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Drop splashing is a very common phenomenon when liquid drops impact on solid surfaces. In this study, picosecond laser fabricated hybrid superhydrophobic/-philic (SH/SHL) surfaces with designed patterns are successfully applied to control drop splashing on solid surfaces. Using high-speed imaging, the water drop impact behaviors on differently patterned hybrid SH/SHL surfaces were investigated. The experimental results show that the water drop splashing could be restrained greatly on patterned hybrid SH/SHL surfaces, compared with SH or SHL surfaces. On a hybrid SH/SHL surface with a 2 mm diameter circular SH pattern, the drop splashing for a Weber number up to 600 (the corresponding impact velocity is 4.2 m/s) can be totally suppressed. Moreover, we found that the oriented distribution of splashing can be regulated by the shape and size of SH patterns. These results suggest that patterned hybrid SH/SHL surfaces could be a practical approach to regulate or control drop splashing.

Underwater acoustic absorption metasurfaces (UAAMs), featured with artificial periodic unit cells as acoustic micro-absorbers, are crucial for the enhancement of the underwater stealth, energy transition, sonar detection, etc. How to implement the acoustic metasurfaces for practical engineering applications requires the support of efficient manufacturing techniques. Here we present a simple way of laser texturing for fabrication of the patterned superhydrophobic surface on glass fiber reinforced plastic (GFRP). Unlike the traditional acoustic absorbing material whose thickness should match the corresponding wavelength, the laser textured superhydrophobic micro-grooves have thickness less than the absorption sound wavelength by 2–3 orders of magnitude but promisingly demonstrate over 88% of the underwater incident acoustic power absorption from 50 kHz to 250 kHz. The physical mechanism of the UAAM ascribes to the multiple interface scattering effect induced by the air layer between water and superhydrophobic micro-nano structures.

Anti-biofouling technology is based on specifically designed materials and coatings. This is an enduring goal in the maritime industries, such as shipping, offshore oil exploration, and aquaculture. Recently, research of the relationship between wettability and antifouling effectiveness has attracted considerable attention, due to the anti-biofouling properties of the lotus leaf and shark skin. In this study, super-hydrophobic surfaces (SHSs) with controllable periodic structures were fabricated on AISI304 stainless steel by a picosecond laser, and their anti-biofouling performance were investigated by seawater immersion for five weeks in summertime. The results showed that the specimens with SHS demonstrate significant anti-biofouling effect as compared with the bare stainless steel plate. We observed that nearly 50% decrease of the average microbe attachment area ratio (Avg. MAAR) could be obtained. The micro-groove SHS with more abundant hierarchical micro-nano structures showed better anti-biofouling performance than the micro-pit SHS.

The equation of probability distribution function for mean fibre orientation in a turbulent boundary layer is derived, in which the correlation terms of the fluctuating velocity, fluctuating angular velocity with the fluctuating probability distribution function are related to the gradient of mean probability distribution function and the dispersion coefficients in order to make the equation be solvable. The finite-difference method is used to solve the equation numerically. The results show that the fibres tend to align with the streamline, which is in agreement qualitatively with the experimental result given by visualization. The fibre aspect-ratio has a significant effect on the orientation distribution of fibres, while the effect of the distance from the wall is negligible.

We have carried out the hohlraum experiments about radiation temperature scaling on the Shenguang-II (SG-II) laser facility with eight laser beams of 0.35 μm, pulse duration of about 1.0 ns and total energy of 2000 J. The reradiated x-ray flux through the laser entrance hole was measured using a soft x-ray spectrometer. The measured peak radiation temperature was 170 eV for the standard hohlraum and 150 eV for the 1.5-scaled one. We have derived the radiation temperature scaling law, in which the laser hohlraum coupling efficiency is included. With an appropriate coupling efficiency, the coincidences between experimental and scaling hohlraum radiation temperatures are rather good.

We calculate conductance of an Aharonov–Bohm (AB) interferometer for which a single-level quantum dot in the Coulomb blockade regime is embedded in one of its arms. Using the Schrodinger equations and taking into account the Coulomb interaction on the dot, we calculate conductance G as a function of flux threaded through the ring and as a function of gate voltage V applied to the dot. It is found that the AB oscillations of G() depend on the particle occupation on the dot, controlled by V. If the system is closed, there is no loss of particles, G() is periodic and G() = G(−), satisfying the Onsager relation. In this case G() can reach its maximum value, 2e2/h, at the resonance. When the system is open, one has G()≠G(−), G() yields a phase shift which depends on the loss rate of electrons in this open system.

