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| 1 | Variational Principle of Instability of Atmospheric Motions显示文摘Problems of instability of rotating atmospheric motions are investigated by using nonlinear governing equations and the variational principle. The method suggested in this paper is universal for obtaining criteria of instability in all models with all possible basic flows. For example, the model can be barotropic or baroclinic, layer or continuous, quasi-geostrophic or primitive equations; the basic flow can be zonal or nonzonal, steady or unsteady.Although the basic flows possess a great deal of variety, they all are the stationary points in the functional space determined by an appropriate invariant functional. The basic flow is an unsteady one if the conservation of angular momentum is included in the associated functional.The second variation, linear or nonlinear, gives the criteria of instability. Especially, the general criteria of instability for unsteady basic flow, orographically disturbed flow as well as nongeostrophic flow are first obtained by the method described in this paper.It is also | 曾庆存 | 1989 | Advances in Atmospheric Sciences1989，6，2： | 17 |
| 2 | Planetary Stationary Waves in the Atmosphere Part I: Orographic Stationary Waves显示文摘It is proposed that the orographic stationary waves are required by long-term balance of momentum in the atmosphere with zonally asymmetric orographic forcing. This hypothesis may be confirmed successfully with the theoretical model of geostrophic waves. In the Part I, we will explain the observed phase distributions of orographic stationary waves at middle and high latitudes of the Northern Hemisphere, according to the long-term balance of zonal momentum over the stationary orographic forcing. It is revealed that the geographic distribution of stationary waves depends not only on local topgraphy but also on mean circulation fields and angular momentum flux in the atmosphere. So these waves cannot be simulated by the models in a restricted area. | Yong. L. McHall | 1991 | Advances in Atmospheric Sciences1991，8，2： | 7 |
| 3 | Approximation of weak sense stationary stochastic processes from local averages显示文摘We show that a weak sense stationary stochastic process can be approximated by local averages. Explicit error bounds are given. Our result improves an early one from Splettstosser. | Zhan-jie SONG Wen-chang SUN Shou-yuan YANG Guang-wen ZHU | 2007 | Science China Mathematics2007，50，4： | 7 |
| 4 | JUMP AND BIFURCATION OF DUFFING OSCILLATOR UNDER NARROW-BAND EXCITATION显示文摘The jump and bifurcation of Duffing oscillator with hardening springsubject to narrow-band random excitation are systematically and comprehensivelyexamined. It is shown that, in a certain domain of the space of the oscillator andexcitation parameters, there are two types of more probable motions in the stationaryresponse of the Duffing oscillator and jumps may occur. The jump is a transition ofthe response from one more probable motion to another or vise versa. Outside thedomain the stationary response is either nearly Gaussian or like a diffused limit cycle.As the parameters change across the boundary of the domain the qualitative behaviorof the stationary response changes and it is a special kind of bifurcation. It is alsoshown that, for a set of specified parameters, the statistics are unique and they areindependent of initial condition. It is pointed out that some previous results andinterpretations on this problem are incorrect. | 朱位秋 吴淇泰 鲁民清 | 1994 | Acta Mechanica Sinica1994，10，1： | 7 |
| 5 | Planetary Stationary Waves in the Atmosphere Part II: Thermal Stationary Waves显示文摘The contribution of thermal forcing to the planetary stationary waves will be studied also by assuming that heat balance in stationary waves over zonally asymmetric thermal forcing must be maintained over a long time period. Using the same model of geostrophic waves introduced in Part I, we may explain successfully the observed and simulated responses to the thermal forcing in the atmosphere, such as the wave 1 structure at high levels of middle latitudes, the seasonal changes of the stationary waves in the Northern Hemisphere, the opposite phase distributions of stationary waves at high and low levels of the subtropical regions in both hemispheres and so on. | Yong. L. McHall | 1991 | Advances in Atmospheric Sciences1991，8，2： | 6 |
