C₂H <i>N</i> = 1 − 0 and N₂H⁺<i>J</i> = 1 − 0 observations of <i>Planck</i> Galactic cold clumps

Liu, X.-C.,Wu, Y.,Zhang, C.,Liu, T.,Yuan, J.,Qin, S.-L.,Ju, B.-G.,Li, L.-X. EDP Sciences 2019 Astronomy and astrophysics Vol.622 No.-

<P>A survey of C2H <I>N</I> = 1 − 0 and N2H<SUP>+</SUP><I>J</I> = 1 − 0 toward <I>Planck</I> Galactic cold clumps (PGCCs) was performed using the Purple Mountain Observatory’s 13.7 m telescope. C2H and N2H<SUP>+</SUP> were chosen to study the chemical evolutionary states of PGCCs. Among 121 observed molecular cores associated with PGCCs, 71 and 58 are detected with C2H <I>N</I> = 1 − 0 and N2H<SUP>+</SUP><I>J</I> = 1 − 0, respectively. The detected lines of most sources can be fitted with a single component with compatible <I>V</I>LSR and line widths, which confirms that these PGCC cores are very cold (with gas temperatures 9-21 K) and quiescent while still dominanted by turbulence. The ratio between the column densities of C2H and N2H<SUP>+</SUP> (<I>N</I>(C2H)/<I>N</I>(N2H<SUP>+</SUP>)) is found to be a good tracer for the evolutionary states of PGCC cores. Gas-grain chemical model can reproduce the decreasing trend of <I>N</I>(C2H)/<I>N</I>(N2H<SUP>+</SUP>) as a function of time. The cores with the lowest abundances of N2H<SUP>+</SUP> (<I>X</I>[N2H<SUP>+</SUP>] < 10<SUP>−10</SUP>) are the youngest, and have nearly constant abundances of C2H. In evolved cores with <I>X</I>[N2H<SUP>+</SUP>] ~10<SUP>−9</SUP>, abundances of C2H drop quickly as the exhaustion of carbon atoms. Although these PGCC cores are in different evolutionary states, they are all quite young (< 5 × 10<SUP>5</SUP> yr) with <I>N</I>(C2H) > <I>N</I>(N2H<SUP>+</SUP>). Mapping observations are carried out toward 20 PGCC cores. The PGCC cores in Cepheus have lower <I>N</I>(C2H)/<I>N</I>(N2H<SUP>+</SUP>) and larger line widths compared with those in Taurus. This implies that PGCC cores in Taurus are less chemically evolved than those in Cepheus.</P>

Fabrication of p-Type Nitrogen-Doped MgZnO by Depressing N-Related Donors

B. Yao,Z. P. Wei,Y. F. Li,D. Z. Shen,Y. M. Lu,Z. Z. Zhang,B. H. Li,C. J. Zheng,X. H. Wang,J. Y. Zhang,D. X. Zhao,X. W. Fan,Z. K. Tang 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

Wurtzite nitrogen-doped MgZnO (MgZnO:N) films were grown on c-plane sapphire by using plasma-assisted molecular beam epitaxy with radical NO as the oxygen source and nitrogen dopant. P-type conduction of MgZnO:N was obtained by decreasing the donor defects ((N2)O, VO, etc.) through annealing, revealing a hole concentration of 6.1 × 1017 cm−3 and a mobility of 6.42 cm2/Vs. Furthermore, as-grown p-type films with a hole concentration of 1 × 1017 cm−3 and a mobility of 3 cm2/Vs were obtained by decreasing the (N2)O double donor defect through control of the plasma conditions. ZnMgO:N/ZnO p-n junctions were obtained by using these p-type films. ode-like, rectifying I-V characteristics with a threshold voltage of about 5 V and a different reverse leakage current were observed at room temperature.

