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In this paper, a high quality ultraviolet light-emitting diodes (UV-LEDs) at 375 nm was developed using a heavy Si-doping technique with metal organic chemical vapor deposition. By using high-resolution X-ray diffraction, the full width at half-maximum of the rocking curve shows that the GaN film inserting a heavily Si-doped GaN layer (Si-HDL) had high crystalline quality. From the transmission electron microscopy image, the threading dislocation density was decreased after inserting a Si-HDL between undoped and n-doped GaN layers by nanoscale epitaxial lateral overgrowth. As a result, a much smaller reverse current and a higher light output were achieved. The improvement of light output at an injection current of 20 mA was enhanced by 40%. Therefore, we can use an in-situ nano pattern without complex photolithography and etching process and improve the internal quantum efficiency of UV-LEDs.

The original plan is to use vibro-stone column composite foundation to treat a large oil tank foundation. The result of strengthening is not satisfactory because of some factors, such as difficulty to control quality and long construction period etc. Treated ground can not meet the design requirements. The key in treatment design of tank foundation lies in bearing capacity and deformation of foundation, especially in non-uniform deformation. Through the analysis of site conditions, composite foundation of CFG piles is adopted. It is designed according to strength and deformation of dual control theory. Experimental results show that the compound used in foundation design is appropriate.

To investigate the effect of ADAM10 inhibitor GI254023X on the proliferation and apoptosis of multiple myeloma H929 cell line and its mechanisms.H929 cells were treated with different concentrations of GI254023X, the proliferation-inhibitive curve was assayed and plotted by CCK-8 method, the cell viability and apoptosis were detected by flow cytometry with Annexin V/7-AAD double staining. The cleavage of Notch1 protein (cleaved notch1) was determined by Western blot. The transcripts of Notch1 target gene Hes-1 were detected by real-time PCR.The GI254023X inhibited the proliferation of H929 cells in the time- and dose- dependent manners. As compared with the control group, the apoptosis of cells increased along with enhancement of GI254023X concentration; The expression of cleaved Notch1 was down-regulated after the treatment with GI254023X. The levels of Hes-1 mRNA transcripts in H929 cells was reduced in GI254023X treated group.GI254023X can remarkably inhibit the proliferation and induce the apoptosis of H929 cells. Its mechanism may be associated with inbihition of Notch1 activation.

1H NMR metabonomics approach was used to reveal the chemical difference of urine between patients with Xiao-Chaihu Tang syndrome (XCHTS) and healthy participants (HP). The partial least square method was used to establish a model to distinguish the patients with Xiao-Chaihu-Tang syndrome from the healthy controls. Thirty-four endogenous metabolites were identified in the 1H NMR spectrum, and orthogonal partial least squares discriminant analysis showed the urine of patients with Xiao-Chaihu Tang syndrome and healthy participants could be separated clearly. It is indicated that the metabolic profiling of patients with Xiao-Chaihu Tang syndrome was changed obviously. Fifteen metabolites were found by S-pot of OPLS-DA and VIP value. The contents of leucine, formic acid, glycine, hippuric acid and uracil increased in the urine of patients, while threonine, 2-hydroxyisobutyrate, acetamide, 2-oxoglutarate, citric acid, dimethylamine, malonic acid, betaine, trimethylamine oxide, phenylacetyl glycine, and uridine decreased. These metabolites involve the intestinal microbial balance, energy metabolism and amino acid metabolism pathways, which is related with the major symptom of Xiao-Chaihu Tang syndrome. The patients with Xiao-Chaihu Tang syndrome could be identified and predicted correctly using the established partial least squares model. This study could be served as the basis for the accurate diagnostic and reasonable administration of Xiao-Chaihu-Tang syndrome.

To reveal the underlying mechanism of doxorubicin induced hepatotoxicity, an NMR-based metabolomic approach combined with multivariate statistical analysis was used to observe its metabolic alternations of rat liver. Sixteen differential metabolites between model rats and normal rats were characterized as potential pathological biomarkers related to doxorubicin induced hepatotoxicity. Six pathways, including phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, phenylalanine metabolism, glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, and tyrosine metabolism were regarded as the targeted metabolic pathways according to Metabolic Pathway Analysis (MetPA). The results suggested that the metabolic perturbations in rats with doxorubicin induced hepatotoxicity were mainly involved in amino acid metabolism, lipid pathways, purine metabolism, energy metabolism, dysfunction of biotransformation and oxidative stress. The investigation revealed the effects of doxorubicin on liver in a holistic metabolic way, which laid a foundation for further studies on its toxicity mechanism.

To investigate the effect of alantolactone on perliferation and apoptosis of multiple myeloma (MM) RPMI-8226 cells, and to explore its possible mechism in vitro and in vivo.The RPMI-8226 cells were treated with alantolactone (1, 2.5, 5, 7.5 and 10 µmol/L) for 48 h, cell viability was detected by CCK-8 assay and the value of IC50 was calculated; The RPMI-8226 cells were treated with alantolactone (2.5, 5 and 7.5 µmol/L) for 48 h, the apoptotic rate was detected by flow cytmetry with Annexin V/PI staining; the expression level of cleaved caspase-3 and phosphorylation of ERK were measured by Western blot; the nude mice was used to further confirm the proapoptotic effect of alantolactone on MM cells in vivo.The alantolactone inhibited RPMI-8226 cell viability remarkably with a dose-dependent manner; the IC50 value of RPMI-8226 cells at 48 h was 4.32 ± 0.15 µmol/L; the apoptotic rate increased observably with a dose-dependent manner; the levels of cleaved-caspase-3 increased and the phosphorylation of ERK decreased significantly; as compared to control, the volum of tumor was much smaller, the expression levels of Ki67 and p-ERK decreased.The alantolactone can efficiently inhibit the proliferation and induce the apoptosis of multiple myeloma RPMI-8226 cells in vitro and in vivo through inhibiting the activation of ERK signal pathway.