| 6 | Periodic Solution and Ergodic Stationary Distribution of Stochastic SIRI Epidemic Systems with Nonlinear Perturbations显示文摘This paper formulates two stochastic nonautonomous SIRI epidemic systems with nonlinear perturbations.The main aim of this study is to investigate stochastic dynamics of the two SIRI epidemic systems and obtain their thresholds.For the nonautonomous stochastic SIRI epidemic system with white noise,the authors provide analytic results regarding the stochastic boundedness,stochastic permanence and persistence in mean.Moreover,the authors prove that the system has at least one nontrivial positive T-periodic solution by using Lyapunov function and Hasminskii’s theory.For the system with Markov conversion,the authors establish sufficient conditions for positive recurrence and existence of ergodic stationary distribution.In addition,sufficient conditions for the extinction of disease are obtained.Finally,numerical simulations are introduced to illustrate the main results. | ZHANG Weiwei MENG Xinzhu DONG Yulin | 2019 | Journal of Systems Science & Complexity2019，32，4： | 6 |
| 7 | Beam and image experiment of beam deflection electron gun for distributed X-ray sources显示文摘Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative system concepts in X-ray and computer tomography. This paper proposes a novel electron beam focusing, shaping,and deflection electron gun for distributed X-ray sources.The electron gun uses a dispenser cathode as an electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflection. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. Two identical half-rectangle opening electrodes are controlled by adjusting the potential of the two electrodes to control the electron beam trajectory, and then, multifocal spots are obtained on the anode target. The electron gun can increase the spatial density of the distributed X-ray sources, thereby improving the image quality. The beam experimental results show that the focal spot sizes of the deflected(deflected amplitude 10.5 mm)and non-deflected electron beams at full width at half maximum are 0.80 mm 90.50 mm and 0.55 mm 90.40 mm, respectively(anode voltage 160 kV; beam current 30 mA). The imaging experimental results demonstrate the excellent spatial resolution and time resolution of an imaging system built with the sources, which has an excellent imaging effect on a field-programmable gate array chip and a rotating metal disk. | Cheng-Jun Tan Chuan-Xiang Tang Wen-Hui Huang Qing-Xiu Jin Ying-Chao Du Qun Luo Pei-Dong Wu Dong-Hai Liu Lu-Ming Zhang Cong Xu | 2019 | Nuclear Science and Techniques2019，30，3： | 6 |
| 8 | 高效液相色谱纤维素衍生物类手性固定相拆分泮托拉唑对映体显示文摘 | 唐淑含 赵荣淑 任洁 王东凯 郭丽霞 赵怀清 | 2006 | 色谱2006，24，2： | 5 |
| 9 | 慢性阻塞性肺疾病患者血清瘦素水平与炎性反应相关性显示文摘目的 探讨慢性阻塞性肺疾病(COPD)患者血清瘦素水平变化及其与炎性反应的关系,了解瘦素在COPD患者炎症反应过程中的作用及其意义.方法 选择COPD患者共58例,COPD急性加重期(Ⅰ组)30例,COPD缓解期(Ⅱ组)28例,正常对照组28例.测定和计算各组的多项营养指标,包括身高、体重、体重指数(BMI)、理想体重百分比(NM%)、体脂百分比(fat%).用酶联免疫吸附试验法(ELISA)测定58例COPD患者和28例正常人的血清瘦素、肿瘤坏死因子-α(TNF-α)、白细胞介素-8(IL-8)、超敏C-反应蛋白(hs-CRP)水平及肺功能,分析瘦素与各项参数的相关性.结果 ①COPD患者的各营养指标:BMI、NM%、fat%均显著低于正常对照组(P<0.01).②COPD I组血清瘦素、TNF-α、IL-8、hs-CRP均显著高于正常组与COPDⅡ组(P<0.01);COPDⅡ组血清瘦素低于正常组(P<0.01),TNF-α、IL-8、hs -CRP高于对照组(P<0.01);③COPD患者的瘦素含量与BMI、NM%、fat%、TNF-α、IL-8、hs -CRP水平显著正相关.结论 血清瘦素在COPD急性加重期明显高于缓解期,并与营养参数、TNF-α、IL-8、hs -CRP呈显著正相关,提示瘦素可能与COPD的疾病本身和全身炎症反应有关,可作为COPD急性加重期的炎症标志物. | 梁红卫 黄兰卿 | 2010 | 中国实用医刊2010，37，15： | 5 |
| 10 | Blocking Distributions in the Atmosphere显示文摘The zonal momentum generation in forced stationary waves may exceed the requirement for momentum balance after long, if the waves do not change their patterns. This suggests that the changes in stationary wave patterns would be required by maintenance of momentum balance over the external forcings. It will be found that the low frequency anomalies like blocking regimes may produce reversed zonal momentum variations, if they happen in the observed centre areas. The zonal momentum balance in the stationary waves may be maintained effectively by alternation between the normal and blocking circulation regimes. Thus, from the point of long-term zonal momentum balance, we may explain the geographical distributions of the blocking centres and the seasonal variations in blocking areas and frequencies. | Yong. L. McHall | 1991 | Advances in Atmospheric Sciences1991，8，3： | 4 |
| 11 | THE WAVELET DETECTION OF THE JUMP AND CUSP POINTS OF A REGRESSION FUNCTION显示文摘Wavelets are applied to a regression model with an additive stationary noise. By checking the empirical wavelet coefficients with significantly large absolute values across fine scale levels, the jump points are detected first. Then the cusp points are identified by checking the wavelet coefficients with significantly large absolute values which are secondly large only to the previous wavelet coefficient across fine scale levels. All estimators are shown to be consistent. | 李元 谢衷洁 | 2000 | Acta Mathematicae Applicatae Sinica2000，16，3： | 4 |