To study the application of memristor in chaotic system, we employ the smooth continuous nonlinear flux-controlled memristor model and feedback control technique to design a hyperchaotic system based on the simplified Lorenz system. By using memristor as a positive feedback of the simplified Lorenz system, the dimensionless mathematical model is derived. The differences between the memristor-based chaotic system and ordinary chaotic system are then further studied. Firstly, the stable equilibrium and unstable equilibrium point sets of the system are analyzed theoretically, and it is found that the system has infinite equilibrium points including stable and unstable equilibrium points. The stable and unstable ranges of the system with different parameters are also determined. Theoretical analysis shows that the system has the same symmetry as the simplified Lorenz system. Thus the system has rich dynamical behaviors, such as limit cycle, chaotic attractor, and hyper-chaotic attractor. Secondly, by the methods of bifurcation diagram, Lyapunov exponent spectrum, Poincar section, and Spectral Entropy algorithm, the dynamical behaviors of the system are analyzed in detail. By calculating the Lyapunov exponent spectrum, the dynamical behaviors are studied and they change with system parameters and the initial conditions of memristor respectively. The maximum positive Lyapunov exponent of the memristor-based Lorenz hyperchaotic system is higher than that of the simplified Lorenz system, which indicates the memristor-based Lorenz hyperchaotic system is more complex. Further, we find all the complex dynamical behaviors to be coexisting with the infinite equilibrium sets, which is quite different from those of many ordinary hyper-chaotic systems. Meanwhile, we observe the attractors coexisting and state transition phenomenon in this system, caused by changing the initial conditions of the memristor. State transition phenomenon is then further studied by means of phase portraits and spectral entropy algorithm for the first time. Finally, by using operational amplifiers, diodes and other discrete components, we design an equivalent circuit of the smooth continuous nonlinear flux-controlled memristor model, and the equivalent circuit is used to design and realize the analog electronic circuit of the memristor-based Lorenz hyper-chaotic system. By using an analog oscilloscope, the phase portraits of hyper-chaotic attractor are observed clearly. The state transition phenomenon can also be seen using the oscilloscope. It is found that the circuit experimental results are in agreement with those of the theoretical analysis and numerical simulation. It verifies that the system is physically realizable, and lays a strong foundation for its applications in engineering. Next, we will try to investigate the chaotic secure communication based on this hyper-chaotic system.

The crystallographic and magnetic structures of Nd2Fe17Nx (x=2.5, 3.0, 5.5) at room temperature were refined by Rietveld analysis of neutron powder diffraction data. We found that Nd2Fe17Nx has a Th2Zn17 type structure (S. G. Rm) and the nitrogen atoms occupy both 9e and 18g sites simultaneously and at different rates.

The anisotropy constants K of γ-Fe2O3, Co-γ-Fe2O3 and Co ultrafine particles precipitated in Cu-Co alloy have been measured by using the equations for describing the relaxation of superparamagnetic particles. It is found that the anisotropy constant K of Co-γ-Fe2O3 fine particles is greater than that of γ-Fe2O3 by about 50%; the K value of Co ultrafine particles of a radius equal to 36 A is greater than that of to 48 A by about 100%. This phenomenon has been interpreted as the existence of surface anisotropy of the Co ultrafine particles.

In this paper, we investigate the spectrum properties of the lasing without population inversion in a three-level atomic system under an action of an externally applied microwave field. The probed absorption spectrum is obtained by solving the density matrix equation of this system. The results show that the absorption profile has a multi-peak structure, and exhibits obviously negative absorption (light amplification) in a specific range under the action of strong microwave field. The characteristic of the light amplification without population inversion according to the three level atomic system is demonstrated by the quantitative analysis of populations related to the probe levels.

Based on the definitions of fractional-order differential and Adomian decomposition algorithm, the numerical solution of the fractional-order simplified Lorenz system is investigated. Results show that compared with the Adams-Bashforth-Moulton algorithm, Adomian decomposition algorithm yields more accurate results and needs less computing as well as memory resources. It is even more accurate than Runge-Kutta algorithm when solving the integer order system. The minimum order of the simplified Lorenz system solved by using Adomian decomposition algorithm is 1.35, which is much smaller than 2.79 achieved by the Adams-Bashforth-Moulton algorithm. Dynamical characteristics of the system are studied by the phase diagram, bifurcation analysis, and complexities are calculated by employing the spectral entropy (SE) algorithm and C0 algorithm. Complexity results are consistent with the bifurcation diagrams, for which mean complexity can also reflect the dynamic characteristics of a chaotic system. Complexity decreases with increasing order q, and there are little influences on complexity versus changes of parameter c when the system is chaotic. It provides a theoretical and experimental basis for the application of fractional-order chaotic system in the field of encryption and secure communication.

