Spectroscopy of a canonically quantized horizon

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(英文)合成,与DNA和两个新的铜(II)的抗增殖活性相互作用配合甲斑蝥素和苯并咪唑衍生物

Synthesis,interaction with DNA and antiproliferative activities of two novel Cu(II)complexes with norcantharidin and benzimidazolederivativesWen-Ji Song a ,b ,Qiu-Yue Lin a ,b ,⇑,Wen-Jiao Jiang b ,Fang-Yuan Du b ,Qing-Yuan Qi b ,⇑,Qiong Wei ba Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces,Zhejiang Normal University,321004,PR China bCollege of Chemical and Life Science,Zhejiang Normal University,321004,PR Chinah i g h l i g h t sTwo novel Cu(II)complexes withnorcantharidin derivatives have been synthesized.Complexes structure was determined by X-ray diffraction.The complexes and ligands bound DNA moderately via partial intercalation modes.Complexes could cleave plasmid DNA via hydroxyl radical mechanism. Complex(1)has strongest activity against human hepatoma cells.g r a p h i c a l a b s t r a c tTwo novel complexes [Cu(L)2(Ac)2]Á3H 2O(1)(L =N-2-methyl benzimidazole demethylcantharate imide,C 15H 13N 2O 3,Ac =acetate,C 2H 3O 2)and [Cu(bimz)2(DCA)](2)(bimz =benzimidazole,C 7H 6N 2;DCA =dem-ethylcantharate,C 8H 8O 5)were synthesized and characterized.The DNA-binding properties of complexes were investigated by electronic absorption spectra,ﬂuorescence spectra,viscosity measurements and agarose gel electrophoresis.The interaction between the complexes and bovine serum albumin (BSA)was investigated by ﬂuorescence spectra.The antiproliferative activities of the complexes against human hepatoma cells (SMMC7721)were tested in vitro .a r t i c l e i n f o Article history:Received 23June 2014Received in revised form 17August 2014Accepted 23August 2014Available online 1September 2014Keywords:NorcantharidinBenzimidazole derivatives Copper complex DNA bindingAntiproliferative activitya b s t r a c tTwo novel complexes [Cu(L)2(Ac)2]Á3H 2O (1)(L =N-2-methyl benzimidazole demethylcantharate imide,C 16H 15N 3O 3,Ac =acetate,C 2H 3O 2)and [Cu(bimz)2(DCA)](2)(bimz =benzimidazole,C 7H 6N 2;DCA =dem-ethylcantharate,C 8H 8O 5)were synthesized and characterized by elemental analysis,infrared spectra and X-ray diffraction techniques.Cu(II)ion was four-coordinated in complex 1,Cu(II)ion was ﬁve-coordi-nated in complex 2.A large amount of intermolecular hydrogen-bonding and p –p stacking interactions were observed in these complex structures.The DNA-binding properties ofthese complexes were inves-tigated using electronic absorption spectra,ﬂuorescence spectra,viscosity measurements and agarose gel electrophoresis.The interactions between the complexes and bovine serum albumin (BSA)were investi-gated by ﬂuorescence spectra.The antiproliferative activities of the complexes against human hepatoma cells (SMMC7721)were tested in vitro .And the results showed that these complexes could bind to DNA in moderate intensity via partial intercalation,and complexes 1and 2could cleave plasmid DNA through hydroxyl radical mechanism.Title complexes could effectively quench the ﬂuorescence of BSA through/10.1016/j.saa.2014.08.0691386-1425/Ó2014Elsevier B.V.All rights reserved.⇑Corresponding authors.Address:Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces,Zhejiang Normal University,321004,PR China (Q.Y.Lin).Tel.:+8657982283353;fax:+8657982282269.E-mail addresses:sky51@ (Q.-Y.Lin),Qingyuanqi@ (Q.-Y.Qi).static quenching.Meanwhile,title complexes had stronger antiproliferative effect compared to L and Na2(DCA)within the tested concentration range.And complex1possessed more antiproliferative active than complex2.Ó2014Elsevier B.V.All rights reserved.IntroductionIn recent years,the interactions of Cu(II)complexes with DNA and protein molecules drew more and more scholars’attention [1,2].Copper(II)complexes are well suited for DNA hydrolysis due to the strong Lewis acid properties of the cupric ion.Several copper(II)complexes have been developed as artiﬁcial nucleases, and showed versatile DNA cleavage properties in the absence or presence of a redox agent[3,4].Planar heterocyclic based complexes have received consider-able interest in nucleic-acid chemistry because of their diverse chemical reactivity,unusual electronic properties,and peculiar structure,which results in non-covalent interactions with DNA [5].Benzimidazole derivatives possess a variety of biological activ-ities and pharmacological effects.Several compounds containing benzimidazole group,have been reported to exhibit antimicrobial, anticancer,antifungal and anti-inﬂammatory activities[6]. Especially,the combinations of the pharmaceutical agents with some metal ions can further improve their biological activity.Demethylcantharidin(NCTD,7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylc acid anhydride)and disodium demethylcantharate (Na2(DCA)),as the derivatives of cantharidin,have been applied in clinical use[7].Meanwhile,demethylcantharate(DCA)could inhibit the activities of protein phosphatases1(PP1)and2A(PP2A)effec-tively[8,9].A range of amines were applied to react with norcantha-ridin,and results showed high level of cytotoxicity[10,11].Based on our previous investigations and as a continuation of our research program on complexes containing demethylcanthari-din[12,13],we synthesized two novel Cu(II)complexes containing demethylcantharidin.The interactions of these complexes with DNA and bovine serum albumin(BSA)were investigated.In addi-tion,antiproliferative activities against human hepatoma cells (SMMC-7721)were tested in vitro.Experimental sectionsMaterials and instrumentsAll reagents and chemicals were obtained from commercial sources.Demethylcantharidin(NCTD,C8H8O4)was obtained from Nanjing Zelang Medical Technology Co.Ltd.;Na2(DCA)was prepared in accordance with the literature described technique[14];2-ami-nomethylbenzimidazole dihydrochloride(ambiÁ2HCl)was pre-pared using the literature technique[15];benzimidazole(bimz, C7H6N2)and ct-DNA were obtained from Sinopharm Chemical Reagent Co.Ltd.;ct-DNA(q=200l g mLÀ1,c=3.72Â10À4mol LÀ1), with A260/A280=1.8–2.0,was prepared using50mmol LÀ1NaCl; Plasmid DNA(pDsRed2-C1)was purchased from Clontech Co.Ltd. America;Bovine Serum Albumin(BSA)was purchased from Beijing BioDee BioTech Co.Ltd.and was stored at4°C;BSA(q= 500l g mLÀ1,c=7.47Â10À6mol LÀ1)was prepared using 5mmol LÀ1NaCl solution;MTT(methyl thiazolyl tetrazolium)was purchased from the Sigma Company;Human hepatoma cells (SMMC-7721)was purchased from Shanghai Institute of Cell Bank. Other chemical reagents in analytical reagent grade were used with-out further puriﬁcation.Elemental analyses of C,H and N were carried out in Vario EL III elemental analyzer.Infrared spectra were obtained using the KBr disc method by NEXUS-670FT-IR spectrometer in the spectral range of4000–400cmÀ1.Diffraction intensities of the complexes were collected at293K on Bruker SMART APEX II CCD diffractom-eter.Electronic absorption spectra were obtained using UV-2501 PC spectrophotometer.Viscosity experiments were carried on Ubbelodhe viscometer.Fluorescence emission spectra were obtained by Perkin–Elmer LS-55spectroﬂuorometer.Agarose gel electrophoresis was performed on PowerPac Basic electrophoresis apparatus(BIO-RAD).Gel image formation were obtained on UNI-VERSAL HOOD11-S.N.(BIO-RAD Laboratories).Synthesis of LN-2-methyl benzimidazole demethylcantharate imide (L=C16H15N3O3)was prepared in accordance to the literature tech-niques[16].Mixture of1mmol norcantharidin(NCTD),1mmol2-aminomethylbenzimidazole dihydrochloride,1mmol cadmium acetate,and10mL distilled water was sealed in a25mL Teﬂon-lined stainless vessel and heated at433K for3d,then cooled slowly to room temperature.The solution was thenﬁltered and was allowed to stand still for3weeks until forming colorless crystals.Anal.Calcd. (%)for C16H15N3O3:C,64.65;H,5.05;N,14.14.Found(%):C,64.62;H, 5.03;N,14.16.IR(KBr pellet,cmÀ1):1617,1392(t(C@O));1446 (t(C@N));1258,1033,1001(t(C A O A C)).Synthesis of the complexesSynthesis of the complex1In a20mL weighing bottle,Cu(Ac)2ÁH2O(0.06g,0.3mmol)was dissolved in water(2mL).The L(0.089g,0.3mmol)solution in mixed solvents of water and ethanol(2:1,v/v)(10mL)was then added dropwisely with stirring under room temperature.The mix-ture solution wasﬁltered after two hours.One week after,blue crystals with suitable size for single-crystal X-ray diffraction were obtained.Anal.Calcd.(%)for C36H42N6O13Cu(1):C,52.05;H,5.06; N,10.12.Found(%):C,52.01;H,5.03;N,10.29.IR(KBr pellet, cmÀ1):3445(t(OH));1572,1395(t(C@O));1464(t(C@N));1254, 1057,984(t(C A O A C)).Synthesis of the complex2A mixture of Cu(Ac)2ÁH2O(0.5mmol)and Na2DCA(0.5mmol) was dissolved in water.And1.0mmol benzimidazole(bimz)in ethanol was added dropwisely into the mixed solution and stirring at room temperature.The solution wasﬁltered after two hours. One week later,blue crystals with suitable size for single-crystal X-ray diffraction were obtained.Anal.Calcd.(%)for Cu(C22H20 N4O5)(2):C,54.55;H,4.13;N,11.57.Found(%):C,54.25;H, 4.01;N,11.78.IR(KBr pellet,cmÀ1):3432(t(OH));1635,1396 (t(C@O));1432(t(C@N));1251,1032,981(t(C A O A C)).DNA bindingElectronic absorption spectraElectronic absorption spectra were collected at25°C byﬁxing the concentrations of the complexes,with DNA concentration ranging from0to7.44Â10À5mol LÀ1.Absorption spectra mea-surements were carried out at200–400nm,and DNA in Tris–HCl buffer solution(pH=7.4)was used as reference.W.-J.Song et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy137(2015)122–128123Fluorescence spectraFluorescence quenching experiments were carried out by add-ing DNA solutions(0–7.44Â10À4mol LÀ1)to the samples contain-ing2.00Â10À5mol LÀ1complexes.The mixture were diluted by Tris–HCl buffer solution(pH=7.4).Fluorescence for1was recorded at excitation wavelength(k ex)of248nm and emission wavelength(k em)between250nm and500nm.Fluorescence for 2was recorded at244nm excitation wavelength(k ex)and emis-sion wavelength(k em)between255nm and450nm(k em).Viscosity measurementViscosity measurements were pounds were added to DNA solution(3.72Â10À4mol LÀ1)with microsyringes. The concentration of the compounds were controlled within the range of0–3.33Â10À6mol LÀ1.The relative viscosities g were cal-culated using equation[17]:g=(t–t0)/t0,where t0and t represent theﬂow time of DNA solution through the capillary in the absence and presence of complex.The average values of three replicated measurements were used to evaluate the viscosity of the samples. Data were presented as(g/g0)1/3versus the ratio of the concentra-tion of compounds to DNA,where g was the viscosity of DNA in the presence of compound and g0was the viscosity of DNA. Interaction with pDsRed2-C1plasmid DNAInteractions between the complexes and pDsRed2-C1plasmid DNA were studied using agarose gel electrophoresis.The samples were incubated at37°C for3h,followed by addition of0.25% bromo-phenol blue and1mmol LÀ1EDTA.The DNA cleavage prod-ucts were submitted to electrophoresis in1.0%agarose gel contain-ing0.5l g mLÀ1ethidium bromides.The bands were photographed.Interaction with BSAFluorescence spectraThe complexes(0–26.7Â10À9mol LÀ1)were added to solution containing4.98Â10À7mol LÀ1BSA and Tris–HCl buffer(pH=7.4). Fluorescence spectra were obtained by recording the emission spectra(285–480nm)at excitation wavelength of280nm.Antiproliferative activity evaluationThe antiproliferative activities of the compounds(1,2,L and Na2(DCA))were evaluated by human hepatoma cells(SMMC-7721).The MTT assay was applied to measure the antiproliferative activities[18].The compounds were dissolved in DMSO as 100mmol LÀ1stock solutions,and diluted in culture medium before using.The target concentration of DMSO in the medium was less than0.1%,and it did not interfere with the tested bioactiv-ity results[19].Cells were seeded for24h before adding com-pounds,and incubated for72h.Then100l L MTT(1mg mLÀ1, dissolved in DMEM nutrient solution)was added into each well and incubated for4h(37°C).The absorbance was measured by microplate reader at570nm.The inhibition rate was