135 research outputs found

    CO Emission Delineating the Interface between the Milky Way Nuclear Wind Cavity and the Gaseous Disk

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    Based on the MWISP survey, we study high-z CO emission toward the tangent points, in which the distances of the molecular clouds (MCs) are well determined. In the region of l=12-26 deg and |b|<5.1 deg, a total of 321 MCs with |z|> 110 pc are identified, of which nearly 30 extreme high-z MCs (EHMCs at |z|> 260 pc) are concentrated in a narrow region of R_GC=2.6-3.1 kpc. The EHMC concentrations, together with other high-z MCs at R_GC=2.3-2.6 kpc, constitute molecular crater-wall structures surrounding the edges of the HI voids that are physically associated with the Fermi bubbles. Intriguingly, some large high-z MCs, which lie in the crater-walls above and below the Galactic plane, show cometary structures with the head toward the plane, favouring the scenario that the entrained molecular gas moves with the multi-phase flows from the plane to the high-z regions. We suggest that the Milky Way nuclear wind has a significant impact on the Galactic gaseous disk. The powerful nuclear wind at ~3-6 Myr ago is likely responsible for the observational features, (1) the enhanced CO gas lying in the edges of the HI voids, (2) the deficiency of atomic and molecular gas within R_GC<3 kpc, (3) the possible connection between the EHMC concentrations and the 3-kpc arm, and (4) the elongated high-z MCs with the tail pointing away from the Galactic plane.Comment: 27 pages, 7 Figures, 1 Table. To appear in ApJ. Comments are welcome

    Understanding the Kinetic Energy deposition within Molecular Clouds

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    According to the structures traced by 13^{13}CO spectral lines within the 12^{12}CO molecular clouds (MCs), we investigate the contributions of their internal gas motions and relative motions to the total velocity dispersions of 12^{12}CO MCs. Our samples of 2851 12^{12}CO MCs harbor a total of 9556 individual 13^{13}CO structures, among which 1848 MCs (∼\sim 65%\%) have one individual 13^{13}CO structure and the other 1003 MCs (∼\sim 35%\%) have multiple 13^{13}CO structures. We find that the contribution of the relative motion between 13^{13}CO structures (σ13CO,re\sigma_{\rm ^{13}CO, re}) is larger than that from their internal gas motion (σ13CO,in\sigma_{\rm ^{13}CO, in}) in ∼\sim 62%\% of 1003 MCs in the `multiple' regime. In addition, we find the σ13CO,re\sigma_{\rm ^{13}CO, re} tends to increase with the total velocity dispersion(σ12CO,tot\sigma_{\rm ^{12}CO, tot}) in our samples, especially for the MCs having multiple 13^{13}CO structures. This result provides a manifestation of the macro-turbulent within MCs, which gradually becomes the dominant way to store the kinetic energy along with the development of MC scales.Comment: 15 pages, 13 figures, accepted for publication in Ap

    Relative velocities between 13^{13}CO structures within 12^{12}CO Molecular clouds

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    Velocity fields of molecular clouds (MCs) can provide crucial information on the merger and split between clouds, as well as their internal kinematics and maintenance, energy injection and redistribution, even star formation within clouds. Using the CO spectral lines data from the Milky Way Imaging Scroll Painting (MWISP) survey, we measure the relative velocities along the line of sight (Δ\DeltaVLOS_{\rm LOS}) between 13^{13}CO structures within 12^{12}CO MCs. Emphasizing MCs with double and triple 13^{13}CO structures, we find that approximately 70%\% of Δ\DeltaVLOS_{\rm LOS} values are less than ∼\sim 1 km s−1^{-1}, and roughly 10%\% of values exceed 2 km s−1^{-1}, with a maximum of ∼\sim 5 km s−1^{-1}. Additionally, we compare Δ\DeltaVLOS_{\rm LOS} with the internal velocity dispersion of 13^{13}CO structures (σ13CO,in\sigma_{\rm ^{13}CO,in}) and find that about 40%\% of samples in either double or triple regime display distinct velocity discontinuities, i.e. the relative velocities between 13^{13}CO structures are larger than the internal linewidths of 13^{13}CO structures. Among these 40%\% samples in the triple regime, 33%\% exhibit signatures of combinations through the two-body motion, whereas the remaining 7%\% show features of configurations through the multiple-body motion. The Δ\DeltaVLOS_{\rm LOS} distributions for MCs with double and triple 13^{13}CO structures are similar, as well as their Δ\DeltaVLOS_{\rm LOS}/σ13CO,in\sigma_{\rm ^{13}CO,in} distributions. This suggests that relative motions of 13^{13}CO structures within MCs are random and independent of cloud complexities and scales.Comment: 16 pages, 11 figures, accepted for publication in A

    A Systematic Study of Associations between Supernova Remnants and Molecular Clouds

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    We universally search for evidence of kinematic and spatial correlation of supernova remnant (SNR) and molecular cloud (MC) associations for nearly all SNRs in the coverage of the MWISP CO survey, i.e. 149 SNRs, 170 SNR candidates, and 18 pure pulsar wind nebulae (PWNe) in 1 deg < l < 230 deg and -5.5 deg < b < 5.5 deg. Based on high-quality and unbiased 12CO/13CO/C18O (J = 1--0) survey data, we apply automatic algorithms to identify broad lines and spatial correlations for molecular gas in each SNR region. The 91% of SNR-MC associations detected previously are identified in this paper by CO line emission. Overall, there could be as high as 80% of SNRs associated with MCs. The proportion of SNRs associated with MCs is high within the Galactic longitude less than ~50 deg. Kinematic distances of all SNRs that are associated with MCs are estimated based on systemic velocities of associated MCs. The radius of SNRs associated with MCs follows a lognormal distribution, which peaks at ~8.1 pc. The progenitor initial mass of these SNRs follows a power-law distribution with an index of ~-2.3 that is consistent with the Salpeter index of -2.35. We find that SNR-MC associations are mainly distributed in a thin disk along the Galactic plane, while a small amount distributed in a thick disk. With the height of these SNRs from the Galactic plane below ~45 pc, the distribution of the average radius relative to the height of them is roughly flat, and the average radius increases with the height when above ~45 pc.Comment: 77 pages, 20 figures, 4 tables (with machine-readable versions), accepted for publication in ApJ

