Quantum generative adversarial networks based on a readout error mitigation method with fault tolerant mechanism

Readout errors caused by measurement noise are a significant source of errors in quantum circuits,which severely affect the output results and are an urgent problem to be solved in noisy-intermediate scale quantum(NISQ)computing.In this paper,we use the bit-flip averaging(BFA)method to mitigate frequent readout errors in quantum generative adversarial networks(QGAN)for image generation,which simplifies the response matrix structure by averaging the qubits for each random bit-flip in advance,successfully solving problems with high cost of measurement for traditional error mitigation methods.Our experiments were simulated in Qiskit using the handwritten digit image recognition dataset under the BFA-based method,the Kullback-Leibler(KL)divergence of the generated images converges to 0.04,0.05,and 0.1 for readout error probabilities of p=0.01,p=0.05,and p=0.1,respectively.Additionally,by evaluating the fidelity of the quantum states representing the images,we observe average fidelity values of 0.97,0.96,and 0.95 for the three readout error probabilities,respectively.These results demonstrate the robustness of the model in mitigating readout errors and provide a highly fault tolerant mechanism for image generation models.

Formation and evolution of the strike-slip faults in the central Sichuan Basin, SW China

Based on 3D seismic and drilling data, the timing, evolution and genetic mechanism of deep strike-slip faults in the central Sichuan Basin are thoroughly examined by using the U-Pb dating of fault-filled carbonate cement and seismic-geological analysis. The strike-slip fault system was initially formed in the Late Sinian, basically finalized in the Early Cambrian with dextral transtensional structure, was overlaid with at least one stage of transpressional deformation before the Permian, then was reversed into a sinistral weak transtensional structure in the Late Permian. Only a few of these faults were selectively activated in the Indosinian and later periods. The strike-slip fault system was affected by the preexisting structures such as Nanhuanian rifting normal faults and NW-striking deep basement faults. It is an oblique accommodated intracratonic transfer fault system developed from the Late Sinian to Early Cambrian to adjust the uneven extension of the Anyue trough from north to south and matches the Anyue trough in evolution time and intensity. In the later stage, multiple inversion tectonics and selective activation occurred under different tectonic backgrounds.

晶体生长的缺陷机制

Crystal growth is a complicated phase transition process.A perfect mechanism for practical crystal growth process has not been proposed and well recognized up till now.A model,i.e.screw dislocation model presented by F.C.Frank for imperfect crystal growth was adopted during early 1950’s.No systemic research on defects other than screw dislocation has been conducted during a quite long time. Since 1980’s,we have engaged systematically in the investigation of the defect mechanism of crystal growth,and our conclusion is that any defect providing step sources in the growing surface can make contribution to continuous crystal growth.These steps contain both complete(whole)steps and sub steps(incomplete steps).

Internal structure of Longmenshan fault zone at Hongkou outcrop,Sichuan,China,that caused the 2008 Wenchuan earthquake

This paper reports the internal structures of the Beichuan fault zone of Longmenshan fault system that caused the 2008 Wenchuan earthquake, at an outcrop in Hongkou, Sichuan province, China. Present work is a part of comprehensive project of Institute of Geology, China Earthquake Administration, trying to understand deformation processes in Longmenshan fault zones and eventually to reproduce Wenchuan earthquake by modeling based on measured mechanical and transport properties. Outcrop studies could be integrated with those performed on samples recovered from fault zone drilling, during the Wenchuan Earthquake Fault Scientific Drilling （WFSD） Project, to understand along-fault and depth variation of fault zone properties. The hanging wall side of the fault zone consists of weakly-foliated, clayey fault gouge of about 1 m in width and of several fault breccia zones of 30-40 m in total width. We could not find any pseudotachylite at this outcrop. Displacement during the Wenchuan earthquake is highly localized within the fault gouge layer along narrower slipping-zones of about 10 to 20 mm in width. This is an important constraint for analyzing thermal pressurization, an important dynamic weakening mechanism of faults. Overlapping patterns of striations on slickenside surface suggest that seismic slip at a given time occurred in even narrower zone of a few to several millimeters, so that localization of deformation must have occurred within a slipping zone during coseismic fault motion. Fault breccia zones are bounded by thin black gouge layers containing amorphous carbon. Fault gouge contains illite and chlorite minerals, but not smectite. Clayey fault gouge next to coseismic slipping zone also contains amorphous carbon and small amounts of graphite. The structural observations and mineralogical data obtained from outcrop exposures of the fault zone of the Wenchuan earthquake can be compared with those obtained from the WFSD-1 and WFSD-2 boreholes, which have been drilled very close to the Hongkou outcrop. The presence of carbon and graphite, observed next to the slipping-zone, may affect the mechanical properties of the fault and also provide useful information about coseismic chemical changes.

