Objectives: We analyzed the clinical characteristics of patients with pulmonary mycobacterial disease diagnosed as coincidental pulmonary infection due to Mycobacterium species. Materials and Methods: One hundred sixt...Objectives: We analyzed the clinical characteristics of patients with pulmonary mycobacterial disease diagnosed as coincidental pulmonary infection due to Mycobacterium species. Materials and Methods: One hundred sixty patients satisfied the diagnostic criteria of nontuberculous mycobacterial disease proposed by American Thoracic Society during the last seven years. Six patients (3.8%) were coincidental pulmonary infection due to two Mycobacterium species. We investigated the background, laboratory findings, microbiological findings, radiological findings, treatment and prognosis. Results: There were six patients, 3 males and 3 females, with a mean age of 71.7 years. The causative microorganisms of coincidental pulmonary infection consisted of Mycobacterium avium + Mycobacterium intracellulare in two patients, Mycobacterium avium + Mycobacterium kansasii in one, Mycobacterium intracellulare + Mycobacterium chelonae in one, Mycobacterium intracellulare + Mycobacterium abscessus in one, and Mycobacterium intracellulare + Mycobacterium tuberculosis in one. Regarding the radiological findings, the distribution of the lesion was frequently shown in both the right middle and left lingula lobes, but the extent of the lesion was limited within the unilateral lung field. Centrilobular small nodules with bronchiectasis were recognized in all patients and cavities or infiltration shadows were recognized in half of them on chest computed tomography. A definite diagnosis was obtained by bronchoalveolar lavage fluid in four patients and expectorated sputum in two. Combined chemotherapy was performed for two patients and that for pulmonary tuberculosis in one. Conclusions: Coincidental pulmonary infection due to Mycobactterium species occurred at a low percentage. Although most patients were elderly with underlying disease and clinical features were compatible with pulmonary Mycobacterium avium complex disease, the prognosis was comparatively good with and without treatment.展开更多
The high-entropy alloy composite coatings AlCu_(2)Ti(NiCr)_(2)-(WC)_(x)(x denotes powder feeding speeds,including 0,25,50,and 75 r/min)were prepared by plasma cladding using a hybrid mode of AlCu_(2)(NiCr)_(2)Ti cable...The high-entropy alloy composite coatings AlCu_(2)Ti(NiCr)_(2)-(WC)_(x)(x denotes powder feeding speeds,including 0,25,50,and 75 r/min)were prepared by plasma cladding using a hybrid mode of AlCu_(2)(NiCr)_(2)Ti cable-type welding wire(CWW)and tungsten carbide(WC)powder.The effect of WC powder feeding speed on the microstructure,hardness,and wear properties of the prepared coatings was investigated.The results show that the coatings consist of body-centered cubic main phases and face-centered cubic secondary phases,with carbide reinforcement phases formed due to the addition of WC.The hardness and wear resistance of the coatings are significantly improved compared to the TC11 substrate.When WC powder feeding speed is set at 50 r/min,the coating exhibits optimal wear resistance,with a minimum volume wear rate of 8.5869×10^(-6)mm^(3)·N^(-1)·m^(-1),greatly improving the wear properties of TC11 surface.The coincident CWW-powder plasma cladding provides a viable method for the preparation of highentropy alloy composite coatings with enhanced wear resistance.展开更多
This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-...This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications.展开更多
Texture and grain boundary character distribution of Cu interconnects with different line width for as-deposited and annealed conditions were measured by EBSD. All specimens appear mixed texture and （111） texture is...Texture and grain boundary character distribution of Cu interconnects with different line width for as-deposited and annealed conditions were measured by EBSD. All specimens appear mixed texture and （111） texture is the dominate component.As-deposited interconnects undergo the phenomenon of self-annealing at RT,in which some abnormally large grains are found. Lower aspect ratio of lines and anneal treatment procured larger grains and stronger （111） texture. Meanwhile, the intensity proportion of other textures with lower strain energy to （111） texture is decreased. As-deposited specimens reveal （111）（112？ and （111） （231） components, （111） （110） component appeared and （111） （112？ and （111） （231） components were developed during the annealing process. High angle boundaries are dominant in all specimens, boundaries with a misorientation of 55°-60° and ∑3 ones in higher proportion, followed by lower boundaries with a misorientation of 35°-40° and 29 boundaries. As the aspect ratio of lines and anneal treatment increase,there is a gradual in- crement in ∑3 boundaries and a decrease in ∑9 boundaries.展开更多
Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a dia...Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a diagnostic challenge. Therefore, we performed a review of the recent literature and developed an evidence-based diagnostic algorithm to guide clinicians in characterising these lesions. Simple cysts are the most common cystic liver disease, and diagnosis is based on typical USG characteristics. Serodiagnostic tests and microbubble contrast-enhanced ultrasound (CEUS) are invaluable in differentiating complicated cysts, echinococcosis and cystadenoma/cystadenocarcinoma when USG, CT and MRI show ambiguous findings. Therefore, serodiagnostic tests and CEUS reduce the need for invasive procedures. Polycystic liver disease (PLD) is arbitrarily defined as the presence of > 20 liver cysts and can present as two distinct genetic disorders: autosomal dominant polycystic kidney disease (ADPKD) and autosomal dominant polycystic liver disease (PCLD). Although genetic testing for ADPKD and PCLD is possible, it is rarely performed because it does not affect the therapeutic management of PLD. USG screening of the liver and both kidneys combined with extensive family history taking are the cornerstone of diagnostic decision making in PLD. In conclusion, an amalgamation of these recent advances results in a diagnostic algorithm that facilitates evidence-based clinical decision making.展开更多
The transient electromagnetic(TEM)method becomes more urgent than ever for marine ex-ploration due to abundant resource reserves and the increasing undersea engineering construction activities,especially in the offsho...The transient electromagnetic(TEM)method becomes more urgent than ever for marine ex-ploration due to abundant resource reserves and the increasing undersea engineering construction activities,especially in the offshore exploration of mineral deposits such as Sanshandao gold mine.However,the re-search and application of TEM method in marine environment are still challenged by many problems.Such contradiction motivates our study on the coincident-loop TEM in seafloor exploration.The TEM response of coincident loops is firstly derived in the integral form,based on the potential functions in Helmholtz equ-ations for a magnetic source locating in the whole-space layered model.The frequency-domain vertical magnetic field is described as the Hankel integral with double first-order Bessel functions of first kind.Se-condly,the time-domain induced voltage is obtained by transforming the frequency-domain response through the cosine transform and then taking the derivative of time.To simultaneously solve the Hankel transform and the cosine transform,a novel algorithm is introduced by adapting the fixed-point quadra-ture and extrapolation via the Shanks transformation.Finally,a typical conductivity model for marine po-lymetallic deposit is designed to investigate the characteristic of TEM response under various conditions.Numerical results demonstrate that existence of conductive seawater causes the TEM response to increase significantly and decay slower.The air-sea reflected electromagnetic waves lead to a significantly large fake negative response(NR)in shallower seawater with depth less than 300 m.Increase in the height of loops will weaken and delay the anomaly response and shorten the observation time-window.The height of configu-ration should be no more than 100 m for shallower targets and 50 m for deeper targets,respectively.The observation time-window should cover 10-1000 ms.Increase in the radius of loops only enhances the TEM response proportionally but hardly improves the relative anomaly.The vertical resolution on the low-resistivity target approximates 20 m for the configuration considered in the study.Decreases in D.C.resistivity and chargeability cause the positive response(PR)to increase significantly and decay more ra-pidly.Meanwhile,the NR is advanced and enlarged significantly and decays slower compared with the PR.The influence of time constant is not monotony and there exists an optimal value for producing the maxi-mum NR.As the frequency parameter increases,the PR is caused to decay more rapidly without magni-tude change and the NR is advanced and decays more rapidly with significant increase in magnitude.The influence of frequency parameter is more pronounced than that of time constant.展开更多