    Effect of Cu doping on the microstructure and mechanical properties of AlTiVN-Cu nanocomposite coatings

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    Cu phase has been incorporated into hard coatings to form nanocomposite structure, which not only enhanced the hardness but also the toughness due to excellent ductility of copper. In this study, a single Al67Ti33-V-Cu spliced target was used to prepare the AlTiVN-Cu nanocomposite coatings, and the effect of Cu doping on microstructure and mechanical properties of AlTiVN-Cu coatings has been investigated. The results showed that the deposition rate linearly increased from 3.8 to 13.4 nm/min when Cu content increased from 2.6 to 46.7 at.%. AlTiVN-Cu coatings exhibited a Ti-Al-V-N solid-solution phase with strong (111) preferred orientation at low Cu contents below 8.3 at.%. When Cu content increased above 22.6 at.%, Cu atoms grew up into metallic crystallites and strongly suppressed crystal growth of nitride coatings due to repeated nucleation. With increasing Cu content, the microstructure transferred from compact columnar to dense featureless, and then to coarse columnar structure. AlTiVN-Cu(2.6 at.%) coating exhibited a super hardness of 41.1 GPa and an excellent toughness with a high H3/E*2 ratio of 0.24

    Synthesis of Icariin-Zinc and its Protective Effect on Exercise Fatigue and Reproductive System Related Glands in Male Rats

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    Background: Icariin, a traditional Chinese medicine, plays a protective role in the treatment of exercise fatigue. Zinc, a trace element, plays an important role in the reproductive system. Therefore, we aimed to synthesize an Icariin-Zinc complex (by chemical means) and verify its protective effect on exercise fatigue and the reproductive system using animal experiments.Methods: The icariin-zinc complex was prepared by the reaction of icariin carbonyl and zinc ions (molar ratio 1:3). The molecular formula and structural formula of the complex were identified and tested. Fifty-six rats selected by swimming training were randomly divided into six groups: static control, exercise control, icariin, gluconate zinc (G-Zn group), icariin glucose zinc and icariin-zinc exercise ( low, high dose/L-E group, H-E group) groups. These groups respectively received the following doses: 1 ml/100 g, daily gavage with NS (for the first two groups), 45 mg/kg icariin, 110 mg/kg Gluconate Zinc, Icariin glucose zinc (45 mg/kg Icariin and 110 mg/kg Gluconate Zinc), 60 mg/kg icariin zinc and 180 mg/kg icariin zinc. After 3 weeks of gavage, we conducted 6 weeks of exhaustive swimming training. Test indices such as exhaustive swimming time of rats and body weight were evaluated after the last training exercise. The seminal vesicles, testes, and prostate gland were weighed, and their indices were calculated. The levels of testosterone (in the plasma) and glycogen (in the liver and muscle homogenates) were also evaluated using ELISA.Results: Compared with the static control group, the exhaustive swimming time of the rats in each group was prolonged. Compared with the other groups, the exhaustive swimming time of the L-E and H-E groups was significantly longer (p &lt; 0.01); the Icariin-Zinc complex significantly increased the exhaustive swimming time of the rats. Compared with the static control group, the plasma testosterone content of the L-E and H-E groups increased significantly (p &lt; 0.05). Compared with the exercise control group and G-Zn group, the plasma testosterone content of the H-E group also increased significantly (p &lt; 0.01). The Icariin-Zinc complex significantly increased the serum levels of testosterone in rats. Compared with the control group, the muscle glycogen reserves of each group decreased, indicating that the muscle glycogen reserves of the rats decreased after swimming. Compared with other groups, the Icariin-Zinc complex can reduce the level of glycogen in the muscles, indicating that it can increase the utilization efficiency of glycogen in muscles. Compared with the static control and exercise control groups, the testicular weight of rats in the administration groups increased slightly. The Icariin-Zinc complex increased the testicular weight, indicating that the function of the reproductive system was improved to some extent.Conclusion: Icariin-Zinc can significantly prolong the exhaustive swimming time, improve exercise ability, and increase the plasma testosterone level (which is beneficial for improving the reproductive ability of male rats). Moreover, the beneficial effect of Icariin-Zinc on the glycogen content, testis index, and other reproductive system glands is dose-dependent

    A pan-cancer proteomic perspective on The Cancer Genome Atlas.

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    Protein levels and function are poorly predicted by genomic and transcriptomic analysis of patient tumours. Therefore, direct study of the functional proteome has the potential to provide a wealth of information that complements and extends genomic, epigenomic and transcriptomic analysis in The Cancer Genome Atlas (TCGA) projects. Here we use reverse-phase protein arrays to analyse 3,467 patient samples from 11 TCGA 'Pan-Cancer' diseases, using 181 high-quality antibodies that target 128 total proteins and 53 post-translationally modified proteins. The resultant proteomic data are integrated with genomic and transcriptomic analyses of the same samples to identify commonalities, differences, emergent pathways and network biology within and across tumour lineages. In addition, tissue-specific signals are reduced computationally to enhance biomarker and target discovery spanning multiple tumour lineages. This integrative analysis, with an emphasis on pathways and potentially actionable proteins, provides a framework for determining the prognostic, predictive and therapeutic relevance of the functional proteome
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