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Estimating Black Hole Masses of AGNs using Ultraviolet Emission line Properties

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Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 396-410页

作者： Min-zhi Kong Xue-Bing wu Ran Wang Jin-lin Han National Astronomical Observatories Chinese Academy of Sciences Beiiing 1000121 Department of Astronomy Peking University Beijing 100871

Based on measured broad line region sizes in the reverberation-mapping AGN sample, two new empirical relations are introduced to estimate the central black hole masses of radio-loud high-redshift （z 〉 0.5） AGNs. First, using the archival IUE/HST spectroscopy data at UV band for the reverberation-mapping objects, we obtained two new empirical relations between the BLR size and Mg Ⅱ/C Ⅳ emission line luminosity. Secondly, using the newly determined black hole masses of the reverberation-mapping sample as calibration, we found two new relationships for determining the black hole mass with the full width at half maximum and the luminosity of Mg Ⅱ/C Ⅳ line. We then apply the relations to estimate the black hole masses of the AGNs in the Large Bright Quasar Survey and a sample of radio-loud quasars. For the objects with small radio-loudness, the black hole mass estimated using the RBLR-LMg Ⅱ/C Ⅳ relation is consistent with that from the RBLR-L3000 A/1350 A relation. For radio-loud AGNs, however, the mass estimated from the RBLR-LMg Ⅱ/C Ⅳ relation is systematically lower than that from the continuum luminosity L3000 A/13S0 A Because jets could have significant contributions to the UV/optical continuum luminosity of radio-loud AGNs, we emphasize once again that for radio-loud AGNs, the emission line luminosity may be a better tracer of the ionizing luminosity than the continuum luminosity, so that the relations between the BLR size and UV emission line luminosities should be used to estimate the black hole masses of high redshift radio-loud AGNs.

关键词： galaxies: nucleus -- galaxies: high-redshift-- quasars: emission lines -- ultraviolet: galaxies

Artificial Management Improves Soil Moisture, C, N and P in an Alpine Sandy Meadow of Western China

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Pedosphere 2011年第3期21卷 407-412页

作者： wu Gao-lin LI Wei ZHAO ling-Ping SHI zhi-Hua State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Yangling712100 (China) Institute of Soil and Water Conservation of Chinese Academy of Sciences and Ministry of Water Resource Yangling712100 (China) Key Laboratory of Arid and Grassland Ecology of the Ministry of Education Lanzhou University Lanzhou 730000 (China)

Regeneration of degraded grassland ecosystems is a significant issue in restoration ecology globally. To understand the effects of artificial management measures on alpine meadows, we surveyed topsoil properties including moisture, organic carbon (SOC), nitrogen (N), and phosphorus (P) contents five years after fencing and fencing + reseeding management practices in a sandy meadow in the eastern Qinghai-Tibetan Plateau, northwestern China. Both the fencing and fencing + reseeding management practices significantly increased soil moisture storage, SOC, total N, available N, total P, and available P, as compared to the unmanaged control. Fencing plus reseeding was more effective than fencing alone for improving soil C, N, and P contents. These suggested that rehabilitation by reseeding and fencing generally had favorable effects on the soil properties in degraded sandy alpine meadows, and was an effective approach for restoration of degraded meadow ecosystems of the Qinghai-Tibetan Plateau.

关键词： degraded ecosystem fencing reseeding restoration ecology soil properties

Geomechanics model test and numerical simulation of 2G-NPR bolt support effect in an active fault tunnel

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Journal of Mountain Science 2022年第9期19卷 2729-2741页

作者： REN Shu-lin HE Man-chao lin Wei-jun ZHANG Teng-wu TAO zhi-gang State Key Laboratory for Geomechanics&Deep Underground Engineering Beijing 100083China School of Mechanics and Civil Engineering China University of Mining&Technology Beijing 100083China 3 Department of Civil and Environmental EngineeringUniversity of AlbertaEdmonton T6G 1H9Canada

Active faults are a common adverse geological phenomenon that can occur during tunnel excavation and has a very negative impact on the construction and operation of the *** this paper,the grade IV rock surrounding the cross-fault tunnel with poor geological conditions has been chosen for the *** support capacity of 2^(nd) Generation-Negative Poisson’s Ratio(2G-NPR)bolt in an active fault tunnel has been carried out on the basis of relevant results obtained from the geomechanical model test and numerical investigations of failure model for existing unsupported fault *** investigation shows that surrounding rock of the tunnel is prone to shear deformation and crack formation along the fault,as a result,the rock mass on the upper part of the fault slips as a ***,small-scale deformation and loss of blocks are observed around the tunnel;however,the 2G-NPR bolt support is found to be helpful in keeping the overall tunnel intact without any damage and *** to the blocking effect of fault,the stress of the surrounding rock on the upper and lower parts of the fault is significantly different,and the stress at the left shoulder of the tunnel is greater than that at the right *** asymmetrical arrangement of 2G-NPR bolts can effectively control the asymmetric deformation and instability of the surrounding *** present numerical scheme is in good agreement with the model test results,and can reasonably reflect the stress and displacement characteristics of the surrounding rock of the *** comparison to unsupported and ordinary PR(Poisson’s Ratio)bolt support,2G-NPR bolt can effectively limit the fault slip and control the stability of the surrounding rock of the fault *** research findings may serve as a guideline for the use of 2G-NPR bolts in fault tunnel support engineering.