Hot compression tests of Fe-Cr-Ni-Mo-N super-austenitic stainless steel were carried out in the temperature range of 950-1150℃with a strain rate of 0.01-10 s-1,in which dynamic recrystallization(DRX)mechanisms and co...Hot compression tests of Fe-Cr-Ni-Mo-N super-austenitic stainless steel were carried out in the temperature range of 950-1150℃with a strain rate of 0.01-10 s-1,in which dynamic recrystallization(DRX)mechanisms and coincident site lattice(CSL)boundary evolution in consideration of adiabatic heating were investigated.The results show that discontinuous DRX was the main DRX mechanism.Due to the high stacking fault energy(162-173 mJ/m2),subgrain evolution occurring in dynamic recovery process was stimulated at high temperatures and high strain rates.DRX behavior was accelerated by higher strain rate and adiabatic heating.Also,amounts of fine annealing twin boundaries were observed in the specimens deformed at higher strain rates and higher temperatures.By analyzing the length fractions of∑3 boundary in overall boundaries and in CSL boundaries,the results indicate that∑3 regeneration mechanism and new twinning mechanism take effect concurrently for twin-related grain boundary when the specimens were deformed at 950℃with a strain rate of 0.01-10 s-1.With increasing strain rate or deformation temperature,the propagation of∑3 boundaries was mainly dominated by new twinning mechanism.展开更多
Comparing with ordinary ploycrystalline materials sized to μm grade,the slip morphology of the coarse grained polycrystalline pure Al is characterized by:(1)several slip domains occur in a grain,and in same domain,se...Comparing with ordinary ploycrystalline materials sized to μm grade,the slip morphology of the coarse grained polycrystalline pure Al is characterized by:(1)several slip domains occur in a grain,and in same domain,several slip systems operate at same time or one after another intensely,a beautiful and neat slip pattern is forming on the specimen surface;(2)for high Σ-value coincident and random grain boundaries,the grain boundary affecting zone (GBAZ),bout 50—120μm wide,is favourable site to form intergranular crack at early fa- tigue life easily,and migration or slide of the boundaries were often observed.While low Σ-value near-coincident grain boundaries show a higher degree of slip continuity and strain compatibility than high Σ-value ones.Intergranular crack is not easily nucleated at low Σ-value near-coincident boundaries;and(3)due to suppression of grain boundary slip at triple grain boundary node,the high Σ-value and random grain boundary among the three boundaries of tricrystal crack easily during cyclic deformation.展开更多
A calculation method based on a combination of Dg parallelism rule, good matching site（GMS） analysis, CSL/DSCL（coincidence site lattice/displacement shift complete lattice） and the O-lattice theory has been applie...A calculation method based on a combination of Dg parallelism rule, good matching site（GMS） analysis, CSL/DSCL（coincidence site lattice/displacement shift complete lattice） and the O-lattice theory has been applied to interpret the observation of the habit plane（HP） of the d precipitates and the linear defects in the HP in an Inconel 718 superalloy. The small scattering in the HP orientation around an ideal rational plane is interpreted by the existence of a mixture of two types of steps with different heights and inclinations. These steps play a significant role to enhance the degree of matching in the HP. They are associated with secondary dislocations, with Burgers vectors of 1/6 （1 1 2）y/1/3（0 0 1）, and with a direction parallel to a near-invariant line along （110）y. The spacing of the secondary dislocations projected on the terrace plane is around 6.3 nm. The calculated dislocation structure is in good agreement with the observation.展开更多
The optimization of hot compression technique of as-cast 0Cr23Ni13 stainless steel at high strain rate was discussed,and its corrosion resistance was evaluated after hot compression treatment experimentally.By adjusti...The optimization of hot compression technique of as-cast 0Cr23Ni13 stainless steel at high strain rate was discussed,and its corrosion resistance was evaluated after hot compression treatment experimentally.By adjusting the dynamic recrys-tallization(DRX)ratio of 0Cr23Nil3 stainless steel during hot pressing,the content of low Σ coincident site lattice(ΣCSL)grain boundaries is increased,and the grain orientation is optimized.The results show that ferrite and austenite are completely recrystallized at 1050 and 1150℃,respectively.The number of grains in the<111>and<101>directions increases significantly,the corrosion potential increases,and the corrosion current density decreases,which will signifi-cantly improve the corrosion resistance of 0Cr23Nil3 stainless steel.After the optimization of grain boundary distribution,corrosion resistance is noticeably improved due to the existence of lowΣCSL boundaries.The interference effect of lowΣCSL grain boundary on random grain boundary network becomes intense with the increase in DRX ratio,which is the fundamental measure to improve the corrosion resistance.展开更多
In this paper, the author gives a new section theorem in L-convex spaces. And as its applications, the author proves a coincident theorem and a two-functional minimax theorem established in L-convex spaces.