calculated accordingly.The errors quoted were standard deviations,which three replicates were involved in the calculation[20].Crystal structure determinationSingle crystals,sized0.345mmÂ0.279mmÂ0.214mm(1) and0.345mmÂ0.287mmÂ0.156mm(2),were used for X-ray diffraction analysis.The structures were solved by direct methods and reﬁned by full-matrix least-squares techniques using the SHEL-XTL-97program package[21,22].All non-hydrogen atoms were reﬁned anisotropically.Besides the hydrogen atoms on oxygen atoms,which were located from the difference Fourier maps,other hydrogen atoms were generated geometrically.Crystal data and experimental details for structural analyses are listed in Table1. Results and discussionStructural description of complexesTwo novel complexes have been characterized by X-ray single crystal diffraction.The spectral results indicated that the space groups of the complexes were C2/C(1)and Pna21(2).Selected bond lengths and angles of complexes1,2were listed in Tables2and3. Hydrogen bond lengths and angles of complex1,2were listed in Tables S1and S2.Molecular structures of the title complexes were shown in Fig.1.The packing diagram was shown in Fig.S1.In complex1,the Cu(II)ion was four-coordinated.Each Cu(II) coordinated with two imine nitrogen N(2)(or N(2A))from ligand (L),and two oxygen atoms of different carboxyl groups from acetate ions,forming electrically neutral complex.This molecule was cen-trally symmetric,with the symcenter at the centre of CuN2O2.The bond angles of O(1)A Cu(1)A O(1)#1,O(1)A Cu(1)A N(2),O(1)#1A Cu(1)A N(2)#1and N(2)A Cu(1)A N(2)#1are88.38(14)°,90.23 (10)°,90.23(10)°and97.25(14)°,respectively,all of which are close 90°.Thus,a slightly distorted quadrangle was formed around Cu(1) by N(1),N(2),O(1),and O(3).The composition of the complex was [Cu(L)2(Ac)2]Á3H2O(1).Fig.S1showed that the hydrogen-bonding formed due to the presence of the nitrogen atoms and the oxygen atoms from the imide(L)and acetate ligands,and crystallization water molecules.The complex is rich in intramolecular and intermo-lecular hydrogen bonds,such as N(1)A H(1A)...O(1W);O(3W)A H(3WA)...O(4);O(2W)A H(2WA)...O(2).These hydrogen-bonding stabilized this crystal structure.In complex2,Cu(II)ion wasﬁve-coordinated.Each Cu(II)coor-dinated with two azomethine nitrogen N(1)(or N(3))from two bimz,two carboxylate oxygen atoms O2and O3in two different carboxylate groups,and one bridge oxygen atoms O1from dem-ethylcantharate,forming a distorted tetragonal pyramid structure. The composition of the complex was[Cu(bimz)2(DCA)](2).Fig.S1 showed that the hydrogen-bonding formed due to the presence of the nitrogen atom from the bimz and the oxygen atoms from demethylcantharate,such as N(2)A H(2A)...O(5)#1,N(4)A H(4A)... O(3)#2.Meanwhile,complexes1and2contain the benzimidazole group,resulting k–k stacking effects among the complexes.There-fore,we concluded that the synergistic effect,including p–p stack-ing and hydrogen-bonding interactions,existed between the complexes and biomacromolecule,which could be the fundamen-tal cause of the biological activity change found in macromolecules [23].DNA binding studiesElectronic absorption spectraThe application of electronic absorption spectroscopy is one of the most useful techniques in DNA-binding studies[24].Changes observed in the UV spectra upon titration can provide evidence for the intercalative interaction mode pattern,since hypochro-mism would occur from p–p stacking interactions[25].To further investigate the possible binding modes and to obtain the binding constants(K b)of complex to DNA,we also studied the effect of DNA titration to the title complexes by electronic absorption spec-tra at298K.Results are shown in Fig.2((a):1;(b):2).The intrinsic binding constant(K b)was determined by the equa-tion:[DNA]/(e A–e F)=[DNA]/(e B–e F)+1/[K b(e B–e F)],where[DNA] was the concentration of DNA,e A,e F and e B corresponded to the apparent extinction coefﬁcient,the extinction coefﬁcient for the124W.-J.Song et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy137(2015)122–128W.-J.Song et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy137(2015)122–128125Table1Crystal data of complex1and2.Complex12Chemical formula CuC36H42N6O13CuC22H20N4O5 Formula weight794.28483.97Crystal system Monoclinic Orthorhombic Space group C2/C Pna21a(Å)21.572(4)15.8667(3) b(Å)11.3687(19)9.9975(2)c(Å)17.371(4)12.5228(2) a(°)90.0090.00b(°)111.528(18)90.00c(°)90.0090.00Volume(Å3)3963.0(13)1986.46(6) Z44Crystal size(mm)0.345Â0.279Â0.2140.345Â0.287Â0.156 Shape Block BlockFig. beled ORTEP diagrams of complex1(a)and2(b)with30%thermalprobability ellipsoids shown.complexes1and2are quenched in presence of DNA.The plexes showed strong emission bands at around297nm(1 nm(2),as shown in Fig.3.According to the Stern–Volmer equation:F0/F=1+K sv[Q],F0and F represent theﬂuorescence intensities in the absence and presence of quencher,respectively [Q]is the quencher concentration and K sv is the Stern–Volmer constant,K sv were calculated as 4.26Â103mol LÀ1(1)Â103mol LÀ1(2).The binding intensity of complex1 stronger than complex2,this is consistent to the results found electronic absorption spectra.Viscosity measurementsfurther study the binding mode of the compounds interact-with DNA,DNA viscosity at25°C was investigated(Fig.experimental data showed that the relative viscosity of steadily decreased after adding complexes and L,and it increase after adding benzimidazole.But there was no signiﬁcant viscosity change occurred after adding Na2DCA.The possible expla-nation is that the complexes and L were partially inserted to DNA base pairs and resulting in a kink in the DNA helix,therefore decreased the DNA effective length[29].Because of the planar benzimidazole ring could also insert to the DNA base pair,and the steric hindrances of complexes were enhanced due to the non-planar structure of demethylcantharate(DCA).From Fig.4, the interactions of complex(1)with DNA is signiﬁcantly stronger than complex(2).The result agrees with the electronic absorption spectra andﬂuorescence spectra conclusion.Interaction with pDsRed2-C1plasmid DNAThe cleavage reaction on pDsRed2-C1plasmid DNA can be mon-itored by agarose gel electrophoresis.When pDsRed2-C1plasmid DNA is subjected to electrophoresis,different migration speeds were observed[30].Relatively fast migrations were observed at the intact supercoil form(Form I).If scission occurs on one strand (nicking),the supercoil will partially relax to generate a slow moving open-circular form(Form II)[31].Absorption spectra of the complex1(a)and2(b)in the presence of increasing amount of DNA.[complex]=3.00Â10À6mol LÀ1,from(1)to(5):Â105=0,0.74,1.48,2.24and2.98mol LÀ1,respectively.(b).[DNA]Â103.72,5.58and7.44mol LÀ1,respectively.3.Fluorescence spectra of the complex1(a)and2(b)in the absence presence of increasing the amount of DNA;insert in Figs.3–5:ﬂuorescence quenching curve of the complex by DNA.k ex=248nm(1),k ex=244nm [complex]=2Â10À5mol LÀ1;[DNA]/(10À4mol LÀ1),from1to5:0,1.86,3.72,7.44,respectively.4.Effect of increasing amounts of the compounds on the relative viscosity[DNA]=3.72Â10À4mol LÀ1;[complex]/10À6=0,0.67,1.33,2.00,2.67mol LÀ1,respectively.5gave the electrophoretograms of the interactionRed2-C1plasmid DNA with increasing concentrations of complexes. Complexes are capable of cleaving plasmid DNA when the concen-of complexes was greater than500l M.When the concentra-complexes increased,the amount of Form I diminished gradually,and Form II paring channel4–6, cleavage ability of complexes was enhanced by adding ascorbic order to investigate the reaction mechanism,dimethylsulfox-(DMSO)was introduced to the experimental design.DMSO scavenger could inhibit the cleavage ability of complexes signiﬁcantly in channel5and7.With increasing amount of acid(V c),Cu(II)complex was reduced to Cu(I)complex.complex then reacts with dissolved oxygen generating superoxide anion(O2À),hydrogen peroxide(H2O2)and hydroxyl (ÅOH).Finally,the ROS attacks the plasmid DNA leading single and double DNA strand breaks.So the cleavage hydroxyl radical mechanism[32].Interaction with BSAFluorescence spectra and quenching mechanismresults of title complexes quenching the BSAﬂuorescence ing,which generated via intense interaction[36].Binding constants and binding sitesAssuming there were n identical and independent binding sites in protein,the binding constant K A can be calculated using equation[37]:lg(F0–F)/F=lg K A+n lg[Q].The values of K A were 1.59Â106L molÀ1(1), 5.4Â104L molÀ1(2),and 2.78Â104L molÀ1(Na2DCA).The values of n were0.88(1),0.68(2)and 0.66(Na2DCA).The results indicated that strong bindingElectrophoretic separation of pDsRed2-C1DNA induced by complexesLane1:DNA alone;lane2:DNA+complex(250l M);lane3:DNA(500l M);lane4:DNA+complex(750l M);lane5:DNA++DMSO(750l M);lane6:DNA+complex(750l M)+V c(750complex(750l M)+V c(750l M)+DMSO(750l M).[DNA]=3.06.Fluorescence spectra of BSA in the absence and the presence of complex2(b)Inset:Stern–Volmer plots of theﬂuorescence titration data ofcomplexes.[BSA]=4.98Â10À7mol LÀ1;[complex]Â109=0,6.67,13.3,20.0,mol LÀ1,from(1)to(5),respectively(a):complex1,(b):complex2.7.Inhibition effects of compounds on SMMC-7721cell growth.Data representmean+S.D.and all assays were performed in triplicate for three independentexperiments.interaction existed between the complexes and BSA.The binding intensity of complexes was stronger than Na2DCA,and the binding site of complexes was one.Antiproliferative activity evaluationAs shown in Fig.7,the antiproliferative activity of complex1, complex2,L and Na2DCA at the given concentration showed a dose-dependent manner against human hepatoma cells(SMMC-7721)in vitro.The inhibition ratios tested revealed that complex1and2had strong antiproliferative activities against human hepatoma cells (SMMC-7721)lines in vitro compare to L and Na2DCA.The inhibi-tion rates of complex(1)against SMMC-7721lines(IC50=24.55±0.48l mol LÀ1)is much higher than that of L(IC50=116.63±2.66 l mol LÀ1)[38].The inhibition rates of complex(1)against SMMC-7721lines is much higher than complex(2)(IC50=41.82±3.90 l mol LÀ1).The inhibition rates of two novel complexes were higher than that of the transition metal complexes of demethyl-cantharate and thiazole derivatives[12,13]against SMMC-7721 cells.which suggests that various compositions and structures of complexes would lead to different antiproliferative activities,and this can be important in designing and synthesizing novel anti-cancer drugs[39].It is clear that the strong interaction found between complexes and biomacromolecules(DNA or BSA)is directly correlated to the antiproliﬁferative activity of complexes.ConclusionsTwo novel Cu(II)complexes[Cu(L)2(Ac)2]Á3H2O(1)(L=N-2-methyl benzimidazole demethylcantharate imide,C16H15N3O3, Ac=acetate,C2H3O2)and[Cu(bimz)2(DCA)](2)(bimz=benzimid-azole,C7H6N2;DCA=demethylcantharate,C8H8O5)were synthe-sized and characterized.The crystal structure of complex1and2 were determined by X-ray diffraction.These complexes had strong DNA and BSA binding intensity and high inhibition rates against human hepatoma cells(SMMC-7721)in plex(1)had intense antiproliferative activities against the human hepatoma cells(SMMC-7721)in vitro,which had the potential to develop as an anti-cancer drug in the future.AcknowledgmentWe thank Institute of Zhejiang Academy of Medical Science for helping with antiproliferative activity test.Appendix A.Supplementary materialCrystallographic data for the structure reported in this article has been deposited with the Cambridge Crystallographic Data Center CCDC909444(1),918105(2).Copies of the data can be obtained free of charge on application to the CCDC,12Union Road,Cambridge CB21EZ,UK(deposit@).The packing diagrams of complexes were shown in Fig.S1.Hydrogen bond lengths and angles of complex1,2were listed in Tables S1and S2.Supplementary data associated with this article can be found,in the online version,at 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Spectroscopy and Spectral Analysis

