a therapeutic benefit in steatohepatitis. 展开更多
关键词 Metabolic dysfunction-associated steatohepatitis Carboxyl ester lipase Fatty acid synthase De novo lipogenesis Treatment
下载PDF
Research progress on classification,source,application of phytosterol esters,and their thermal oxidation stability
6
作者 Dami Li Shangde Sun Jingnan Chen 《Grain & Oil Science and Technology》 CAS 2024年第1期1-11,共11页
Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailab... Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailability than free phytosterols.In recent years,phytosterol esters have attracted increasing attention.However,during food processing,phytosterol esters are susceptible to degradation at high temperatures,resulting in certain losses and formation of potentially harmful substances for humans.This paper reviews the relevant literatures and updates on the thermal oxidation stability of phytosterol esters in recent years from the following aspects:(i)Sources,physiological activities,and applications of phytosterol esters;(ii)Oxidation mechanism of phytosterol esters;(iii)Effects of phytosterols species,the volume of addition,food matrix,heating temperature and time,and antioxidants on the thermal loss and oxidation stability of phytosterol esters.The research progress on the safety of phytosterol esters is also discussed in detail.Additionally,the prospects for future research are highlighted. 展开更多
关键词 Thermal stability Loss rate Oxidation mechanism Phytosterol esters
下载PDF
Non-flammable long chain phosphate ester based electrolyte via competitive solventized structures for high-performance lithium metal batteries
7
作者 Li Liao Zhiqiang Han +16 位作者 Xuanjie Feng Pan Luo Jialin Song Yin Shen Xiaoshuang Luo Xinpeng Li Xuanzhong Wen Bo Yu Junchen Chen Bingshu Guo Mingshan Wang Yun Huang Hongmei Zhang Mengmeng Yin Jiangtao Liu Yuanhua Lin Xing Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期156-165,I0004,共11页
Safety remains a persistent challenge for high-energy-density lithium metal batteries(LMBs).The development of safe and non-flammable electrolytes is especially important in harsh conditions such as high temperatures.... Safety remains a persistent challenge for high-energy-density lithium metal batteries(LMBs).The development of safe and non-flammable electrolytes is especially important in harsh conditions such as high temperatures.Herein,a flame-retardant,low-cost and thermally stable long chain phosphate ester based(tributyl phosphate,TBP)electrolyte is reported,which can effectively enhance the cycling stability of highly loaded high-nickel LMBs with high safety through co-solvation strategy.The interfacial compatibility between TBP and electrode is effectively improved using a short-chain ether(glycol dimethyl ether,DME),and a specially competitive solvation structure is further constructed using lithium borate difluorooxalate(LiDFOB)to form the stable and inorganic-rich electrode interphases.Benefiting from the presence of the cathode electrolyte interphase(CEI)and solid electrolyte interphase(SEI)enriched with LiF and Li_(x)PO_(y)F_(z),the electrolyte demonstrates excellent cycling stability assembled using a 50μm lithium foil anode in combination with a high loading NMC811(15.4 mg cm^(-2))cathode,with 88%capacity retention after 120 cycles.Furthermore,the electrolyte exhibits excellent high-temperature characteristics when used in a 1-Ah pouch cell(N/P=0.26),and higher thermal runaway temperature(238℃)in the ARC(accelerating rate calorimeter)demonstrating high safety.This novel electrolyte adopts long-chain phosphate as the main solvent for the first time,and would provide a new idea for the development of extremely high safety and high-temperature electrolytes. 展开更多
关键词 Non-flammable electrolyte Long chain phosphate ester Solvation structure Lithium metal batteries Battery safety
下载PDF
Study on the regulatory effect of liver X receptor in HEK293 cells by six main diterpene esters in Semen Euphorbiae
8
作者 Si-Yuan Ma Fan-Miao Kong +8 位作者 Xiao-Tong Wei Jun-Li Zhang Hai-Ting Zhu Xin-Ning Zhang Yu-Feng Hu Ming-Rui Jiang Hui-Nan Wang Yi-Cen Xu Ying-Zi Wang 《TMR Modern Herbal Medicine》 CAS 2024年第2期35-40,共6页
Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effe... Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effect of the main diterpene ester components in Semen Euphorbiae on the viability of HEK293 cells were studied by MTT assay.The LXR-Luc plasmid vector was transfected into HEK293 cells and treated with Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)for 24 h.The effect of the main diterpene ester components of Semen Euphorbiae on LXR-Luc luciferase activity was investigated by dual luciferase reporter gene system,and the expression of LXRαprotein was detected by Western Blot.Results:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)could significantly reduce the relative luciferase activity(RLU)of LXRα,and the expression level of LXRαprotein was significantly down-regulated.Conclusion:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)can inhibit the expression of LXR protein level,which may be achieved by inhibiting the transcriptional activity of LXR. 展开更多