In reference to the method of the Conference Board,the coincident indexes for China are constructed from a sample period between January 1990 and May 2012 and by51 chosen component indicators.The resulting coincident ...In reference to the method of the Conference Board,the coincident indexes for China are constructed from a sample period between January 1990 and May 2012 and by51 chosen component indicators.The resulting coincident indexes have higher correlations with gross domestic product(GDP) growth rates than the China Economic Monitoring and Analysis Center(CEMAC) coincident index over the sample period between February2005 and May 2012.The peaks and troughs of the growth rates in several indicators are identified.The total number of peaks and troughs in the resulting coincident index is the same with the CEMAC coincident index.Unfortunately,these troughs don't signify recessions in the Chinese economy because the financial system has not seen a negative growth rate over the specific sample periods.The impacts of the Southeast Asian Financial Crisis and subprime mortgage crisis on the business cycle could be dated via a smoother index from HP filtering to the coincident index.展开更多
We analyze the spin coincidence experiment considered by Bell in the derivation of Bells theorem. We solve the equation of motion for the spin system with a spin Hamiltonian, Hz, where the magnetic field is only in th...We analyze the spin coincidence experiment considered by Bell in the derivation of Bells theorem. We solve the equation of motion for the spin system with a spin Hamiltonian, Hz, where the magnetic field is only in the z-direction. For the specific case of the coincidence experiment where the two magnets have the same orientation the Hamiltonian Hz commutes with the total spin Iz, which thus emerges as a constant of the motion. Bells argument is then that an observation of spin up at one magnet A necessarily implies spin down at the other B. For an isolated spin system A-B with classical translational degrees of freedom and an initial spin singlet state there is no force on the spin particles A and B. The spins are fully entangled but none of the spin particles A or B are deflected by the Stern-Gerlach magnets. This result is not compatible with Bells assumption that spin 1/2 particles are deected in a Stern-Gerlach device. Assuming a more realistic Hamiltonian Hz + Hx including a gradient in x direction the total Iz is not conserved and fully entanglement is not expected in this case. The conclusion is that Bells theorem is not applicable to spin coincidence measurement originally discussed by Bell.展开更多
In this paper, we study an application of deep learning to the advanced laser interferometer gravitational wave observatory(LIGO)and advanced Virgo coincident detection of gravitational waves(GWs) from compact binary ...In this paper, we study an application of deep learning to the advanced laser interferometer gravitational wave observatory(LIGO)and advanced Virgo coincident detection of gravitational waves(GWs) from compact binary star mergers. This deep learning method is an extension of the Deep Filtering method used by George and Huerta(2017) for multi-inputs of network detectors.Simulated coincident time series data sets in advanced LIGO and advanced Virgo detectors are analyzed for estimating source luminosity distance and sky location. As a classifier, our deep neural network(DNN) can effectively recognize the presence of GW signals when the optimal signal-to-noise ratio(SNR) of network detectors ≥ 9. As a predictor, it can also effectively estimate the corresponding source space parameters, including the luminosity distance D, right ascension α, and declination δ of the compact binary star mergers. When the SNR of the network detectors is greater than 8, their relative errors are all less than 23%.Our results demonstrate that Deep Filtering can process coincident GW time series inputs and perform effective classification and multiple space parameter estimation. Furthermore, we compare the results obtained from one, two, and three network detectors;these results reveal that a larger number of network detectors results in a better source location.展开更多
A prototype of time-of-flight positron emission computed tomography （TOF-PET） has been developed for acquiring the coincident detection of 511 keV γ-rays produced from positron annihilation. It consists of two 80.5...A prototype of time-of-flight positron emission computed tomography （TOF-PET） has been developed for acquiring the coincident detection of 511 keV γ-rays produced from positron annihilation. It consists of two 80.5 minx80.5 mm LYSO scintillator arrays （composed of 35 ×35 pixel finger crystals） with the position sensitive photomultiplier tubes R2487 as the readout. Each array is composed of 2 mm ×2m×15 mm finger crystals and the average pixel pitch is 2.30 mm. The measured results indicate that the TOF information has the potential to significantly enhance the image quality by improving the noise variance in the image recon- struction. The best spatial resolution （FWHM） of the prototype for the pairs of 511 keV T-rays is 1.98 mm and 2.16 mm in the x and y directions, respectively, which are smaller than the average pixel pitch of 2.30 mm.展开更多