Spectroscopy and Spectral AnalysisSpectroscopy is a branch of science that deals with the study of the interaction between matter and electromagnetic radiation. Spectral analysis is a technique that is used to identify and measure the properties of substances based on the electromagnetic radiation that they emit, absorb, or scatter. The study of spectroscopy and spectral analysis is essential to many fields, including chemistry, physics, environmental science, and biomedical research.Types of SpectroscopyThere are several types of spectroscopy, each based on the type of electromagnetic radiation used. The most common types of spectroscopy include:1. Absorption SpectroscopyAbsorption spectroscopy is a technique that measures the amount of radiation absorbed by a sample. This type of spectroscopy is used to identify the chemical composition and concentration of a substance. Absorption spectroscopy can be used in the ultraviolet, visible, and infrared regions of the electromagnetic spectrum.2. Emission SpectroscopyEmission spectroscopy measures the amount of radiation emitted by a substance. This type of spectroscopy is used to identify the chemical composition of a substance and the temperature and pressure of the environment. Emission spectroscopy can be used in the ultraviolet, visible, and infrared regions of the electromagnetic spectrum.3. Fluorescence SpectroscopyFluorescence spectroscopy is a technique that measures the amount of radiation emitted by a substance when it is excited by light of a particular wavelength. This type of spectroscopy is used to identify the presence of certain substances in a sample, such as proteins and DNA molecules. Fluorescence spectroscopy can be used in the ultraviolet and visible regions of the electromagnetic spectrum.4. Raman SpectroscopyRaman spectroscopy is a technique that measures the scattered radiation produced when a sample is irradiated with a laser beam. This type of spectroscopy is used to identify the chemical composition and structure of a substance. Raman spectroscopy can be used in the visible and near-infrared regions of the electromagnetic spectrum.Applications of Spectroscopy and spectral analysis have a wide range of applications in various fields, including:1. ChemistrySpectroscopy is used extensively in chemistry to identify the chemical composition and properties of substances. Spectroscopy is used to determine the purity of a substance, study chemical reactions, and analyze the structure of molecules.2. PhysicsIn physics, spectroscopy is used to study the properties of materials, such as their electronic and magnetic properties. Spectroscopy is used to study the interactions between atoms and molecules and to investigate the behavior of quantum systems.3. Environmental ScienceSpectroscopy is used in environmental science to study the properties of soil, water, and air. Spectroscopy can be used to identify pollutants in the environment and to monitor the quality of drinking water and industrial wastewater.4. Biomedical ResearchIn biomedical research, spectroscopy is used to study the properties of biological molecules, such as proteins and DNA. Spectroscopy is used to image and diagnose diseases, such as cancer, and to monitor the effectiveness of treatments.ConclusionSpectroscopy and spectral analysis are powerful tools for studying the properties of matter and electromagnetic radiation. There are several types of spectroscopy, each with its own strengths and applications. Spectroscopy and spectral analysis are used in many fields, including chemistry, physics, environmental science, and biomedical research, and have a wide range of applications.。

原子吸收光谱法的英文

原子吸收光谱法的英文Title: Atomic Absorption Spectroscopy: Principles and ApplicationsAtomic absorption spectroscopy (AAS) is a powerful analytical technique used to determine the concentration of specific elements in various samples, including metals in environmental, biological, and industrial contexts. This method is widely valued for its sensitivity, precision, and ability to analyze complex mixtures.The principle of atomic absorption spectroscopy is based on the absorption of light by free atoms in the gaseous state. The process begins with the atomization of the sample, which can be achieved through techniques such as flame atomization or graphite furnace atomization. In flame atomization, the sample is introduced into a flame, where it is vaporized and atomized. In graphite furnace atomization, a small amount of the sample is placed in a graphite tube, where it is heated to high temperatures to produce atoms.Once the sample is atomized, a light source, typically a hollow cathode lamp, emits light at a specific wavelength corresponding to the element being analyzed. As the light passes through the vaporized sample, some of it is absorbed by the atoms, leading to a decrease in the intensity of the transmitted light. This decrease is measured using a spectrometer, and the absorbance is directly related to the concentration of the element in the sample.AAS has numerous applications across various fields. In environmental analysis, it is used to detect heavy metals in water and soil, ensuring compliance with safety regulations. In clinical laboratories, AAS helps in determining trace elements in biological fluids, which is crucial for diagnosing health conditions. Additionally, it is widely used in metallurgy and food safety to analyze the composition of alloys and food products.Despite its advantages, AAS also has some limitations.It can only analyze one element at a time, which can be time-consuming when multiple elements need to be measured. Additionally, the presence of interfering substances can affect the accuracy of the results.In conclusion, atomic absorption spectroscopy is an invaluable tool in analytical chemistry, providing accurate and reliable data for various applications. Its ability to detect trace elements with high sensitivity makes it essential in fields ranging from environmental science to healthcare. As technology advances, AAS continues to evolve, promising even more efficient and comprehensive analysis in the future.。

spectroscopy 光谱技术介绍

IAP 5.301波谱------------------------------------------------------------------------------------------------------- 化学工作者用波谱（IR，UV-Vis，NMR）来测定分子结构。