Quantifying herbicide dose-response and resistance in <i>Echinochloa</i> spp. by measuring root length in growth pouches

Zhang, C. J.,Lim, S. H.,Kim, J. W.,Song, J. S.,Yook, M. J.,Nah, G.,Valverde, B. E.,Kim, D. S. Canadian Science Publishing 2015 Canadian journal of plant science. Revue canadienn Vol.95 No.6

<P> Zhang, C. J., Lim, S. H., Kim, J. W., Song, J. S., Yook, M. J., Nah, G., Valverde, N. E. and Kim, D. S. 2015. Quantifying herbicide dose-response and resistance in Echinochloa spp. by measuring root length in growth pouches. Can. J. Plant Sci. 95: 1181-1192. The aim of the presented study was to develop a bioassay for rapid diagnosis of herbicide dose-response and resistance in Echinochloa. Pre-germinated seeds of Echinochloa spp. were incubated in growth pouches (18 cm×16.5 cm) containing herbicide solutions in a range of concentrations. Shoot and root lengths were measured after 6 d of incubation. Dose-responses estimated by measuring root lengths in the growth pouches were well-described by the log-logistic dose-response model and similar to those estimated by a whole-plant assay. Accurate dose-response curves were successfully generated for several herbicides with different modes of action, suggesting that the growth pouch method can be used for herbicide bioassays. The suitability of the growth pouch method for rapid diagnosis of acetyl coenzyme-A carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor resistance in Echinochloa spp. was also tested. For cyhalofop-butyl, resistant and susceptible biotypes were discriminated at 180-300 mg a.i. L<SUP>−1</SUP> and 80-120 mg a.i. L<SUP>−1</SUP> for barnyardgrass (E. crus-galli) and late watergrass (E. oryzicola), respectively. For penoxsulam, the discriminatory dosage was 350-500 mg a.i. L<SUP>−1</SUP> for barnyardgrass and 650-1000 mg a.i. L<SUP>−1</SUP> for late watergrass. The method was further used to identify late watergrass biotypes resistant and susceptible to two other ALS inhibitors, azimsulfuron and bispyribac-sodium. Our results show that the growth pouch method can be reliably used in herbicide dose-response studies and to diagnose herbicide resistance in Echinochloa spp., with significant time and cost savings compared with conventional whole-plant assays. </P>

THE TAOS PROJECT: RESULTS FROM SEVEN YEARS OF SURVEY DATA

Zhang, Z.-W.,Lehner, M. J.,Wang, J.-H.,Wen, C.-Y.,Wang, S.-Y.,King, S.-K.,Granados, Á,. P.,Alcock, C.,Axelrod, T.,Bianco, F. B.,Byun, Y.-I.,Chen, W. P.,Coehlo, N. K.,Cook, K. H.,de Pater, I.,Kim American Institute of Physics 2013 The Astronomical journal Vol.146 No.1

<P>The Taiwanese-American Occultation Survey (TAOS) aims to detect serendipitous occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (<10<SUP>–3</SUP> events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS monitors typically ~500 stars simultaneously at a 5 Hz readout cadence with four telescopes located at Lulin Observatory in central Taiwan. In this paper, we report the results of the search for small Kuiper Belt objects (KBOs) in seven years of data. No occultation events were found, resulting in a 95% c.l. upper limit on the slope of the faint end of the KBO size distribution of q = 3.34-3.82, depending on the surface density at the break in the size distribution at a diameter of about 90 km.</P>

Expression Analysis of the Mx Gene and Its Genome Structure in Chickens

Yin, C.G.,Du, L.X.,Li, S.G.,Zhao, G.P.,Zhang, J.,Wei, C.H.,Xu, L.Y.,Liu, T.,Li, H.B. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.7

Among the known interferon-induced antiviral mechanisms, the Mx pathway is one of the most powerful pathways. The Mx protein has direct antiviral activity and inhibits a wide range of viruses by blocking an early stage of the viral replication cycle. Cloning, characterization, and expression of Mx in vivo and in vitro have been conducted. The chicken Mx gene spans 21 kb and is made up of 14 exons and 13 introns, of which the promoter region was analyzed. The real-time PCR results showed that Mx expression was increased in chicken embryo fibroblasts (CEF) after 12- and 24-h induction with polyI: C. Induction of Mx expression by poly I: C in vivo revealed tissue-specific patterns among the chicken tissues tested. A trace expression of Mx was detected in healthy chicken liver tissues from adult chickens without inducement; the expression levels in the liver, heart, and gizzard were higher than in the muscle and kidney. This is the first report to demonstrate the expression of a glutathione-S-transferase-tagged-Mx fusion protein of 75 KDa, as well as the biological activity tested by SDS-PAGE and western blotting.

