Real Hypersurfaces in Complex Two-plane Grassmannians with {\mathfrak{D}^{\bot}}-Parallel Shape Operator

In this paper we consider a new notion of ${\mathfrak{D}^{\bot}}$ -parallel shape operator for real hypersurfaces in complex two-plane Grassmannians ${G_2(\mathbb{C}^{m+2})}$ and give a non-existence theorem for a Hopf hypersurface in ${G_2(\mathbb{C}^{m+2})}$ with ${\mathfrak{D}^{\bot}}$ -parallel shape operator.     

Hypersurfaces with isometric Reeb flow in complex hyperbolic two-plane Grassmannians

We classify the real hypersurfaces with isometric Reeb flow in complex hyperbolic two-plane Grassmannians _SU2,m/S(_U2⋅_Um)${\mathit{SU}}_{2,m}/S(U_2\cdot U_m)$, m?2$m?2$. Each can be described as a tube over a totally geodesic _SU2,m−1/S(_U2⋅_Um−1)${\mathit{SU}}_{2,m-1}/S(U_2\cdot U_{m-1})$ in _SU2,m/S(_U2⋅_Um)${\mathit{SU}}_{2,m}/S(U_2\cdot U_m)$ or a horosphere whose center at infinity is singular.     

Estimating the depth and lifetime of a fluorescent inclusion in a turbid medium using a simple time-domain optical method

A simple time-domain optical method for estimating the depth (d) and lifetime (tau) of fluorescent inclusions in a turbid medium is described. We demonstrate the method for depth and lifetime estimation of a fluorescent inclusion directly by fitting a monoexponential decay (tau(eff)) of the temporal position of the temporal point-spread function and the measurement of its maximum temporal position (t(max)). Since both of these measurements are intensity independent, this method provides a robust and efficient approach. This method is validated with experimental data.     

Photocurrent measurements on GaAs1−xNx epilayers grown by metalorganic chemical vapor deposition

GaAs_1−xN_x epilayers were grown on a GaAs(0 0 1) substrate by metalorganic chemical vapor deposition. Composition was determined by high resolution X-ray diffraction. Band gap was measured from 77 to 400 K by using photocurrent measurements. The photocurrent spectra show clear near-band-edge peak and their peak energies drastically decrease with increasing nitrogen composition due to band gap bowing in the GaAs_1−xN_x epilayers. Those red shifts were particularly notable for low nitrogen compositions. However, the shifts tended to saturate when the nitrogen composition become higher than 0.98%. When the nitrogen composition is in the range 1.68–3.11%, the measured temperature dependence of the energy band gap was nicely fitted. However, the properties for the nitrogen composition range 0.31–0.98% could not be fitted with a single fitting model. This result indicates that the bowing parameter reaches 25.39 eV for low nitrogen incorporation (x=0.31%), and decreases with increasing nitrogen composition.     

The tri-methyl-Sb flow and the surfactant time effect on InGaAsN/GaAs-strained MQWs grown by MOCVD

The tri-methyl-Sb flow and the surfactant time dependence of photocurrent (PC) spectra was studied on InGaAsN/GaAs-strained multiple quantum wells (MQWs) structures grown by using metalorganic chemical vapor deposition (MOCVD). The structural properties of InGaAsN/GaAs-strained MQWs were investigated by using high-resolution X-ray diffraction (HRXRD). In the case of InGaAsN/GaAs-strained MQWs, an increase in compressive strain from an analysis of the satellite peaks in HRXRD was observed on increasing the tri-methyl-Sb flow and the surfactant time. For InGaAsN/GaAs-strained MQWs, the peaks observed in the photocurrent spectra were preliminarily assigned to electron–heavy hole (e₁–hh) and electron–light hole (e₁–lh) fundamental excitonic transitions. Their peaks are red-shifted with increasing tri-methyl-Sb flow and surfactant time. But the photocurrent peak is blue-shifted at the surfactant time of . It seems to be due to the improvement of structure properties at interface owing to a surfactant-suppressing surface diffusion phenomenon during growth. We compared this with the result of the experimental energies for InGaAsN/GaAs-strained MQWs.     

Crystal structure of a macrocyclic tetraamine isocyanato zinc(II) complex

The complex, [Zn(L)(NCO)]Cl · 3H₂O (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane), has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/n with a = 10.530(3), b = 9.315(2), c = 27.188(3) Å, = 92.58(1)°, V = 2664.1(9)ų, and Z = 4. The zinc atom is in a distorted squarepyramidal environment with the four nitrogen atoms of the macrocycle and one nitrogen atom of the isocyanate ligand.     

Synthesis and crystal structure of macrocyclic nickel(II) complex bridged by chromate

A novel compound catena-(-CrO₄-O,O)[Ni(L¹)Ni(L²)] 3H₂O (1) (L¹ = 3,5,10,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane and L² = 2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane) has been synthesized for the first time and structurally characterized. 1 crystallizes in the triclinic space group P with a = 9.623(1), b = 10.084(1), c = 12.723 (3) Å, = 66.74(2), = 75.20(1), = 72.02(1)°, V = 1066.2(3) ų, and Z = 2. The coordination environment around the Ni(II) ions is an axially elongated octahedron with the secondary amines of the isomeric ligands and two oxygen atoms of [CrO₄]^2–.