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BACKGROUND: Chameleon diamond is a kind of color diamond with photochromic and thermochromic phenomenon. If the chameleon diamond is placed in a dark room or heated for a long time, it can change from greenish yellow to fancy yellow, and return to its original color when the diamond cools. Previous studies on chameleon diamond mainly focus on spectral characteristics. Through testing a large number of samples, the gemological and spectral characteristics of chameleon diamond are summarized. The characteristics of chameleon diamond, including persistent yellow phosphorescence, 480nm absorption band, mainly the A-aggregate of nitrogen, and proposed a model to explain the thermochromic and photochromic phenomenon of chameleon diamond.The characteristics of chameleon diamond discovered by previous studies are also found in a few yellow diamonds. Diamonds colored by the 480nm band shows yellow fluorescence and phosphorescence under short wave ultraviolet light, low nitrogen content, high concentrations of defects related to hydrogen and nickel, but no obvious thermochromic and photochromic phenomena. Previous studies of the chameleon diamond and similar yellow diamonds were separated and did not compare the two similar diamonds. OBJECTIVES: To ascertain the difference of spectral characteristics and defect types between chameleon diamonds and similar yellow diamonds and then analyze the causes of thermochromic phenomenon of chameleon diamond, and have a deeper comprehend of the possible structure of the center responsible of the chameleon effect. METHODS: Firstly, two chameleon diamond samples and four similar yellow diamond samples were collected to observe the color changes of the diamonds before and after heating. Top illumination and scattering illumination were used to observe the internal characteristics and color distribution of the samples. The fluorescence and phosphorescence characteristics of diamonds at long wave （365nm） and short wave （254nm） were observed by ordinary fluorescent lamp. The fluorescence and phosphorescent characteristics and growth structure of the samples under ultra-violet light were observed by Diamond View MT. Secondly, in order to investigate the causes of thermochromism in chameleon diamond, the absorption characteristics of diamond samples in the range of ultraviolet visible light were collected before and after heating, and compared with those of similar yellow diamonds. Analyze the differences in absorption spectra between chameleon diamond and similar yellow diamond, explore the causes of thermochromic phenomena. Finally, infrared spectrometer was used to collect the infrared spectrum of diamond samples and analysis of the types and impurity elements of diamond samples. Through the comparative analysis of the infrared spectrum of samples, the differences in the types and contents of nitrogen and hydrogen impurities between chameleon diamond and similar yellow diamond were obtained.The laser Raman spectrometer was used to collected PL spectra of the samples at liquid nitrogen temperature by using 473nm,532nm and 830nm lasers. By comparing the PL characteristics of chameleon diamond and similar yellow diamond, the differences between the two defects were obtained. RESULTS: The color distribution of the 6 diamond samples was uniform. After heating, the chameleon diamond samples changed color from yellow-green to yellow, similar yellow diamonds had no obvious color change. Under long and short wavelength UV light, the samples were yellow fluorescence without phosphorescence. The performance of the samples in this study is consistent under long and short wavelength ultraviolet light, but it is different from the previous study results that the chameleon diamond has persistent yellow phosphorescence, which further indicates that the chameleon effect is not directly related to the phosphorescence. Under ultra-violet light, the samples were all green fluorescence with irregular patterns which were markedly similar to diamonds colored by the480nm band. Chameleon diamonds showed moderate green phosphorescence. All the samples have C defect absorption continuum combines with of 480nm absorption band. The specific wide absorption band of 650-800nm is obvious in chameleon diamond. After being heated, the 480nm and 650-800nm absorption band of chameleon diamond completely disappeared. However, the 480nm absorption band of similar yellow diamonds is weakened or has no obvious change. Therefore, the poor thermal stability of 480nm and 650-800nm absorption band is responsible for the thermochromic phenomenon of chameleon diamonds. The infrared absorption characteristics of chameleon diamond mainly show A-center absorption, isolated nitrogen and hydrogen-related features can be seen. In addition to the characteristic 1430cm-1 wide absorption which has a different origin than the platelet-related1430cm-1 feature in Cape diamond. The similar yellow diamond has higher nitrogen content, and the degree of nitrogen aggregation is higher, and does not show any type Ib character. The broadband emission of all samples