High-velocity frictional behavior of Longmenshan fault gouge from Hongkou outcrop and its implications for dynamic weakening of fault during the 2008 Wenchuan earthquake

High-velocity friction experiments were conducted on clayey fault gouge collected from Hongkou outcrop of Beichuan fault, located at the southwestern part of Longmenshan fault system that caused the disastrous 2008 Wenchuan earthquake. The ultimate purpose of this study is to reproduce this earthquake by modeling based on measured frictional properties. Dry gouge of about 1 mm in thickness was deformed dry at slip rates of 0.01 to 1.3 m/s and at normal stresses of 0.61 to 3.04 MPa, using a rotary-shear high-velocity frictional testing machine. The gouge displays slip weakening behavior as initial peak friction decays towards steady-state values after a given displacement. Both peak friction and steady-state friction remain high at slow slip rates are exam- ined and gouge only exhibits dramatic weakening at high slip rates, with steady-state friction coefficient values of about 0.1 to 0.2. Specific fracture energy ranges from 1 to 4 MN/m in our results and this is of the same order as seismically determined values. Low friction coefficients measured on experimental faults are in broad agree- ment with lack of thermal anomaly observed from temperature measurements in WFSD-1 drill hole （Wenchuan Earthquake Fault Scientific Drilling Project）, which can be explained by even smaller friction coefficient for the Wenchuan earthquake fault. High-velocity friction experiments with pore water needs to be done to see if even smaller friction is attained or not. Shiny slickenside surfaces form at high slip rates, but not at slow slip rates. Slip zone with slickenside surface changes its color to dark brown and forms duplex-like microstructures, which are similar to those microstructures found in the fault gouges from the Hongkou outcrop. Detailed comparisons between experimentally deformed gouge samples and WFSD drill cores in the future will reveal how much we could reproduce the dynamic weakening processes in operation in fault zones during Wenchuan earthquake at present.

DESCRIPTION AND PREDICTION OF CATASTROPHE OF VIBRATION STATE FOR FAULTY ROTORS

A sudden increase of vibration amplitude with no foreboding often results in an abrupt breakdown of a mechanical system.The catastrophe of vibration state of a faulty rotor is a typical nonlinear phenomenon,and very difficult to be described and predicted with linear vibration theory.On the basis of nonlinear vibration and catastrophe theory,fhe eatastrophe of the vibration amplitude of the faulty rotor is described;a way to predict its emergence is developed.

Origin and growth mechanisms of strike-slip faults in the central Tarim cratonic basin, NW China

Through fault structure analysis and chronology study, we discuss the origin and growth mechanisms of strike-slip faults in the Tarim Basin.(1) Multiple stages strike-slip faults with inherited growth were developed in the central Tarim cratonic basin. The faults initiation time is constrained at the end of Middle Ordovician of about 460 Ma according to U-Pb dating of the fault cements and seismic interpretation.(2) The formation of the strike-slip faults was controlled by the near N-S direction stress field caused by far-field compression of the closing of the Proto-Tethys Ocean.(3) The faults localization and characteristics were influenced by the pre-existing structures of the NE trending weakening zones in the basement and lithofacies change from south to north.(4) Following the fault initiation under the Andersonian mechanism, the strike-slip fault growth was dominantly fault linkage, associated with fault tip propagation and interaction of non-Andersonian mechanisms.(5) Sequential slip accommodated deformation in the conjugate strike-slip fault interaction zones, strong localization of the main displacement and deformation occurred in the overlap zones in the northern Tarim, while the fault tips, particularly of narrow-deep grabens, and strike-slip segments in thrust zones accumulated more deformation and strain in the Central uplift. In conclusion, non-Andersonian mechanisms, dominantly fault linkage and interaction, resulted in the small displacement but long intraplate strike-slip fault development in the central Tarim Basin. The regional and localized field stress, and pre-existing structures and lithofacies difference had strong impacts on the diversity of the strike-slip faults in the Tarim cratonic basin.

On the spatial characteristic of the short-term and imminent anomalies of underground water behaviors before strong earthquake

Observational results of underground water regime (water level and flow) in some strong earthquakes and moderate earthquakes (in this paper we also call them by 'strong earthquakes')in Chinese mainland are studied and the following conclusions are obtained. For one strong earthquake, the spatial distributions of the anomalies which include medium term anomalies of one year scale, short term anomalies and imminent anomalies, and underground water stations without the anomalies were mainly related to the causative mechanism and active master faults (active abyssal faults or strongly active faults) around the focal region; The spatial distribution of the anomalies coincided with the specific relation among the anomalies, the focal site, the causative mechanism and active master faults. Finally, the mechanism of the relation was briefly discussed, and the importance about the research result in this paper was set forth.