关键词 Semen Euphorbiae diterpene esters HEK293 LXR dual luciferase reporter gene system
下载PDF
Recent Advances of Sensitive Electrochemical Sensing Platforms for Rapid Detection of Phthalate Acid Esters
9
作者 Xiuxiu Dong Lili Zhang +2 位作者 Meicai Ge Minfu Wu Qijian Niu 《Instrumentation》 2024年第2期9-23,共15页
As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migr... As a kind of plasticizer,phthalic acid esters(PAEs)are often added to plastics to enhance elasticity,transparency,durability and prolong service life.However,it does not chemically bind to plastics and is easy to migrate to the environment.It is difficult to degrade in the environment,and it is also enriched in the human body through the food chain and respiration,which will lead to obvious adverse reactions such as decreased learning and memory function and neurobehavioral disorders.Due to the toxicity,universality and low concentration limitations of PAEs in the environment and food,it is essential to achieve rapid and sensitive detection of PAEs in soil,atmosphere,water and food.Electrochemical(EC)sensors have the advantages of simplicity,fast,low cost,portability,easy operation,high specificity and high sensitivity,so they are applied for the detection of PAEs.Although there are a large number of studies on the detection of PAEs by EC sensors,there is no review on this aspect.In this review,we introduce the detection of PAEs from classical EC sensors,electrochemiluminescence(ECL)sensors and photo-electrochemical(PEC)sensors in the past five years.This review is beneficial to understanding the construction of EC sensors and the detection mechanism of PAEs.We also propose that the development of rapid,accurate and real-time detection methods of PAEs is key to assessing risk and preventing related diseases. 展开更多
关键词 phthalate acid esters electrochemical sensor DETERMINATION
下载PDF
2-Hydroxymalonitrile——A Useful Reagent for One-step Synthesis of α-Hydroxy Esters
10
作者 YANG Jianxin YIN Yunxing +5 位作者 HE Zhenmin MA Li LI Xin ZHANG Zhiliu LIN Xiaojuan MA Rujian 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2015年第3期321-324,共4页
α-Hydroxy carboxylic esters and their derivatives are key substructures in a variety of biologically active natural products and numerous pharmaceuticals[1-3].A variety of methods for the synthesis of α-hydroxyester... α-Hydroxy carboxylic esters and their derivatives are key substructures in a variety of biologically active natural products and numerous pharmaceuticals[1-3].A variety of methods for the synthesis of α-hydroxyesters via homologation of aldehydes or ketones have been developed and frequently used in organic synthesis[4-14].These approaches are generally based on the following routes(Scheme 1). 展开更多
关键词 α-hydroxy ester One-pot synthesis 2-hydroxymalononitrile
原文传递
Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline 被引量:1
11
作者 张倩 乌东北 包伯荣 《Journal of Shanghai University(English Edition)》 CAS 2009年第1期72-75,共4页
The synergistic extraction of Pr^3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect o... The synergistic extraction of Pr^3+ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester (P507, HL) and 8-Hydroxyquinoline (HQ) in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3+ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3+. 展开更多
关键词 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester 8-hydroxyquinoline (HQ) synergistic extraction praseodymium
下载PDF
Research on the Sizing Performance of Starch Grafted Poly-hydroxy Alkyl-acid Esters
12
作者 郭腊梅 郭良红 《Journal of Donghua University(English Edition)》 EI CAS 2010年第3期316-320,共5页
Starch grafted poly-hydroxy alkyl-acid esters were prepared via graft polymerization.Different characteristics of grafted starches were tested such as viscosity,viscosity stability,adhesion as well as properties of si... Starch grafted poly-hydroxy alkyl-acid esters were prepared via graft polymerization.Different characteristics of grafted starches were tested such as viscosity,viscosity stability,adhesion as well as properties of sized yarns.Sizing performance was analyzed from the aspect of physical and chemical reactions between polymer molecules.It shows that starch grafted poly-hydroxy alkyl-acid esters have excellent sizing performance and could absolutely be used as sizes for polyester-cotton yarns. 展开更多
关键词 grafted starch hydroxy alkly-acid esters sizing agent polylactide(PLA) PHB
下载PDF
Facile Resolution of Racemic 4-Phenyl-2-hydroxy Butyrate via Enzymatic Esterification and Transesterification
13
作者 Jin wang Xu Zu yi Li 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第12期927-928,共2页
The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.