occurred mainly as one band centered at 700nm, this band consists of a dozen of peaks from 595nm to 725nm in steps of about 10nm.Additionally sharp peaks at 753,771,799,818,838,845nm present in the chameleon diamond samples. This spectrum is virtually identical to that reported previously for diamonds containing the 480nm absorption band. Chameleon diamonds and similar yellow diamonds all contain nitrogen-vacancy, nickel-nitrogen related defects, but the amount of defects are different. Chameleon diamonds cannot be effectively distinguished based on the PL spectral. The PL spectrum analysis showed that the nickel impurity was responsible for the green fluorescence of the samples under ultra-violet light. CONCLUSIONS: This study focuses on the comparative analysis of gemology, UV-visible absorption, infrared absorption and photoluminescence characteristics of chameleon diamond and its similar yellow diamond. Chameleon diamond is Ia diamond, the total nitrogen, as well as the A-center concentration, is relatively low, and show some type Ib character, such as 1240cm-1 absorption. Chameleon diamond has 480nm and 650-800nm absorption bands, that were responsible for chameleon effect. The characteristics of chameleon diamond in this study are roughly same as those in previous studies. Absorption bands of 650-800nm and absorption peaks of1430cm-1 （unrelated to platelet） are the main differences between the chameleon diamond and similar yellow diamond sample. It is inferred that the absorption band of 650-800nm and the absorption peak of 1430cm-1 are related to the center causing the thermochromic phenomenon. Although similar yellow diamond samples also have 480nm center, their thermal stability is different from that of chameleon diamonds. The reason for this phenomenon is unknown, therefor further studies are needed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Through visiting the jadeite market, the existence of inorganic material-filled jadeite is known, but there is a lack of identification basis due to rare references. OBJECTIVES: To understand the identification characteristics of inorganic material-filled jadeite. METHODS: Two types of inorganic materials, water glass and silica sol, were used to fill low-grade jadeite in the simulation experiment. Conventional gemological tests, fluorescence image observation with DiamondViewTM, Fourier transform infrared (FTIR) spectroscopy, and laser-induced breakdown spectroscopy (LIBS) were used to test the inorganic filled jadeite samples. RESULTS: The transparency, color, density and structure of jadeite were improved after filling. Under the DiamondViewTM, the jadeite particles in the sample showed green fluorescence, and the filling around the cracks and between the particles displayed blue fluorescence with non-uniform distribution. Mid-infrared reflectance spectrum analysis showed that the spectra of silica sol and water-glass were slightly different from each other. The absorption peaks of the samples filled with inorganic materials at 1162 cm-1, 1070 cm-1, 949 cm-1, 579 cm-1, 529 cm-1 and 470 cm-1 gradually weakened, and the peak shape gradually became smooth or disappeared. In addition, the differences between the jadeite and inorganic filled jadeite can be determined by the near-infrared spectral morphology and the shape of the absorption peak changed in the range of 7062 cm-1, 5204 cm-1 and 4537 cm-1. The laser-induced breakdown spectroscopy demonstrated that the content of the silicon in the jadeite filled with silicon sol or sodium and potassium water-glass was higher. The high potassium content was an important feature for the jadeite filled by sodium and potassium water-glass. CONCLUSIONS: The samples effect of the simulation experiment needs to be improved, but the identification characteristics of the filled jadeite with inorganic materials are recognized, which has caused a further breakthrough in the enhancement and treatment of jadeite identification. [ABSTRACT FROM AUTHOR]

Uncaria rhynchophylla contains large amount of alkaloids and abounds in natural resources, and has the function of heat-clearing for calming liver and wind-calming for calming frightened. In order to make clear the material basis of stems and leaves of U. rhynchophlla, in this paper, the chemical constituents of stems and leaves from U. rhynchophylla and their antitumor activities were studied. The extracts were isolated and purified by using silical gel, Sephadex LH-20, semi-HPLC, and the structures of the compounds were identified by physicochemical property and spectrum analysis. The antitumor activities of chemical constituents against K562, HEL cell lines were assessed by MTT method. Seven compounds were isolated and identified from stems of U. rhynchophylla as 3, 4, 5-trimethoxyphenol(1),scutellarin(2), isohydrohydrogenine(3), dehydroramine(4), Vallesiachotamine(5), isorhynchophylline(6), rhynchophylline(7). Twelve compounds were isolated and identified from leaves of U. rhynchophylla as octadecanol(8), β-sitosterol(9), tridecanoicacid(10), 2-methyl-5,7-dihydroxy-chroone-7-O-β-D-glucopyranoside(11), oleanolic acid(12), quercetin(13), ivy aglycone(14), kaempferol(15),(6R, 9R )-9-hydroxymegastigman-4-en-3-one(16), ursolic(17), epicatechin(18), emodin methylether(19). The results of antitumor activities were as follows:(1)Compounds 3 and 5 inhibited the activities of HEL cell lines, and IC50 values were 17.96 and 73.01 μg·mL-1; Compound 5 inhibited the activities of K562 cell lines, and IC50 values were 16.45 μg·mL-1, which indicate that some compounds from stems of U. rhynchophylla have certain antitumor activities.(2)Compounds 1, 8,10 and 16 were isolated from this plant for the first time. This study shed the scientific light on reasonable utilization and sustainable development of plant resources. [ABSTRACT FROM AUTHOR]