Three-dimensional characteristics of focal fault of 1995 M_S=6.5 Wuding earthquake occurring in Yunnan Province

By means of the hypocenter distribution and focal mechanism of Wuding Ms=6.5 earthquake sequence occurred in1995. the space orientation and activity characteristics of focal fault of Wuding earthquake have been studied fromthe three-dimensional space-time process. The results indicate that the focal fault of Wuding earthquake is a subsurface, NWW-trending, upright and right-lateral strike slip fault which is consistent with the intensity distributionin foe meizoseisfnal region. Although the large-scale NS-trending Tanglang-Yimen active fault passes through theearthquake region. it is irrelevant to the Ms=6.5 Wuding main earthquake. Since the relationship between thestrong earthquake and the shallow geological active fault can not be determined, the crustal deep structure shouldbe studied. The method proposed in the paper can be used to distinguish the focal fault in the deep crust.

Some Problems Concerning Geologic Structure with Double Layers in Urban Underground Lifeline Engineering

Underground lifeline engineering (ULE for short) in modern city demands the appreciation of an active fault in buried bedrock . Generally speaking , a large number of urban geological textures of a basement may all be simplified into a dual geological texture model , i. e., the upper part of the basement consists of loose covering layer and the lower part consists of bedrock . The study of an active fault should include three parts of contents , i . e ., to determine the lower time limit of activity of the fault , and the time limit must be recognized by both of designing engineers and geologists ; on the basis of the studies of repetition periods of earthquake occurrence to deter mine whether the fault moves or not during the allowed time of efficacy of buildings and constructions ; for the sake of engineering practice , the active rate of the fault must be given . The fault with different active mechanism has different effects on the ULE . The authors studied the effect of lateral non-uniform overburden site on the ULE by means of the supersonic earthquake modelling . Owing to the lateral non - uniformity of the covering sediments , there occurs an obvious jump of amplitude of the seismic wave propagation near the contact surface between two different sedi ments . In addition , from the modelling experiment curves it may be seen that the different focus mechanisms and different medium characters may also exert an effect in different degrees .

Basic research on machinery fault diagnostics： Past, present, and future trends

Machinery fault diagnosis has progressed over the past decades with the evolution of machineries in terms of complexity and scale. High-value machineries require condition monitoring and fault diagnosis to guarantee their designed functions and performance throughout their lifetime. Research on machinery Fault diagnostics has grown rapidly in recent years. This paper attempts to summarize and review the recent R＆D trends in the basic research field of machinery fault diagnosis in terms of four main aspects： Fault mechanism, sensor technique and signal acquisition, signal processing, and intelligent diagnostics. The review discusses the special contributions of Chinese scholars to machinery fault diagnostics. On the basis of the review of basic theory of machinery fault diagnosis and its practical applications in engineering, the paper concludes with a brief discussion on the future trends and challenges in machinery fault diagnosis.

Overview of Fault Diagnosis Theory and Method for Permanent Magnet Machine

Permanent magnet(PM)machines have been widely used in a variety of industrial and military applications due to their definite advantages of high power density and high efficiency.In some applications such as electric vehicles(EVs)and aircrafts,high reliability and security of the PM machine are critical.Hence,there is rapidly growing interest in strategies to improve the reliability and security of the PM machine from both academia and industry,where fault diagnosis is a requirement.In this paper,common faults of the PM machine are discussed,state of the art in fault diagnosis of PM machine are overviewed in detail,and different fault diagnosis methods are analyzed and compared.Finally,the development tendency of fault diagnosis techniques for the PM machine is prospected.

Influence of Temperature on Stacking Fault Energy and Creep Mechanism of a Single Crystal Nickel-based Superalloy

The influence of temperatures on the stacking fault energies and deformation mechanism of a Re- containing single crystal nickel-based superalloy during creep at elevated temperatures was investigated by means of calculating the stacking fault energy of alloy, measuring creep properties and performing contrast analysis of dislocation configuration. The results show that the alloy at 760 ℃ possesses lower stacking fault energy, and the stacking fault of alloy increases with increasing temperature. The defor- mation mechanism of alloy during creep at 760 ℃ is 7＇ phase sheared by 〈110〉 super-dislocations, which may be decomposed to form the configuration of Shockley partials plus super-lattice intrinsic stacking fault, while the deformation mechanism of alloy during creep at 1070 ℃ is the screw or edge super- dislocations shearing into the rafted 7＇ phase. But during creep at 7（50 and 980 ℃, some super- dislocations shearing into 7＇ phase may cross-slip from the {111} to {100} planes to form the K-W locks with non-plane core structure, which may restrain the dislocations slipping to enhance the creep resis- tance of alloy at high temperature. The interaction between the Re and other elements may decrease the diffusion rate of atoms to improve the microstructure stability, which is thought to be the main reason why the K-W locks are to be kept in the Re-containing superalloy during creep at 980 ℃.