2,284 research outputs found
The Structure of 1-\u3cem\u3etert\u3c/em\u3e-butyl-2,2,3,4,4-pentamethylphosphetane 1-oxide, C\u3csub\u3e12\u3c/sub\u3eH\u3csub\u3e25\u3c/sub\u3eOP
The Personal Tax Advantage of Equity
We compute the value of a firm that pays its cash flows each period through share repurchases in a dynamic environment where personal taxes are paid on realized capital gains and dividends. These results provide a measure of the personal tax advantages of equity financing relative to debt financing, which are often cited as increasing the cost of debt. The initial price of the firm depends on the present value of the taxes paid, which, in turn, depends on the initial price. We solve this valuation problem in closed form in a deterministic setting and numerically in a stochastic setting. We find significant valuation effects from the tax protection afforded by the equity basis. The tax savings are on the order of 40-50\% of the taxes paid by the shareholders of firm that distributes cash through dividends, and the cost of capital is reduced by approximately .8 to 1.2 percentage points through the use of repurchases relative to dividends.
A 1:2 co-crystal of 2,2′-thiodibenzoic acid and triphenylphosphane oxide: crystal structure, Hirshfeld surface analysis and computational study
The asymmetric unit of the title co-crystal, 2,20-thiodibenzoic acid–triphenylphosphane oxide (1/2), C14H10O4S2C18H15OP, comprises two molecules of 2,20
-thiodibenzoic acid [TDBA; systematic name: 2-[(2-carboxyphenyl)sulfanyl]benzoic acid] and four molecules of triphenylphosphane oxide [TPPO;systematic name: (diphenylphosphoryl)benzene]. The two TDBA molecules are
twisted about their disulfide bonds and exhibit dihedral angles of 74.40 (5) and 72.58 (5) between the planes through the two SC6H4 residues. The carboxylic acid groups are tilted out of the planes of the rings to which they are attached forming a range of CO2/C6 dihedral angles of 19.87 (6)–60.43 (8). Minor conformational changes are exhibited in the TPPO molecules with the range of dihedral angles between phenyl rings being �2.1 (1) to �62.8 (1). In the
molecular packing, each TDBA acid molecule bridges two TPPO molecules via hydroxy-O—HO(oxide) hydrogen bonds to form two three-molecule aggregates. These are connected into a three-dimensional architecture by TPPO-C—HO(oxide, carbonyl) and TDBA-C—H(oxide, carbonyl) interactions. The importance of HH, OH/HO and CH/HC contacts to the calculated Hirshfeld surfaces has been demonstrated. In terms of individual
molecules, OH/HO contacts are more important for the TDBA (ca 28%) than for the TPPO molecules (ca 13%), as expected from the chemical composition of these species. Computational chemistry indicates the four independent hydroxy-O—HO(oxide) hydrogen bonds in the crystal impart
about the same energy (ca 52 kJ mol-1), with DTBA-phenyl-C—HO(oxide) interactions being next most stabilizing (ca 40 kJ mol-1)
Periodic Mean-Field Solutions and the Spectra of Discrete Bosonic Fields: Trace Formula for Bose-Hubbard Models
We consider the many-body spectra of interacting bosonic quantum fields on a
lattice in the semiclassical limit of large particle number . We show that
the many-body density of states can be expressed as a coherent sum over
oscillating long-wavelength contributions given by periodic, non-perturbative
solutions of the, typically non-linear, wave equation of the classical
(mean-field) limit. To this end we construct the semiclassical approximation
for both the smooth and oscillatory part of the many-body density of states in
terms of a trace formula starting from the exact path integral form of the
propagator between many-body quadrature states. We therefore avoid the use of a
complexified classical limit characteristic of the coherent state
representation. While quantum effects like vacuum fluctuations and gauge
invariance are exactly accounted for, our semiclassical approach captures
quantum interference and therefore is valid well beyond the Ehrenfest time
where naive quantum-classical correspondence breaks down. Remarkably, due to a
special feature of harmonic systems with incommesurable frequencies, our
formulas are generically valid also in the free-field case of non-interacting
bosons.Comment: submitted to Phys. Rev.
