The Standard Quantum Limit of Coherent Beam Combining

Coherent beam combining refers to the process of generating a bright output beam by merging independent input beams with locked relative phases. We report the first quantum mechanical noise limit calculations for coherent beam combining and compare our results to quantum-limited amplification. Our coherent beam combining scheme is based on an optical Fourier transformation which renders the scheme compatible with integrated optics. The scheme can be layed out for an arbitrary number of input beams and approaches the shot noise limit for a large number of inputs

Stability of the iterative solutions of integral equations as one phase freezing criterion

A recently proposed connection between the threshold for the stability of the iterative solution of integral equations for the pair correlation functions of a classical fluid and the structural instability of the corresponding real fluid is carefully analyzed. Direct calculation of the Lyapunov exponent of the standard iterative solution of HNC and PY integral equations for the 1D hard rods fluid shows the same behavior observed in 3D systems. Since no phase transition is allowed in such 1D system, our analysis shows that the proposed one phase criterion, at least in this case, fails. We argue that the observed proximity between the numerical and the structural instability in 3D originates from the enhanced structure present in the fluid but, in view of the arbitrary dependence on the iteration scheme, it seems uneasy to relate the numerical stability analysis to a robust one-phase criterion for predicting a thermodynamic phase transition.Comment: 11 pages, 2 figure

Spin-wave spectrum of copper metaborate in the commensurate phase 10K<T<21K

We have investigated the spin-wave spectrum of copper metaborate, CuB$_2$O$_4$, by means of inelastic neutron scattering in the commensurate magnetic phase. We have found two branches of spin-wave excitations associated with the two magnetic sublattices Cu(A) and Cu(B), respectively. In the temperature regime $10K \le T \le 21K$, where only the Cu(A) magnetic moments are ordered, the interaction between the two sublattices is found to be negligible. With this approximation we have determined the `easy plane' exchange parameters of the Cu(A) subsystem within standard spin-wave theory.Comment: 4 figure

Synthesis of Phosphorothioate Oligonucleotides with Stereodefined Phosphorothioate Linkages

A method for solid‐phase synthesis of stereodefined PS‐oligos via an oxathiaphospholane approach using pure P‐diastereomers of nucleoside oxathiaphospholane monomers is described. The oxathiaphospholane monomers are synthesized by phosphitylation of 5′‐O‐DMTr‐N‐protected deoxyribonucleosides with 2‐chloro‐spiro‐4,4‐pentamethylene‐1,3,2‐oxathiaphospholane followed by sulfurization. The procedure is general and may be applied to other analogs, depending on the aldehyde (or mercaptoalcohol) used. Starting from an 18O‐labeled mercaptoalcohol, the corresponding 18O‐labeled phosphitylating reagent and nucleoside monomers can be obtained and used for synthesis of labeled stereodefined PS‐oligos, which are useful for studying mechanisms of enzymatic reactions. Details are provided for chromatographic separation of the 5′‐O‐DMTr‐N‐protected‐deoxyribonucleoside‐3′‐O‐(2‐thio‐spiro‐4,4‐pentamethylene‐1,3,2‐oxathiaphospholane)s into their P‐diastereomers, and for manual solid‐phase synthesis of PS‐oligos. Oxidation of 5′‐O‐DMTr‐N‐protected‐deoxyribonucleoside‐3′‐O‐(2‐thio‐spiro‐4,4‐pentamethylene‐1,3,2‐oxathiaphospholane)s with selenium dioxide yields their 2‐oxo‐analogs, which are suitable either for elongation of stereodefined PS‐oligos with segments consisting of unmodified nucleotide units possessing phosphate internucleotide linkages, or for generating isotopomeric 18O‐labeled PO‐oligos of predetermined P‐chirality.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143684/1/cpnc0417.pd

Non-existence of normal tokamak equilibria with negative central current

Recent tokamak experiments employing off-axis, non-inductive current drive have found that a large central current hole can be produced. The current density is measured to be approximately zero in this region, though in principle there was sufficient current drive power for the central current density to have gone significantly negative. Recent papers have used a large aspect-ratio expansion to show that normal MHD equilibria (with axisymmetric nested flux surfaces, non-singular fields, and monotonic peaked pressure profiles) can not exist with negative central current. We extend that proof here to arbitrary aspect ratio, using a variant of the virial theorem to derive a relatively simple integral constraint on the equilibrium. However, this constraint does not, by itself, exclude equilibria with non-nested flux surfaces, or equilibria with singular fields and/or hollow pressure profiles that may be spontaneously generated.Comment: 5 pages, 3 figures. Submitted to Physics of Plasmas, Feb. 14, 2003. Revised Feb. 24, 2003. Vers. 2: revised May 29 to clarify points raised by referee, add references to recent work. July 18, accepted for publicatio

Effect of seed inoculation and foliar fertilizing on structure of soybean yield and yield structure in Western Polissya of Ukraine

Growing soybeans requires adjustment of micronutrient nutrition on poorly fertile soils. Foliar fertilization can overcome the deficiency of micronutrients in plants in the most important period. Three factorial field experiment to study foliar fertilization with complex micronutrients, seed inoculation by Bradyrhizobium japonicum in two soybean varieties (Kassidy and ES Mentor) was conducted. Foliar fertilization with Quantum oil and WUXAL Oilseed significantly increased certain elements in soybean yield structure. Fertilizer WUXAL Oilseed with a higher concentration of Mo, Mn and B more effectively increased the number of pods and seeds from the plant and formed a higher yield in soybeans. Foliar fertilization with WUXAL Oilseed and Quantum oil increased seed yield to 3.00 t ha-1 and 2.94 t ha-1 , respectively in regard to variant without fertilizing, where yield was 2.71 t ha-1 . Variety Kassidy had greater number of pods and seeds, seed weight in comparison to foliar fertilizing ES Mentor. Seed inoculation gaves a stable increase in yield under different foliar fertilizations in varieties Kassidy and ES Mentor

Correction of adma-induced preeclampsia with the use of phosphodiesterase 5 and selective inhibitor of arginase II ZB49-0010

Simulation experimental ADMA-like preeclampsia was carried out by administering the rats with L-NAME during 14-20 days of pregnancy. In animals, there was an increase in blood pressure, proteinuria, impaired microcirculation in the placenta, the violation of the regulation of vascular tone and destructive changes in the ischemic placenta. The use of phosphodiesterase 5 and selective inhibitor of arginase II ZB49-0010 leads to the expression of morphological and functional correction of violations occurring in modeling of experimental preeclampsi