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31.
Micah I. Krichevsky 《Analytica chimica acta》1981,133(4):747-751
An interactive information system, MICRO-IS, is described. It comprises morphological, physiological, biochemical, and Chromatographic data describing microbial strains. A wide variety of retrieval, management, and editing functions can be invoked with easy-to-learn, user-oriented commands. 相似文献
32.
Differential electrical excitation of the auditory nerve 总被引:4,自引:0,他引:4
The multichannel cochlear prosthesis requires an electrode stimulus configuration which produces a stimulus field spatially localized to each electrode. In this paper, a three-dimensional discrete resistance model of the cochlea was developed which exhibits electrical response properties similar to those observed during electrical stimulation of the cochlea. The model results suggest that the spatial attenuation of current within the cochlea varies greatly in magnitude, depending on the stimulus configuration. In addition, the model suggests that the spatial attenuation of current in both the auditory nerve fiber endings in the organ of Corti and in the myelinated fibers within the cochlear ground paths is different from the voltage attenuation in the scalar fluids. Therefore the efficacy with which a particular stimulus configuration differentially excites local terminal auditory nerve fiber populations cannot be deduced from scalar voltage measurements which have previously been recorded in the literature. Consequently physiological experiments were performed in the cat to measure the current distributions in the terminal nerve fiber region for monopolar and bipolar stimulation of the scala tympani, and also for stimulation between the scala tympani and the scala vestibuli. The mean length constants measured in the basal turn for these stimuli were found to be 12, 3, and 7.5 mm, respectively. 相似文献
33.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA 《Physical review letters》2005,95(5):051802
We present a measurement of the Zgamma production cross section and limits on anomalous ZZgamma and Zgammagamma couplings for form-factor scales of lambda = 750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eegamma (mumugamma) final state using 320(290) pb(-1) of pp(-1) collisions at square root of s = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are /h(10,30)Z/ < 0.23, /h(20,40)Z/ < 0.020, /h(10,30)gamma/ < 0.23, and /h(20,40)gamma/ < 0.019 for lambda = 1000 GeV. 相似文献
34.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Anderson S Andrieu B Arnoud Y Askew A Asman B Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V 《Physical review letters》2005,94(10):102001
We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel. 相似文献
35.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Arov M Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Bagby L Baldin B Balm PW Banerjee P Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begalli M Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I 《Physical review letters》2005,95(17):171801
We present a study of the decay B0(s) --> J/psiphi. We obtain the CP-odd fraction in the final state at time zero, Rperpendicular = 0.16 +/- 0.10(stat) +/- 0.02 (syst), the average lifetime of the (B0(s), B0(s)) system, tau(B0(s)) = 1.39(+0.13)(-0.16)(stat)(+0.01)(-0.02)(syst) ps, and the relative width difference between the heavy and light mass eigenstates, DeltaGamma/Gamma tripple bond (GammaL - GammaH)/Gamma = 0.24(+0.28)(-0.38)(stat)(+0.03)(-0.04)(syst). With the additional constraint from the world average of the lifetime measurements using semileptonic decays, we find tau(B0(s)) = 1.39 +/- 0.06 ps and DeltaGamma/Gamma = 0.25(+0.14)(-0.15). For the ratio of the B0(s) and B0 lifetimes we obtain tau(B0(s))/tau(B0) = 0.91 +/- 0.09(stat) +/- 0.003(syst). 相似文献
36.
When a single DNA molecule is stretched beyond its normal contour length, a force-induced melting transition is observed. Ethidium binding increases the DNA contour length, decreases the elongation upon melting, and increases the DNA melting force in a manner that is consistent with the ethidium-induced changes in duplex DNA stability known from thermal melting studies. The DNA stretching curves map out a phase diagram and critical point in the force-extension-ethidium concentration space. Intercalation occurs between alternate base pairs at low forces and between every base pair at high forces. 相似文献
37.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA 《Physical review letters》2005,95(15):151805
A search for associated production of charginos and neutralinos is performed using data recorded with the D0 detector at a pp center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. This analysis considers final states with missing transverse energy and three charged leptons, of which at least two are electrons or muons. No evidence for supersymmetry is found in a data set corresponding to an integrated luminosity of 320 pb-1. Limits on the product of the production cross section and leptonic branching fraction are set. For the minimal supergravity model, a chargino lower mass limit of 117 GeV at the 95% C.L. is derived in regions of parameter space with enhanced leptonic branching fractions. 相似文献
38.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA 《Physical review letters》2005,95(9):091801
We report the first direct search for the Kaluza-Klein (KK) modes of Randall-Sundrum gravitons using dielectron, dimuon, and diphoton events observed with the D0 detector operating at the Fermilab Tevatron pp(-) Collider at sqrt[s]=1.96 TeV. No evidence for resonant production of gravitons has been found in the data corresponding to an integrated luminosity of approximately equal to 260 pb(-1). Lower limits on the mass of the first KK mode at the 95% C.L. have been set between 250 and 785 GeV, depending on its coupling to standard model particles. 相似文献
39.
We report the observation of collective-emission-induced, velocity-dependent light forces. One-third of a falling sample containing 3 x 10(6) cesium atoms illuminated by a horizontal standing wave is stopped by cooperatively emitting light into a vertically oriented, confocal resonator. We observe decelerations up to 1500 m/s(2) and cooling to temperatures as low as 7 microK, well below the free-space Doppler limit. The measured forces substantially exceed those predicted for a single two-level atom. 相似文献
40.
Elena V. Black 《Proceedings of the American Mathematical Society》2001,129(5):1283-1288
Let and be finite groups and let be a hilbertian field. We show that if has a generic extension over and satisfies the arithmetic lifting property over , then the wreath product of and also satisfies the arithmetic lifting property over . Moreover, if the orders of and are relatively prime and is abelian, then any extension of by (which is necessarily a semidirect product) has the arithmetic lifting property.