波谱：是测定物质在不同波长下吸收辐射量的技术（基于分子能级的量子化）●分子处于量子化的能级上（转动、振动以及电子的量子态）。

●分子吸收不连续分布的能量（ΔE）而被激发到更高能级。

●我们可以通过电磁辐射来激发分子。

●分子具有取决于其结构的特定吸收光谱。

●特征吸收可以提供有用的结构信息。

----------------------------------------------------------------------------------------------------------------------怎么知道什么类型电磁辐射可用呢？* 无线电频率的电磁辐射用于NMR波谱中。

红外光谱（振动能级）●化学键不是刚性的，他们在不停地振动。

●不同振动模式比其它运动形式具有更高的能量，复杂有机分子具有很多种振动模式（复杂！）。

●一个含有n个原子的非线性分子具有3n-6种可能的基本振动模式！●所幸的是，不同的官能团（分子的一部分）具有特定的特征吸收。

●通过观察红外光谱（透过率vs波数），根据吸收带可以确定哪些官能团存在。

●波数等于每厘米所含波的数目（波数，1/λ)。

-------------------------------------------------------------------------------------------------------紫外-可见(UV-Vis)光谱（电子能级）●简单地看，原子就像一个极小的太阳系，电子绕原子核转动就像行星围绕太阳旋转一样。

这个简单的比喻使我们的认识更加直观，但这并不对应于我们所认识到的原子的实际情况。

紫外荧光光谱法英语

紫外荧光光谱法英语Ultraviolet Fluorescence Spectroscopy.Ultraviolet fluorescence spectroscopy is an analytical technique that employs the fluorescence emitted by molecules excited by ultraviolet (UV) light to characterize chemical species. This method has found widespread applications in various fields, including chemistry, biochemistry, pharmacology, and environmental science.Principles of UV Fluorescence Spectroscopy.The principle of UV fluorescence spectroscopy lies in the absorption of UV light by molecules, which then emit light at longer wavelengths, known as fluorescence. This emission occurs when the absorbed energy causes electronsin the molecules to transition from a lower energy state to an excited state. As the electrons relax back to the lower energy state, they emit radiation in the form of light. The wavelength and intensity of this emitted light arecharacteristic of the specific molecular structure and can be used for identification and quantification.Instrumentation.UV fluorescence spectroscopy requires specialized instrumentation, primarily a UV-Vis spectrophotometer with a fluorescence detector. These instruments typically consist of a light source, a monochromator to select a specific wavelength of UV light, a sample compartment, and a detector to measure the emitted fluorescence. Modern spectrophotometers often incorporate advanced features such as multi-wavelength excitation and emission scanning, which provide richer spectral information.Applications of UV Fluorescence Spectroscopy.1. Biochemical Analysis: UV fluorescence spectroscopyis widely used in biochemistry to study protein-ligand interactions, protein conformational changes, and nucleic acid structure. Fluorescent probes can be attached to specific sites on proteins or nucleic acids, allowing theirbehavior to be monitored under different conditions.2. Drug Discovery and Pharmacology: This technique is employed in drug discovery to screen potential drugs for their binding affinity to biological targets. By monitoring the changes in fluorescence upon drug binding, researchers can assess the affinity and selectivity of drugs.3. Environmental Science: UV fluorescence spectroscopy has been used to monitor pollutants in water and air. Fluorescent tracers can be used to trace the fate and transport of pollutants, providing insights into environmental contamination and remediation.4. Materials Science: In materials science, UV fluorescence spectroscopy is used to study the optical properties of materials, such as quantum dots and fluorescent dyes. This technique can provide information about the energy levels and electronic states of these materials, which is crucial for their applications in optoelectronic devices.Advantages and Limitations.Advantages:High Sensitivity: UV fluorescence spectroscopy can detect very low concentrations of fluorescent species, making it suitable for trace analysis.Selectivity: By choosing specific excitation and emission wavelengths, UV fluorescence spectroscopy can provide information about specific components in complex mixtures.Non-Destructive: This technique does not require the destruction of samples, allowing multiple measurements to be performed on the same sample.Limitations:Fluorescent Probe Dependence: The application of UV fluorescence spectroscopy often relies on the availability of suitable fluorescent probes or dyes. Not all moleculesexhibit strong fluorescence, limiting the scope of this technique.Interference from Background Fluorescence: The presence of background fluorescence from the sample matrixor solvents can interfere with the measurement, affecting the accuracy and reliability of results.Instrument Cost and Maintenance: Specialized UV-Vis spectrophotometers with fluorescence detection capabilities can be costly, and regular maintenance is required toensure accurate measurements.Conclusion.UV fluorescence spectroscopy is a powerful analytical tool that has found widespread applications in various fields. Its ability to provide sensitive and selective information about molecular structure and interactions has made it a valuable resource for researchers in biochemistry, pharmacology, environmental science, and materials science. Despite its limitations, UV fluorescence spectroscopycontinues to evolve and improve, providing new insights into the behavior and properties of chemical species.。

近红外光谱法英文

近红外光谱法英文Near-Infrared SpectroscopyNear-infrared spectroscopy (NIRS) is a powerful analytical technique that has gained widespread recognition in various scientific and industrial fields. This non-invasive method utilizes the near-infrared region of the electromagnetic spectrum, typically ranging from 700 to 2500 nanometers (nm), to obtain valuable information about the chemical and physical properties of materials. The versatility of NIRS has led to its application in a diverse array of industries, including agriculture, pharmaceuticals, food processing, and environmental monitoring.One of the primary advantages of NIRS is its ability to provide rapid and accurate analysis without the need for extensive sample preparation. Unlike traditional analytical methods, which often require complex sample extraction and processing, NIRS can analyze samples in their natural state, allowing for real-time monitoring and decision-making. This efficiency and non-destructive nature make NIRS an attractive choice for applications where speed and preservation of sample integrity are crucial.In the field of agriculture, NIRS has become an invaluable tool for the assessment of crop quality and the optimization of farming practices. By analyzing the near-infrared spectra of plant materials, researchers can determine the content of various nutrients, such as protein, carbohydrates, and moisture, as well as the presence of contaminants or adulterants. This information can be used to guide precision farming techniques, optimize fertilizer application, and ensure the quality and safety of agricultural products.The pharmaceutical industry has also embraced the use of NIRS for a wide range of applications. In drug development, NIRS can be used to monitor the manufacturing process, ensuring the consistent quality and purity of active pharmaceutical ingredients (APIs) and finished products. Additionally, NIRS can be employed in the analysis of tablet coatings, the detection of counterfeit drugs, and the evaluation of drug stability during storage.The food processing industry has been another significant beneficiary of NIRS technology. By analyzing the near-infrared spectra of food samples, manufacturers can assess parameters such as fat, protein, and moisture content, as well as the presence of adulterants or contaminants. This information is crucial for ensuring product quality, optimizing production processes, and meeting regulatory standards. NIRS has been particularly useful in the analysis of dairy products, grains, and meat, where rapid and non-destructive testing is highly desirable.In the field of environmental monitoring, NIRS has found applications in the analysis of soil and water samples. By examining the near-infrared spectra of these materials, researchers can obtain information about the presence and concentration of various organic and inorganic compounds, including pollutants, nutrients, and heavy metals. This knowledge can be used to inform decision-making in areas such as soil management, water treatment, and environmental remediation.The success of NIRS in these diverse applications can be attributed to several key factors. Firstly, the near-infrared region of the electromagnetic spectrum is sensitive to a wide range of molecular vibrations, allowing for the detection and quantification of a variety of chemical compounds. Additionally, the ability of NIRS to analyze samples non-destructively and with minimal sample preparation has made it an attractive choice for in-situ and real-time monitoring applications.Furthermore, the development of advanced data analysis techniques, such as multivariate analysis and chemometrics, has significantly enhanced the capabilities of NIRS. These methods enable the extraction of meaningful information from the complex near-infrared spectra, allowing for the accurate prediction of sample propertiesand the identification of subtle chemical and physical changes.As technology continues to evolve, the future of NIRS looks increasingly promising. Advancements in sensor design, data processing algorithms, and portable instrumentation are expected to expand the reach of this analytical technique, making it more accessible and applicable across a wider range of industries and research fields.In conclusion, near-infrared spectroscopy is a versatile and powerful analytical tool that has transformed the way we approach various scientific and industrial challenges. Its ability to provide rapid, non-invasive, and accurate analysis has made it an indispensable technology in fields ranging from agriculture and pharmaceuticals to food processing and environmental monitoring. As the field of NIRS continues to evolve, it is poised to play an increasingly crucial role in driving innovation and advancing our understanding of the world around us.。

原子吸收光谱的英文

原子吸收光谱的英文原子吸收光谱的英文是"atomic absorption spectroscopy"。

这是一种分析技术，用于测量和确定样品中各种金属元素的浓度。

这种技术基于原子的能级跃迁，当样品中的金属离子吸收特定波长的光时，其能级会从低能级跃迁至高能级，从而生成吸收光谱。

以下是23句中英双语例句：1. Atomic absorption spectroscopy is commonly used in analytical chemistry to determine the concentration of metal ions in samples.原子吸收光谱常用于分析化学中，用于测定样品中金属离子的浓度。

2. The atomic absorption spectrum of each metal elementis unique and can be used for identification purposes.每种金属元素的原子吸收光谱是独特的，可用于鉴定目的。

3. Atomic absorption spectroscopy is a sensitive method for detecting trace amounts of metals in environmental samples.原子吸收光谱是一种敏感的方法，可用于检测环境样品中微量金属。

4. The technique of atomic absorption spectroscopy involves the use of a specific light source, such as ahollow-cathode lamp.原子吸收光谱技术涉及使用特定的光源，例如中空阴极灯。

5. Atomic absorption spectroscopy can be used in various industries, including pharmaceutical, environmental, and food industries.原子吸收光谱可应用于各个行业，包括制药、环境和食品行业。