This paper reviews the fabrication technology and performance characteristics of current-injected GaN-based vertical-cavity surface-emitting lasers (VCSELs) with hybrid distributed Bragg reflectors (DBRs). The GaN-based VCSEL consists of a ten-pair Ta2O5/SiO2 top DBR, a 7 λ-thick optical cavity embedded with 10 InGaN/GaN multiquantum wells, and a 29-pair AlN/GaN bottom DBR. Lasing action is observed under continuous-wave operation at room temperature. The laser characteristics, such as temperature-dependent laser threshold current, emission wavelength, and spontaneous emission coupling factors, have been measured and discussed.

A new carbon nanotube (CNTs)–poly acrylonitrile (PAN) composite electrolyte was prepared by the thermal polymerization of acrylonitrile (AN) with CNTs for solid-state dye sensitized solar cells (DSSCs). It was found that the uniform CNT–PAN composite was formed due to the thermal polymerization of AN on CNTs. The strong bonding between CNTs and PAN could be confirmed by the characterization of XPS and Raman spectroscopy, resulting in the lowering of crystallinity and the increasing the ionic conductivity of composite electrolytes. On comparison with bare CNTs and the other composite electrolytes, the formation of triiodide (I3−) ions in CNT–PAN composite electrolytes was drastically increased which was expected from the high ionic conductivity of electrolyte via I3−/I− redox couple. DSSCs fabricated with CNT–PAN composite electrolytes achieved relatively high conversion efficiency of 3.9% with an open circuit voltage (VOC) of 0.57 V, short circuit current density (JSC) of 10.9 mA/cm2 and fill factor of 63.6%, which attributed to supply the higher extent of I3− ions from CNT–PAN composite electrolyte during the charge transport process.

Plasma Chemical Vapor Deposition ( PCVD ) is an important application in making optical fiber core rod. The resonator is the key part for PCVD application. But the existing resonator have several serious disadvantages: its working is not stable; the size of deposited substrate tube is small(Ø31mm); the deposition rate is low(2.5g/min) and the deposition effect is unsymmetrical; the fabrication of the resonator is very difficult and expensive. Therefore, a new type of resonator, a cylinder resonator, is designed to overcome the above disadvantages. The cylinder resonator supports bigger substrate tube (Max Ø60mm) and higher deposition rate(3.2g/min) than existing ones, while its working is also more stable. Since the structure is more simple, the fabrication is easier and cheaper. The corresponding microwave theoretical method of the new resonator designing is also introduced with the necessary computer simulation, as well as test running. And TE111 mode microwave is the Fundamental Mode of the cylinder resonator. The cylinder resonator has been applied in normal production for 4 years, which is better for bigger size core rod making, improving the optical fiber quality and saving cost. It is estimated, after modification with the cylinder resonator and 10kW microwave generator, a PCVD lathe can yield 30% more rods than before.

A natural hybrid species in Petrocosmea named Longianthera in Yanshan County, Yunnan Province is confirmed for the first time based on molecular and morphological evidence. The character count procedure of the variable characters show that Longianthera populations are characteristic of the intermediate morphological traits between its putative parents Yanshan and Petrocosmea martinii. The nuclear ribosomal internal transcribed spacer region and three chloroplast regions of matK, trnL-F, and trnT-L are sequenced in the putative hybrid and the related species. Both alignment of DNA sequences and the phylogenetic trees could exclude all the other species in Petrocosmea as the parental species except for Yanshan and P. martinii. Eight haplotypes in the 31 internal transcribed spacer sequences and six haplotypes in 42 cpDNA sequences were found from 14 individuals of Longianthera populations. The analyses of DNA sequences, haplotypes, and phylogenetic trees indicate that Longianthera is likely a hybrid species between its putative parents Yanshan and P. martinii, in which Yanshan might be the most possible maternal parent. Several factors may contribute to the natural hybridization between these two parental species in Petrocosmea, such as the overlapped geographic distribution, habitats, flowering periods, and shared pollinators. Finally, the new species of Yanshan and the natural hybrid species of Longianthera are described.

We investigate the optical and electrical characteristics of the GaN-based light emitting diodes (LEDs) grown on micro- and nano-scale patterned silicon substrate (MPLEDs and NPLEDs). The transmission electron microscopy images reveal the suppression of threading dislocation density in InGaN/GaN structure on nano-pattern substrate due to nano-scale epitaxial lateral overgrowth. The plan-view and cross-section cathodoluminescence mappings show less defective and more homogeneous active quantum-well region growth on nano-porous substrates. From temperature-dependent photoluminescence (PL) and low temperature time-resolved PL measurement, NPLEDs have better carrier confinement and higher radiative recombination rate than MPLEDs. In terms of device performance, NPLEDs exhibit smaller electroluminescence peak wavelength blue shift, lower reverse leakage current and decrease in efficiency droop when compared with the MPLEDs. These results suggest the feasibility of using NPSi for the growth of high quality and power LEDs on Si substrates.