Two linear systems are obtained by employing linearization technique in a simplified Lorenz system, and a two-scroll chaotic attractor is generated via the control method. Multi-scroll chaotic attractors are generated by extending the saddle-focus equilibrium points with index 2. Dynamic characteristics of the multi-scroll chaotic system are analyzed by observing the phase diagrams, bifurcation diagrams, Poincaré sections and calculating the largest Lyapunov exponent. A circuit for the multi-scroll attractor is designed and simulated. The numerical simulation result and the circuit simulation result are consistent with each other. To apply the multi-scroll chaotic systems to image encryption, an improved hybrid encryption algorithm is designed based on the multi-scroll chaotic system and advanced encryption standard (AES), and its encryption performances are analyzed. The results show that the improved hybrid encryption has a higher security.

Determination of the aircraft lightning attachment points which can provide the basis for the design of aircraft lightning protection, is a prerequisite for the division of lightning strike zones and the lightning test of aircraft components. In this paper, a novel numerical simulation method based on fractal theory is presented to simulate lightning attachment points on airplane. Firstly, the discharge gap distance, lightning starting coordinates, aircraft attitudes, discharge times and other parameters are determined according to the relevant provisions about aircraft lightning attachment point test in standard SAE-ARP5416. Then, according to the fractal theory, the dielectric breakdown model is used to simulate the fractal growth of the lightning leaders, which accords with physical mechanisms and geometric characteristics of nature lightning. Finally, considering the case where the aircraft itself triggers the bi-directional leader, we obtain the distribution of aircraft lightning attachment points. Because the probability distribution of lightning attachment points on aircraft F-4 obtained through the simulating is almost in line with those obtained through actual aircraft flight test and laboratory test, the proposed method is verified. The proposed method provides a potential way of simulating the lightning attachment points on aircraft. And this method can be used as the foundation of the aircraft lightning protection design and future related research work.

A three-dimensional grid multi-scroll chaotic system is presented by simplifying a generalized Jerk system. The analog circuit system is designed and realized by using positive-type second generation current conveyers. Compared with the chaotic circuit realized by traditional op amp, the chaotic circuit based on current conveyers can generate grid multi-scroll attractors at high frequency, and also has the advantages of simple circuit structure, and few components. Finally, the grid multi-scroll chaotic attractor are observed through using an oscilloscope, and the physical realizability of chaotic circuit is verified by circuit experiment. The results of circuit experiments and numerical simulations are accordant.

To obtain compound attractors between different chaotic systems, based on theoretical analysis, numerical simulation, and circuit simulation methods, compound attractors between different 2-scroll systems, between different multi-scroll chaotic systems, between 2-scroll system and 2-wing system and between multi-scroll system and multi-wing system, are designed via switching control. Dynamical characteristics of the system are analyzed by observing the attractor phase diagram, the largest Lyapunov exponent and the Poincaré section. A circuit for a compound multiple scroll-multiple wing chaotic attractor is designed and simulated. Numerical simulation and circuit simulation are consistent with each other. It shows that the method of obtaining compound attractors between different chaotic systems via switching control is correct.

To analyze the complexity of chaotic pseudo-random sequences accurately, spectral entropy (SE) algorithm is used to analyze chaotic pseudo-random sequences generated by Logistic map, Gaussian map or TD-ERCS system. The SE algorithm has few parameters, and has high robustness with the sequence length N (the only parameter) and the pseudo-random binary number K. Using sliding window method, the evolution features are analyzed, and complexity of discrete chaotic systems with different initial conditions and system parameters are calculated. The results show that SE algorithm is effective for analyzing the complexity of the chaotic pseudo-random sequences, and TD-ERCS is a high complexity system with wide parameter range, and has the best complex performance among the three chaotic systems. The complexity of the same chaotic system with different initial values fluctuates within a small range. It provides a theoretical and experimental basis for the applications of chaotic sequences in the field of information security.