吸收光谱简介 Absorption Spectrum An Introduction 英语作文论文

吸收光谱简介Absorption Spectrum AnIntroductionWhat is Absorption Spectrum?The absorption spectrum of a material can be defined as the fraction of the incident radiation which is absorbed by that material over a wide range of frequencies. The molecular and atomic composition of a material is used to determine the absorption spectrum. Fundamental radiation is generally observed at those frequencies which get mixed with the energy difference that takes place between two mechanical states of the molecules.The absorption takes place because of the transition between these two states and it is known as the absorption line. The spectrum is composed of several absorption lines. The frequencies where such absorption lines develop along with their relative intensities generally depend on the molecular structure and electronic structure of the sample. The frequencies also depend on molecular interactions. In the sample, the crystal structure is found in solids and on different environmental factors like pressure, temperature, electromagnetic fields, etc.What is Absorption Spectrum?Assingment Experts will explain Absorption Sepctrum in deatils. The absorption spectrum of a material can be defined as the fraction of theincident radiation which is absorbed by that material over a wide range of frequencies. The molecular and atomic composition of a material is used to determine the absorption spectrum. Fundamental radiation is generally observed at those frequencies which get mixed with the energy difference that takes place between two mechanical states of the molecules.The absorption takes place because of the transition between these two states and it is known as the absorption line. The spectrum is composed of several absorption lines. The frequencies where such absorption lines develop along with their relative intensities generally depend on the molecular structure and electronic structure of the sample. The frequencies also depend on molecular interactions. In the sample, the crystal structureis found in solids and on different environmental factors like pressure, temperature, electromagnetic fields, etc.The absorption lines also possess a definite shape and width which are fundamentally determined by the density of states for spectral density of the system. Absorption lines are generally classified by the feature of quantum mechanical change taking place in an atom or molecule. Rotational states sometimes get changed and give result in the development of rotational lines which are found in the region of the microwave spectrum. On the other hand, vibrational lines in correspondence to vibrational state changes in the molecule are found in the area of infrared region. The electronic lines are composed of several changes taking place in the electronic state of a molecule or atom whichare found in the ultraviolet and visible region.It can be noticed that there are various dark lines in the sun’s spectrum. These lines are developed by the atmosphere of the Sun which absorbs light at different wavelengths resulting in different light intensity at the wavelength to appear dark. The molecules and atoms present in a gas absorb certain light wavelengths. The pattern of the lines is very unique with respect to each element which provides us information about the elements which help in making the sun’s atmosphere. The absorption spectra can be observed from spatial regions in the presence of a cooler gas line between in a hotter source and the earth.The absorption spectra can also be observed from the planets with atmospheres, stars, and galaxies. In analyzing the light of the Sun, aspectrometer is used. The spectrometer is a device which separates light by colour and energy. In separating light by colour and energy, the image of the spectrum of the sun gets created. This is quite similar to the absorption spectrum. The dark lines are the areas where the light gets absorbed by different elements present in the Sun’s outer layers. The lowest energy is represented by red light and the highest energy is represented by blue light.The black gaps or lines in the spectrum of the sun are termed as absorption lines. The gas present in the sun’s outer layers develops the absorption lines by absorbing the light. There are different elements such as Helium, hydrogen, carbon, and other smaller quantities of heavy elements in the sun. When the sunlight shines, the elements the energy gets absorbed by the atoms. The atoms can only absorb the lightrelevant to the energy the atoms need. The gaps in the spectrum of the Sun get developed and help in informing the formation of the sun. The emission spectrum is quite different from the absorption spectrum.In developing an absorption spectrum, the light needs to shine through a gas but in creating and emission spectrum a gas needs to be heated up. The atoms present in the gas get absorbed the energy only for a short tenure. The atoms get energetic and jiggled up by heating the gas because of the concentration of a high level of energy. The energy is emitted or re-released as light eventually. Absorption spectrum takes place when the light passes through a dilute and cold gas and characteristic frequencies get absorbed by the atoms present in the gas. The re-emitted light cannot be emitted in a similardirection which is followed by absorbed Photon because of which dark lines in the spectrum are created in the absence of light. The absorption spectrum is the dark lines. The absorption spectrum is defined as an Electromagnetic Spectrum in which the radiation intensity at some specific wavelengths gets decreased. An absorbing substance gets manifested as bands or dark lines. Medically, the absorption spectrum is also defined as an Electromagnetic Spectrum in which radiation intensity at specific ranges of wavelength is manifested as dark lines.X-ray absorptions are highly associated with the excitation taking place in the inner shell electrons in an atom. These changes generally get combined to develop a new absorption line which is typically found in the combined energy develop mainly during the changes. The changes are mainly radiation-vibrationstransitions. The energy which is typically found in the quantum mechanical change fundamentally determines the absorption line frequency. The frequency can get shifted because of several interactions. The magnetic and electric fields can give result in a shift.The interactions with some of the neighbouring molecules can also cause shifts. Absorption lines of any gas-phase molecule can get shifted typically when the molecule is present in either solid or liquid phase and involves in interacting with neighbouring molecules strongly. The shape and width of the absorption lines are generally determined by the observation instrument. The physical environment radiation and material absorbing of that material also determine the shape and width of absorption lines. Now our experts from Instant AssingnmentHelp will tell you about the relationship between Absorption Spectrum andThe relation between Transmission and absorption spectraTransmission and absorption spectra are interconnected. Transmission and absorption spectra are found to represent similar information. Transmission spectrum can be calculated from the absorption spectrum only. Absorption spectrum can also be calculated from transmission spectra. Mathematical transformation is used in calculating either the absorption spectrum or transmission spectrum. It has been observed that a transmission spectrum has maximum intensities where thewavelengths of the absorption spectrum are quite weak because of the transmission of more light through the sample takes place. Similarly, an absorption spectrum is found to have maximum intensities at its wavelengths where the absorption rate is quite stronger.The absorption spectrum is also related to any emission spectrum. Now, it is important to understand the concept of the emission spectrum. The process by which a substance can release energy is known as emission process. The energy which is released from a substance through any emission process can be found in electromagnetic radiation from. Emission can take at any frequency of absorption which makes the absorption lines to gets determined from the emission spectrum. But it is to be remembered that the emissionspectrum will always have different intensity pattern where it becomes distinguished from that of the absorption spectrum. Hence, it can be said that the absorption spectrum and emission spectrum can never be equivalent. The emission spectrum can be used to calculate the absorption spectrum with the application of effective theoretical models and other relevant information from where quantum mechanical states of a substance can be understood.Relationship between Absorption spectrum and reflection and scattering spectraThe absorption spectrum is also related to reflection and scattering spectra. The scattering and reflection spectra of any material getinfluenced by the absorption spectrum and index of refraction of that material. Extinction coefficient quantifies the absorption spectrum and index coefficients along with extinction coefficients which are related through Kramers-Kroening relation quantitatively. Therefore, it can be said that reflection or scattering spectrum standardize absorption spectrum can give rise to absorption spectrum.Reflection or scattering spectrum assumptions or models need to be simplified so that it can lead to effect an approximation of the derivation of absorption spectra. In the domain of chemical analysis, we can find the use of absorption spectroscopy because of the quantitative nature and specificity of the absorption spectrum. The specificity enables the compounds to get distinguished from each other in a mixture whichmakes absorption spectroscopy to be highly useful in different applications. For example, the presence of any pollutant in the air can be identified by the use of infrared gas analyzers.These analyses are also used to distinguish the air pollutant from oxygen, water, nitrogen, and other constituents. The specificity is also helpful in allowing several unknown samples to get rightly identified. It can be done by comparing the measured spectrum with the findings of reference spectra. It has been found that qualitative information of any sample can also be determined even if the information is not present in a library. For example, infrared spectra have several characteristics absorption bands which help in indicating the presence of carbon-oxygen bond or Carbon hydrogen bonds.Absorption spectrum can also be related to the quantity of material present with the use of Beer-Lambert law. This relationship is established quantitatively. In determining the typical compound concentration, it needs knowledge of the absorption coefficient of the compound. The absorption coefficient can be known from several reference sources and can be measured by accessing calibre standard spectrum with an available target concentrationabsorption spectrumAbsorption spectroscopy and its applicationAbsorption spectroscopy is one of the methods with the help of which a substance can get characterized by the support of wavelengths at which the spectrum of colour gets absorbedduring the passage of light through a substance solution. It is one of the fundamentally used methods used in assessing the chromospheres concentrations in the solutions. Absorption spectroscopy can also be explained as a non-destructive technique which is widely used by biochemists and biologists to assess the characteristic parameters and cellular components of functional molecules.This quantification is highly important in the domain of systems biology. In developing metabolic pathway quantitative depiction, various variables and parameters are needed which are to be assessed experimentally. Ultraviolet-visible absorption spectroscopy is used in producing experimental data which help in modelling techniques of system biology. These techniques use kinetic parameters andconcentrations of enzymes of signalling on metabolic pathways, fluxes, and intercellular metabolic concentrations. Absorption spectroscopy also describes the usage of the technique in quantifying bio-molecules and investigating bio-molecular interactions.Absorption spectroscopy is a significant technique which is used in chemistry to study simple inorganic species. It refers to spectroscopic techniques which are used in measuring radiation absorption as a function of wavelength or frequency when the interaction between absorption radiation and sample takes place. Photons are absorbed by the samples from the field of radiation. The absorption intensity varies as a frequency function and this absorption intensity is the absorption spectrum. Absorption spectroscopy is fundamentallyperformed across an absorption spectrum or electromagnetic spectrum.In the domain of analytical chemistry, absorption spectroscopy is used to assess the presence of any specific substance in a sample. In several cases, absorption spectroscopy is also used to quantify the quantity of a substance. In the domain of analytical applications, ultraviolet-visible and infrared spectroscopy is commonly observed. In the study of atomic physics, remote sensing, molecular physics, and astronomical spectroscopy, the use of absorption spectroscopy are widely observed.There are various experimental approaches which are used to measure the absorption spectrum. The most commonly used arrangement is to guide the regeneratedradiation beam at the sample in detecting the radiation intensity passing through it. The transmitted energy can be applied in calculating the absorption. The sample arrangement source and detection technique are also very used quite significantly depending on the objective of the experiment and that of the frequency range.Advantages of absorption spectroscopyThere can be several advantages of absorption spectroscopy because it can be used as an analytical method where measurements can be accomplished