Evaluation of VIIRS, GOCI, and MODIS Collection 6 AOD retrievals against ground sunphotometer observations over East Asia

Xiao, Q.,Zhang, H.,Choi, M.,Li, S.,Kondragunta, S.,Kim, J.,Holben, B.,Levy, R. C.,Liu, Y. Copernicus GmbH 2016 Atmospheric Chemistry and Physics Vol.16 No.3

<P>Abstract. Persistent high aerosol loadings together with extremely high population densities have raised serious air quality and public health concerns in many urban centers in East Asia. However, ground-based air quality monitoring is relatively limited in this area. Recently, satellite-retrieved Aerosol Optical Depth (AOD) at high resolution has become a powerful tool to characterize aerosol patterns in space and time. Using ground AOD observations from the Aerosol Robotic Network (AERONET) and the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia Campaign, as well as from handheld sunphotometers, we evaluated emerging aerosol products from the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP), the Geostationary Ocean Color Imager (GOCI) aboard the Communication, Ocean, and Meteorology Satellite (COMS), and Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) (Collection 6) in East Asia in 2012 and 2013. In the case study in Beijing, when compared with AOD observations from handheld sunphotometers, 51 % of VIIRS Environmental Data Record (EDR) AOD, 37 % of GOCI AOD, 33 % of VIIRS Intermediate Product (IP) AOD, 26 % of Terra MODIS C6 3 km AOD, and 16 % of Aqua MODIS C6 3 km AOD fell within the reference expected error (EE) envelope (±0.05 ± 0.15 AOD). Comparing against AERONET AOD over the Japan-South Korea region, 64 % of EDR, 37 % of IP, 61 % of GOCI, 39 % of Terra MODIS, and 56 % of Aqua MODIS C6 3 km AOD fell within the EE. In general, satellite aerosol products performed better in tracking the day-to-day variability than tracking the spatial variability at high resolutions. The VIIRS EDR and GOCI products provided the most accurate AOD retrievals, while VIIRS IP and MODIS C6 3 km products had positive biases. </P>

Radiation damage in helium ion – irradiated reduced activation ferritic/martensitic steel

L.D. Xia,W.B. Liu,H.P. Liu,J.H. Zhang,H. Chen,Z.G. Yang,C. Zhang 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.1

Nanocrystalline reduced activation ferritic/martensitic (RAFM) steel samples were prepared using surfacemechanical attrition treatment (SMAT). Un-SMATed and SMATed reduced activation ferritic/martensitic samples were irradiated by helium ions at 200 C and 350 C with 2 dpa and 8 dpa, respectively,to investigate the effects of grain boundaries (GBs) and temperature on the formation of Hebubbles during irradiation. Experimental results show that He bubbles are preferentially trapped at GBsin all the irradiated samples. Bubble denuded zones are clearly observed near the GBs at 350 C, whereasthe bubble denuded zones are not obvious in the samples irradiated at 200 C. The average bubble sizeincreases and the bubble density decreases with an increasing irradiation temperature from 200 C to350 C. Both the average size and density of the bubbles increase with an increasing irradiation dose from2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples butnot in the un-SMATed samples irradiated in the same conditions, which indicate t

Electrical properties and deep traps spectra of a-plane GaN films grown on r-plane sapphire

Polyakov, A.Y.,Smirnov, N.B.,Govorkov, A.V.,Markov, A.V.,Sun, Q.,Zhang, Y.,Yerino, C.D.,Ko, T.S.,Lee, I.H.,Han, J. Elsevier 2010 Materials science & engineering. B, Advanced funct Vol.166 No.3