关键词 Res Facile Resolution of Racemic 4-Phenyl-2-hydroxy Butyrate via Enzymatic esterification and Transesterification
下载PDF
Synthesis of Bis(4'-hydroxyphenyl)-toluene-2, 4-diurethane for Main Chain Liquid Crystalline Poly(urethane-ester)s
14
作者 Yan Qing LIAN Ming Qi LI +1 位作者 Qi Xiang ZHOU De Shan LIU(Institute of Polymer Science and Engineering, Department of Chemical Engineering,Tsinghua University, Beijing 100084) 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第5期439-442,共4页
A new methodology was advanced that mesogenic cores appeared after theformation of urethane groups and during the monomer-to-polymer transition. A newdiphenol monomer, bis(4'-hydroxy-phenyl)-toluene-2 (BHPTU), was... A new methodology was advanced that mesogenic cores appeared after theformation of urethane groups and during the monomer-to-polymer transition. A newdiphenol monomer, bis(4'-hydroxy-phenyl)-toluene-2 (BHPTU), was obtainedby the reaction of 2,4-tolulene diisocyanate with hydroquinone in dioxane or N,N-dimethyl-acetandde. The reaction process was monitored by FTIR, and the product was investigated bylH NMR and elemental analysis (EA). A liquid crystalline poly(urethane-ester) was obtainedusing the BHPTU monomer. 展开更多
关键词 liquid crystalline polymer poly(urethane-ester) synthesis
下载PDF
Pollution characteristics and risk assessment of organophosphate esters in aquaculture farms and natural water bodies adjacent to the Huanghe River delta
15
作者 Jinyu CHAO Song FENG +2 位作者 Yingdong HAO Jianing LIN Bin ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期251-266,共16页
To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture c... To date,little attention has been paid to the effects of organophosphate esters(OPEs)pollution on aquacultural environment and aquatic product safety.Huanghe(Yellow)River delta area is one of the largest aquaculture centers in China,where ecological security protection is crucial in the national strategy of China.To explore the pollution characteristics,bioaccumulation,and health risks of OPEs in aquaculture farms in the Huanghe River delta and natural water bodies in the adjacent seas,five species of organisms from different farm types nearby the Huanghe River delta,and the corresponding culture water and sediments were sampled in this study.The total concentrations of Σ_(13)OPEs in water,sediments,and organisms were 51.53-272.18 ng/L,52.63-63.17 ng/g dry weight(dw),and 46.82-108.90 ng/g dw,respectively.Among the five types of culture ponds,the water samples from the swimming crab and hairy crab culture ponds exhibited higher OPEs,the concentration of OPEs in the sediments from the few ponds was relatively balanced,and the OPEs in the organism from the holothurian ponds was higher.Tris(1,3-dichloro-2-isopropyl pho sphate)(TDCP)was the main contaminant in water samples and tripropyl phosphate(TPrP)in sediments and organisms.However,trisphenyl phosphate(TPhP)showed the strongest bioaccumulation ability,followed by 2-ethylhexyl diphenyl phosphate(EHDPP)and TPrP.The bioaccumulation capacities of the five species were as follows:prawn>holothurian>hairy crab>swimming crab>carp.These five types of organisms,as main seafood in human consumption,were at low risk of negative impacts of pollution.However,the risk from the mixture of organophosphate flame retardants(OPFRs)still requires more attention due to the increasing consumption and production in the world. 展开更多
