[en] New firing patterns, composed of a stochastic alternation of two periodic bursts, were generated near each bifurcation point of period adding bifurcation scenario without chaos in the experimental neural pacemaker, in the stochastic Chay model but not in the deterministic model. It was a stochastic transition between two neighboring bursting and exhibited approximate integer multiple characteristics. Autonomous stochastic resonance (ASR) was verified to be the cause of the generation of this stochastic alternation pattern in the stochastic Chay model. The stochastic transition between two periodic superthreshold bursts generated near a critical phase in the two trajectories was the underlying basis of the effect of ASR. The results showed that except the Hopf bifurcation point, ASR could be generated in a series of period adding bifurcation points, and indicated that noise played more extensive roles in neural coding than recognized before

[en] We have studied effects of ion irradiation in GaN nanowires using classical molecular dynamics simulations. Nanowires with diameters of 3 and 4 nm were irradiated with 100 Ar ions at energies of 100 eV to 10 keV corresponding to ion fluence of about 3×10¹⁴ ions/cm². The structure of the nanowires was analyzed along with sputtering yields and mechanical properties in the form of Young’s modulus. The results show a total sputtering yield of up to 8.3 sputtered atoms per ion and preferential sputtering of nitrogen with gallium to nitrogen ratio approximately 0.7. The Young’s modulus of the nanowires was observed to decrease as a function of the irradiation dose with the largest relative effect observed for ion energies of 1 and 10 keV

[en] When multi-wire proportional counters are used for monitoring of mixed contamination of α and β radioactivity, both of the signals should be distinguished as far as possible from requirement of radiation protection. The rules provided by the recommendation standard of International Electrotechnical Committee (IEC) and the national standard of China indicate: For fixed personal surface contamination monitoring assembly, the response of the α-counting channel to β events should be smaller than 1% of response of the α-counting channel to α events, and the response of β-counting channel to β events should be smaller than that of the response of α-counting channel to the same events. To distinguish one kind of signal from another, amplitude discrimination method is used usually. (3 figs)

[en] To understand the general distribution of the electric field intensity in the large-area flow-gas multiwire proportional counter, an approximate physical model is suggested for numerical calculation and the field intensity distribution that is the relative result based on limited conditions is obtained. The relation between the distribution and some geometric parameters of the counter, such as the interval between the neighbor wires and the anode-to-cathode distance, is presented. This is advantageous for the design and application of the multiwire proportional counter. (authors)

[en] It is experimentally proved that the butane can be used as an operating gas of the proportional counter. The operating performances of the counter with the butane are quite similar to that with the methane. A KX-50 butane flow proportional counter is described and its plateau characteristic is determined. For this counter, the plateau length, the slope of the plateau, the background count rate is 600 V, 1.7% per 100 V, 0.02s^-1 for ²³⁹Pu α source and about 500 V, 1.8% per 100 V, 3s^-1 for ⁹⁰Sr-⁹⁰Y source, respectively

[en] Surface electrical properties of Fe implanted Al₂O₃ followed by thermal annealling are presented. The Rutherford backscattering technique, Auger electron spectra and X-ray electron spectra have been used to study the structure of the implanted layer, the implanted ion range and the ion profile. Finally, the conduction mechanism in the implanted layer is discussed briefly

[en] A method of predicting the growth of fatigue cracks in the corners of nozzles of pressure vessels was proposed. The method was based on the Paris' law and a modified Newman-Raju solution for stress intensity factor (SIF). Experimental data including 100 hole edge cracks in tension, 6 nozzle corner cracks in a spherical vessel and 4 nozzle corner cracks in a cylindrical vessel under internal pressure were analysed to demostrate the success of application of the method. The results showed that the proposed method can be satisfactorily used in engineering estimation of fatigue life. (orig.)

[en] Objective: To select properly the esophageal metallic stent to treat the dysphagia and strictures of advanced esophageal cancer. Methods: To place esophageal metallic stent for 72 cases of advanced esophageal cancer. Results: Dysphagia were markedly improved or completely alleviated together with esophageal and mediastinal fistula sealed completely after the procedure. Conclusions: The complications will be reduced by the proper selection of esophageal metallic stent and also for resuming of food intake

[en] Foam material of low density is the preferred medium for X-ray radiation transport experiment, and the low energy X-ray radioscopy is the important technology for foam density measuring. The every error origin in the process of foam density measuring was investigated. According to the international general method, the component uncertainties were combined and expanded respectively to obtain the uncertainty evaluation.The results indicate that, the horizontal resolution is over 10 μm,the measuring uncertainty of density is under 4.7%, at the same time, it has applied in SG II physical experiment successfully, and has acquired satisfactory effect. (authors)

[en] Highlights: • LPA-SWCNTs have been abundantly fabricated by a facile, time-saving, economical and non-hazardous method using DC arc discharge technique in low-pressure air. • The electromagnetic and microwave absorption properties of LPA-SWCNTs, CoFe_2O_4 nanocrystals and LPA-SWCNT/CoFe_2O_4 nanocomposites were investigated and the LPA-SWCNT/CoFe_2O_4 nanocomposites exhibited excellent microwave absorption properties. • The Debye theory and impedance matching were used to analyze the electromagnetic parameters and microwave absorption properties. - Abstract: Single-walled carbon nanotubes were facilely and abundantly synthesized by low-pressure air arc discharge method (LPA-SWCNTs), and CoFe_2O_4 nanocrystals were synthesized by a nitrate citric acid sol–gel auto-ignition method. The electromagnetic and microwave absorption properties of LPA-SWCNTs, CoFe_2O_4 nanocrystals and their nanocomposites were investigated. The LPA-SWCNT/CoFe_2O_4 nanocomposites showed excellent microwave absorption properties. The minimum efficient reflection loss is −30.7 dB at 12.9 GHz for 10 wt% of LPA-SWCNTs in the nanocomposites, and an effective absorption bandwidth with a reflection loss below −10 dB is 7.2 GHz. The Debye equation and impedance matching were introduced to explain the microwave absorption properties. Compared with the single-component materials, the LPA-SWCNT/CoFe_2O_4 nanocomposites are an excellent candidate for microwave absorbers