To analyze the complexity of chaotic sequence correctly, complexity of systems, including typical discrete chaotic systems and continuous chaotic systems, are investigated based on the FuzzyEn algorithm. Compared with ApEn, SampEn and Intensive statistical complexity algorithm, the FuzzyEn algorithm is an effective measure algorithm for analyzing chaotic sequence complexity, and it has low sensitivity to and slight dependences on phase space dimension (m), similar tolerance (r) and sequence length (N), better robustness and measure value continuities. Results of the complexities of chaotic systems show that the complexity of continuous chaotic systems are much smaller than those of the discrete chaotic systems. However, having been disturbed by high complex discrete chaotic pseudo-random sequences or classical m-series, the pseudo-random sequences of continuous chaotic systems increase their complexities significantly. Our result provides a theoretical basis for the application of chaotic sequences to the field of cryptography and secure communication.

The security of a class of hyperchaotic image encryption algorithms is analysed. The results show that the shuffling process can be separated from the confusion process, and the formulas of encryption are simple, which makes the ciphertext cannot resist the attacks from chosen plaintext and ciphertext. Then we propose an improved and enhanced algorithm based on hyperchaos. The improved algorithm includes two rounds of encryption operation. The theoretical analyses and the experimental results indicate that the improved algorithm can overcome these flaws and has better cryptographic performances in resisting differential attacks and speed of encryption.

To analyze the complexity of the chaotic sequences, based on the intensive statistical complexity algorithm, the complexities of the discrete TD-ERCS and continuous simplified Lorenz chaotic systems were investigated respectively, and the complexities of the chaotic sequences with different system parameters were calculated. The complexities of pseudo-random sequences of the continuous chaotic systems disordered by m-series and chaotic pseudo-random sequences were analyzed. The results indicate that the intensive statistical complexity algorithm is an effective method for analyzing the complexity of the chaotic sequences, and the complexity of the discrete chaotic systems is larger than that of the continuous ones. However, after disordering by m-series or chaotic pseudo-random sequences, the complexities of the pseudo-random sequences can be increased significantly. This study provides a theoretical basis for the applications of chaotic sequences in the field of secure communication and information encryption.

In this paper, the close-coupling method and the Tang-Toennies potential are applied to the collisions of 3He,4He,9He and 10He with H2 systems when the incident energy is 07 eV. The vibrational and rotational excitation cross sections are calculated. By analyzing the partial wave cross sections, the changing tendencies of the partial wave cross sections with the quantum number and reduced mass in the isotopic substitution systems are obtained.

To study the characteristics of the chaotic systems and their applications, an electronic circuit of simplified Lorenz chaotic system with one parameter is designed and experimented with discrete components. The system parameters correspond to the circuit element parameters. By regulating the variable resistor in the circuit, dynamic behaviors including limit cycle, pitchfork bifurcation, period-doubling bifurcation, chaos, and route to chaos by period-doubling bifurcation, are observed. The necessary condition for the existence of chaos in the fractional-order simplified Lorenz system is deduced. The lowest order of the fractional-order simplified Lorenz system and the variation law of the lowest order with system parameters are determined. Circuit simulations and experiments show that the simplified Lorenz system has rich dynamic characteristics, and that theoretical analysis and circuit experiment are accordant with each other.

By observing the phase diagram and using the behavior complexity algorithm, the complexity of chaotic pseudo-random sequences generated by the new TD-ERCS discrete chaotic system is analyzed in detail, and the rules of complexity variety are investigated. Based on the Kolmogorov complexity, from one-dimensional time series to multidimensional phase space restructure, the complexity values of TD-ERCS discrete chaotic pseudo-sequences are calculated by using the Limpel-Ziv algorithm, ApEn algorithm and PE algorithm, respectively. The results show that the behavior complexity of TD-ERCS system is high, and the complexity value changes a little with the change of the parameters of TD-ERCS system. TD-ERCS system is a discrete chaotic system with the steady complexity, and the pseudo-random sequences generated by TD-ERCS are suitable for use in information encryption and spread spectrum communications.

According to the symmetry, Taylor series expansion formulas were derived for the magnetic multipole fields and field parameters were defined. Theoretical calculation formulas of field parameters of magnetic multipole field were obtained for saddle coils with the Biot_Savart law and the magnitudes of field parameter were analyzed. The rules of calculating field parameters and the high order derivatives of field parameters were also given. Our results may provide a theoretical basis for some applications of the magnetic multipole fields.

