interaction of electrons with acoustic and optical phonons

Ngày tải lên: 22/03/2014, 11:20

... Inc. opticalwaveutilizingthestimulatedemissioninamediumwherepopulation inversionisproducedbyexcitation.Thestateofthemediumwith populationinversioniscalledthelaser-activestate.Insemiconductor injectionlasers,populationinversionisrealizedthroughinjectionof minoritycarrierswithahighenergyinthevicinityofap–njunctionby supplyingaforwardcurrent.Althoughinthischapterthepossibilityof enhancementofopticalpowerbystimulatedphotonemissionwasshown basedonconsiderationofthestatesofanelectronandtheenergy eigenstatesoftheopticalfield,thisdiscussiondoesnotensurethepossibility ofenhancementofopticalamplitudeincludingthephase,i.e.,thecoherent amplificationofanopticalwave.Thepossibilityofcoherentamplification willbediscussedonthebasisofananalysisusingthedensitymatrixin Chap.3.Spontaneousemissionalsotakesplaceinparalleltothelaser action.Itaffectssignificantlythelaserperformances;e.g.,itgivesrisetothe laseroscillationthresholdandthequantumnoiseintheoutputlight. REFERENCES 1.W.Heitler,TheQuantumTheoryofRadiation,OxfordUniversityPress, Oxford(1954). 2.A.Yariv,QuantumElectronics,JohnWiley,NewYork(1967). 3.L.I.Schiff,QuantumMechanics,McGraw-Hill,NewYork(1968). 4.Y.Fujii,OpticalandQuantumElectronics(inJapanese),Kyoritsu,Tokyo(1978). 5.M.SargentIII,M.O.Scully,andW.E.Lamb,Jr,LaserPhysics,Addison- Wesley,Reading,MA(1974). 6.D.Marcuse,PrinciplesofQuantumElectronics,AcademicPress,NewYork (1980). 7.K.Shimoda,IntroductiontoLaserPhysics(inJapanese),Iwanami,Tokyo (1983). 8.P.MeystreandM.SargentIII,ElementsofQuantumOptics,Springer, Berlin(1991). 9.T.Suhara,QuantumElectronics(inJapanese),Ohmsha,Tokyo(1993). 36Chapter2 Copyright ... j j i of the electron and the eigenstates jn m i of optical field of each mode m. Here J is a label for the combination of electron states and states of field modes ( j and {n m }), and jC J i ... photons are deduced, and the possibility of optical wave amplification in population-inverted states is shown. 2.1 QUANTIZATION OF OPTICAL WAVES AND PHOTONS 2.1.1 Expression of Optical Waves by Mode...

Ngày tải lên: 23/10/2013, 20:15

... region within the d and e bands of collagen fibrils. Two chemical derivatives of collagens and of positive peptides were prepared by N-acetylation and N-methylation of the primary amino group of Lys/Hyl ... interact with fibrillar c ollagens through its protein core and to localize at d and e bands of the c ollagen fibril banding pattern. Using a s olid-phase assay, we have determined the interaction of ... spectra of a recombinant decorin purified in the absence of chaotropic agents, with the exception of the wavelength of the minimum (215–216 instead of 218 nm) and very different to the spectrum of...

Ngày tải lên: 21/02/2014, 15:20

... a mixture of annexin A1 and A2 and that the 35 kDa proteins are a mixture of annexin A5 and proteolytic fragments of annexin A1 and annex- in A2. Purified recombinant annexin A1, annexin A2 and annexin ... shown as thin dotted lines in (C) and (D). The result obtained in the presence of dicalcin and all of the annexins (E) was compared with the calcu- lated sum of each of the initial rates obtained ... localize in the cilia of frog olfactory and respiratory epithelium [7]. To understand the possible association of annexin A1, annexin A2 and annexin A5 with the function of dical- cin, we examined...

Ngày tải lên: 07/03/2014, 05:20

... addition of saporin and for cells shocked with dimethylsulfoxide after a 4 °C toxin incubation (Figs 2B and 3A). Sandvig et al. [28] have further shown that cells coincubated with dimethylsulfoxide and ... Department of Molecular Biology and Microbiology and Biomolecular Science Center, University of Central Florida, FL, USA 2 Department of Chemistry and Biomolecular Science Center, University of Central ... University of Central Florida Department of Molecular Biology and Micro- biology and an AIRC grant to M. S. Fabbrini. Partial support was provided by the Broad Medical Research Program of the Eli and...

Ngày tải lên: 07/03/2014, 05:20

... absence and presence of ATP, respec- tively, and 0.06 m )1 Æs )1 for rabbit Hb, which illustrates the high reactivity of carp Hb and the decreased rate of reaction with T-state stabilization and ... study show that the reaction of nitrite with deoxyHb is favored over that with oxy- Hb at intermediate So 2 values and that the formation of NO and HbNO from the reaction with deoxyHb is substantial ... reaction of nitrite with deoxyHb (Fig. 1A) and with Hb with an initial So 2 of 46% (Fig. 1B). When nitrite reacted with carp deoxyHb in a nitro- gen atmosphere, the concentration of deoxyHb decreased...