Electrical properties, deep traps spectra and luminescence spectra were studied for two undoped a-plane GaN (a-GaN) films grown on r-plane sapphire using metalorganic chemical vapor deposition and differing by structural perfection. For sample A, the a-GaN film was directly deposited on AlN buffer. A two-step growth scheme was implemented for sample B, including an initial islanding growth stage and a subsequent enhanced lateral growth. Preliminary detailed X-ray analysis showed that the stacking faults density was 8x10<SUP>5</SUP>cm<SUP>-1</SUP> for sample A and 1.7x10<SUP>5</SUP>cm<SUP>-1</SUP> for sample B. Electrical properties of a-GaN films were largely determined by deep traps with a level near E<SUB>c</SUB> -0.6eV, with other prominent traps having the activation energy of 0.25eV. The Fermi level was pinned by the E<SUB>c</SUB> -0.6eV deep traps for sample A, but shifted to the vicinity of the shallower 0.25eV traps for sample B, most likely due to the reduced density of the 0.6eV traps. This decrease of deep traps density is accompanied by a very pronounced improvement in the overall luminescence intensity. A correlation of the observed improvement in deep traps spectra and luminescence efficiency with the improved crystalline quality of the films is discussed.

Deletion of the Lmna Gene Induces Growth Delay and Serum Biochemical Changes in C57BL/6 Mice

Ruan, J.,Liu, X.G.,Zheng, H.L.,Li, J.B.,Xiong, X.D.,Zhang, C.L.,Luo, C.Y.,Zhou, Z.J.,Shi, Q.,Weng, Y.G. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.1

The A-type lamin deficient mouse line ($Lmna^{-/-}$) has become one of the most frequently used models for providing insights into many different aspects of A-type lamin function. To elucidate the function of Lmna in the growth and metabolism of mice, tissue growth and blood biochemistry were monitored in Lmna-deficient mice, heterozygous ($Lmna^{+/-}$) and wide-type ($Lmna^{+/+}$) backcrossed to C57BL/6 background. At 4 weeks after birth, the weight of various organs of the $Lmna^{-/-}$, $Lmna^{+/-}$ and $Lmna^{+/+}$ mice was measured. A panel of biochemical analyses consisting of 15 serological tests was examined. The results showed that Lmna deficient mice had significantly decreased body weight and increased the ratio of organ to body weight in most of tissues. Compared with $Lmna^{+/+}$ and $Lmna^{+/-}$ mice, $Lmna^{-/-}$ mice exhibited lower levels of ALP (alkaline phosphatase), Chol (cholesterol), CR (creatinine), GLU (glucose), HDL (high-density lipoprotein cholesterol) and higher levels of ALT (alanine aminotransferase) (p<0.05). $Lmna^{-/-}$ mice displayed higher AST (aspartate aminotransferase) values and lower LDL (lowdensity lipoprotein cholesterol), CK-MB (creatine kinase-MB) levels than $Lmna^{+/+}$ mice (p<0.05). There were no significant differences among the three groups of mice with respect to BUN (blood urea nitrogen), CK (creatine kinase), Cyc C (cystatin C), TP (total protein), TG (triacylglycerols) and UA (uric acid) levels (p>0.05). These changes of serological parameters may provide an experimental basis for the elucidation of Lmna gene functions.

Control of the surface atomic population of Rh_0.5Pd_0.5 bimetallic nanoparticles supported on CeO₂

Bernardi, F.,Grass, M.E.,Hong, Y.P.,Chang, R.,Jabeen, N.,Zhang, C.,Eichhorn, B.W.,Seo, B.,Alayoglu, S.,Hussain, Z.,Joo, S.H.,Liu, Z. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.260 No.-

<P>Rh0.5Pd0.5/CeO2 bimetallic nanoparticles were subjected to reducing and oxidizing atmospheres at different temperatures and characterized by means of the Ambient Pressure X-Ray Photoelectron Spectroscopy (AP-XPS). The surface atomic population is calculated for all cases. By using a high temperature pretreatment at 480 degrees C in H-2 atmosphere, it was possible to control the surface atomic population with Pd atoms frozen at the skin layer even in an oxidizing atmosphere, which is not observed without high temperature pre-treatment (Rh atoms at the skin layer). The change of the Rh/Pd surface segregation behavior after the high temperature pre-treatment is attributed to the geometrical factor of Strong Metal Support Interaction (SMSI) effect, i.e., the occurrence of the ceria capping layer around nanoparticles. (C) 2015 Elsevier B.V. All rights reserved.</P>