Fe74Al4Sn2P10C2B4Si4 powder were prepared by water atomization. It has been shown that this alloy has big glass-forming ability (GFA) and high stability against heating. Amorphous alloy powder can be got in size smaller than 400 mesh. Quality factor of the powder core made from this amorphous powder is remarkably higher than that of MPP in high frequency range, which means the core loss of the amorphous powder core is lower than that of MPP. The electrical resistivity of amorphous powder is much higher than that of MPP powder, that is why the amorphous powder core has lower core loss in the high frequency range.

In this paper the time characteristics of soft X-ray diode (XRD) is studied. XRD is the importance component of soft X-ray spectrometer,which measures the soft X-ray spectrum emited by laser-plasma.The experiment utilizes the 200TW laser facility with energy ～6J and pulse width ～30fs at the Laser Fusion Research Center of CAEP.The Au foil target irradiated by laser pulse produced X-ray emission, the filter(Al)-XRD system measures the X-ray signal.The high frequency cable (SUJ-50) transmits the electrical signal, a broad band oscillograph (TDS694C and TDS6604B) registers the signal.Linearity fit and comparison analysis of experimental data are performed.

Synchronization of a new chaotic system called Liu chaotic system is studied.Based on Lyapunov stabilization theorem and nonlinear feedback control method,the sufficient conditions and range of the controller's parameter for self_synchronization of Liu chaotic systems are derived.By combining the parameter adaptive control method and the nonlinear feedback control method,the synchronization of Liu system at speed with unified chaotic systems is implemented.Simulation results validate the proposed synchronization methode.

To analyze the security of tangent-delay ellipse reflecting cavity-map system (TD-ERCS) from the point view of cryptography, a simple pseudo-random number generator (PRNG) is proposed with parallel TD-ERCS in this paper. Users' keys are n o longer fixed, and can be chosen in the interval [264, 26 72] arbitr arily in the PRNG. By testing the basic statistic characteristics such as equili brium, runs and correlation of the binary pseudo-random sequences (viz. TD-ERCS sequences) being generated from the PRNG, and comparing with m-sequences, the lo gistic sequences, Chebyshev sequences and SCQC sequences, the experimental resul ts show that TD-ERCS sequences have better statistic characteristics.

The reflectivity of grazing soft x-ray planar mirror is studied.The Beijing Synchrotron Radiation Facility-3W1B beam line with beam current 40—120 mA,the storage ring electron energy 2 GeV,photon energy 50—1500 eV are used.We have improved the calibration method.The x-ray diode detectors of planar mirror facility are replaced by AXUV-100.Therefore,2 to 3 orders of magnitude for the ratio of signal to noise can be increased,and the calibration region from (150—270 eV)to (50—1500 eV)is expanded.The reflectivity calibration curves for C,Si,Ni,and Au planar mirror in different grazing angles are given.Finally,the values obtained in experiment and calculation are compared and analyzed.

Supersonic radiation transport, where the ratio of the radiation wave front velocity to the material sound speed was more than 10, has been investigated experimentally in the low-density foam. Four beams of 0.35μm laser with pulse d uration of 1ns and 2kJ of total energy entered into a hohlraum to create intense x-ray radiation that heated C66H12

A high Z cylindrical hohlraum was used to produce xray radiation flux, whic h was used to drive shock waves in an Al step sample. The radiation temperature i s 15 5eV. Experiments were carried ont on `Shenguang II' laser facility, with eight 2 50J, 0.35μm wavelength, 1ns Gaussian laser pulses. The planar and preheatfre e s ho ck wave was generated and a clear image of shock and preheat wave was obtained . The shock wave velocity and pressure was 31.2km/s and 17.5×1011Pa, respectively.The radiation temperature measured by streaked pyrometer, was consistent with th at measured with a soft x-ray spectrometer which views through the laser entran ce hole.

Based on the physical model of ellipse reflecting cavity, the tangent-delay operation is proposed to change the evolution route of the systems , and a new class of discrete chaotic map systems is deduced based on the tangen t-delay operation. Simulation experiments show that the discrete chaotic systems have many special properties such as the maximum Lyapunov exponent is over zero , unchangeable equiprobability distribution and zero correlation in total field, there exists a square chaotic attractor when tangent delays one unit, and becom e ergodic state when tangent delays more units than one. The discrete chaotic sy stems can generate 2 independent pseudo-random sequences together. All of the pr operties suggest that the class of chaos systems possesses the potential applica tion in encryption.