We presented a study of high-performance GaN-based light emitting diodes (LEDs) using a GaN nanopillars (NPs) structure grown on sapphire substrate by integrating RF-plasma molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). Nanoscale air voids were clearly observed at the interface between GaN NPs and the overgrown GaN layer by cross-sectional scanning electron microscopy. It can increase the light-extraction efficiency due to additional light scattering. The transmission electron microscopy images suggest the air voids between GaN NPs introduced during nanoscale epitaxial lateral overgrowth of GaN can suppress the threading dislocation density. Moreover, Raman spectrum demonstrated that the strain of the GaN layer grown on GaN NPs was effectively eliminated, resulting in the reduction of quantum-confined Stark effect in InGaN/GaN quantum wells. Consequently, the LEDs fabricated on the GaN NPs template exhibit smaller electroluminescent peak wavelength blue shift and great enhancement of the light output (70% at 20 mA) compared with the conventional LEDs.

We present a study of high quality (1 1 ¯ 0 1) GaN films and the InGaN/GaN multiple quantum wells (MQWs) using epitaxial lateral overgrowth (ELO) technique by atmospheric pressure metal organic chemical vapor deposition (MOCVD). The smooth coalescence of the stripes and surface morphology was measured by scanning electron microscope (SEM) and atomic force microscopy (AFM). Due to reduction in internal electric field, semipolar InGaN/GaN MQWs have higher radiative recombination rate from time-resolved photoluminescence (TRPL) measurement. In addition, from degree of polarization (DOP) measurement, we observed higher polarization ratio attributed to the induced anisotropic compressive strain.

The effects of post-annealing conducted at 500–650 °C on structural, electrical and optical properties of ZnO film fabricated on GaAs (1 0 0) substrate by atmospheric pressure metal-organic chemical vapor deposition are investigated. X-ray diffraction analyses show that the Zn3As2 and ZnGa2O4 phases are produced for the specimens post-annealed at 500 °C and above. Hall measurements indicate that stable p-type ZnO films with hole concentration ranging from 4.7 × 1018 to 8.7 × 1019 cm−3 can be obtained by modulating the annealing temperature from 500 to 600 °C. In particular, room-temperature photoluminescence (PL) measurements indicate that the superior-quality p-type film could be achieved by a post-annealing treatment at 600 °C. Moreover, low temperature PL spectra at 10 K are dominated by the acceptor-related luminescence mechanisms for the films post-annealed at 550 °C and above. The ionization energy of acceptor was calculated to be 133–146 meV, which is in good agreement with that theoretically predicted for the AsZn–2VZn complex in ZnO. The interdiffused arsenic atoms in the film post-annealed at 600 °C are suggested to form the AsZn–2VZn complex quite effectively, resulting in the most enhanced p-type conductivity and improved material quality.

Chirita D. Don, a large genus in the subfamily Cyrtandroideae of Gesneriaceae, has been the subject of much debate whether it is a natural group or not. In addition, the highly heterogeneous Chirita has also been very problematic with regard to delimitation and subdivision. Here we used the nrDNA internal transcribed spacer and cpDNA trnL-F for molecular phylogenetic analaysis, combined with morphological data. Our results suggest that Chirita is an artificial, polyphyletic genus. The most important character that defines Chirita, the dorso-ventrally oblique and bilamellar stigma, has evolved convergently in different clades of diandrous Cyrtandroideae. Chirita sensu stricto only includes the species of Chirita sect. Chirita, whereas Chirita sect. Microchirita is an independent clade located at the basal node of the phylogenetic tree. Chirita sect. Liebigia is closely related to Didymocarpus with an entire stigma unlike other species of Chirita. The species of Chirita sect. Gibbosaccus, Chiritopsis, Primulina, and Wentsaiboea form a monophyletic group that is sister to a strongly supported clade comprising four monotypic genera Paralagarosolen, Calcareoboea, Petrocodon, and Tengia. We further analyzed the morphological evolution of Chirita and identified a series of morphological synapomorphies for the monophyletic groups revealed herein, and thereby provide a taxonomic treatment in this study.

Lateral variations of the karst of deep buried tunnel engineering is big. The heterogeneity of it is strong. The tunnel is combined with Changsha Rail Transit Line 2 at one section of the first phase construction. Under the urban environmental conditions, it is considered to use auxiliary seismic wave imaging method assistanting with Rayleigh surface wave method. It is the detection and prediction method of comprehensive geological analysis of karst hazard, which identified the underground targets of deep buried tunnel effectively. To avoid a single technique multiple solutions, it can reflect the complexity of karst formations geological features objectively. Therefore, it can reduce the risk of drilling and take appropriate treatment measures to provide adequate and reliable basis.