关键词： Tunnel engineering Fault 2G-NPR bolt Geomechanics model test Numerical simulation

Sands modeling constrained by high-resolution seismic data

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第11期8卷 1858-1863页

作者： ZHANG Feng LI zhi-ping WANG He-lin wu Jian TAN Zhen-hua School of Energy Resources China University of Geology Beijing 100083 China Institute of Petroleum Exploration and Development Dagang Oilfield Tianjin 300280 China Shallow Water Exploration and Development Company Dagang Oilfield Tianjin 300280 China Institute of Petroleum Exploration and Development PetroChina Company Limited Beijing 100083 China

In the phase of field evaluation, the changing of interwell reservoir may be out of control if the geological model was built only on well data due to few existing wells. The uncertainty of the interwell reservoir interpolation based only on well data can be decreased by comprehensive utilization of geological, logging and seismic data, especially by using highly relative seismic properties from 3D seismic data adjusted by well point data to restrict interpolation of geological properties. A 3D-geological model which takes the sand body as the direct modeling object was built through stacking the structure, reservoir and water/oil/gas properties together in 3D space.

关键词： Reservoir geological modeling Seismic inversion Sand control modeling

Enhancing the radiosensitivity of colorectal cancer cells by reducing spermine synthase through promoting autophagy and DNA damage

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World Journal of Gastrointestinal Oncology 2024年第12期16卷 4716-4727页

作者： Yu-Bin Guo Yue-Ming wu zhi-Zhao lin Guangdong Provincial Key Laboratory of Gastroenterology Department of GastroenterologyNanfang HospitalSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

BACKGROUND Colorectal cancer(CRC),the third most common cancer worldwide,has increasingly detrimental effects on human *** resistance diminishes treatment *** suggest that spermine synthase(SMS)may serve as a potential target to enhance the *** To investigate the association between SMS and radiosensitivity in CRC cells,along with a detailed elucidation of the underlying *** Western blot was adopted to assess SMS expression in normal colonic epithelial cells and CRC cell ***116 cells were transfected with control/SMS-specific shRNA or control/pcDNA3.1-SMS *** included cell viability,colony formation,and apoptosis via MTT assays,colony formation assays,and flow *** was studied in SMS-specific shRNA-transfected HCT116 cells post-4 Gy radiation,evaluating cell viability,colony formation,apoptosis,DNA damage(comet assays),autophagy(immunofluorescence),and mammalian target of rapamycin(mTOR)pathway protein expression(western blot).RESULTS Significant up-regulation of SMS expression levels was observed in the CRC cell *** down-regulation of SMS expression,cellular viability and colonyforming ability were markedly suppressed,concomitant with a notable increase in apoptotic ***,attenuation of SMS expression significantly augmented the sensitivity of HCT116 cells to radiation therapy,evidenced by a pronounced elevation in levels of cellular DNA damage and *** tantly,down-regulation of SMS corresponded with a marked reduction in the expression levels of proteins associated with the mTOR signaling *** Knocking down SMS attenuates the mTOR signaling pathway,thereby promoting cellular autophagy and DNA damage to enhance the radiosensitivity of CRC cells.

关键词： Spermine synthase Colorectal cancer Radiosensitivity Autophagy DNA damage

Coupling analysis of transmission lines excited by space electromagnetic fields based on time domain hybrid method using parallel technique

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Chinese Physics B 2020年第9期29卷 249-254页

作者： zhi-Hong Ye Xiao-lin wu Yao-Yao Li School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China School of Electronic and Information Engineering Beihang UniversityBeijing 100083China

We present a time domain hybrid method to realize the fast coupling analysis of transmission lines excited by space electromagnetic fields, in which parallel finite-difference time-domain (FDTD) method, interpolation scheme, and Agrawal model-based transmission line (TL) equations are organically integrated together. Specifically, the Agrawal model is employed to establish the TL equations to describe the coupling effects of space electromagnetic fields on transmission lines. Then, the excitation fields functioning as distribution sources in TL equations are calculated by the parallel FDTD method through using the message passing interface (MPI) library scheme and interpolation scheme. Finally, the TL equations are discretized by the central difference scheme of FDTD and assigned to multiple processors to obtain the transient responses on the terminal loads of these lines. The significant feature of the presented method is embodied in its parallel and synchronous calculations of the space electromagnetic fields and transient responses on the lines. Numerical simulations of ambient wave acting on multi-conductor transmission lines (MTLs), which are located on the PEC ground and in the shielded cavity respectively, are implemented to verify the accuracy and efficiency of the presented method.