without any contact between the sample and the instrument. Radiation which travels between an instrument and a sample contains some important spectral information and measurement which is done remotely. Remote spectral sensing is quite significant indifferent situations. For example, hazardous and toxic environments can be measured without risking any instrument or operator.The material of the sample needs not to be brought into direct contact with any instrument which can prevent cross-contamination at a possible rate. Remote spectral measurements have certain challenges as compared to that of the laboratory measurements. To reduce such challenges, differential optical absorption spectroscopy has become quite popular because it mainly emphasizes on the features of differential absorption and erasers broadband absorption like the extinction of aerosol extinction because of Rayleigh scattering. This technique is used in airborne, ground-based, and satellite-based measuring actions. There are certain ground-based techniques whichprofile the possibilities of retrieving stratospheric and tropospheric trace gas profiles.The absorption lines also possess a definite shape and width which are fundamentally determined by the density of states for spectral density of the system. Absorption lines are generally classified by the feature of quantum mechanical change taking place in an atom or molecule. Rotational states sometimes get changed and give result in the development of rotational lines which are found in the region of the microwave spectrum. On the other hand, vibrational lines in correspondence to vibrational state changes in the molecule are found in the area of infrared region. The electronic lines are composed of several changes taking place in the electronic state of a molecule or atom which are found in the ultraviolet and visible region.Itcan be noticed that there are various dark lines in the sun’s spectrum. These lines are developed by the atmosphere of the Sun which absorbs light at different wavelengths resulting in different light intensity at the wavelength to appear dark. The molecules and atoms present in a gas absorb certain light wavelengths. The pattern of the lines is very unique with respect to each element which provides us information about the elements which help in making the sun’s atmosphere. The absorption spectra can be observed from spatial regions in the presence of a cooler gas line between in a hotter source and the earth.The absorption spectra can also be observed from the planets with atmospheres, stars, and galaxies. In analyzing the light of the Sun, a spectrometer is used. The spectrometer is adevice which separates light by colour and energy. In separating light by colour and energy, the image of the spectrum of the sun gets created. This is quite similar to the absorption spectrum. The dark lines are the areas where the light gets absorbed by different elements present in the Sun’s outer layers. The lowest energy is represented by red light and the highest energy is represented by blue light.The black gaps or lines in the spectrum of the sun are termed as absorption lines. The gas present in the sun’s outer layers develops the absorption lines by absorbing the light. There are different elements such as Helium, hydrogen, carbon, and other smaller quantities of heavy elements in the sun. When the sunlight shines, the elements the energy gets absorbed by the atoms. The atoms can only absorb the light relevant to the energy the atoms need. The gapsin the spectrum of the Sun get developed and help in informing the formation of the sun. The emission spectrum is quite different from the absorption spectrum.In developing an absorption spectrum, the light needs to shine through a gas but in creating and emission spectrum a gas needs to be heated up. The atoms present in the gas get absorbed the energy only for a short tenure. The atoms get energetic and jiggled up by heating the gas because of the concentration of a high level of energy. The energy is emitted or re-released as light eventually. Absorption spectrum takes place when the light passes through a dilute and cold gas and characteristic frequencies get absorbed by the atoms present in the gas. The re-emitted light cannot be emitted in a similar direction which is followed by absorbed Photonbecause of which dark lines in the spectrum are created in the absence of light. The absorption spectrum is the dark lines. The absorption spectrum is defined as an Electromagnetic Spectrum in which the radiation intensity at some specific wavelengths gets decreased. An absorbing substance gets manifested as bands or dark lines. Medically, the absorption spectrum is also defined as an Electromagnetic Spectrum in which radiation intensity at specific ranges of wavelength is manifested as dark lines.X-ray absorptions are highly associated with the excitation taking place in the inner shell electrons in an atom. These changes generally get combined to develop a new absorption line which is typically found in the combined energy develop mainly during the changes. The changes are mainly radiation-vibrations transitions. The energy which is typically foundin the quantum mechanical change fundamentally determines the absorption line frequency. The frequency can get shifted because of several interactions. The magnetic and electric fields can give result in a shift.The interactions with some of the neighbouring molecules can also cause shifts. Absorption lines of any gas-phase molecule can get shifted typically when the molecule is present in either solid or liquid phase and involves in interacting with neighbouring molecules strongly. The shape and width of the absorption lines are generally determined by the observation instrument. The physical environment radiation and material absorbing of that material also determine the shape and width of absorption lines. Now our experts from Instant AssingnmentHelp will tell you about the relationship between Absorption Spectrum andThe relation between Transmission and absorption spectraTransmission and absorption spectra are interconnected. Transmission and absorption spectra are found to represent similar information. Transmission spectrum can be calculated from the absorption spectrum only. Absorption spectrum can also be calculated from transmission spectra. Mathematical transformation is used in calculating either the absorption spectrum or transmission spectrum. It has been observed that a transmission spectrum has maximum intensities where thewavelengths of the absorption spectrum are quite weak because of the transmission of more light through the sample takes place. Similarly, an absorption spectrum is found to have maximum intensities at its wavelengths where the absorption rate is quite stronger.The absorption spectrum is also related to any emission spectrum. Now, it is important to understand the concept of the emission spectrum. The process by which a substance can release energy is known as emission process. The energy which is released from a substance through any emission process can be found in electromagnetic radiation from. Emission can take at any frequency of absorption which makes the absorption lines to gets determined from the emission spectrum. But it is to be remembered that the emissionspectrum will always have different intensity pattern where it becomes distinguished from that of the absorption spectrum. Hence, it can be said that the absorption spectrum and emission spectrum can never be equivalent. The emission spectrum can be used to calculate the absorption spectrum with the application of effective theoretical models and other relevant information from where quantum mechanical states of a substance can be understood.Relationship between Absorption spectrum and reflection and scattering spectraThe absorption spectrum is also related to reflection and scattering spectra. The scattering and reflection spectra of any material getinfluenced by the absorption spectrum and index of refraction of that material. Extinction coefficient quantifies the absorption spectrum and index coefficients along with extinction coefficients which are related through Kramers-Kroening relation quantitatively. Therefore, it can be said that reflection or scattering spectrum standardize absorption spectrum can give rise to absorption spectrum.Reflection or scattering spectrum assumptions or models need to be simplified so that it can lead to effect an approximation of the derivation of absorption spectra. In the domain of chemical analysis, we can find the use of absorption spectroscopy because of the quantitative nature and specificity of the absorption spectrum. The specificity enables the compounds to get distinguished from each other in a mixture whichmakes absorption spectroscopy to be highly useful in different applications. For example, the presence of any pollutant in the air can be identified by the use of infrared gas analyzers.These analyses are also used to distinguish the air pollutant from oxygen, water, nitrogen, and other constituents. The specificity is also helpful in allowing several unknown samples to get rightly identified. It can be done by comparing the measured spectrum with the findings of reference spectra. It has been found that qualitative information of any sample can also be determined even if the information is not present in a library. For example, infrared spectra have several characteristics absorption bands which help in indicating the presence of carbon-oxygen bond or Carbon hydrogen bonds.Absorption spectrum can also be related to the quantity of material present with the use of Beer-Lambert law. This relationship is established quantitatively. In determining the typical compound concentration, it needs knowledge of the absorption coefficient of the compound. The absorption coefficient can be known from several reference sources and can be measured by accessing calibre standard spectrum with an available target concentrationabsorption spectrumAbsorption spectroscopy and its applicationAbsorption spectroscopy is one of the methods with the help of which a substance can get characterized by the support of wavelengths at which the spectrum of colour gets absorbed during the passage of light through a substancesolution. It is one of the fundamentally used methods used in assessing the chromospheres concentrations in the solutions. Absorption spectroscopy can also be explained as a non-destructive technique which is widely used by biochemists and biologists to assess the characteristic parameters and cellular components of functional molecules.This quantification is highly important in the domain of systems biology. In developing metabolic pathway quantitative depiction, various variables and parameters are needed which are to be assessed experimentally. Ultraviolet-visible absorption spectroscopy is used in producing experimental data which help in modelling techniques of system biology. These techniques use kinetic parameters and concentrations of enzymes of signalling onmetabolic pathways, fluxes, and intercellular metabolic concentrations. Absorption spectroscopy also describes the usage of the technique in quantifying bio-molecules and investigating bio-molecular interactions.Absorption spectroscopy is a significant technique which is used in chemistry to study simple inorganic species. It refers to spectroscopic techniques which are used in measuring radiation absorption as a function of wavelength or frequency when the interaction between absorption radiation and sample takes place. Photons are absorbed by the samples from the field of radiation. The absorption intensity varies as a frequency function and this absorption intensity is the absorption spectrum. Absorption spectroscopy is fundamentallyperformed across an absorption spectrum or electromagnetic spectrum.In the domain of analytical chemistry, absorption spectroscopy is used to assess the presence of any specific substance in a sample. In several cases, absorption spectroscopy is also used to quantify the quantity of a substance. In the domain of analytical applications, ultraviolet-visible and infrared spectroscopy is commonly observed. In the study of atomic physics, remote sensing, molecular physics, and astronomical spectroscopy, the use of absorption spectroscopy are widely observed.There are various experimental approaches which are used to measure the absorption spectrum. The most commonly used arrangement is to guide the regeneratedradiation beam at the sample in detecting the radiation intensity passing through it. The transmitted energy can be applied in calculating the absorption. The sample arrangement source and detection technique are also very used quite significantly depending on the objective of the experiment and that of the frequency range.Advantages of absorption spectroscopyThere can be several advantages of absorption spectroscopy because it can be used as an analytical method where measurements can be accomplished without any contact between the sample and the instrument. Radiation which travels between an instrument and a sample contains some important spectral information and measurement which is done remotely. Remote spectral sensing is quite significant indifferent situations. For example, hazardous and toxic environments can be measured without risking any instrument or operator.The material of the sample needs not to be brought into direct contact with any instrument which can prevent cross-contamination at a possible rate. Remote spectral measurements have certain challenges as compared to that of the laboratory measurements. To reduce such challenges, differential optical absorption spectroscopy has become quite popular because it mainly emphasizes on the features of differential absorption and erasers broadband absorption like the extinction of aerosol extinction because of Rayleigh scattering. This technique is used in airborne, ground-based, and satellite-based measuring actions. There are certain ground-based techniques which。