The structural, electrical, and optical properties of ZnO films fabricated by atmospheric pressure metal organic chemical vapor deposition (AP-MOCVD) under various gas flow ratios of [H2O]/[DEZn] (VI/II ratio) ranging from 0.55 to 2.74 were systematically examined. Hall effect measurements exhibited an evident effect of the VI/II ratio on the conduction type of the intrinsic films. An n-type film was fabricated at the VI/II ratio=0.55; however, p-type ZnO films with the hole concentration of the order of 1017 cm−3 could be achieved at VI/II ratios higher than 1.0. In particular, the highest mobility of 91.6 cm2/V s and the lowest resistivity of 0.369 Ω cm have been achieved for the specimen fabricated at the VI/II ratio=1.10. Moreover, room-temperature photoluminescence (PL) measurements demonstrated an interstitial Zn (Zni) donor defect related emission at 2.9 eV for the n-type film, while a Zn vacancy (VZn) acceptor defect related one at 3.09 eV for the p-type films. The existence of material intrinsic ...

The title polymeric complex [Cu(C4H2O4)(C10H8N2)]n·2nH2O was prepared and its crystal structure was determined by X-ray diffraction methods. The crystal belongs to space group P21/c with cell dimensions of a = 1.0104(1), b = 1.9952(2), c = 0.7357(2) nm, β= 98.38(2)° and Z = 4. The complex forms zig-zag chains along crystallographic axis c via Cu—O (carboxyl) bond in the apical direction. Each repeated unit consists of a square pyramidal Cu(II) centre with one maleate dianion and one 2,2′-bipyridine forming a basal plane. Adjacent chains link to each other by H-bonding between carboxyl groups and crystalline water. The distance of 0.3482 nm between parallel bipyridine rings shows a π-π stacking interaction. The title complex was also characterized by IR, UV and ESR spectra.

The phylogenetic placement of the Old World Gesneriaceae genera Ramonda, Conandron, Bournea, Thamnocharis, and Tengia, all characterized by actinomorphic flowers, has been the subject of much debate. Actinomorphy in Gesneriaceae is rare, with most species exhibiting zygomorphic flowers. The actinomorphic genera have historically been considered "primitive" and lumped in the tribe Ramondeae separate from the remaining Old World Gesneriaceae. In this study, we used nuclear (ITS) and plastid (trnL-F) DNA for molecular phylogenetic analysis of these five genera along with representative species across the Cyrtandroideae. Our results show that the actinomorphic genera are scattered over several otherwise zygomorphic clades within Cyrtandroideae, and along with previous data, indicate that Ramondeae is an unnatural group. Floral actinomorphy has evolved convergently in different alliances of Old World Gesneriaceae. Ramonda is sister to Haberlea, Bournea is apparently paraphyletic, Conandron seems rather isolated, and Tengia is close to Petrocodon and sister to a group of Chirita sect. Gibbosaccus together with Calcareoboea. We hypothesize that the evolution from zygomorphy to actinomorphy with novel combinations of characters is possibly due to shifts in pollination strategies, such as a switch from nectar- to pollen-rewards.

Tetrabutylammonium 4-(2-bromothiophene-5-sulfanilamide)-benzoate crystallizes in C2/C lattice with a = 18.3389(17), b = 16.540(16), c = 15.8280(15) A, β = 116.959(2), V = 4279.5(7) A3, Z = 4, and R = 0.0560. In the structure a very short centrosymmetric hydrogen bond and C=O···Br halogen bond interactions, together with N–H···O and C–H···O hydrogen bonds give a three-dimensional network. A extremely short O–H···O hydrogen bond is observed between the two neighboring 4-(2-bromothiophene-5-sulfanilamide)-benzoates. The H atom is fixed at the crystallographic inversion center and bridges the two benzoates to form an anion dimer. Halogen bonds also aid in forming the interest structure in crystal.

Tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene that encodes a member of the immunoglobulin superfamily, which is involved in the progression of some types of cancer. Several studies have shown that loss of TSLC1 expression is strongly correlated to methylation of the gene promoter, thus leading to poor prognosis in these cancers. However, the role of TSLC1 in cutaneous melanoma (CM) has not been examined. The purpose of this study was to understand the molecular mechanisms and clinical significance of TSLC1 inactivation in CM. The expression and promoter methylation of TSLC1 were analyzed in 120 CMs. TSLC1 expression was examined by immunohistochemistry, whereas its methylation status was determined by methylation-specific PCR. TSLC1 expression was lost in 84 of 120 (70%) CMs; 36 (30%) CMs were scored as positive for TSLC1 protein expression. The TSLC1 promoter was methylated in 58 (48.33%) of 120 CMs. The incidence of the loss of expression and methylation of TSLC1 significantly increased as the tumor stage advanced (P=0.032 and 0.0021, respectively). Furthermore, in CM, disease-related survival was significantly shorter in patients with tumors losing TSLC1 or harboring methylated TSLC1 (P=0.0003 and 0.0329, respectively). The epigenetic silencing of TSLC1 through methylation is an important event in the pathogenesis of CM, and TSLC1 provides an indicator for poor prognosis.