.As an application of the theoretical results,in this paper,we study the symmetric reduction and Hamilton-Jacobi theory for the underwater ve-hicle with two internal rotors as a regular point reducible RCH system,in t....As an application of the theoretical results,in this paper,we study the symmetric reduction and Hamilton-Jacobi theory for the underwater ve-hicle with two internal rotors as a regular point reducible RCH system,in the cases of coincident and non-coincident centers of the buoyancy and the gravity.At first,we give the regular point reduction and the two types of Hamilton-Jacobi equations for a regular controlled Hamiltonian(RCH)system with sym-metry and a momentum map on the generalization of a semidirect product Lie group.Next,we derive precisely the geometric constraint conditions of the reduced symplectic forms for the dynamical vector fields of the regular point reducible controlled underwater vehicle-rotor system,that is,the two types of Hamilton-Jacobi equations for the reduced controlled underwater vehicle-rotor system,by calculations in detail.These work reveal the deeply internal relationships of the geometrical structures of the phase spaces,the dynamical vector fields and the controls of the system.展开更多
文摘Objectives: We analyzed the clinical characteristics of patients with pulmonary mycobacterial disease diagnosed as coincidental pulmonary infection due to Mycobacterium species. Materials and Methods: One hundred sixty patients satisfied the diagnostic criteria of nontuberculous mycobacterial disease proposed by American Thoracic Society during the last seven years. Six patients (3.8%) were coincidental pulmonary infection due to two Mycobacterium species. We investigated the background, laboratory findings, microbiological findings, radiological findings, treatment and prognosis. Results: There were six patients, 3 males and 3 females, with a mean age of 71.7 years. The causative microorganisms of coincidental pulmonary infection consisted of Mycobacterium avium + Mycobacterium intracellulare in two patients, Mycobacterium avium + Mycobacterium kansasii in one, Mycobacterium intracellulare + Mycobacterium chelonae in one, Mycobacterium intracellulare + Mycobacterium abscessus in one, and Mycobacterium intracellulare + Mycobacterium tuberculosis in one. Regarding the radiological findings, the distribution of the lesion was frequently shown in both the right middle and left lingula lobes, but the extent of the lesion was limited within the unilateral lung field. Centrilobular small nodules with bronchiectasis were recognized in all patients and cavities or infiltration shadows were recognized in half of them on chest computed tomography. A definite diagnosis was obtained by bronchoalveolar lavage fluid in four patients and expectorated sputum in two. Combined chemotherapy was performed for two patients and that for pulmonary tuberculosis in one. Conclusions: Coincidental pulmonary infection due to Mycobactterium species occurred at a low percentage. Although most patients were elderly with underlying disease and clinical features were compatible with pulmonary Mycobacterium avium complex disease, the prognosis was comparatively good with and without treatment.
基金National Natural Science Foundation of China(51764038)Gansu Science and Technology Planning Project(2022JR5RA314,22YF7WA151,22YF7GA138,23CXGA0151)+1 种基金Gansu Provincial Department of Education:Industrial Support Plan Project(2022CYZC-31)Gansu Provincial Association of Science and Technology Innovation Driving Force Project(GXH20230817-10)。
文摘The high-entropy alloy composite coatings AlCu_(2)Ti(NiCr)_(2)-(WC)_(x)(x denotes powder feeding speeds,including 0,25,50,and 75 r/min)were prepared by plasma cladding using a hybrid mode of AlCu_(2)(NiCr)_(2)Ti cable-type welding wire(CWW)and tungsten carbide(WC)powder.The effect of WC powder feeding speed on the microstructure,hardness,and wear properties of the prepared coatings was investigated.The results show that the coatings consist of body-centered cubic main phases and face-centered cubic secondary phases,with carbide reinforcement phases formed due to the addition of WC.The hardness and wear resistance of the coatings are significantly improved compared to the TC11 substrate.When WC powder feeding speed is set at 50 r/min,the coating exhibits optimal wear resistance,with a minimum volume wear rate of 8.5869×10^(-6)mm^(3)·N^(-1)·m^(-1),greatly improving the wear properties of TC11 surface.The coincident CWW-powder plasma cladding provides a viable method for the preparation of highentropy alloy composite coatings with enhanced wear resistance.
文摘This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications.
文摘Texture and grain boundary character distribution of Cu interconnects with different line width for as-deposited and annealed conditions were measured by EBSD. All specimens appear mixed texture and （111） texture is the dominate component.As-deposited interconnects undergo the phenomenon of self-annealing at RT,in which some abnormally large grains are found. Lower aspect ratio of lines and anneal treatment procured larger grains and stronger （111） texture. Meanwhile, the intensity proportion of other textures with lower strain energy to （111） texture is decreased. As-deposited specimens reveal （111）（112？ and （111） （231） components, （111） （110） component appeared and （111） （112？ and （111） （231） components were developed during the annealing process. High angle boundaries are dominant in all specimens, boundaries with a misorientation of 55°-60° and ∑3 ones in higher proportion, followed by lower boundaries with a misorientation of 35°-40° and 29 boundaries. As the aspect ratio of lines and anneal treatment increase,there is a gradual in- crement in ∑3 boundaries and a decrease in ∑9 boundaries.