荧光光谱法英文

荧光光谱法英文Fluorescence SpectroscopyFluorescence spectroscopy is a powerful analytical technique that has found widespread applications in various fields, including chemistry, biology, materials science, and environmental studies. This analytical method is based on the measurement of the emission of light by a substance that has been excited by the absorption of light or other forms of energy. The process of fluorescence involves the absorption of energy by molecules or atoms, followed by the subsequent emission of light at a longer wavelength than the absorbed light.The fundamental principle of fluorescence spectroscopy is that when a molecule or atom is exposed to light, it can absorb the energy of the incoming photons, causing electrons within the molecule or atom to be excited to higher energy levels. This excitation is a temporary state, and the electrons will eventually return to their ground state, releasing the excess energy in the form of a photon. The energy of the emitted photon is typically lower than the energy of the absorbed photon, resulting in a shift in the wavelength of the emitted light compared to the absorbed light. This wavelength shift is known as the Stokes shift, and it is a key characteristic offluorescence.The intensity and wavelength of the emitted light are influenced by various factors, such as the chemical structure of the fluorescent molecule, the solvent environment, temperature, and the presence of other compounds that can interact with the excited molecules. By analyzing the characteristics of the emitted light, researchers can gain valuable insights into the properties and behavior of the sample under investigation.Fluorescence spectroscopy has a wide range of applications in various fields. In chemistry, it is used for the identification and quantification of organic and inorganic compounds, as well as the study of reaction kinetics and molecular interactions. In biology, fluorescence spectroscopy is employed for the investigation of protein structure and dynamics, the detection and quantification of biomolecules, and the study of cellular processes. In materials science, this technique is used to characterize the properties of polymers, semiconductors, and nanomaterials, among others.One of the key advantages of fluorescence spectroscopy is its high sensitivity, which allows for the detection and quantification of analytes at very low concentrations. Additionally, the technique is non-invasive and can be performed in real-time, making it a valuable tool for in-situ and online monitoring applications. Furthermore, thedevelopment of advanced fluorescent probes and labeling techniques has expanded the versatility of fluorescence spectroscopy, enabling the visualization and tracking of specific molecules or cellular components in complex biological systems.Despite its many benefits, fluorescence spectroscopy also faces some limitations. The presence of interfering compounds, quenching effects, and the potential for photobleaching of the fluorescent molecules can challenge the reliability and accuracy of the measurements. Researchers are constantly working to address these challenges through the development of new instrumentation, data analysis methods, and sample preparation techniques.In conclusion, fluorescence spectroscopy is a powerful and versatile analytical tool that has made significant contributions to various scientific disciplines. As technology continues to advance, the applications of this technique are expected to expand further, providing researchers with new opportunities to gain a deeper understanding of the world around us.。

冷原子光谱法英语

冷原子光谱法英语Okay, here's a piece of writing on cold atom spectroscopy in an informal, conversational, and varied English style:Hey, you know what's fascinating? Cold atom spectroscopy! It's this crazy technique where you chill atoms down to near absolute zero and study their light emissions. It's like you're looking at the universe in a whole new way.Just imagine, you've got these tiny particles, frozen in place almost, and they're still putting out this beautiful light. It's kind of like looking at a fireworks display in a snow globe. The colors and patterns are incredible.The thing about cold atoms is that they're so slow-moving, it's easier to measure their properties. You can get really precise data on things like energy levels andtransitions. It's like having a super-high-resolution microscope for the quantum world.So, why do we bother with all this? Well, it turns out that cold atom spectroscopy has tons of applications. From building better sensors to understanding the fundamental laws of nature, it's a powerful tool. It's like having a key that unlocks secrets of the universe.And the coolest part? It's just so darn cool! I mean, chilling atoms to near absolute zero? That's crazy science fiction stuff, right?。

分子光谱学研究英语

分子光谱学研究英语Molecular spectroscopy is a branch of spectroscopy that deals with the interaction of matter and electromagnetic radiation in the molecular level. It involves the study of the absorption, emission, and transmission of light by molecules, and the information obtained from these interactions can be used to determine the structure, energy states, and dynamics of molecules. Molecular spectroscopy plays a crucial role in various fields such as chemistry, physics, biology, and materials science.The fundamental principle of molecular spectroscopy is the interaction between electromagnetic radiation and matter, which leads to transitions between different energy states of the molecules. These transitions can be electronic, vibrational, or rotational, depending on the type of radiation involved and the nature of the molecular system.Electronic spectroscopy involves transitions betweendifferent electronic states of a molecule, which are typically separated by large energy gaps. This type of spectroscopy is commonly used to study the electronic structure of molecules, including their bonding, electronic configuration, and excited states. UV-visible spectroscopy and infrared spectroscopy are examples of electronic spectroscopy techniques.Vibrational spectroscopy involves transitions between different vibrational states of a molecule, which are typically separated by smaller energy gaps. This type of spectroscopy is useful for studying the vibrational modes of molecules and their interactions with other molecules or their environment. Techniques such as infrared spectroscopy and Raman spectroscopy are commonly used for vibrational spectroscopy.Rotational spectroscopy involves transitions between different rotational states of a molecule, which are separated by even smaller energy gaps. This type of spectroscopy is useful for studying the rotational motion of molecules and their interactions with other molecules ortheir environment. Microwave spectroscopy is a common technique used for rotational spectroscopy.Molecular spectroscopy has a wide range of applications in various fields. In chemistry, it is used to determine the structure and composition of molecules, to identify unknown compounds, and to study the mechanisms of chemical reactions. In physics, molecular spectroscopy is used to understand the quantum mechanical properties of molecules and their interactions with electromagnetic radiation. In biology, it is used to study the structure and function of biological molecules such as proteins and nucleic acids. In materials science, molecular spectroscopy can be used to characterize the properties of materials and to understand their interactions with light.In addition to its fundamental importance in understanding the interaction of matter and electromagnetic radiation, molecular spectroscopy has numerous practical applications. For example, it is used in the development of new materials and technologies, such as solar cells, LEDs, and lasers. It is also used in environmental science tomonitor pollution and to detect harmful chemicals. In medicine, molecular spectroscopy is used in diagnostictests and in the development of new drugs and treatments.In conclusion, molecular spectroscopy is a crucialfield of study that has applications in various disciplines. It provides insights into the structure, dynamics, and interactions of molecules, and has the potential to lead to new discoveries and technological advancements in many fields.。

紫外-可见-近红外吸收光谱英文

紫外-可见-近红外吸收光谱英文UV-Visible-NIR Absorption Spectroscopy.UV-Visible-NIR absorption spectroscopy, is a type of electromagnetic spectroscopy that measures the absorption of light by a sample as a function of wavelength. The wavelength range of UV-Visible-NIR absorption spectroscopy spans from ultraviolet (UV) to near-infrared (NIR) regions of the electromagnetic spectrum, covering wavelengths from approximately 200 nm to 2500 nm. This technique is widely used in various fields, including chemistry, physics, materials science, and biology, for qualitative and quantitative analysis of substances.Principles of UV-Visible-NIR Absorption Spectroscopy:The fundamental principle of UV-Visible-NIR absorption spectroscopy is the interaction of light with molecules or atoms in a sample. When light passes through a sample, some of the light energy may be absorbed by the sample'smolecules, causing electrons within the molecules to transition from a lower energy level to a higher energy level. The energy difference between these levels corresponds to the frequency or wavelength of the absorbed light.The absorption of light by a sample is governed by the Beer-Lambert law, which states that the absorbance of a sample is directly proportional to the concentration of the absorbing species and the path length of the light beam through the sample. The absorbance is defined as the logarithm of the ratio of the incident light intensity to the transmitted light intensity.Instrumentation:A UV-Visible-NIR absorption spectrometer consists of several key components:1. Light source: Typically a deuterium or xenon lamp that emits a continuous spectrum of light covering the UV-Visible-NIR range.2. Monochromator: A device that separates the light from the source into individual wavelengths using a prism or grating.3. Sample holder: A cell or cuvette that holds the sample in the path of the light beam.4. Detector: A photodetector, such as a photomultiplier tube or a charge-coupled device (CCD), that measures the intensity of the transmitted light.Applications:UV-Visible-NIR absorption spectroscopy has a wide range of applications in various fields:1. Qualitative analysis: Identification of compounds based on their characteristic absorption spectra.2. Quantitative analysis: Determination of the concentration of specific compounds in a sample.3. Structural characterization: Elucidation of the molecular structure and functional groups present in a compound.4. Reaction monitoring: Tracking the progress of chemical reactions in real-time.5. Materials characterization: Analysis of the optical properties and electronic structure of materials.6. Medical diagnostics: Non-invasive detection and monitoring of diseases and disorders.Advantages:1. High sensitivity: Can detect low concentrations of analytes.2. Wide applicability: Can be used to analyze a wide variety of substances in different states (solid, liquid, or gas).3. Non-destructive: Does not alter or damage the sample.4. Relatively simple and inexpensive instrumentation: Compared to other spectroscopic techniques.Limitations:1. Limited information: Provides only information about the electronic transitions of molecules, not theirmolecular structure.2. Interfering substances: Can be affected by the presence of other absorbing species in the sample.3. Sample preparation: May require sample preparationor dilution for accurate measurements.。