| 12 | A Semilinear Parabolic System Arising in the Nuclear Reactors显示文摘This note studies the following initial boundary value problem, which arises in the nuclear | 顾永耕 王明新 | 1994 | Chinese Science Bulletin1994，39，19： | 4 |
| 13 | Experimental and numerical investigations of bonding interface behavior in stationary shoulder friction stir lap welding显示文摘Stationary shoulder friction stir lap welding(SSFSLW) was employed to weld 2024 aluminum alloy. A coupled Eulerian-Lagrangian(CEL) model was developed to investigate the lap interface behavior during SSFSLW. Numerical results of material movement and equivalent plastic strain were in good agreement with the experimental work. With increasing welding speed, the distances from the hook tip to the top surface of the upper workpiece on the retreating side(RS) and the advancing side(AS) increase, while the distance between two wave-shaped alclads decreases. A symmetric interface bending is observed on the AS and the RS during plunging, while the interface bending on the AS is bigger than that on the RS during welding. The peak temperature of the interface on the AS is higher than that on the RS. The equivalent plastic strain gradually increases as the distance to the weld center decreases, and its peak value is obtained near the bottom of the weld. | Q.Wen W.Y.Li W.B.Wang F.F.Wang Y.J.Gao V.Patel | 2019 | Journal of Materials Science & Technology2019，35，1： | 4 |
| 14 | Aggregate modeling and analysis of air conditioning load using coupled Fokker–Planck equations显示文摘Demand response has gained significant attention recently with the increasing penetration of renewable energy sources in power systems. Air conditioning loads are typical thermostatically controlled loads which can play an active role in ancillary services by regulating their aggregated power consumption. The aggregation of air conditioners is essential to the control of air conditioning loads. In this paper, linear state equations are proposed to aggregate air conditioning loads by solving coupled Fokker–Planck equations(CFPEs) using the finite difference method. By analyzing the numerical stability and convergence of the difference scheme, the grid spacings, including temperature step and time step, are properly determined according to the maximal principle. Stationary solutions of the CFPEs are obtained by analytical and numerical methods. Furthermore, a classification method using dimension reduction is proposed to deal with the problem of heterogeneous parameters and interval estimation is applied to describe the stochastic behavior of air conditioning loads. The simulation results verify the effectiveness of the proposed methods. | Dingyi CHENG Wen ZHANG Yutian LIU | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，6： | 4 |
| 15 | A Problem Related to Nonlinear Stability Criteria for Multi-layer Quasi-geostrophic Flow显示文摘The second author studied the nonlinear stability of N-layer quasi-geostrophic flow subject to perturbations of parameters and initial data, and established the stability criteria for the flow in question, which involve finding out the lowest eigenvalue of an elliptic boundary value problem.In this paper when the domain is a periodic zonal channel, a formula of the lowest eigenvalue is established, which is useful for further studies and practical applications. | 刘永明 穆穆 | 1992 | Advances in Atmospheric Sciences1992，9，3： | 4 |
| 16 | Nonlinear Planetary Wave Instability and Blocking显示文摘The instability of geostrophic wave circulations related to the nonlinear processes involved in the zonal mean heat balance equations is studied. It is found that the planetary waves may be destabilized by thermal forcing in specific baroclinic layers, called the breaking layers. The critical conditions of the instability will be given. In the troposphere, these conditions may be provided in blocking regions and the development of planetary perturbations is characterized distinctly by the unset, maintenance and decay of observed blocks. The whole blocking episode cannot be described as either the barotropic or baroclinic process only. The limitations on the study of wave-wave interaction using spectral models or spectrum analyses will be discussed also. | Yong.L.McHall | 1992 | Advances in Atmospheric Sciences1992，9，2： | 4 |