文摘Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a diagnostic challenge. Therefore, we performed a review of the recent literature and developed an evidence-based diagnostic algorithm to guide clinicians in characterising these lesions. Simple cysts are the most common cystic liver disease, and diagnosis is based on typical USG characteristics. Serodiagnostic tests and microbubble contrast-enhanced ultrasound (CEUS) are invaluable in differentiating complicated cysts, echinococcosis and cystadenoma/cystadenocarcinoma when USG, CT and MRI show ambiguous findings. Therefore, serodiagnostic tests and CEUS reduce the need for invasive procedures. Polycystic liver disease (PLD) is arbitrarily defined as the presence of > 20 liver cysts and can present as two distinct genetic disorders: autosomal dominant polycystic kidney disease (ADPKD) and autosomal dominant polycystic liver disease (PCLD). Although genetic testing for ADPKD and PCLD is possible, it is rarely performed because it does not affect the therapeutic management of PLD. USG screening of the liver and both kidneys combined with extensive family history taking are the cornerstone of diagnostic decision making in PLD. In conclusion, an amalgamation of these recent advances results in a diagnostic algorithm that facilitates evidence-based clinical decision making.
基金This research was supported by the National Key R&D Program of China(No.2018YFC0603806).
文摘The transient electromagnetic(TEM)method becomes more urgent than ever for marine ex-ploration due to abundant resource reserves and the increasing undersea engineering construction activities,especially in the offshore exploration of mineral deposits such as Sanshandao gold mine.However,the re-search and application of TEM method in marine environment are still challenged by many problems.Such contradiction motivates our study on the coincident-loop TEM in seafloor exploration.The TEM response of coincident loops is firstly derived in the integral form,based on the potential functions in Helmholtz equ-ations for a magnetic source locating in the whole-space layered model.The frequency-domain vertical magnetic field is described as the Hankel integral with double first-order Bessel functions of first kind.Se-condly,the time-domain induced voltage is obtained by transforming the frequency-domain response through the cosine transform and then taking the derivative of time.To simultaneously solve the Hankel transform and the cosine transform,a novel algorithm is introduced by adapting the fixed-point quadra-ture and extrapolation via the Shanks transformation.Finally,a typical conductivity model for marine po-lymetallic deposit is designed to investigate the characteristic of TEM response under various conditions.Numerical results demonstrate that existence of conductive seawater causes the TEM response to increase significantly and decay slower.The air-sea reflected electromagnetic waves lead to a significantly large fake negative response(NR)in shallower seawater with depth less than 300 m.Increase in the height of loops will weaken and delay the anomaly response and shorten the observation time-window.The height of configu-ration should be no more than 100 m for shallower targets and 50 m for deeper targets,respectively.The observation time-window should cover 10-1000 ms.Increase in the radius of loops only enhances the TEM response proportionally but hardly improves the relative anomaly.The vertical resolution on the low-resistivity target approximates 20 m for the configuration considered in the study.Decreases in D.C.resistivity and chargeability cause the positive response(PR)to increase significantly and decay more ra-pidly.Meanwhile,the NR is advanced and enlarged significantly and decays slower compared with the PR.The influence of time constant is not monotony and there exists an optimal value for producing the maxi-mum NR.As the frequency parameter increases,the PR is caused to decay more rapidly without magni-tude change and the NR is advanced and decays more rapidly with significant increase in magnitude.The influence of frequency parameter is more pronounced than that of time constant.
基金The authors would like to acknowledge the financial supports from the National Natural Science Foundation of China(U1460204,U1660117).
文摘Hot compression tests of Fe-Cr-Ni-Mo-N super-austenitic stainless steel were carried out in the temperature range of 950-1150℃with a strain rate of 0.01-10 s-1,in which dynamic recrystallization(DRX)mechanisms and coincident site lattice(CSL)boundary evolution in consideration of adiabatic heating were investigated.The results show that discontinuous DRX was the main DRX mechanism.Due to the high stacking fault energy(162-173 mJ/m2),subgrain evolution occurring in dynamic recovery process was stimulated at high temperatures and high strain rates.DRX behavior was accelerated by higher strain rate and adiabatic heating.Also,amounts of fine annealing twin boundaries were observed in the specimens deformed at higher strain rates and higher temperatures.By analyzing the length fractions of∑3 boundary in overall boundaries and in CSL boundaries,the results indicate that∑3 regeneration mechanism and new twinning mechanism take effect concurrently for twin-related grain boundary when the specimens were deformed at 950℃with a strain rate of 0.01-10 s-1.With increasing strain rate or deformation temperature,the propagation of∑3 boundaries was mainly dominated by new twinning mechanism.
