[en] Under the assumpation of the average ion model, this article gives the equations of probabilities of bound electrons in the n-th energy state of atoms. The initial value of z' (the number of free electrons per atom is given according to the ionization of the highest energy states of atoms which are assumed to be in ground state. For Z, its initial value can be specified easily by solving Z from E_n

[en] Objective: To analyze the correlation between the metal components and MRI signal intensities of gallstones, to investigate the causes of gallstone signal features on MRI. Methods: The MRI data and the metal components of the gallstones in vivo and in vitro of 30 patients were retrospectively analyzed. The MR sequences, namely 3D fast spoiled gradient-echo with fat saturation T₁-weighted imaging (3D-FSPGR-FS T₁WI), fast spoiled gradient-echo with fat saturation T₁-weighted imaging (FSPGR-FS T₁WI), fast imaging employing steady-state acquisition (FIESTA) and fast spin-echo T₂-weighted imaging with fat saturation (FSE-FS T₂WI) were performed on the gallstones in vivo and in vitro. According to the characteristics of the surface and cross section, gallstones were divided into pigment gallstones(n = 16) and cholesterol gallstones(n = 14). The MR signal characteristics of the gallstones were observed and the signal intensity rates of the gallstones were calculated. Preoperatively, the signal intensity rates of cholesterol and pigment stones of each MR sequence were compared by using t test and Marara-Whiteraey U test. Postoperatively, the signal intensity rates of the fresh, dried and re-soaked gallstones were compared by using paired t test and Wilcoxora test. The correlation between the signal intensity rates of gallstones on the 3D-FSPGR-FS sequence and their metal components was analyzed by using Liraear Regressiora analysis. Results: The pigment gallstones showed high signal intensity on the 3D-FSPGR-FS T₁WI. The signal intensity rates of the pigment gallstones were higher than the rates of the cholesterol gallstones on the 3D-FSPGR-FS T₁WI, which were 2.02 ± 0.53 and 0.51 ± 0.24 (t = 10.26, P < 0.01), respectively. On the 3D-FSPGR-FS T₁WI, the signal intensity rates of the drying pigment stones were significantly lower than the rates of the fresh ones, the rates of the two states of the pigment gallstones were 0.21 ± 0.06 and 1.42 ± 0.35(t = 13.49, P < 0.01 ), respectively. The signal intensity rates of pigment gallstones showed significant rebound after re-soaking, the rates of the two states of the pigment gallstones were 0.21 ± 0.06 and 1.68 ± 0.86(t = -6.63, P < 0.01) Respectively. The metal components of pigment gallstones were significantly higher than the cholesterol stones. In the pigment gallstones and cholesterol gallstones, the medians of the Calcium were 28.186 and 2.347 mg/g(Z = -4.66, P < 0.01), respectively. For pigment gallstones, there was a significant correlation between the calcium and the signal intensity rate on 3D-FSPGR-FS T₁WI. The regression equation of linear regression analysis was SI = 65.40 logCa -166.67. Conclusions: The pigment gallstones containing much more water and metal showed high signal intensity on 3D-FSPGR-FS T₁WI. The Calcium in the pigment gallstones may be the main cause for this MR appearance. (authors)

[en] The quasi-optical ECRH transmission system of HL-1 tokamak includes 80 waveguide, ellipsoidal mirrors, taper, miter bend, vertical and horizontal microwave channel of the tokamak and ceramic window etc. Using this system, both O-mode and X-mode experiments with top injecting and O-mode experiment with horizontal injecting can be performed. The power more than 1 MW is able to pass through the system. It is shown that the Gauss beam, produced by gyrotron, with unchanged line polarization feature after passing through the system can be injected into the plasma, and the transmission efficiency is about 90%

[en] The mechanical behaviors of single crystalline micro-sized tungsten whiskers were experimentally characterized using nanoindentation. Nucleation and multiplication of dislocations were seen as displacement burst or pop-in events in the load–displacement curves during loading segment. The Hertzian contact theory and Kick's law were used to describe the elastic deformation of the material, whereas the theoretical strength of the perfect tungsten whiskers can be derived from the critical pop-in load. The elastic–plastic deformation after the pop-in agrees well with the Taylor relation. Either only one major pop-in or a series of discontinuities was observed in the experiments, attributed to the different critical loads at which the first pop-in occurs. Creep behaviors of the whiskers were also investigated under a constant load for 600 s. The stress exponent n was calculated using the displacement–time curve and agrees well with the value obtained using the traditional tensile creep testing method. The creep behavior is dominated by the dislocation-controlled (power-law) mechanism with an n of ∼5. Additionally, the stress exponent n is proved to increase with increasing the holding load, and remains stable with increasing the loading rate in the range of testing parameters selected in the experiments