To study on chemical constituents and bioactivity of Larix gmelinii needles, separation and purification of ethyl acetate extract from Larix gmelinii needles were carried out by silica gel column chromatography，semi-preparative high performance liquid chromatography，and re-crystallization. The structures of isolated compounds wrere identified by analysis of spectra of MS，NMR，and compared wdth the reported conferences. The antibacterial activity of the extract ■was also tested. The results 'were as follo'ws: Compounds 1-15 wrere isolated from the ethyl acetate extract and identified as Larixol ( 1)，( 2R)-5, 4,-dihydroxy-6-methyl-7-methoxy flavone ( 2 ), 2', 4,-dihydroxy-4, 6,-dimethoxydihydro- chalcone (3) , 2,,4-dihydroxy-4,,6,-dimethoxy-chalcone (4) , 2,,4,-dihydroxy-4,6,-dimethoxy-chalcone (5) , isorham- netin (6)，4'，5-dihydroxy-7-methoxy-8-methyl flavone (7)， kaempferol (8)， p-sitosterol (9)， stigmasterol (10)， daucosterol (11)，vanillic acid (12)，hydroxyl-benzoic acid (13)， dimethyl - matairesinol (14)，and 15-nonacosanol (15). Compounds 2，4，5，and 7 were isolated from the genus Pinus for the first time. The result of antibacterial activity indicated that the inhibition rates of ethyl acetate extract to Escherichia coli，Bacillus subtilis，B. cereus，and Staphylococcus aureus were 55%-70%，53%-72%，61%-71%，33%-65%，respectively，at the concentration range of 5-100 mg • mL 1. The results of this study wall provide a theoretical basis for further study on the chemical composition and pharmacological activity of Larix gmelinii. [ABSTRACT FROM AUTHOR]

Using TAW-2000 servo testing machine and Germany VallenAMSY-6 acoustic emission signal acquisition system, the acoustic emission characteristics of marble under uniaxial compression, constant amplitude cyclic loading and unloading and tiered cyclic loading and unloading were studied. In addition, using Fast Fourier Transformation (FFT),the acoustic emission spectrum characteristics of marble under uniaxial compression and Kaiser points and Felicity points in the process of tiered cyclic loading and unloading were analyzed. Test results show that: Firstly, main frequency locate mainly in two areas, which are the regions less than 200 kHz and near 300 kHz, and the main frequency varies from low frequency to high frequency and the amplitude of main frequency declines on the whole with the increasing stress. Secondly, a new indicator to reflect acoustic emission waveform information, namely SF (secondary frequency) -by-MF (main frequency) ratio α, was put forward and in the process of uniaxial compression test SF (secondary frequency)-by-MF (main frequency) shows ascendant trend. Thirdly, the change of main frequency at Kaiser point and Felicity point is not obvious and the SF (secondary frequency)-by-MF (main frequency) ratio at Felicity point is higher than the one at Kaiser point in the hierarchical cyclic loading and unloading process. At last, by regarding AE (Acoustic Emission) counts at the point of stress in the second cycle whose stress is equal to the peak stress of first cycle as the "significant increased" scale of Kaiser effect, obvious Felicity effect is showed. [ABSTRACT FROM AUTHOR]

A complex protection scheme for power distribution line based on information fusion of power current and fault transient current was presented. In this scheme, band pass filters were connected at boundaries of protected zones in parallel. Due to the attenuation of transient component of fault current at frequency pass-band of the device, the difference of transient current spectrum energy in the frequency band between internal faults and external faults was strengthened. The results of PSCAD / EMTDC simulation prove the obvious difference, and protection setting value can be chosen based on the results of simulation. For reducing the loss of information caused by "Discount Rule", the basic belief assignments of transient current and power current were set up by full subset reference vector method. Two evidences were fused by the D-S evidence combination theory, and a decision-making method based on the basic belief assignment was used to discriminate the internal faults. The simulation results prove that the scheme is an available mine 6/10 kV distribution line protection solution, which can not only discriminate internal faults or external faults, but also can ensure protection reliability under lighting strike or switch operating. [ABSTRACT FROM AUTHOR]