In recent year, Mn2O3 nanomaterials exhibit a high surface area, narrow pore size distribution, large pore volume, and high thermal stability. MnOx materials have shown promising candidates for active electrode materials for various electrochemical systems like fuel cells, supercapacitors etc., due to their high specific capacitance, low cost, abundance and environmentally benign nature. In this work, the mesoporous Mn2O3 nanoparticles (NPs) were synthesized by manganese acetate, citric acid and sodium hydroxide through hydrothermal process at 150 oC for 3h. The synthesized mesoporous Mn2O3 NPs were characterized in terms of their morphology, surface, crystalline, electrochemical and electrochemical properties. For supercapacitor applications, the synthesized mesoporous Mn2O3 NPs based electrode showed the excellent specific capacitance (Csp) of 460 Fg−1 through good electrocatalytic activity by observing good electrochemical properties in 6M KOH. Excellent Csp might be explained by the facts in improving the surface area, porous surface and uniformity, which might favor in generating large active sites and fast ionic transport over the good electrocatalytic surface of the Mn2O3 electrode. The fabricated supercapacitors exhibited good cycling stability after 1000 cycles by maintaining ~ 86% of initial Csp.

A new species of Gesneriaceae, Hemiboea crystallina Y.M.Shui & W.H.Chen from China and Vietnam, is described and illustrated. The new species is diagnostic by the combination of its inflated nodes, glabrous stem, glabrous and lanceolate leaves, 4-winged involucre, margin-reflected calyx segments and the glabrous surface inside corolla. Among the species without hairy ring inside corolla, its morphological distinctiveness from the most similar species, Hemiboea flaccida Chun ex Z.Y.Li, is discussed.

Gallium-doped ZnO films were grown on p-Si(111) substrates by atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD) using diethylzinc and water as reactant gases and triethyl gallium (TEG) as a n-type dopant gas. The structural, electrical, and optical properties of ZnO:Ga films obtained by varying the flow rate of TEG from 0.56to3.35μmol∕min were examined. X-ray diffraction patterns and scanning electron microscopy images indicated that Ga doping plays a role in forming microstructures in ZnO films. A flat surface with a predominant orientation (101) was obtained for the ZnO:Ga film fabricated at a flow rate of TEG=2.79μmol∕min. This film also revealed a lowest resistivity of 4.54×10−4Ωcm, as measured using the van der Pauw method. Moreover, low temperature photoluminescence (PL) emission recorded at 12K demonstrated the Burstein Moss shift of PL line from 3.365to3.403eV and a line broadening from 100to165meV as the TEG flow rate varied from 0.56to2.79μmol∕min. This blueshift behavior o...

Ga-doped zinc oxide (ZnO:Ga) films were grown on glass substrate by atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD) using diethylzinc and water as reactant gases and triethyl gallium (TEG) as an n-type dopant gas. The structural, electrical and optical properties of ZnO:Ga films obtained at various flow rates of TEG ranging from 1.5 to 10 sccm were investigated. X-ray diffraction patterns and scanning electron microscopy images indicated that Ga-doping plays an important role in forming microstructures in ZnO films. A smooth surface with a predominant orientation of (101) was obtained for the ZnO:Ga film grown at a flow rate of TEG = 7.5 sccm. Moreover, a lowest resistivity of 3.6 × 10 − 4 Ω cm and a highest mobility of 30.4 cm 2 V − 1 s − 1 were presented by the same sample, as evaluated by Hall measurement. Otherwise, as the flow rate of TEG was increased, the average transmittance of ZnO:Ga films increased from 75% to more than 85% in the wavelength range of 400–800 nm, simultaneously with a blue-shift in the absorption edge. The results obtained suggest that low-resistivity and high-transparency ZnO films can be obtained by AP-MOCVD using Ga-doping sufficiently to make the films grow degenerate and effect the Burstein–Moss shift to raise the band-gap energy from 3.26 to 3.71 eV.

Two new acetonyl-bearing sesquiterpenes, dysifragilisins A and B (1 and 2, resp.), have been isolated from the Hainan marine sponge Dysidea fragilis. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analyses and by comparison of their NMR data with those of structurally related compounds. A plausible biogenetic pathway is proposed for the origin of compounds 1 and 2.

A high-quality AlN/GaN distributed Bragg-reflectors (DBR) was successfully grown on sapphire substrate by low-pressure metal-organic chemical vapor deposition using ultra-thin AlN/GaN superlattice insertion layers (SLILs). The reflectivity of AlN/GaN DBR with ultra-thin AlN/GaN SLIL was measured and achieved blue peak reflectivity of 99.4% at 462 nm. The effect of ultra-thin AlN/GaN superlattice insertion layer was examined in detail by transmission electron microscopy, and indicated that the crack of AlN/GaN DBR can be suppress by inserting AlN/GaN SLIL. For electronic properties, the turn on voltage is about 4.1 V and CW laser action of vertical-cavity surface-emitting laser (VCSEL) was achieved at a threshold injection current of 1.4 mA at 77 K, with an emission wavelength of 462 nm.

by Lu-Lu Yua), Zhen-Yu Lib), Chong-Sheng Pengc), Zhi-Yong Li*a), and Yue-Wei Guo*b) a) Key Laboratory of Microbial Metabolism, Ministry of Education, China, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China b) State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Science, Zu Chong Zhi Rd. 555, Shanghai 201203, P. R. China (phone: þ 86-21-50805813; e-mail: ywguo@mail.shcnc.ac.cn) c) School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China

Two new Daphniphyllum alkaloids, 4,21-deacetyl-deoxyyuzurimine (1) and macropodumine L (2), together with the two known related alkaloids, have been isolated from the bark of Daphniphyllum macropodum Miq. The structures of the new compounds were elucidated on the basis of the detailed analysis of spectroscopic data, chemical method, and by comparison of the spectroscopic data with those of known compounds. Compounds 2 and 4 exhibited weak cytotoxicity against human carcinoma cell lines SMMC-7721 and HO-8910.