| 17 | Novel polymer system for molecular imprinting polymer against amino acid derivatives显示文摘Molecular imprinting polymers (MIPs) against N-Cbz-L-Tyr were prepared utilizing different polymer systems and evaluated in HPLC mode. It was found that MEP utilizing cocktail functional monomers, acrylamide + 2-vinylpyridine showed better molecular recognition and better separation ability for the template molecule than those utilizing other functional monomers. MIP utilizing trimethylolpropane trimethacrylate as cross-linker showed higher load capacity and separation factor than those utilizing ethylene glycol dimethacrylate as cross-linker. Increasing the concentration of competing solvent, acetic acid weakened the ionic interaction and hydrogen bonding between the analyte and the functional monomers, 2-vinylpyridine and acrylamide, when the template enantiomer was separated by HPLC. Therefore increasing of the concentration of acetic acid leads to decreasing of capacity factor, separation factor and resolution. | 王进防 周良模 刘学良 王清海 朱道乾 | 2000 | Chinese Journal of Chemistry2000，18，4： | 4 |
| 18 | Short-Term Dynamic Radar Quantitative Precipitation Estimation Based on Wavelet Transform and Support Vector Machine显示文摘Currently,Doppler weather radar in China is generally used for quantitative precipitation estimation(QPE)based on the Z–R relationship.However,the estimation error for mixed precipitation is very large.In order to improve the accuracy of radar QPE,we propose a dynamic radar QPE algorithm with a 6-min interval that uses the reflectivity data of Doppler radar Z9002 in the Shanghai Qingpu District and the precipitation data at automatic weather stations(AWSs)in East China.Considering the time dependence and abrupt changes of precipitation,the data during the previous 30-min period were selected as the training data.To reduce the complexity of radar QPE,we transformed the weather data into the wavelet domain by means of the stationary wavelet transform(SWT)in order to extract high and low-frequency reflectivity and precipitation information.Using the wavelet coefficients,we constructed a support vector machine(SVM)at all scales to estimate the wavelet coefficient of precipitation.Ultimately,via inverse wavelet transformation,we obtained the estimated rainfall.By comparing the results of the proposed method(SWTSVM)with those of Z=300×R1.4,linear regression(LR),and SVM,we determined that the root mean square error(RMSE)of the SWT-SVM method was 0.54 mm per 6 min and the average Threat Score(TS)could exceed 40%with the exception of the downpour category,thus remaining at a high level.Generally speaking,the SWT-SVM method can effectively improve the accuracy of radar QPE and provide an auxiliary reference for actual meteorological operational forecasting. | Changjiang ZHANG Huiyuan WANG Jing ZENG Leiming MA Li GUAN | 2020 | Journal of Meteorological Research2020，34，2： | 4 |
| 19 | STATIONARY DISTRIBUTIONS OF INFINITE PARTICLE SYSTEMS WITH NONCOMPACT STATE SPACE.显示文摘This paper deals with the preblem of existence and uniqueness of the stationary distributions (abbr., s. d.’s) for the processes constructed in [4] .The main results are stated in § 1. For the reader’s convenience we first restate the existence theorems (Theorem 1 and 2) of the processes given in [4]. Then two existence theorems (Theorem 3 and 4) and a uniqueness theorem (Theorem 5) for the s. d.’s of the processes are presented. The last result (Theorem 6), as an application of the previous ones, is about the Schlgl model which comes from nonequilibrium statisticali physics. The details of the proofs of Theorem 3—6 are given in § 2—4. | 陈木法 | 1989 | Acta Mathematica Scientia1989，9，1： | 3 |
| 20 | Representation of microscale ocean wavenumber spectrum correct to the second order显示文摘In this paper, the analytical representations of four wave source functions in high-frequency spectrum range are given on the basis of ocean wave theory and dimensional analysis, and the perturbation method is used to solve the governing equations of ocean wave high-frequency spectrum on the basis of the temporally stationary and locally homogeneous scale relations of microscale wave. The microscale ocean wavenumber spectrum correct to the second order has an explicit structure, its first order part represents the equilibrium between dif- ferent source functions, and its second order part represents the contribution of microscale wave propagation. | YUAN Yeli2 & HUA Feng1,2,3 1. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China 2. Key Laboratory of Marine Science and Numerical Modeling, State Oceanic Administration, Qingdao 266061, China 3. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China | 2005 | Science China Earth Sciences2005，48，4： | 3 |
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