文摘Comparing with ordinary ploycrystalline materials sized to μm grade,the slip morphology of the coarse grained polycrystalline pure Al is characterized by:(1)several slip domains occur in a grain,and in same domain,several slip systems operate at same time or one after another intensely,a beautiful and neat slip pattern is forming on the specimen surface;(2)for high Σ-value coincident and random grain boundaries,the grain boundary affecting zone (GBAZ),bout 50—120μm wide,is favourable site to form intergranular crack at early fa- tigue life easily,and migration or slide of the boundaries were often observed.While low Σ-value near-coincident grain boundaries show a higher degree of slip continuity and strain compatibility than high Σ-value ones.Intergranular crack is not easily nucleated at low Σ-value near-coincident boundaries;and(3)due to suppression of grain boundary slip at triple grain boundary node,the high Σ-value and random grain boundary among the three boundaries of tricrystal crack easily during cyclic deformation.
基金financially supported by the National Natural Science Foundation of China (Grant No. 51671111)the National Key Research and Development Program of China (Grant No. 2016YFB0701304)
文摘A calculation method based on a combination of Dg parallelism rule, good matching site（GMS） analysis, CSL/DSCL（coincidence site lattice/displacement shift complete lattice） and the O-lattice theory has been applied to interpret the observation of the habit plane（HP） of the d precipitates and the linear defects in the HP in an Inconel 718 superalloy. The small scattering in the HP orientation around an ideal rational plane is interpreted by the existence of a mixture of two types of steps with different heights and inclinations. These steps play a significant role to enhance the degree of matching in the HP. They are associated with secondary dislocations, with Burgers vectors of 1/6 （1 1 2）y/1/3（0 0 1）, and with a direction parallel to a near-invariant line along （110）y. The spacing of the secondary dislocations projected on the terrace plane is around 6.3 nm. The calculated dislocation structure is in good agreement with the observation.
基金This research was financially supported by the Science and Technology Major Project of Gansu Province(Grant No.17ZD2GB012)the City Key Research and Development Plan of Jiayuguan(Grant Nos.20-16).
文摘The optimization of hot compression technique of as-cast 0Cr23Ni13 stainless steel at high strain rate was discussed,and its corrosion resistance was evaluated after hot compression treatment experimentally.By adjusting the dynamic recrys-tallization(DRX)ratio of 0Cr23Nil3 stainless steel during hot pressing,the content of low Σ coincident site lattice(ΣCSL)grain boundaries is increased,and the grain orientation is optimized.The results show that ferrite and austenite are completely recrystallized at 1050 and 1150℃,respectively.The number of grains in the<111>and<101>directions increases significantly,the corrosion potential increases,and the corrosion current density decreases,which will signifi-cantly improve the corrosion resistance of 0Cr23Nil3 stainless steel.After the optimization of grain boundary distribution,corrosion resistance is noticeably improved due to the existence of lowΣCSL boundaries.The interference effect of lowΣCSL grain boundary on random grain boundary network becomes intense with the increase in DRX ratio,which is the fundamental measure to improve the corrosion resistance.
基金the Scientific Research Common Program of Beijing Municipal Commission of Education(KM200610005014)
文摘In this paper, the author gives a new section theorem in L-convex spaces. And as its applications, the author proves a coincident theorem and a two-functional minimax theorem established in L-convex spaces.
基金the support provided by Ford Foundation,Stanford SCID and National Planning Office of Philosophy and Social Science(Approval No.12 & ZD038)
文摘In reference to the method of the Conference Board,the coincident indexes for China are constructed from a sample period between January 1990 and May 2012 and by51 chosen component indicators.The resulting coincident indexes have higher correlations with gross domestic product(GDP) growth rates than the China Economic Monitoring and Analysis Center(CEMAC) coincident index over the sample period between February2005 and May 2012.The peaks and troughs of the growth rates in several indicators are identified.The total number of peaks and troughs in the resulting coincident index is the same with the CEMAC coincident index.Unfortunately,these troughs don't signify recessions in the Chinese economy because the financial system has not seen a negative growth rate over the specific sample periods.The impacts of the Southeast Asian Financial Crisis and subprime mortgage crisis on the business cycle could be dated via a smoother index from HP filtering to the coincident index.