High-quality GaN layer was successfully grown on a SiO 2 nanorod-array patterned sapphire substrate (NAPSS) using metal-organic chemical vapor deposition by a nanoscaled epitaxial lateral overgrowth (NELO) method. From tunneling electron microscope images, well coalescence and turned dislocations are parallel to the surface direction were clearly observed. The Raman shift measurement shows the residual stress in GaN was greatly reduced from 1.359 to 0.652 GPa when compared to a GaN on flat sapphire substrate. Also, a high-efficiency GaN-based light-emitting diodes (LEDs) were demonstrated on the NELO NAPSS GaN, the respective output power and external quantum efficiency of the NELO NAPSS LEDs were estimated to be 22 mW and 40.2% at an injection current of 20 mA, showing an enhancement factor of 52% over conventional LEDs. The significant improvement resulted from both the enhanced light extraction assisted by the NAPSS, and the reduced dislocation densities using the NELO method.

A new species of Gesneriaceae, Chirita maguanensis Z.Y.Li, H.Jiang & H.Xu, is described from Southern Yunnan, China. It is similar to C. eburnea Hance in its large, fleshy, white and parallel-veined bracts, but differs by having broad and oblique leaves with a repand–crenate or crenate margin, suborbicular bracts, membranous, white calyx, purple corolla-tube, 2-parted lower lip of stigma and lower disc. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 269–273.

Three new N-containing sesquiterpenes, isofarnesyl formamide (2), 7-formamido-7,8-dihydro-α-bisabolane (3), 4,5-epi-10-isothiocyanatoisodauc-6-ene (4), and a known sesquiterpene, farnesyl formamide (1), were isolated from the Hainan marine sponge Axinyssa sp. The structures of the new compounds were elucidated by detailed analyses of their spectroscopic data and by comparison of their NMR data with those of structurally related compounds.

Five new sesquiterpenes, named lingshuiolides A (1) and B (2), lingshuiperoxide (6), isodysetherin (10), and spirolingshuiolide (12), along with several known related analogues (7- 9, 11, and 13- 15), were isolated from the Hainan marine sponge Dysidea septosa. The structures of new compounds 1, 2, 6, 10, and 12 were determined by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds. The absolute configuration of lingshuiolide B (2) was established by using the modified Mosher's method. Spirolingshuiolide (12) represents the first example of a sesquiterpene with a rearranged drimane skeleton. Compounds 7- 9 and 15 exhibited significant inhibitory activity against human protein tyrosine phosphatase 1B (hPTP1B), an enzyme involved in the regulation of insulin signaling. In particular, 15 showed the most potent effect, with an IC 50 value of 1.9 microg/mL.

Indium nitride (InN) epilayers have been successfully grown on Si (111) substrates with low-temperature (450°C) grown InN and high-temperature (1050°C) grown AlN (InN∕AlN) double-buffer layers by atmospheric-pressure metal-organic chemical vapor deposition (AP-MOCVD). X-ray diffraction characterizations indicated that highly (0001)-oriented hexagonal InN was grown on Si (111) substrate. Photoluminescence (PL) analyses performed at room temperature showed a strong emission at 0.72eV with a full width at half maximum of 121meV. Excitation intensity dependent measurements demonstrated the PL mechanism to be the band-to-band transition. Time-resolved PL could be fitted by a single exponential exhibiting an ordered film and a recombination lifetime of around 0.85ns. In particular, transmission electron microscopy characterizations indicated that the use of AlN first buffer is very important to achieve a structurally uniform (0001)-oriented InN epilayer on Si (111) by AP-MOCVD.

Silicon-rich nitride (SRN) films that can exhibit an intense white-light emission were fabricated by atmospheric pressure chemical vapor deposition. SRN films were deposited on Si substrates using gaseous SiH2Cl2 (DCS) and NH3 as the source materials for Si and N, respectively. The deposition temperature was kept at 850 °C, and H2 was used as the carrier gas with its flow rate modulated to maintain chamber pressure at 1 atm during the deposition. The optical properties of films obtained at various deposition times from 15 to 60 min were examined by photoluminescence (PL) measurement. An intense luminescence band (1.5–3.5 eV) was observed by the naked eye for all as-deposited samples. Besides, time-resolved PL exhibited a short radiative lifetime of about 1 ns for SRN films. Moreover, high resolution plan-view transmission electron microscopy demonstrated the existence of Si dots in SRN films with the dot sizes ranging from 2 to 6 nm and a dot density of about 4×1012/cm2. On the basis of the results obtained, we considered that the related luminescence mechanism for SRN films is connected to crystalline Si dots produced therein.

