73,925 research outputs found
Empress Wu the Great Tang Dynasty China
No full textEurope and Great Britain have had many sovereign queens in the course of history. In ancient China, there was none of that. Only one Empress ever ruled China in her own name Empress Wu. Given her startling performance in a world of deadly intrigue and shifting loyalties, Wu is still respected as an effective and clear-sighted ruler.Intro -- Preface -- Chapter 1. Origins of a Future Sovereign -- The Wu Family -- Wu's Father Rises from a Merchant to a Nobleman -- Mr. Wu Marries Up -- Mr. Wu Becomes a Governor -- Mr. Wu Leaves His Family Bereft -- The Establishment of the Tang Dynasty -- Mr. Wu's Sponsor Becomes the Second Emperor of the Tang Dynasty -- Empress Changsun and a Few of the Courtiers -- Chapter 2. Miss Wu Becomes an Imperial Concubine -- The Sons Vie for the Succession -- Selecting the Crown Prince -- Introduction to the Crown Prince -- Sent to a Nunnery -- The New Emperor Reigns -- Empress Wang Brings Wu Back to the Palace -- Empress Wang and Concubine Xiao Unite against Concubine Wu -- Concubine Wu Fights Back -- The Courtiers Take Sides -- Empress Wang and Her Supporters Take a Mis-Step -- Empress Wang and the Crown Prince are Removed -- Wu Becomes Empress -- Chapter 3. From Empress to Empress Dowager -- Advancing Supporters and Annihilating Opponents -- Taking Part in Politics -- The Pleasures of Traveling -- Relationship With Her Children -- Chapter 4. The Empress Dowager Consolidates Her Power -- Standing at the Top -- View from the Summit -- Chapter 5. Rebellions -- The Largest Rebellion -- The Rebellions of the Princes Li -- Other Rebellions -- Abuse of Power at Every Level -- Chapter 6. Picking Favorites -- Naming a Successor -- Empress Wu's Favorites -- Chapter 7. Relations with Other Nations -- Tibet -- Korea -- The Tujue Clan -- Japan and Arabia -- Chapter 8. Famous Legends About Empress Wu -- Face Reading -- Flowers Blooming in Winter -- Other LegendsEurope and Great Britain have had many sovereign queens in the course of history. In ancient China, there was none of that. Only one Empress ever ruled China in her own name Empress Wu. Given her startling performance in a world of deadly intrigue and shifting loyalties, Wu is still respected as an effective and clear-sighted ruler.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
One-dimensional inorganic semiconductor nanostructures: Controlled growth and potential applications
No full textX-ray polarization in relativistic jets
No full textWe investigate the polarization properties of Comptonized X-rays from relativistic jets in active galactic nuclei (AGN) using Monte Carlo simulations. We consider three scenarios commonly proposed for the observed X-ray emission in AGN: Compton scattering of blackbody photons emitted from an accretion disc; scattering of cosmic microwave background (CMB) photons and self-Comptonization of intrinsically polarized synchrotron photons emitted by jet electrons. Our simulations show that for Comptonization of disc and CMB photons, the degree of polarization of the scattered photons increases with the viewing inclination angle with respect to the jet axis. In both cases, the maximum linear polarization is ≈20 per cent. In the case of synchrotron self-Comptonization (SSC), we find that the resulting X-ray polarization depends strongly on the seed synchrotron photon injection site, with typical fractional polarizations P≈ 10–20 per cent when synchrotron emission is localized near the jet base, while P≈ 20–70 per cent for the case of uniform emission throughout the jet. These results indicate that X-ray polarimetry may be capable of providing unique clues to identify the location of particle acceleration sites in relativistic jets. In particular, if synchrotron photons are emitted quasi-uniformly throughout a jet, then the observed degree of X-ray polarization may be sufficiently different for each of the competing X-ray emission mechanisms (synchrotron, SSC or external Comptonization) to determine which is the dominant process. However, X-ray polarimetry alone is unlikely to be able to distinguish between disc and CMB Comptonization
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Discovery of an optical counterpart to the hyperluminous X-ray source in ESO 243-49
No full textThe existence of black holes of masses similar to 10(2)-10(5)M(circle dot) has important implications for the formation and evolution of star clusters and supermassive black holes. One of the strongest candidates to date is the hyperluminous X-ray source (HLX1), possibly located in the S0- a galaxy ESO 243-49, but the lack of an identifiable optical counterpart had hampered its interpretation. Using the Magellan telescope, we have discovered an unresolved optical source with R = 23.80 +/- 0.25 mag and V = 24.5 +/- 0.3 mag within HLX1's positional error circle. This implies an average X-ray/optical flux ratio similar to 500. Taking the same distance as ESO 243-49, we obtain an intrinsic brightness M-R = -11.0 +/- 0.3 mag, comparable to that of a massive globular cluster. Alternatively, the optical source is consistent with a main-sequence M star in the Galactic halo (for example an M4.4 star at approximate to 2.5 kpc). We also examined the properties of ESO 243-49 by combining Swift/Ultraviolet/Optical Telescope (UVOT) observations with stellar population modelling. We found that the overall emission is dominated by a similar to 5-Gyr-old stellar population, but the UV emission at approximate to 2000 angstrom is mostly due to ongoing star formation at a rate of similar to 0.03M(circle dot) yr(-1). The UV emission is more intense (at least a 9 sigma enhancement above the mean) north-east of the nucleus, in the same quadrant as HLX1. With the combined optical and X-ray measurements, we put constraints on the nature of HLX1. We rule out a foreground star and a background AGN. Two alternative scenarios are still viable. HLX1 could be an accreting intermediate mass black hole in a star cluster, which may itself be the stripped nucleus of a dwarf galaxy that passed through ESO 243-49, an event which might have caused the current episode of star formation. Or, it could be a neutron star in the Galactic halo, accreting from an M4-M5 donor star