The principles of fluorescence spectroscopy

The principles of fluorescencespectroscopyFluorescence spectroscopy is a rapidly progressing branch of science that has contributed significantly to material science, environmental science, life science, and many other fields. This technique involves the measurement of light emitted by a luminescent sample when it is excited with light of a particular wavelength. Fluorescence spectroscopy plays a vital role in the study of structural and dynamic properties of materials at the molecular level. In this article, we will discuss the principles of fluorescence spectroscopy and its applications.Principle of fluorescence spectroscopyFluorescence spectroscopy is based on the principle of absorption and emission of light. When a molecule is excited by absorbing light of a particular wavelength, it absorbs the energy of the photon and moves to a higher energy state. This excited state is unstable and is rapidly deactivated by releasing the excess energy in the form of heat or by emitting a photon of light at longer wavelength than the absorbed photon. This process is called fluorescence.The emitted light intensity and wavelength depend on the nature of the molecule, its environment, and the properties of the excitation source. The fluorescence spectra contain valuable information about the structure, concentration, conformation, and dynamics of the molecule. By analyzing the spectra, one can gain insight into the molecular interactions, binding, and transport of the biomolecules, as well as the photophysical properties of the chromophores.Types of fluorescence spectroscopyFluorescence spectroscopy can be classified into various types based on the excitation and detection modes, as well as the sample types. Here are some common types of fluorescence spectroscopy:1. Steady-state fluorescence spectroscopy: This technique measures the steady-state fluorescence intensity of the sample under constant excitation. It provides information about the quantum yield, lifetime, and spectral characteristics of the fluorescence.2. Time-resolved fluorescence spectroscopy (TRFS): This technique measures the time-resolved fluorescence intensity of the sample by using a pulsed excitation source and a detector with a fast response time. It provides information about the fluorescence lifetime, rotational correlation time, and energy transfer rates of the molecules.3. Fluorescence resonance energy transfer (FRET): This technique measures the energy transfer from a donor fluorophore to an acceptor fluorophore that is in close proximity to the donor. It provides information about the distance, orientation, and conformational changes of the biomolecules.4. Fluorescence anisotropy: This technique measures the polarization of the emitted light relative to the polarization of the excitation light. It provides information about the dynamics and mobility of the fluorophores in the solution.Applications of fluorescence spectroscopyFluorescence spectroscopy has a wide range of applications in diverse fields such as biochemistry, biophysics, pharmaceuticals, materials science, environmental science, and many others. Here are some of the common applications of fluorescence spectroscopy:1. Protein structure and function: Fluorescence spectroscopy is widely used to study the structure and function of proteins, including folding, conformational changes, ligand binding, and enzymatic reactions. It provides valuable information about the kinetics, thermodynamics, and mechanism of protein interactions.2. DNA and RNA: Fluorescence spectroscopy is used to study the conformation, dynamics, and interactions of DNA and RNA molecules, including hybridization, denaturation, and DNA-protein interactions. It has applications in gene expression, DNA sequencing, and DNA damage detection.3. Drug discovery and development: Fluorescence spectroscopy is used in drug discovery and development to screen drugs, assess their efficacy, and monitor their interactions with biological targets. It helps to optimize drug formulations, optimize dosages, and assess pharmacokinetics.4. Environmental monitoring: Fluorescence spectroscopy is used to monitor water quality, air pollution, and soil contaminants. It helps to identify and quantify pollutants, assess health risks, and monitor environmental changes.ConclusionFluorescence spectroscopy is a powerful tool for studying the properties of molecules at the molecular level. It provides valuable information about the structure, dynamics, and interactions of molecules, as well as their applications in diverse fields. By using a combination of different fluorescence spectroscopy techniques, one can explore the photophysical properties of the biomolecules and materials. As fluorescence spectroscopy continues to advance, it promises to open up many new avenues for insights into the basics of matter and biological systems that will be relevant to solving major problems facing society.。

原子吸收光谱英文

原子吸收光谱英文Atomic Absorption SpectroscopyAtomic absorption spectroscopy (AAS) is a technique used for the quantitative determination of the concentration of elements in a sample. It works by measuring the absorption of light by atoms in the sample, which occurs when the atoms are excited to higher energy levels by a light source, such as a flame or a lamp. The absorption of light is specific to each element, so by measuring the amount of light absorbed at a particular wavelength, the concentration of that element in the sample can be determined.AAS is widely used in many fields, including environmental analysis, clinical chemistry, and materials science. It is particularly useful for detecting trace amounts of elements in samples, as it has a high sensitivity and can detect concentrations down to parts per billion.One limitation of AAS is that it can only analyze one element at a time, so if multiple elements are present in a sample, multiple analyses must be performed. Additionally, AAS requires a clean and homogeneous sample, and certain elements can interfere with the analysis of others.Despite these limitations, atomic absorption spectroscopyremains an important analytical technique in many industries. Its high sensitivity, accuracy, and precision make it a valuable tool for analyzing samples in a variety of fields.。

光谱技术在白酒质量控制中的研究进

唐佳代，赵益梅，冉光耀，等. 光谱技术在白酒质量控制中的研究进展[J]. 食品工业科技，2023，44（4）：506−514. doi:10.13386/j.issn1002-0306.2022050161TANG Jiadai, ZHAO Yimei, RAN Guangyao, et al. Research Progress of Spectroscopic Technique in Liquor Quality Control[J].Science and Technology of Food Industry, 2023, 44(4): 506−514. (in Chinese with English abstract). doi: 10.13386/j.issn1002-0306.2022050161· 专题综述 ·光谱技术在白酒质量控制中的研究进展唐佳代1，赵益梅1，冉光耀1，石雨菲1，胡　娜2，孟卓妮1,*（1.茅台学院酿酒工程系，贵州仁怀 564500；2.贵州茅台酒股份有限公司，贵州仁怀 564500）摘　要：白酒质量控制中涉及检测样品成分复杂，采用传统检测方法存在效率较低和环境污染隐患等不足。

因此，无损高效的光谱技术成为了分析白酒酿造过程中关键控制指标与质量监测控制的重要手段。

本文综述了近红外光谱、拉曼光谱、荧光光谱和高光谱成像技术的特点，其中着重介绍光谱技术应用于酿酒原料关键物质组成、大曲理化指标、酒醅和白酒的无损检测，并讨论了光谱技术在白酒质量控制技术和提高白酒品质及安全性的重要意义。

本文进一步提出，未来可扩展光谱技术在白酒检测中的应用范围，如在白酒酿造过程中建立其副产物（酒糟、黄水等）中理化指标的快速检测方法，或进行酱香型基酒三种典型体快速分类，将有益于白酒酿造行业的质量控制效果和提高经济效益。

关键词：近红外光谱，拉曼光谱，荧光光谱，高光谱成像技术，白酒质量控制本文网刊:中图分类号：TS262.3；TS261.7 文献标识码：A 文章编号：1002−0306（2023）04−0506−09DOI: 10.13386/j.issn1002-0306.2022050161Research Progress of Spectroscopic Technique in Liquor QualityControlTANG Jiadai 1，ZHAO Yimei 1，RAN Guangyao 1，SHI Yufei 1，HU Na 2，MENG Zhuoni 1, *（1.Department of Liquor Engineering, Moutai Institute, Renhuai 564500, China ；2.KWEICHOW MOUTAI CO., LTD., Renhuai 564500, China ）Abstract ：The quality control of Baijiu involves complex components of the test samples, and the traditional detection methods have disadvantages such as low efficiency and potential environmental pollution. Therefore, spectroscopy, a kind of non-destructive and efficient technique, has become an important method to analyze the key control index and quality monitoring in the process of liquor-making. In this paper, the characteristics of near-infrared spectroscopy, Raman spectroscopy, fluorescence spectroscopy, and hyperspectral imaging technologies are reviewed, especially for the application of spectroscopy technology in the non-destructive detection of key substances in raw materials of Baijiu,physical and chemical indicators of daqu, fermented grains and Baijiu, the significance of spectroscopy in Baijiu quality control technology and improving Baijiu quality and safety. This paper further proposes that the scope of application of spectroscopic technology in Baijiu detection can be expanded in the future, such as establishing a rapid detection method for physical and chemical indicators in its by-products (distillers, grains, huangshui, etc.), or the rapid classification of three typical types in sauce-flavor base liquors. These researches would be beneficial to the quality control effect and economic benefit of the Chinese liquor-making industry.Key words ：near-infrared spectroscopy ；Raman spectroscopy ；fluorescence spectroscopy ；hyperspectral imaging techno-logy ；Baijiu quality control收稿日期：2022−05−17基金项目：遵义市科学技术局、茅台学院市校联合科技研发资金项目（遵市科合HZ 字[2021]309号）；遵义市科学技术局、茅台学院市校联合科技研发资金项目（遵市科合HZ 字[2022]173号）；贵州省普通高等学校青年科技人才成长项目（黔教合KY 字[2020]228）。

科谱类的小作文100字左右

科谱类的小作文100字左右英文回答，Spectroscopy is a scientific technique used to study the interaction between matter and electromagnetic radiation. It involves the measurement and analysis of the absorption, emission, or scattering of light by a sample. By examining the spectrum of light absorbed or emitted by a substance, scientists can determine its chemical composition and physical properties.Spectroscopy plays a crucial role in various fields, including chemistry, physics, astronomy, and biochemistry. In chemistry, it is used to identify and analyze unknown substances, determine their concentration, and study chemical reactions. In physics, spectroscopy helps in understanding the behavior of atoms and molecules and their interactions with light. Astronomers use spectroscopy to study the composition and temperature of celestial objects. In biochemistry, it is used to investigate the structure and function of biomolecules.中文回答，科谱学是一种科学技术，用于研究物质与电磁辐射的相互作用。

托福听力考前准备需要关注5类词汇

托福听力考前准备需要关注5类词汇在托福备考之前，首先考生对自己的新托福听力词汇量应该有个基本的了解。

可能有的考生会觉得，新托福听力词汇中的生词在短暂的时间内根本无法思考那么多解决方法。

这些方法不应该是一边听一边提醒自己要注意使用，而是养成习惯，变成自己的潜意识，不自觉地使用。

如果问题理解都非常顺利，那么可以做几道题目感受一下听的部分。

在新托福听力词汇中，生词的出现主要有这么几种解决方法：1. 专有名词在文中出现的人名、地名等专有名词通常对考试没有多大影响。

只要考生能够意识到在说的是某个人或者某个地点就行，笔记中的体现可以以大写首字母代替。

甚至有的词在考试界面上会出现，考生只需混个眼熟，之后在做题时能认出来就行。

2. 话题类单词，术语托福英语听力的lecture话题非常广泛，虽然官方指南给出了艺术、生命科学、自然科学和社会科学四大类话题，但事实上这四个话题已经能囊括任何专业知识点了，知识面再广的学生也不可能面面俱到。

当lecture中出现一些专业术语，甚至当这个术语就是考题的中心话题怎么办？既然是术语，文中当然会出现对术语的解释，所以考试只需淡定地等待解释出现即可。

常见的说法有：the definition of …is…can be defined as……， that/which is …… is/are ….例如：Whatis spectroscopy? Well， the simplestdefinition I can give you is that spectroscopy is the study of the interaction between matter and light.Spectroscopy is basically the study of spectra and spectral lines of light， and specificallyfor us， the light from stars.这两句话出自不同话题的两篇文章，但都和spectroscopy(光谱学)这个话题相关，并做了定义。