In 2 Se 3 films were deposited on the p + -Si(1 1 1) substrates by metal-organic chemical vapor deposition (MOCVD) for the first time at temperatures higher than 500 °C. Trimethyl indium (TMI) and H 2 Se were used as the source reactants with the flow ratio of [H 2 Se]/[TMI] being maintained at 6.7. The growth temperature was varied from 350 to 650 °C. Powder X-ray diffraction analyses revealed that the In 2 Se 3 film grown is polycrystalline and has a wurtzite structure when the growth temperature is below 450 °C. Instead, a rhombohedral structure began to appear when the growth temperature is above 450 °C. Besides, SEM observations indicated a surface morphology of columnar structure for all films grown. Optical properties were examined by photoluminescence (PL) measurements. It was found that by conducting the growth at 550 °C a strong PL emission at around 2.14 eV was observed at 20 K. The luminescence mechanism was found to be dominated by the free excitons based on the temperature-dependent PL spectra from 20 to 120 K. However, bound exciton emissions were also observed or even became the dominant band when the films were grown at temperatures lower than 500 °C. Otherwise, the intensity of the 2.14 eV peak reduced greatly when the growth temperature was higher than 550 °C. Power-dependent PL measurements with excitation power varying from 0.1 to 100 mW confirm the luminescent mechanism and the material quality of the film grown at 550 °C. It is concluded that single-phase γ-In 2 Se 3 films can be achieved at temperatures lower than 450 °C; however, good-quality In 2 Se 3 films with the simultaneous appearance of γ- and β-phase structures can be grown at around 550 °C.

Undoped zinc oxide (ZnO) thin films were deposited on Si (100) substrates by atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD). After a nucleation layer of ZnO about 500 A was deposited, top ZnO films with 320–440 nm in thickness were fabricated at temperatures varying from 450 to 600 °C, respectively. X-ray diffraction analyses demonstrate that all the films grown have polycrystalline wurtzite structure. Scanning electron microscopy observations indicate that ZnO films grow with c-axis aligned grains when the deposition temperature is lower than 600 °C. However, 3D microstructures without c-axis alignment were found when the film was deposited at 600 °C. Room temperature photoluminescence (PL) spectra peaking at 3.27–3.29 eV were observed for the ZnO films grown at 450–600 °C. However, only the spectrum from the film grown at 600 °C could present a high intensity ratio of the ultraviolet band to deep-level emissions, which is above 392 and show a minimum full-width at half-maximum of 99 meV for the ultraviolet band. Temperature-dependent PL measurements from 20 to 300 K exhibited the luminescent mechanism of the present ZnO films to be near band excitonic emission.

Well-aligned good-quality carbon nanotube (CNT) array was grown on silicon substrate by atmospheric pressure chemical vapor deposition (APCVD) through SiO2 masking. First, the patterned substrate was pretreated with NH3 and then CNTs were synthesized at 800 °C using Ni as the catalyst, acetylene (C2H2) as the carbon source material and N2 as the carrier gas. Effects of the NH3-pretreatment time, the flow ratio of [C2H2]/[NH3] and the CNT growth time on the qualities of CNT array were analyzed in detail. It was found that good-quality CNTs with an average length of around 15 μm could be grown by pretreating the Si substrate with NH3 for 10 min and then conducting the CNT growth with a flow ratio of [C2H2]/[NH3] = 30/100. Furthermore, the field emission property of CNT array was investigated using a diode structure. It was found that the turn-on electric field decreased with increasing CNT length. The turn-on electric field as low as about 2 V/μm with an emission current density of 10 μA/cm2 was achieved for a CNT-array diode with the tube length near 18 μm. For the same device, the emission current density could be elevated to 10 mA/cm2 with the applied voltage of 3.26 V/μm.

Bark beetle species in natural stands of spruce, Picea crassifolia (Kom.) were investigated in Maixiu Forest Park, Qinghai Province, northwest China, during 2005 and 2007. Two pioneer Ips species, Ips nitidus Eggers and Ips shangrila Cognato and Sun were found. I. nitidus occurs naturally in northwest China. I. shangrila is a new species in the world. In the past, it was confused with I. mannsfeldi Wachtl in China. The damage of these two Ips species has been very severe in Maixiu and the morphological and bio- logical characteristics were studied. I. nitidus starts to fly in early May and prefers the mid to lower part of the host tree to colonize as its habitat. I. shangrila always infests from the top of the trunk, especially in branches larger than 3 cm in diameter in the crowns and sometimes even colonizes entire young trees. The two Ips species are the most destructive secondary bark beetles on P. crassifolia and always cause mortality of trees by their cooperation.

Four new Daphniphyllum alkaloids, namely dehydroxymacropodumine A (1), 4,21-deacetyl-23-demethyl-deoxyyuzurimine (2), 7-oxo-deoxyyuzurimine (3), and 4-acetoxydaphmanidin B (4), together with seven known related alkaloids, were isolated from the bark of Daphniphyllum macropodum Miq. The structures of new compounds 1–4 including relative configurations were elucidated on the basis of detailed spectroscopic data analysis and by comparison with related known compounds. Dehydroxymacropodumine A (1) possesses a rare eleven-membered macrolactone ring representing the second example of this backbone isolated from natural sources.

This work describes the preparation of titanium nitride (TiN) films on Si (111) substrates by atmospheric pressure halide chemical vapor deposition (AP-HCVD). Various TiN films were obtained by exploiting TiCl4 + NH3 gas chemistry with flow ratios [NH3]/[TiCl4] from 0.2 to 1.4, and deposition temperatures (Td) from 600 to 900 °C. When Td = 800 °C gold-colored films with electrical resistivities of under 100 μΩ cm were formed at almost all of the investigated [NH3]/[TiCl4] flow ratios. In particular, a lowest resistivity of about 23.7 μΩ cm, which is quite close to that of bulk TiN, was achieved using an [NH3]/[TiCl4] flow ratio of 0.3. Atomic force microscopy indicated that the root mean square surface roughness of that film was only about 5.1 nm. Under the same [NH3]/[TiCl4] flow ratio as above, X-ray diffraction analyses revealed the presence of a cubic TiN phase with a preferred orientation of (200) for Td ≤ 800 °C, while additional (111) and (220) orientations emerged when the film was deposited at 900 °C. In conclusion, a low resistivity (< 100 μΩ cm) TiN film can be formed by AP-HCVD with very low [NH3]/[TiCl4] flow ratios 0.3–1.4.