Effect of MWCNT-modified graphite felts on hexavalent chromium removal in biocathode microbial fuel cells
No full textMulti-walled carbon nanotubes (MWCNTs) and oxidative acid pretreated MWCNTs (oxidized MWCNTs, O-MWCNTs) were used to modify graphite felts as biocathode electrodes in Cr(vi)-reducing microbial fuel cells (MFCs). The results showed that both MWCNT modifications improved the efficiency of the Cr(vi)-reducing biocathode. In particular, the O-MWCNT modification led to a better performance due to the induced oxygen-containing functional groups on the O-MWCNTs. The O-MWCNT-modified graphite felt significantly promoted the Cr(vi) removal and electricity generation of the MFC. The Cr(vi) removal rate increased to 2.00 ± 0.10 mg L-1 h-1, which was 2.05 times higher than that of the unmodified control. The improvement was ascribed to the strong affinity and capacity of the O-MWCNTs towards microorganisms and Cr(vi) ions. In addition, this study further confirmed that the ex situ biocathode acclimatization method could be an efficient way to screen potential biocathode materials for Cr(vi)-reducing MFCs
Closed reduction with percutaneous Kirschner wire fixation for delayed treatment of distal humeral epiphyseal fracture separation
No full textAbstract
Background: Fracture separation of the distal humeral epiphysis in children is a relatively uncommon injury, predominantly occurring in children under 3 years. It has a high risk of treatment delays. This study aims to evaluate outcomes in the management of fracture separation of the distal humeral epiphysis treated seven or more days postinitial injury.
Methods: A retrospective analysis was conducted on patients diagnosed with fracture separation of the distal humeral epiphysis between November 2016 and October 2023. Inclusion criteria encompassed patients with delayed presentation of fracture separation of the distal humeral epiphysis who underwent surgical intervention seven or more days following the initial injury. Demographic data were collected, and fractures were categorized using the modified DeLee classification. Plain radiographs facilitated the assessment of the carrying angle and postoperative Baumann angle. Clinical outcomes were evaluated using the Flynn criteria.
Results: The study included 12 patients who met the inclusion criteria. The average age at the time of injury was 1.59 years. According to the modified DeLee system, fracture classification identified one type I fracture, eight type II fractures, and three type III fractures. The average duration from injury to surgery was 11.8 days. The mean surgical
duration was 21.5 min. The average follow-up period was 40.7 months. One patient exhibited cubitus varus development. Based on the Flynn criteria, outcomes were as follows: seven patients had excellent outcomes, four had good outcomes, and one had a poor outcome.
Conclusion: Closed reduction with percutaneous K-wire fixation represents a minimally invasive approach suitable for children diagnosed with fracture separation of the distal humeral epiphysis seven or more days post-initial injury. Most of these patients experienced favorable outcomes.
Level of evidenceAbstract
Background: Fracture separation of the distal humeral epiphysis in children is a relatively uncommon injury, predominantly occurring in children under 3 years. It has a high risk of treatment delays. This study aims to evaluate outcomes in the management of fracture separation of the distal humeral epiphysis treated seven or more days postinitial
injury.
Methods: A retrospective analysis was conducted on patients diagnosed with fracture separation of the distal humeral epiphysis between November 2016 and October 2023. Inclusion criteria encompassed patients with delayed presentation of fracture separation of the distal humeral epiphysis who underwent surgical ntervention seven or more days following the initial injury. Demographic data were collected, and fractures were categorized using the modified
DeLee classification. Plain radiographs facilitated the assessment of the carrying angle and postoperative Baumann angle. Clinical outcomes were evaluated using the Flynn criteria.
Results: The study included 12 patients who met the inclusion criteria. The average age at the time of injury was 1.59 years. According to the modified DeLee system, fracture classification identified one type I fracture, eight type II
fractures, and three type III fractures. The average duration from injury to surgery was 11.8 days. The mean surgical duration was 21.5 min. The average follow-up period was 40.7 months. One patient exhibited cubitus varus development. Based on the Flynn criteria, outcomes were as follows: seven patients had excellent outcomes, four had good outcomes, and one had a poor outcome.
Conclusion: Closed reduction with percutaneous K-wire fixation represents a minimally invasive approach suitable for children diagnosed with fracture separation of the distal humeral epiphysis seven or more days post-initial injury. Most of these patients experienced favorable outcomes.
Level of evidence: [AQ: 4
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