The Basic Study on Rare Earth Nd3+ Ion Doped Polymer Optical Waveguide Amplifier
近年来,有机聚合物材料以其独特的性能、低廉的成本受到越来越多的重视。聚合物光电子器件如阵列波导光栅、电光调制器、光开关和光波导放大器等几乎已经涉及了集成光学的各个领域。光波导放大器的原理是利用掺入光波导中的稀土离子在泵浦光作用下产生受激辐射来实现信号光的放大。本论文以三元钕配合物Nd(TTA)3(TPPO)2作为有源材料,制备了硅基聚合物光波导放大器,研究了器件在1060nm波长处的增益特性。所做的具体工作如下: 1.合成了三元钕配合物Nd(TTA)3(TPPO)2(HTTA:2-thenoyltrifluoroacetone,TPPO:triphenylphosphineoxide),将其...In recent years, organic polymer material has been attracting more and more attention because of its unique performance and its low cost. Polymer optoelectronic devices such as arrayed waveguide gratings, electro-opticmodulators, optical switches and waveguide amplifiers has been involved in almost every field of integrated optics. The waveguide amplifer make use of the rare earth ions incorporat...学位:工学硕士院系专业:信息科学与技术学院_工程硕士(电子与通信工程)学号:2312013115312
Molecular mechanisms involved in the generation of calcium signals In insulin secreting cells.
Intracellular Ca 2+ regulates diverse cellular functions in almost all the cells. In the pancreatic ß-cells, Ca 2+ signals are critical for insulin secretion. An increase in the cytoplasmic free Ca 2+ concentration ([Ca 2+ ]i) triggers insulin secretion. Multiple mechanisms increase the [Ca 2+ ]i in the ß-cells, and in this respect depolarization of the plasma membrane and consequent Ca 2+ entry through the voltage-gated Ca 2+ channels is particularly important. For depolarization of ß-cells the closure of KATP channels is essential. In addition, cation channels belonging to Transient Receptor Potential (TRP) family are thought to play important roles in causing depolarization. Previous studies have reported that the Transient Receptor Potential Melastatin-like subtype 5 (TRPM5) channel, a Ca 2+ activated monovalent cation channel, is involved in the stimulus-secretion coupling in the mouse ß-cells. We aimed to study the role of the TRPM5 channel in regulating insulin secretion, and [Ca 2+ ]i in the rat ß-cells.
Another focus of this thesis was to evaluate a new human inluinoma cell line as a model for studying Ca 2+ signaling in the ß-cells. Recently a genetically engineered human insulinoma cell line (EndoC-BH1) has been developed. We studied Ca 2+ signaling in the EndoC-BH1 cells, in an attempt to assess whether these cells could be used as a model for this purpose.
For inhibiting the TRPM5 channels we used triphenyl phosphine oxide (TPPO), a selective and potent pharmacological inhibitor of the channel. We measured insulin secretion from the islets from Sprague-Dawley rats in batch incubations. For measuring [Ca 2+ ]i from single rat ß-cells and EndoC-BH1 cells, we used fura-2 based ratiometric microfluorometry.
We found that TPPO did not inhibit insulin secretion triggered by KCl, or fructose but it significantly reduced insulin secretion in response to glucose, Larginine, and GLP-1. It also significantly inhibited the KATP channel-independent insulin secretion by glucose. TPPO significantly inhibited the [Ca 2+ ]i increase in response to L-arginine. It also inhibited the [Ca 2+ ]i increase triggered by glucose in a KATP channel independent mechanism. However, TPPO did not alter the [Ca 2+ ]i response triggered by KCl, fructose, glucose and GLP-1.
We stimulated the EndoC-BH1 cells with gluocse, GLP-1, KCl, carbachol, Larginine, and tolbutamide. These agents that are known to increase [Ca 2+ ]i in the primary ß-cells also increased [Ca 2+ ]i in the these human insulinoma cells. Moreover, we found that GLP-1 was essential for eliciting Ca 2+ response in the EndoC-BH1 cells upon stimulation by tolbutamide and glucose.