文摘We analyze the spin coincidence experiment considered by Bell in the derivation of Bells theorem. We solve the equation of motion for the spin system with a spin Hamiltonian, Hz, where the magnetic field is only in the z-direction. For the specific case of the coincidence experiment where the two magnets have the same orientation the Hamiltonian Hz commutes with the total spin Iz, which thus emerges as a constant of the motion. Bells argument is then that an observation of spin up at one magnet A necessarily implies spin down at the other B. For an isolated spin system A-B with classical translational degrees of freedom and an initial spin singlet state there is no force on the spin particles A and B. The spins are fully entangled but none of the spin particles A or B are deflected by the Stern-Gerlach magnets. This result is not compatible with Bells assumption that spin 1/2 particles are deected in a Stern-Gerlach device. Assuming a more realistic Hamiltonian Hz + Hx including a gradient in x direction the total Iz is not conserved and fully entanglement is not expected in this case. The conclusion is that Bells theorem is not applicable to spin coincidence measurement originally discussed by Bell.
基金supported by the National Natural Science Foundation of China(Grant Nos.11873001,11633001,11673008,and 61501069)the Natural Science Foundation of Chongqing(Grant No.cstc2018jcyjAX0767)+4 种基金the Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB23040100)Newton International Fellowship Alumni Followon Fundingthe Fundamental Research Funds for the Central Universities Project(Grant Nos.106112017CDJXFLX0014,and 106112016CDJXY300002)Chinese State Scholarship FundNewton International Fellowship Alumni Follow on Funding
文摘In this paper, we study an application of deep learning to the advanced laser interferometer gravitational wave observatory(LIGO)and advanced Virgo coincident detection of gravitational waves(GWs) from compact binary star mergers. This deep learning method is an extension of the Deep Filtering method used by George and Huerta(2017) for multi-inputs of network detectors.Simulated coincident time series data sets in advanced LIGO and advanced Virgo detectors are analyzed for estimating source luminosity distance and sky location. As a classifier, our deep neural network(DNN) can effectively recognize the presence of GW signals when the optimal signal-to-noise ratio(SNR) of network detectors ≥ 9. As a predictor, it can also effectively estimate the corresponding source space parameters, including the luminosity distance D, right ascension α, and declination δ of the compact binary star mergers. When the SNR of the network detectors is greater than 8, their relative errors are all less than 23%.Our results demonstrate that Deep Filtering can process coincident GW time series inputs and perform effective classification and multiple space parameter estimation. Furthermore, we compare the results obtained from one, two, and three network detectors;these results reveal that a larger number of network detectors results in a better source location.
基金Supported by National Natural Science Foundation of China (10305015,10475098)West Light Foundation of Chinese Academy of Sciences(0801010XBB)Major Foundation Program of Chinese Academy of Sciences(O701050YZD)
文摘A prototype of time-of-flight positron emission computed tomography （TOF-PET） has been developed for acquiring the coincident detection of 511 keV γ-rays produced from positron annihilation. It consists of two 80.5 minx80.5 mm LYSO scintillator arrays （composed of 35 ×35 pixel finger crystals） with the position sensitive photomultiplier tubes R2487 as the readout. Each array is composed of 2 mm ×2m×15 mm finger crystals and the average pixel pitch is 2.30 mm. The measured results indicate that the TOF information has the potential to significantly enhance the image quality by improving the noise variance in the image recon- struction. The best spatial resolution （FWHM） of the prototype for the pairs of 511 keV T-rays is 1.98 mm and 2.16 mm in the x and y directions, respectively, which are smaller than the average pixel pitch of 2.30 mm.
文摘.As an application of the theoretical results,in this paper,we study the symmetric reduction and Hamilton-Jacobi theory for the underwater ve-hicle with two internal rotors as a regular point reducible RCH system,in the cases of coincident and non-coincident centers of the buoyancy and the gravity.At first,we give the regular point reduction and the two types of Hamilton-Jacobi equations for a regular controlled Hamiltonian(RCH)system with sym-metry and a momentum map on the generalization of a semidirect product Lie group.Next,we derive precisely the geometric constraint conditions of the reduced symplectic forms for the dynamical vector fields of the regular point reducible controlled underwater vehicle-rotor system,that is,the two types of Hamilton-Jacobi equations for the reduced controlled underwater vehicle-rotor system,by calculations in detail.These work reveal the deeply internal relationships of the geometrical structures of the phase spaces,the dynamical vector fields and the controls of the system.
