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91.
92.
The study of the pseudobinary system Cu(2)SnS(3-)Cu(2)SiS(3) shows that a solid solution (Cu(2)Si(x)Sn(1-x)S(3)) exists in the range 0.4 < or = Si/(Sn+Si) < or = 0.6. Based on diffuse reflectance and photoelectrochemical measurements these compounds show potential as absorber materials for photovoltaic devices. The compounds were prepared at 850 degrees C from copper sulfide, silicon, tin, and sulfur and were analyzed with single-crystal (for x approximately 0.40) and powder diffraction techniques. Optical band gaps of 1.25, 1.35, and 1.45 eV were observed for the three compositions x = 0.39, 0.48, and 0.61; cathodic photocurrent occurring is significant.  相似文献   
93.
The analysis of crystal structures of SF5- or SF4-containing molecules revealed that these groups are often surrounded by hydrogen or other fluorine atoms. Even though fluorine prefers F⋅⋅⋅H over F⋅⋅⋅F contacts, the latter appeared to be important in many compounds. In a significant number of datasets, the closest F⋅⋅⋅F contacts are below 95 % of the van der Waals distance of two F atoms. Moreover, a number of repeating structural motifs formed by contacts between SF5 groups was identified, including different supramolecular dimers and infinite chains. Among SF4-containing molecules, the study focused on SF4Cl compounds, including the first solid-state structure analyses of these reactive species. Additionally, electrostatic potential surfaces of a series of Ph-SF5 derivatives were calculated, pointing out the substituent influence on the ability of F⋅⋅⋅X contact formation (X=F or other electronegative atom). Interaction energies were calculated for different dimeric arrangements of Ph-SF5, which were extracted from experimental crystal structure determinations.  相似文献   
94.
SU‐8 is an important, epoxy‐based, negative photoresist that can create high aspect ratio features. Spectroscopic ellipsometry (SE) is a nondestructive analytical technique that can be performed in the open air. In this study, reflection and transmission SE measurement data were combined to model the optical function of SU‐8 photoresist. The data were fit using three different models: (i) a B‐spline model, (ii) a four‐Gaussian oscillator model with an ultraviolet (UV) and an infrared (IR) pole, and (iii) a Cody–Lorentz model with three additional Gaussian oscillators. All three models successfully fit the data, where the B‐spline model showed the lowest mean squared error. In situ SE data were also collected and fitted to follow possible changes in the optical properties of the SU‐8 during its development. Time‐dependent density functional theory (TD‐DFT) modeling of a complete SU‐8 monomer is qualitatively and quantitatively consistent with the measured optical function.  相似文献   
95.
We propose a new method for the numerical solution of backward stochastic differential equations (BSDEs) which finds its roots in Fourier analysis. The method consists of an Euler time discretization of the BSDE with certain conditional expectations expressed in terms of Fourier transforms and computed using the fast Fourier transform (FFT). The problem of error control is addressed and a local error analysis is provided. We consider the extension of the method to forward-backward stochastic differential equations (FBSDEs) and reflected FBSDEs. Numerical examples are considered from finance demonstrating the performance of the method.  相似文献   
96.
Gaussian factor models futures and forward prices   总被引:1,自引:0,他引:1  
Email: hyndman{at}mathstat.concordia.ca Received on 31 July 2006. Accepted on 19 March 2007. We completely characterize the futures price and forward priceof a risky asset (commodity) paying a stochastic dividend yield(convenience yield). The asset (commodity) price is modelledas an exponential affine function of a Gaussian factors process,while the interest rate and dividend yield are affine functionsof the factors process. The characterization we provide is basedon the method of stochastic flows. We believe this method leadsto simpler and more clear-cut derivations of the futures priceand forward price formulae than alternative methods. Hedginga long-term forward contract with shorter term futures contractsand bonds is also examined.  相似文献   
97.

Abstract  

The compound 5, containing the novel heterocycle 2-oxa-4,7-diazabicyclo[3.3.1]non-3-ene, has been obtained in a synthetic approach toward oxazoles and 1,3-diazepanes of natural product-like complexity from cyclization and rearrangement of δ-lactam cyanamides. When this procedure was applied to a silyl-protected N-((3S,4S,5S)-4,5-dihydroxy-2-oxopiperidin-3-yl)cyanamide (2b) formation of the novel heterobicyclic scaffold 5 was observed along with the expected oxazole (3b) and diazepane (4b) products. The crystal structures of 5 and diazepane 4b are described. Compound 5 crystallized from methanol in the monoclinic system, P21 space group with unit cell parameters a = 15.3402(9), b = 7.2717(4), c = 22.5803(13), β = 106.8620(10) and a cell volume of 2410.5(2) A3.  相似文献   
98.
We consider factor models for interest rates and asset prices where the risk- neutral dynamics of the factors process is modelled by an affine diffusion. We characterize the factors process and bond price in terms of forward–backward stochastic differential equations (FBSDEs), prove an existence and uniqueness theorem which gives the solution explicitly, and characterize the bond price as an exponential affine function of the factors in a new way. Our approach unifies the results, based on stochastic flows, of Elliott and van der Hoek (Finance Stoch 5:511–525, 2001) with the approach, based on the Feynman-Kac formula, of Duffie and Kan (Math Finance 6(4):379–406, 1996), and addresses a mistake in the approach of Elliott and van der Hoek (Finance Stoch 5:511–525, 2001). We extend our results on the bond price to consider the futures and forward price of a risky asset or commodity.   相似文献   
99.
100.
To understand structural variation for personal genomics, an extensive ensemble of large DNA molecules will be required to span large structural variations. Nanocoding, a whole‐genome analysis platform, can analyze large DNA molecules for the construction of physical restriction maps of entire genomes. However, handling of large DNA is difficult and a system is needed to concentrate large DNA molecules, while keeping the molecules intact. Insert technology was developed to protect large DNA molecules during routine cell lysis and molecular biology techniques. However, eluting and concentrating DNA molecules has been difficult in the past. Utilizing 3D printed mesofluidic device, a proof of principle system was developed to elute and concentrate lambda DNA molecules at the interface between a solution and a poly‐acrylamide roadblock. The matrix allowed buffer solution to move through the pores in the matrix; however, it slowed down the progression of DNA in the matrix, since the molecules were so large and the pore size was small. Using fluorescence intensity of the insert, 84% of DNA was eluted from the insert and 45% of DNA was recovered in solution from the eluted DNA. DNA recovered was digested with a restriction enzyme to determine that the DNA molecules remained full length during the elution and concentration of DNA.  相似文献   
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