We conclude that in the rat islets, TRPM5 plays an important role in mediating insulin secretion by glucose, and L-arginine, and in potentiating the glucoseinduced insulin secretion by GLP-1. We also conclude that the EndoC-BH1cells responds by [Ca 2+ ]i increase upon stimulation by several well-known agonists
Cooperative binding in a phosphine oxide-based halogen bonded dimer drives supramolecular oligomerization
The authors thank the Marie Curie Initial Training Network on Replication and Adaption in Networks (ReAd) for financial support (early stage researcher funding to L.M.).Triphenylphosphine oxide forms halogen-bonded (XB) complexes with pentafluoroiodobenzene and a 1,4-diaryl-5-iodotriazole. The stability of these complexes is assessed computationally and by 31P NMR spectroscopy in d8-toluene solution, where both complexes are weakly associated. This knowledge is applied to the design and synthesis of two self-complementary phosphine oxide-iodotriazole hybrids that incorporate a phosphine oxide XB acceptor and a 1,4-diphenyl-5-iodotriazole XB donor within the same molecule. The self-complementary design of these modules facilitates their assembly in both d8-toluene and, surprisingly, d2-DCM into dimers, with significant stabilities, through the formation of halogen-bonded diads. The stability of these assemblies is a result of significant levels of cooperative binding that is present in both solvents. The connection of two of these hybrid units together, using a flexible spacer, facilitates the aggregation of these modules in d2-DCM solution, through halogen bonding, forming oligomeric assemblies.PostprintPeer reviewe
Implementasi Hukum Hak Asasi Manusia Dalam Pengaturan Pencegahan Tindak Pidana Perdagangan Orang Di Indonesia
Upaya pencegahan dan penanggulangan hukum terhadap kejahatan yang banyak terjadi harus dilakukan secara terpadu antar institusi yang berhubungan dengan penegakan hukum yaitu: adanya aparatur yang tertata dengan baik, professional di bidangnya (SDM) serta sarana dan prasarana yang up to date, hukum dalam perwujudan sebagai undang-undang dalam proses penegakan hukum (sistem peradilan pidana/ criminal justice system), yang semakin bermutu dan berorientasi pada kebenaran dan keadilan berdasarkan Pancasila dan UUD 1945, koordinasi serasi antarfungsionaris hukum dan aparatur pemerintah terkait, Partisipasi masyarakat yang harus dimotifikasi, agar kondisi potensial dapat terangkat menjadi kekuatan nyata warga masyarakat yang peduli terhadap kejahatan dan aktif ambil bagian dalam penanggulangan, dan melakukan sikap antisipatif terhadap kejahatan
Mononuclear dysprosium(III) complexes with triphenylphosphine oxide ligands: controlling the coordination environment and magnetic anisotropy
We report the synthesis, structural and magnetic characterization of five mononuclear DyIII ion complexes using triphenylphosphine oxide as a monodentate ligand. They have formulae [DyIII(OPPh3)3(NO3)3] (1), [DyIII(OPPh3)4(NO3)2](NO3) (2), [DyIII(OPPh3)3Cl3] (3), [DyIII(OPPh3)4Cl2]Cl (4) and [DyIII(OPPh3)4Cl2](FeCl4) (5). These complexes are characterized using single crystal X-ray diffraction, which revealed that each complex has a unique coordination environment around the DyIII ion, which results in varying dynamic magnetic behavior. Ab initio calculations are performed to rationalize the observed magnetic behavior and to understand the effect that the ligand and coordination geometry around the DyIII ion has on the single-molecule magnet (SMM) behavior. In recent years, seven coordinate DyIII complexes possessing pseudo ~D5h symmetry are found to yield attractive blocking temperatures for the development of new SMM complexes. However, here we show that the strength of the donor ligand plays a critical role in determining the effective energy barrier and is not simply dependent on the geometry and the symmetry around the DyIII ion. Seven coordinate molecules possessing pseudo D5h symmetry with strong equatorial ligation and weak axial ligation are found to be inferior, exhibiting no SMM characteristics under zero-field conditions. Thus, this comprehensive study offers insight on improving the blocking temperature of mononuclear SMMs
Eigenvalue spectrum for single particle in a spheroidal cavity: A Semiclassical approach
Following the semiclassical formalism of Strutinsky et al., we have obtained
the complete eigenvalue spectrum for a particle enclosed in an infinitely high
spheroidal cavity. Our spheroidal trace formula also reproduces the results of
a spherical billiard in the limit . Inclusion of repetition of each
family of the orbits with reference to the largest one significantly improves
the eigenvalues of sphere and an exact comparison with the quantum mechanical
results is observed upto the second decimal place for . The
contributions of the equatorial, the planar (in the axis of symmetry plane) and
the non-planar(3-Dimensional) orbits are obtained from the same trace formula
by using the appropriate conditions. The resulting eigenvalues compare very
well with the quantum mechanical eigenvalues at normal deformation. It is
interesting that the partial sum of equatorial orbits leads to eigenvalues with
maximum angular momentum projection, while the summing of planar orbits leads
to eigenvalues with except for L=1. The remaining quantum mechanical
eigenvalues are observed to arise from the 3-dimensional(3D) orbits. Very few
spurious eigenvalues arise in these partial sums. This result establishes the
important role of 3D orbits even at normal deformations.Comment: 17 pages, 7 ps figure
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