关键词 organophosphate esters(OPEs) aquaculture farms BIOACCUMULATION health risk assessment
下载PDF
Adsorption of Phthalic Acid Esters by Humic Acid and Its Research Progress
16
作者 Ying LI Xiuqin KONG +6 位作者 Dongxia LUO Yinghai LUO Tong CHEN Fengyu WANG Huaxiu XING Fuqiang LI Miantao LEI 《Meteorological and Environmental Research》 CAS 2023年第4期63-66,共4页
Humic acid is rich in highly electronegative oxygen-containing organic functional groups,so it has high reactivity and can adsorb phthalic acid ester(PAEs)in the environment to reduce the risk of environmental polluti... Humic acid is rich in highly electronegative oxygen-containing organic functional groups,so it has high reactivity and can adsorb phthalic acid ester(PAEs)in the environment to reduce the risk of environmental pollution from PAEs.In this paper,the extraction,characterization and adsorption models of humic acid were reviewed,and the research status of adsorption of PAEs by humic acid was further summarized.Based on these,the feasibility and observable application prospect of humic acid as a cheap adsorbent were analyzed. 展开更多
关键词 Humic acid EXTRACTION CHARACTERIZATION Phthalic acid esters ADSORPTION
下载PDF
Breakdown Voltage Prediction by Utilizing the Behavior of Natural Ester for Transformer Applications
17
作者 P.Samuel Pakianathan R.V.Maheswari 《Intelligent Automation & Soft Computing》 SCIE 2023年第3期2717-2736,共20页
This research investigates the dielectric performance of Natural Ester(NE)using the Partial Differential Equation(PDE)tool and analyzes dielectric performance using fuzzy logic.NE nowadays is found to replace Mineral ... This research investigates the dielectric performance of Natural Ester(NE)using the Partial Differential Equation(PDE)tool and analyzes dielectric performance using fuzzy logic.NE nowadays is found to replace Mineral Oil(MO)due to its extensive dielectric properties.Here,the heat-tolerant Natural Esters Olive oil(NE1),Sunflower oil(NE2),and Ricebran oil(NE3)are subjected to High Voltage AC(HVAC)under different electrodes configurations.The break-down voltage and leakage current of NE1,NE2,and NE3 under Point-Point(P-P),Sphere-Sphere(S-S),Plane-Plane(PL-PL),and Rod-Rod(R-R)are measured,and survival probability is presented.The electricfield distribution is analyzed using the Partial Differential Equation(PDE)tool.NE shows better HVAC with stand capacity under all the electrodes configuration,especially in the S-S shape geometry.The exponential function is developed for the oils under different elec-trode geometry;NE shows a higher survival probability.Likewise,the most influ-ential dielectric properties such as breakdown voltage,kinematic viscosity,and water content are used to develop a Mamdani-based control system model that combines two variables to produce the surface model.The surface model indi-cates that the NE subjected for investigation is less susceptible to moisture effect and higher kinematic viscosity.Based on the surface models of PDE and fuzzy,it is concluded that NE possesses a high survival rate since its breakdown voltage does not react to changes in water content.Hence the application of NE in the transformer application is highly safe and possesses extended life. 展开更多