A new kind of double-disk gold targets were irradiated by 0.35μm intense laser and-the properties of impvoved X-ray spectra were investigated at “Xingguang”laser facilities.-Collision velocities between the-primary and secondary disks' plasmas have been measured.This double-disk target's design has avoided the influence of the spraying plasma from primary disk to a certain extent, and increased the “clearance” for ablated secondary disk. Two soft X-ray spectrometers were used to measure X-ray radiation from the primary and secondary disks, respectively. An X-ray streaked camera was used to obtain time-spactial images emitted from laser-plasma of double-disks targets. Experimental results were-analyzed physically.

CH foam material is filled in the cavities in order to improve planar degree of shock wave driven by X－ray radiation.Wedge－shaped aluminum samples are used to measure time－space streaking images of optical signals from the shock wave.And then the velocity and pressure of the shock wave is obtained.The radiation temp erature is obtained by using the scaled relations between veloctiy of shock wave and radiation temperature.

We use a simple X-ray radiation transport model to simulate and analyze Ｘ-ray radiation transport in cylindrical targets. The simple transport model is introduced, and the relative parameters are given, then the viewing factors are derived and calculated. The numeric methods for the X-ray transport equations based on the simple model are discussed. The scaling relations are obtained from the calculated results. Three kinds of free path relative to transport are advanced.

The method of filter difference which is used to measure X－ray spectrum radiate d from laser－produced plasma has been studied in this paper.The basic principle of the method of filter difference is introduced and the calculated and measure d results of filter difference pair are given.The absolute soft X－ray spectra f rom laser plasma have been measured.Finally the errors of measured spectrum inte nsity are analysed and estimated.

X-ray spectra, angular distributions of X-ray fluxes and evolutions of X-ray spe ctra from the front and the rear of gold foil target with different thickness ha ve been measured on “Xingguang” laser facility, in which the gold foil targets were irradiated by smoothing 1.053μm laser beam . The processes of laser and r adiation ablation to gold foil have been studied. Quantitative X-ray spectra fro m the front and the rear of gold foil under several conditions such as different foil thickness, different laser power densities and X-ray emission angles have been obtained. At the same time, radiative heat wave has also been observed fro m the evolutions of X-ray spectra emitted from the rear of gold foils of differe nt thickness.

The experimental investigation on the X-ray radiation transport is made.The method for studying X-ray transport is analyzed.Two kinds of targets which are source and cylinder targets are investigated separately.From the source target,the initial condition for transport is obtained.From transport target,the transport result is obtained.The experimental results for the two kinds of targets measured by a soft X-ray spectrometer,flat response X-ray diffraction and transmission gratings are given and analyzed using the simple X-ray radiation transport model.Plasma expansion in cylinder targets are investigated.

X-ray reemission from gold disk targets,which were heated by intense soft X-ray radiation((2—6)×1012W·cm-2),had been observed with two time-related soft X-ray spectrometers-The spectra of X-ray reemission were “softer” than those of irradiating X-ray-Temporal evolution of the X-ray reemission was analyzed in terms of a time-modified self-similar solution for the ablative heat wave

Absolute diffraction efficiencies of a transmission grating at a photon energy of 844eV have been calibrated on synchrotron radiation source.With the aid of grating model,all structure parameters of the grating are obtained and absolute diffraction efficiencies for soft X-rays in the range of 100—2000eV are calculated and discussed.

Calibration of the energy response for the soft X-ray detection elements using in the ICF diagnostic are reported.The Beijing synchrotron Radiation Facility (3B1 beam line,photon energy～250—1000eV,radiation flux ～1012photon/s·mm2·mr2·0.1% band-width,beam current ～20—80mA) and target chamber of the reflectometer are used.The source intensity is monitored by AXUV-100 photodiode.The calibration of the energy response for the XRD,filter light film,Ⅱa type diamond photoconductive detector,transmission grating and soft X-ray film are given and analysed.

