摘要：Lumbar degeneration leads to changes in geometry and density distribution of vertebrae,which could further influence the mechanical property and *** study aimed to quantitatively describe the variations in shape and density distribution for degenerated vertebrae by statistical models,and utilized the specific statistical shape model(SSM)/statistical appearance model(SAM)modes to assess compressive strength and fracture *** detailed SSM and SAM were developed based on the 75 L1 vertebrae of elderly men,and their variations in shape and density distribution were quantified with principal component(PC)*** vertebrae were classified into mild(n=22),moderate(n=29),and severe(n=24)groups according to the overall degree of *** computed tomography-based finite element analysis was used to calculate compressive strength for each L1 vertebra,and the associations between compressive strength and PC modes were evaluated by multivariable linear regression(MLR).Moreover,the distributions of equivalent plastic strain(PEEQ)for the vertebrae assigned with the first modes of SSM and SAM at mean±3SD were *** Leave-One-Out analysis showed that our SSM and SAM had good performance,with mean absolute errors of 0.335±0.084 mm and 64.610±26.620 mg/cm3,respectively.A reasonable accuracy of bone strength prediction was achieved by using four PC modes(SSM 1,SAM 1,SAM 4,and SAM 5)to construct the MLR ***,the PEEQ values were more sensitive to degeneration-related variations of density distribution than those of *** density variations may change the deformity type(compression deformity or wedge deformity),which further affects the fracture *** models can identify the morphology and density variations in degenerative vertebrae,and the SSM/SAM modes could be used to assess compressive strength and fracture *** above findings have implications for assisting clinicians in pathological dia

摘要：The fixation and conversion of CO_(2)frommedium-and high-temperature industrial exhaust gases arescientifically important and challenging tasks owing to theharsh conditions ***_(2)O_(3),a stable p-block compound,is surprisingly active in the thermal conversion of hot CO_(2)waste gas,but its underlying mechanism remains *** study,we investigated CO_(2)adsorption and activationacross 11 different Ga_(2)O_(3)-terminated faces using densityfunctional *** transfer and chemical bond analysesrevealed the occurrence of two distinct activation mechanismsinvolving synchronous electron gain and loss,driven by astrong synergetic effect between Ga cations and O anions onthe substrate *** Ga-O synergy enhances the CO_(2)activation efficiency compared with single active sites,with CO_(2)^(δ+) cation more readily capturing H atom than CO_(2)^(δ–).Tothe best of our knowledge,such a dual activation mechanismhas not been reported before,particularly for p-block *** findings provide new insights into the direct catalyticconversion of CO_(2)emissions and offer strategies for the rational design of industrial-grade catalysts for medium-andhigh-temperature CO_(2)tail gas conversion.

摘要：Maximum likelihood recursions were used by Wu （1985） to estimate extreme quantiles of a quantal response curve. For certain choices of initial designs, Wu＇s method performs well. In many fields of application, there often exist some different initial designs which are known as the up-and- down designs. Based on the existing data set from such a design, the authors propose three sequential empirical Bayesian designs by quickly and efficiently exploiting the information in the testing data and known knowledge. The improvement obtained by using the new procedures for the estimation of extreme quantiles is substantial.

摘要：In this paper, we present the design of multilayer microwave absorbers comprised of Co Fe alloy nano-particles and nano-flakes as fillers. The thickness of the unite layer is optimized by using the Genetic Algorithm. Efficient microwave absorptions over a wide frequency band and a range of incident angles are achieved by using multilayer absorbers. We show that the absorbers are effective not only for a planar surface but also for arbitrarily shaped objects as well.

摘要：A backstepping control method is proposed for controlling beam halo-chaos in the periodic focusing channels （PFCs） of high-current ion accelerator. The analysis and numerical results show that the method, via adjusting an exterior magnetic field, is effective to control beam halo chaos with five types of initial distribution ion beams, all statistical quantities of the beam halo-chaos are largely reduced, and the uniformity of ion beam is improved. This control method has an important value of application, for the exterior magnetic field can be easily adjusted in the periodical magnetic focusing channels in experiment.

摘要：The segmented mirror telescope is widely *** aberrations of segmented mirror systems are different from single mirror *** paper uses the Fourier optics theory to analyse the Zernike aberrations of segmented mirror *** concludes that the Zernike aberrations of segmented mirror systems obey the linearity *** design of a segmented space telescope and segmented schemes are discussed,and its optical model is constructed. The computer simulation experiment is performed with this optical model to verify the suppositions. The experimental results confirm the correctness of the model.

摘要：Since product metric on AdS space has played a very important role in Lorentz version of AdS/CFT correspondence, the Yang Mills equation on AdS space with this metric is considered and a static solution is obtained in this paper, which helps to understand the AdS/CFT correspondence of Yang Mills fields.

摘要：According to analysis of the ^14C content in two Japanese trees, that grew over a period of approximately 3000 years, with high time resolution, Miyake et al. found a rapid increase at AD 774-775 and another one at AD 993-994. These increases correspond to high-energy events that happened within those years and radi- ated ＂）,-ray energy of about 7x 1034 erg toward the Earth. The origin of these events is a mystery. Such strong events should have an unusual optical counterpart, and have been recorded in historical literatures. We searched Chinese historical materi- als around AD 744-775 and AD 993-994, but no remarkable event was found except for a violent thunderstorm in AD 775. However, the possibility of a thunderstorm containing so much energy is unlikely. We conclude that the events, which caused the 14C increase, are still unclear. These events most probably had no optical counterpart, and a short gamma-ray burst, giant flare of a soft gamma-ray repeater or a terrestrial γ-ray flash could all be candidates.

摘要：We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thisreview is based on the talks given in several schools and programs for the phenomenologists working on nuclear physicsand particle physics.

摘要：The centrifugal flywheel governor （CFG） is a mechanical device that automatically controls the speed of an engine and avoids the damage caused by sudden change of load torque. It has been shown that this system exhibits very rich and complex dynamics such as chaos. This paper investigates the problem of robust finite-time synchronization of non-autonomous chaotic CFGs. The effects of unknown parameters, model uncertainties and external disturbances are fully taken into account. First, it is assumed that the parameters of both master and slave CFGs have the same value and a suitable adaptive finite-time controller is designed. Second, two CFGs are synchronized with the parameters of different values via a robust adaptive finite-time control approach. Finally, some numerical simulations are used to demonstrate the effectiveness and robustness of the proposed finite-time controllers.