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Nephrite is a kind of valuable jade which forms during metamorphism under greenschist facies conditions. Most investigations focus on the genesis of nephrite, however, the formation age of nephrite remains poorly constrained due to the lack of suitable dating methods. In this paper, the petrological, chemical characteristics, and mineral inclusions of nephrite collected from Luanchuan, Henan, China have been studied by optical and electron microscopy and wavelength-dispersive electron microprobe (EMP). The petrological observations show that nephrite consists mainly of tremolite, minor calcite and titanite, occasionally with rutile, quartz, serpentine, chlorite, pyrite, and apatite. The titanite and tremolite which are intergrown with each other share low-energy grain boundaries. It indicates that the two phases are equilibrated and can be considered as cogenetic. The chemical composition of tremolite is high in Si, Mg, Ca, but low in Fe, Cr, and Ni, which indicates that the nephrite from Luanchuan belongs to the dolomite type rather than the serpentinite type. The petrography of different nephrite structures suggests that the grain size of tremolite was determined by the stress intensity undergone during the nephrite formation progress. In-situ Secondary Ion Mass Spectrometer (SIMS) U–Pb dating of titanite from nephrite yielded an age of 361 ± 4 Ma, which is the first estimate for the time of formation of the Luanchuan nephrite deposit. This investigation provides a powerful in-situ dating method to unravel the age of nephrite, which could be served as a tool for future research on other nephrite deposits.

Zeta potential of micron-size tourmaline powders are studied using the laser granulometer and the Zeta potential analyzer. The result from the experiment shows, in the neutral condition, the micron-size tourmaline is negatively charged under water and Elbaite powder has the highest Zeta potential among all tested ones; the smaller the tourmaline powder is, the higher Zeta potential it has; heat-treated samples under reducing conditions have higher Zeta potential than those under oxidizing conditions by 4~5 mV; Dravites isoelectric point is 3.4, falling within the acid range.

The heterogeneous conglomeration method, chemical precipitation method and Hydroxy combination theory are adopted in the paper through detailed theoretical analysis and contrast experiments. Tourmaline powder surface is completely covered with ZnO by 1.2:1 mass ratio of ZnO to tourmaline powder. Submicron-nanometer powder is achieved due to 78.71 mean particle diameter, the electrical resistivity of composite powder is decreased to 7.45Ω.cm. Improvement of conductive performance extends the application of tourmaline in the field of environmental purification.

High powered pulsed xenon lamp is widely used in laser inertial confinement fusion research as the optical pump source. And the cathode is very important for the performance of xenon lamp when operated as pump sources of lasers. With the development of material and technology new tungsten electrode doped with rare earth elements has been developed as cathode of xenon lamp.

Infrared spectra of ambers from Baltic, Dominica and Myanmar are obtained by Specular Reflection and KBr Pellet Transmission Methods. Although the infrared spectra of these ambers present similar features for ambers from different locations, refined differences in location and intensity of absorption peaks could be identified among them. Between 3000 and 2800 cm(-1), two obvious bands with a weak shoulder peak are seen in the Baltic amber spectrum, whereas there are two bands in the Dominica's and three bands in the Myanmar's. In region of 1740~1690 cm(-1), one band appears at 1732 cm(-1) in the spectra of the Baltic amber sample, distinctly different from those of the Dominican and Myanmar ambers which have a doublet at 1730 and 1695 cm(-1). For the Dominican amber, the intensity of 1730 cm(-1) is much stronger than that of 1695 cm(-1), being contrary to the spectra of the Myanmar amber, whose intensity of 1730 cm(-1) is weaker than that of 1695 cm(-1). Within region of 1300~1000 cm(-1), Baltic amber can be distinguished from other two origin ambers by a horizontal shoulder, often called "Baltic shoulder", with a definite band at 1163 cm(-1). Spectra of the Dominican amber show a unique band at 1240 cm(-1), while spectra of the Myanmar amber have a triplet at 1224, 1130 or 1154 cm(-1) and 1033 cm(-1), like "wave of mountain" altogether. Ratios of absorption intensity of 1381 vs. 1456 cm(-1) are about 0.9, 0.8 and 0.7 respectively for the Baltic, Dominican and Myanmar ambers. These differences of absorption spectra could be used as the identifiable characteristics corresponding to the ambers locality. The correlation between the ambers' infrared spectra and localities is probably due to their age, plant provenance and geological environment indivadually. On the basis of presence and intensity of the bands attributed to exocyclic methylene groups, it is suggested that the Myanmar amber formed earliest, followed by Baltic and then the youngest Dominican. These finding reveals that infrared spectroscopy may have significance for identifing amber locality, and thus potentially have archeological implications in determining source of some ancient ambers.

In this paper, it is proved that every weakly continuous local 2-cocycle of a nest subalgebra of a factor von Neumann algebra with coefficients in the factor von Neumann algebra is a 2-cocycle.

Separate absorption grading charge multiplication avalanche photodiodes (SAGCM APDs) are widely accepted in photon starved optical communication systems due to the presence of large photocurrent gain. In this work, we present a detailed analysis of dark currents of planar-type SAGCM InGaAs–InP APDs with different thicknesses of multiplication layer. The effect of the diffusion process, the generation-recombination process, the tunneling process and the multiplication process on the total leakage current is discussed. A new empirical formula has been established to predict the optimal multiplication layer thickness of SAGCM APDs with dark current limited by generation-recombination at multiplication gain of 8.

The effects of cephradinum and ceftazidime on the metabolism of Escherichia coli (E. coli) DH5alpha was determined by microcalorimetry. The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37 degrees C. The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (Pm) and the time (tm) corresponding to the maximum power output were calculated. The results show that the ceftazidime has a better inhibitory effect on E. coli DH5alpha than cephradinum.

Let N be a nest on a complex separable Hilbert space H, and τ(N) be the associated nest algebra. In this paper, we prove that every biderivation of τ(N) is an inner biderivation if and only if dim0+≠1 or dimH-⊥≠1, and that every generalized biderivation of τ(N) is an inner generalized biderivation if dim0+≠1 and dimH-⊥≠1.