Ngày tải lên: 16/03/2014, 06:20

... 2007 FEBS 2.0 mL), and this was followed by 45 min of heating at 95 °C. After cooling, samples and standards of malondial- dehyde were read at 532 nm against the blank of the stand- ard curve. The ... change the rate of platelet nucleotide hydrolysis. Platelets comprise one of the components of the thrombus microenvironment and of the process of thrombo- regulation. It is known that the rate of platelet ... However, considering the function and the mobility of platelets, we can understand their active role in this process and the importance of such hydrolysis. In line with this, literature data indi- cate...

Ngày tải lên: 16/03/2014, 10:20

... the interaction of TATA box binding protein and TFIIA with DNA. Biochemistry 33, 7033–7040. 4760 E. Trotta et al. (Eur. J. Biochem. 270) Ó FEBS 2003 Interaction of DAPI with individual strands of ... structure of the T-rich strand of the AATÆATT trinucleotide repeat. Our results suggest a novel mechanism of action of DAPI and show the unusual replication feature of a common class of genomic ... favourable and selective interaction with the minor-groove of AÆTandTÆT base-pairs. The molecular mechanism proposed in this work may help in designing new minor-groove binding ligands with sequence-selective...

Ngày tải lên: 16/03/2014, 23:20

Ngày tải lên: 23/03/2014, 03:20

Ngày tải lên: 23/03/2014, 04:21

Ngày tải lên: 31/03/2014, 21:21

Ngày tải lên: 12/06/2014, 11:35

Ngày tải lên: 20/06/2014, 15:20

Ngày tải lên: 21/06/2014, 17:20

... active sites of this enzyme and arginase I. In spite of the rel- atively low agmatinase activity of the Asn149Asp vari- ant, it is clear that the interactions of arginase II with l-arginine and agmatine ... variants. Interaction of arginase II with substrate and manganese ions V. Lo ´ pez et al. 4542 FEBS Journal 272 (2005) 4540–4548 ª 2005 FEBS Insights into the interaction of human arginase II with substrate and ... examine the interaction of human arginase II (EC 3.5.3.1) with sub- strate and manganese ions, the His120Asn, His145Asn and Asn149Asp mutations were introduced separately. About 53% and 95% of wild-type arginase...

Ngày tải lên: 20/02/2014, 02:21

... 5 mL of this, and incubated for 2 h at 24 °C. To remove the unbound antibodies, the beads were washed twice with 5 mL of NaCl ⁄ P i , twice with 5 mL of 100 mm glycine (pH 3.0), and twice with ... S3) [10,19]. Interactions of the truncated TnrA proteins with GlnK and with GS were determined by pulldown and SPR analysis, as described above (Fig. 6). As expected, the C-terminus of TnrA was ... nucleotides, such as ADP, AMP, and GTP, at concentrations of Fig. 3. Influence of various effector molecules on the interaction of GlnK with the His 6 -TnrA surface. GlnK was preincubated with effec- tor molecules...

Ngày tải lên: 06/03/2014, 00:21

... for human Vb5.2 and V b1withK d of 9–11 l M with a fast k ass and a moderately fast k diss . In spite of the reported stimu- lation of V b2.1 bearing T-cells by SSA, we o bserved no measurable interaction. Keywords: ... Consequently, the molecular studies of the interaction of SAgs with their s pecifics ligands will not only advance understanding of the physiological mechanisms of these molecules, but may lead to ... Recognit. 16, 91–101. Ó FEBS 2004 Interaction of human TCR with superantigen SSA (Eur. J. Biochem. 271) 4083 Cloning, expression and interaction of human T-cell receptors with the bacterial superantigen...

Ngày tải lên: 07/03/2014, 16:20

... ) * k on;1 k off;1 AB ð2Þ AB þ B ) * k on;2 k off;2 AB 2 ð3Þ where d½B=dt ¼À2k on;1 ½A½Bþk off;1 ½ABÀk on;2 ½AB[B] þ 2k off;2 ½AB 2 ð4Þ d½AB=dt ¼ 2k on;1 ½A½BÀk off;1 ½AB À k on;2 ½AB[B] þ 2k off;2 ½AB 2 ð5Þ d½AB 2 =dt ... binding of factor X and its Gla-containing fragments to membranes containing 25 mol% PtdSer in the presence of 10 m M Ca 2+ obtained by evaluation of association and dissociation phases (I) and equilibrium ... (1972) Mode of action of vitamin K and calcium binding properties of bovine prothrombin. Bio- chemistry 11, 4961–4964. 24. Stenflo, J. & Ganot, P. (1973) Binding of Ca 2+ to normal and dicoumarol-induced...

Ngày tải lên: 08/03/2014, 23:20

... levels. Thus the drastic reduction in interaction of ND35 and AB Fig. 8. Y2H interaction between MP and CP. (A) pGBK T7 (MP, MP deletion mutants and p53) and pGAD T7 (CP and T Ag) clones were transformed ... similarity with MPs of viruses from other gen- era. Within sobemoviruses, the sequence of the SeMV MP was closest to that of the SBMV-Ark MP (32% sequence identity), and the identity with MPs of other sobemoviruses ... 4. Interaction of rMP with NV. (A) ELISA of rMP and NV inter- action. ELISA plates coated with NV (5 lg) (P1) were blocked with 10% skimmed milk in 1% NaCl ⁄ Pi (block) followed by addition of 5...

Ngày tải lên: 15/03/2014, 00:20