关键词 Power transformer fuzzy logic prediction partial differential equation natural ester exponential function
下载PDF
邻苯二甲酸酯降解功能内生菌群的筛选及定殖效能 被引量:1
18
作者 张帅 王建 +3 位作者 马俊超 高彦征 左翔之 凌婉婷 《中国环境科学》 EI CAS CSCD 北大核心 2024年第3期1554-1561,共8页
为降低邻苯二甲酸酯(PAEs)污染作物对人体健康的威胁,从PAEs污染蔬菜中富集驯化具有PAEs降解高效性和广谱性的功能内生菌群,解析菌群群落组成并优化其降解条件,借助水培体系研究了功能内生菌群在作物体内的定殖效能.高通量测序结果表明... 为降低邻苯二甲酸酯(PAEs)污染作物对人体健康的威胁,从PAEs污染蔬菜中富集驯化具有PAEs降解高效性和广谱性的功能内生菌群,解析菌群群落组成并优化其降解条件,借助水培体系研究了功能内生菌群在作物体内的定殖效能.高通量测序结果表明,从门的分类水平看,菌群主要由变形菌门(Proteobacteria,76.57%)、拟杆菌门(Bacteroidetes,21.04%)和放线菌门(Actinobacteria,2.37%)组成;从属的分类水平看,菌群主要由鞘氨醇杆菌属(Sphingobacterium,33.03%)、代尔夫特菌属(Delftia,40.61%)、假单胞菌属(Pseudomonas,11.70%)、无色杆菌属(Achromobacter,3.04%)和根瘤菌属(Rhizobium,6.90%)组成.在无机盐纯培养体系中,该菌群在7d内对5mg/L的邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸丁基苄基酯(BBP)降解率分别为97.08%、94.47%、98.02%和44.82%.单因素试验结果表明,菌群降解PAEs的最佳条件为:pH值7、25℃、盐度1%、底物浓度5mg/L.水稻水培试验表明,菌群可以定殖到水稻体内并有效促进PAEs的去除,与对照组相比,处理15d后水稻体内DMP、DEP、DBP和∑PAEs含量分别降低了41.09%、45.33%、63.06%和32.3%.菌群的定殖还能够提高水稻根长、株高和生物量,促进水稻的生长.该菌群在降低作物PAEs积累、保障PAEs污染地区农产品质量安全方面具有良好的应用前景,能有效降低作物PAEs污染对人体健康的威胁. 展开更多
关键词 功能内生菌群 邻苯二甲酸酯 降解特性 定殖
下载PDF
日粮添加三丁酸甘油酯对肉鸡生长性能、养分消化率和血清生化指标的影响 被引量:1
19
作者 卢炜 杨海峰 +4 位作者 陈则东 曹云 王明灿 殷韶杰 王永娟 《中国饲料》 北大核心 2024年第4期45-48,共4页
文章旨在研究日粮中添加不同水平三丁酸甘油酯对肉鸡综合性能的影响。本试验将160只体重相近、健康无病的1日龄肉鸡随机分为4组,每组4个重复。对照组肉鸡饲喂基础日粮。试验I、II和III组分别在基础日粮中添加1000、1500、2000mg/kg三丁... 文章旨在研究日粮中添加不同水平三丁酸甘油酯对肉鸡综合性能的影响。本试验将160只体重相近、健康无病的1日龄肉鸡随机分为4组,每组4个重复。对照组肉鸡饲喂基础日粮。试验I、II和III组分别在基础日粮中添加1000、1500、2000mg/kg三丁酸甘油酯。预饲期7d,正试期42d。结果表明,与对照组相比,试验组肉鸡的42日龄体重和平均日增重显著增加(P <0.05),试验II、III组肉鸡的料重比显著降低(P <0.05),但平均日采食量无显著差异(P> 0.05);试验组干物质、粗蛋白质、粗纤维及能量的表观消化率均显著增加(P <0.05);试验组肉鸡血清中总蛋白质含量和高密度脂蛋白含量显著增加(P <0.05),总胆固醇和甘油三酯含量显著降低(P <0.05),各试验组肉鸡血清中低密度脂蛋白含量较对照组无显著差异(P> 0.05)。总的来讲,日粮中添加三丁酸甘油酯能有效改善肉鸡生长性能,提升养分表观消化率,改善血清生化指标,综合考虑,肉鸡日粮中三丁酸甘油酯的最适添加量为1500mg/kg。 展开更多
关键词 三丁酸甘油酯 肉鸡 生长性能 养分消化率 血清生化指标
下载PDF
Synthesis and Polymerization of N,N'-[Bis(4,4'-Hydroxypropyl Methacrylate Phenylester) Pyromellitimide] Thermoset Polymer by Microwave Irradiation
20
作者 Habib Saedi 《Advances in Chemical Engineering and Science》 2016年第2期183-189,共7页
A new difunctional monomer N,N'-[bis(4,4'-hydroxypropyl methacrylate phenyl ester) pyromellitimide] (BHPMEPM), was synthesized by the reaction of the bis(4-carboxyphenyl)-N,N'-pyromelli- timide acid (diaci... A new difunctional monomer N,N'-[bis(4,4'-hydroxypropyl methacrylate phenyl ester) pyromellitimide] (BHPMEPM), was synthesized by the reaction of the bis(4-carboxyphenyl)-N,N'-pyromelli- timide acid (diacid-diimide), and two molar equivalents of glycidylmethacrylate (GMA). The reaction was carried out by microwave radiation. The presence of difunctional groups, double bond groups, makes the monomer a potential material for obtaining thermosetting product. The curing and thermal stability of the crosslinked products were studied by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) techniques. The difunctional monomer and its thermoset polymer were characterized by FT-IR, 1</sup>H-FT-NMR and CHN elemental analysis. 展开更多
关键词 Microwave Radiation Diacid-Diimide Glycidylmethacrylate Pyromellitimide Poly(ester-Imide) DSC TG
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部