关键词： Agrawal model transmission line equations parallel FDTD method message passing interface(MPI)library

Cancer stem cells in glioblastoma—molecular signaling and therapeutic targeting

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Protein & Cell 2010年第7期1卷 638-655页

作者： zhi Huang lin Cheng Olga A.Guryanova Qiulian wu Shideng Bao Department of Stem Cell Biology and Regenerative Medicine Lerner Research InstituteCleveland ClinicClevelandOH 44195USA

Glioblastomas(GBMs)are highly lethal primary brain *** current therapeutic advances in other solid cancers,the treatment of these malignant gliomas remains essentially *** are extremely resistant to conventional radiation and *** and others have demonstrated that a highly tumorigenic subpopulation of cancer cells called GBM stem cells(GSCs)promotes therapeutic *** also found that GSCs stimulate tumor angiogenesis by expressing elevated levels of VEGF and contribute to tumor growth,which has been translated into a useful therapeutic strategy in the treatment of recurrent or progressive ***,stem cell-like cancer cells(cancer stem cells)have been shown to promote *** GBMs rarely metastasize beyond the central nervous system,these highly infiltrative cancers often invade into normal brain tissues preventing surgical resection,and GSCs display an aggressive invasive *** studies suggest that targeting GSCs may effectively reduce tumor recurrence and significantly improve GBM *** studies indicate that cancer stem cells share core signaling pathways with normal somatic or embryonic stem cells,but also display critical distinctions that provide important clues into useful therapeutic *** this review,we summarize the current understanding and advances in glioma stem cell research,and discuss potential targeting strategies for future development of anti-GSC therapies.

关键词： cancer stem cell glioblastoma therapeutic resistance molecular targeting tumor angiogenesis hypoxia response stem cell niche

Contrasting neuropathology and functional recovery after spinal cord injury in developing and adult rats

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Neuroscience Bulletin 2013年第4期29卷 509-516页

作者： Qiuju Yuan Huanxing Su Kin Chiu wutian wu zhi-Xiu lin Department of Anatomy The University of Hong Kong School of Chinese Medicine Faculty of Science The Chinese University of Hong Kong State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences University of Macao State Key Laboratory of Brain and Cognitive Sciences Development and Growth Li Ka Shing Faculty of Medicine The University of Hong Kong Research Center of Reproduction Development and Growth Li Ka Shing Faculty of Medicine The University of Hong Kong GHM Institute of CNS Regeneration Jinan University

Conflicting findings exist regarding the link between functional recovery and the regrowth of spinal tracts across the lesion leading to the restoration of functional contacts. In the present study, we investigated whether functional locomotor recovery was attributable to anatomical regeneration at postnatal day 1 （PN1）, PN7, PN14 and in adult rats two months after transection injury at the tenth thoracic segment of the spinal cord. The Basso, Beattie, and Bresnahan scores showed that transection led to a failure of hindlimb locomotor function in PN14 and adult rats. However, PN1 and PN7 rats showed a significant level of stepping function after complete spinal cord transection. Unexpectedly, unlike the transected PN14 and adult rats in which the spinal cord underwent limited secondary degeneration and showed a scar at the lesion site, the rats transected at PN1 and PN7 showed massive secondary degeneration both anterograde and retrograde, leaving a 〉5-mm gap between the two stumps. Furthermore, retrograde tracing with fluorogold （FG） also showed that FG did not cross the transection site in PN1 and PN7rats as in PN14 and adult rats, and re-transection of the cord caused no apparent loss in locomotor performance in the rats transected at PN1. Thus, these three lines of evidence strongly indicated that the functional recovery after transection in neonatal rats is independent of regrowth of spinal tracts across the lesion site. Our results support the notion that the recovery of locomotor function in developing rats may be due to intrinsic adaptations in the spinal circuitry below the lesion that control hindlimb locomotor activity rather than the regrowth of spinal tracts across the lesion. The difference in secondary degeneration between neonatal and adult rats remains to be explored.

关键词： neonatal spinal cord injury regeneration functional recovery rat

A brief review on Majorana bound states in topological superconductors

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 1-8页

作者： Rui lin zhi Wang School of Physics and Engineering Sun Yat-sen University

Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound states are ideal platform for studying non-Abelian statistics. Meanwhile, they are proposed to be useful in quantum computation. In this review, we introduce the basic concepts and models in this area. We begin from the Kitaev model, which is the most concise model for one-dimensional topological superconductivity. Then, we discuss how to realize this model with spin-orbit coupling in realistic materials. Finally, we show some simple methods to detect the Majorana bound states and study their novel properties with the help of adjacent quantum dots.

关键词： topological superconductor Kitaev model quantum dot