Soft X-ray conversion efficiencies from 0.35μｍ laser-irradiated Au disk and C, Al, Cu foils at different laser intensity on the "Xingguang Ⅱ" high-intensity laser facility (energy ５—９０Ｊ，focal spot～２００μｍ，FWHM４００—８００ｐｓ）were obtained. A simple model was given to explain soft X-ray conversion efficiency from ０.３５μｍ laser-Al plasma interaction. In this model,bccause of heat conduction from the laser-heated spot, the conversion was very small at some low irradiancc limit, while at some high irradiance limit it was bounded by the energy lost in plasma blowoff. Consequently, at laser intensity(2±0.5)×１０１4Ｗ／ｃｍ2,the X-ray conversion efficiency reaches a maximum.

The nuclear magnetic resonance spectrum of 57Fe nuclei in γ - Fe4N alloy has been observed by the coherent spin-echo method. The peculiar line shape of nuclear magnetic resonance of Fe Ⅱ arises from the anisotropic hyperfine interactions and the domain wall excitation.

Radiation temperature in hohlraums is diagnosed using two soft X-ray spectrometers and multi-pinhole soft X-ray streak camera. We have improved the accuracy taking plasma closure effects of the diagnostic hole into consideration. We have obtained 2D-images and processes of the hole closure and radiation temperature in the hohlraums νs time. A preliminary model of the closure effect of diagnostic hole is proposed based on the experimental data.

We present the studies of physical mechanisms of wall and volume emissions of X-ray for different type cavity targets on "Shen-guang" facility. The wavelength 1.053 μm, pulse shape-Gauss type, energy ～500-700J/beam, pulse width ～600-1000ps laser are used to irradiate cylindrical Hohlraum from two ends. The typical target consists of three cylindrical sections of which two ends are absorption-conver-sion regions of laser energy (source region), and the median is imploding region, which is heated by radiation energy from source region. The experiment results of X-ray wall and volume emission and some analyses are presented.

The migration process of Co ions in the cobalt-ferrite epitaxial layer on γ-Fe2 O3 powder has been studied by magnetic thermal annealing method. The activation energy E and coefficient A of Co ions have been measured. An abnormal increase of coercivity of sample annealed in a transverse magnetic field was found. On the basis of Mossbauer and XPS results the reason of this phenomenon is discussed.

Recently the metallic magnetic powders have been recognized to be better materials for high density magnetic recording. Superior quality magnetic tapes have been made with these metallic powders. But there are some problems remined they are easily corrodible and are rather difficult to disperse in the lacquer. To study the causes of chemical instability of these materials and to prevent their corrosion are very important for their applications in practice. The causes of chemical instability of metallic powders are studied by M?ssbauer effect and other experimental methods. Their corrosion may be prevented basically. This study will provide some useful data for their practical applications.

In this report, the γ-Fe2O3 fine particles with Co-doping was investigated by means of M?ssbauer effect of 57Fe.The experimental result indicates that the effective anisotropy constant of the γ-Fe2O3 fine particles doped with Co is about 30% greater than that of the superfine γ-Fe2O3 powder without Co. It provides a further explanation to the increasing of the coercivity of the ordinary needle γ-Fe2O3 powder with Co-doping.

Fine γ-Fe2O3 particles with diameter of 80-700? were prepared. Their saturation magnetization per unit mass σs and specific surface area Sa were measured. An empirical formula σs(s) = σs(∞(1-aSa) was obtained. It was proposed that the fine particles consist of two parts: the first part is the surface layer, whose magnetic moment can not be turned entirely to the field direction by the applied magnetic field, but make an average angle (canting angle) with the field. The second is the inner part of the particles, whose magnetic moment can be aligned along the direction of the applied magnetic field. The above empirical formula can be interpreted very well by this simple model.

Co-absorbed γ-Fe 2 O 3 magnetic powder is divided into two sorts: Co-doped γ-Fe 2 O 3 (known as Co-γ-Fe 2 O 3 ) and Co-ferrite epitaxial γ-Fe 2 O 3 (known as CoFe-γ-Fe 2 O 3 ). The coercivity of Co-absorbed γ-Fe 2 O 3 is 100 to 400 (Oe) greater than the coercivity of γ-Fe 2 O 3 .The causes of the increasing coercivity of Co-absorbed γ-Fe 2 O 3 were studied. The mechanism of increasing coercivity is different between the two sorts of powder: Co (OH) 2 formed on the surface of γ-Fe 2 O 3 raised its surface anisotrpy and the coercivity of Co-γ-Fe 2 O 3 is increased. The cause of increasing coercivity of CoFe-γ-Fe 2 O 3 is the coupling effect between the Co-ferrite epitaxial layer and γ-Fe 2 O 3 .