Diterpenoids, excoagallochaols A–D ( 1 – 4 ), with an unprecedented skeleton, were isolated from the ethyl acetate extract of the stems and leaves of the mangrove Excoecaria agallocha L. The structures of these metabolites were elucidated on the basis of detailed analysis of their spectroscopic data and by comparison with those of related compounds reported in literature.

Four new cembranoid diterpenes, sarcophytonolides I–L (1–4), were isolated from the Hainan soft coral Sarcophyton latum. Their structures were established by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds.

Five new polycyclic Daphniphyllum alkaloids, macropodumines F (1) and G (2), 17-oxoyuzurimine (3), and macropodumines H (4) and I (5), were isolated from the leaves of D. macropodumMiq., collected in Sichuan Province, China. The structures and relative configurations of the new compounds – as well as of four known, related alkaloids – were elucidated on the basis of in-depth spectroscopic and mass-spectrometric analyses, by chemical derivatization, and by comparison of spectroscopic data with those of known compounds.

A low resistivity ohmic contact to poly-GaN was achieved using the multilayer metal combination of Ti (50 A)/Au (100 A)/Ni (100 A)/Au (3000 A). Exactly how rapid thermal annealing (RTA) affects the specific contact resistivity ( ρ c ) was also studied by varying the temperature and duration of annealing. An improvement in ρ c of over one order of magnitude was achieved over the as-deposited condition with good reproducibility by RTA treatment for a total duration of 120 s. In particular, by optimizing the annealing temperature to 400 °C a relatively low ρ c of 1.6 × 10 −5 Ω cm 2 was yielded for the contact of Ti/Au/Ni/Au to poly-GaN with a carrier concentration of (5–6) × 10 17 cm −3 . Related mechanism for the improvement in ρ c was discussed based on the results obtained from X-ray diffraction analysis and transmission electron microscopy observations.

1H NMR-based metabolomic approach combined with multivariate statistical analysis was used to evaluate the quality of 21 Farfarae Flos (FF) samples from different growth regions. Principal component analysis showed that wild and cultivated FF could be separated clearly, suggesting a big chemical difference existed between them. Supervised PLS-DA analysis indicated that the wild samples showed higher levels of secondary metabolites, such as bauer-7-ene-3β, 16α-diol, chlorogenic acid, rutin, 7-(3'-ethylcrotonoyloxy)-1α-(2'-methyl-butyryloxy)-3, 14-dehydro-Z-notonipetranone (EMDNT), tussilagone, β-sitosterol and sitosterone. This is consistent with traditional experience that the quality of wild samples are better than that of cultivated ones. The content of pyrrolizidine alkaloids senkirkine also differed greatly among samples from different habitats. The Pearson correlation analysis showed that senkirkine is positively correlated with 4, 5-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, rutin, kampferol analogues, to a statistically significant extent. The correlation between the toxic compounds and the bioactive components in FF should be further studied.

Growth year is one of the important factors for the quality of Polygala tenufolia. In this study, primary metabolites and secondary metabolites were compared in 1, 2 and 3 years old P. tenufolia cultivated in Shaanxi Heyang. The samples were subjected to ultra-high performance liquid chromatography (UPLC)-quadrupole time-of-flight mass spectrometry (Q-TOF MS) and nuclear magnetic resonance (NMR) analysis, and the obtained data were analyzed using principal component analysis (PCA) and other statistical analysis methods. In addition, content and correlation of different metabolites were also calculated. The results showed no significance between main component contents in 2 year-old and 3 year-old P. Tenufolia, but 1 year-old was statistically different. The contents of primary metabolites, such as fructose, sucrose, and choline increased as time goes on, while glycine and raffinose decreased. The contents of secondary metabolites, such as onjisaponin Fg, polygalasaponin XXVIII, polygalasaponin XXXII increased, while polygalaxanthone III and parts of oligosaccharide multi-ester including tenuifoliose A, tenuifoliose C, tenuifoliose C2 and tenuifoliose H decreased with the extension of the growth years. Growth years has important impact on the quality of P. tenuifolia and the existing growing years of commodity P. tenuifolia have its scientific evidence. This study supplied a new method for the quality evaluation of Chinese medicinal materials.

This work demonstrated the preparation of new and effective antireflection SiC-SiO2 nanocomposite by sol-gel process for Si solar cells. The AR coating was conducted in two steps: i) sol-gel derived precursor was coated on p-type Si wafer by spin coating, and ii) the coated wafer was subjected to annealing at 450°C for 1h. The reflectance analysis revealed that SiC-SiO2 layers presented the relatively low reflectance (7.08%) in wavelengths ranging from 400 to 1000 nm. The fabricated Si solar cell with SiC-SiO2 AR attained very comparable energy conversion efficiency of 16.99% to the Si solar cells with SiNx AR.