[en] Semi-plants of two-years old Phellodendron Chinense Schneid were labeled by ¹⁴CO₂ +CO₂ tracer. Girdled the phloem of the trunk and wrapped the barked trunk with plastic film. After ward, Specimens were made through combusting and then, the radioactivity was measured by Liquid Scintillation Counting (LSC). The results showed that the carrying speed for ¹⁴C-assimilates of non-girdled phloem were 52.0 cm/h which making it possible to carry assimilates from crown to the root system in about 3 hours. It were also indicated the distributing law for ¹⁴C-assimilates of the crown leaves: for the non-girdled, the middle leaves of the crown were highest, bottom lowest and for the girdled, the top became highest while the bottom remained to be unchanged. Additionally, on the 15th day, ¹⁴C-assimilates were detected in the regeneration phloem and the parts beneath the barking position as well as the root system that indicated the physiological function of regenerated phloem had recovered. (authors)

[en] The lower hybrid current drive (LHCD) system on the HL-1M tokamak has been improved significantly in the past year. In order to carry out LHCD experiments with higher RF power, the operation mode with two klystrons in parallel was realized. Several problems were solved in the operation mode that involved frequency, balance of power and phase control. Up to now, the achieved system parameters are as follows: maximum output power of 850 kW, longest operation duration of 1050 ms, the launcher coupling efficiency of 85%

[en] Highlights: • Deformation mechanisms of Sn-0.5Cu are thoroughly examined using EBSD. • Bimodal grain structure of the rolled microstructure is observed. • PSN by Cu₆Sn₅ particles is found the main mechanism of DRX. • 001//RD fibre texture is characterized in the fine DRX nuclei. -- Abstract: A hypoeutectic Sn-0.5wt%Cu alloy was prepared by casting and subsequent rolling under a moderate strain rate (3.5 × 10⁻² s⁻¹) at room temperature. The microstructural evolution including boundary formation, dynamic restoration, twinning, and recrystallization texture was examined using the electron back-scattered diffraction (EBSD) technique, aiming to understand the deformation mechanisms of the Sn-Cu system serving under external stress. The results confirmed that a bimodal grain structure was well established, which could be ascribed to the dislocation activities and dynamic restorations including dynamic recovery (DRV) and dynamic recrystallization (DRX). The Cu₆Sn₅ particle-stimulated nucleation (PSN) was found as the major mechanism of DRX, which was also the dominant factor leading to the formation of 001//RD oriented nuclei. Moreover, DRX nuclei formed along the existing boundaries, resulting in the formation of necklace structure via continuous dynamic recrystallization (CDRX). Twinning involving {301} and {101} twin configurations was identified as the additional mechanism of effective deformation.

[en] An ECRH system with 500 kW/50 ms in the 75 GHz range has been built on the HL-1M tokamak. Top-injection and horizontal-injection antennas have been designed, and quasi-optical transmission developed. During adjustment, optimal experiment conditions and parameters of the ECRH system are obtained. Wave injections with O-mode or X-mode have been performed on the high or low field side. In the HL-1M ECRH experiments, the electron temperature measured with ECE diagnostics increases more than 40%, and negative shear distribution of the plasma current is obtained and the phenomenon of internal fish-bone mode instability has been observed with soft X-ray apparatus

[en] The ECRH water cooling system of HL-2A tokamak has been successfully developed, the maximum flux and pressure of this system reach 94m³·h^-1 and 0.6MPa, respectively. The system design, the pressure control, and the parameter measurement are briefly introduced; the water-resistance calculation under high voltage condition has been done, and the leak electric current in the cooling water loop of the gyrotron-anode has been measured to be less than 1mA. (authors)

[en] The rewritable bistable memory characteristics have been studied in polymethyl methacrylate (PMMA) and carboxylated multi-walled carbon nanotubes (CNT) composite films. The sandwich structure FTO/PMMA + CNTs/Ag devices were prepared by spin coating and vacuum evaporation process. The device exhibited rewritable bistable resistive switching with switch-on voltage of ~ − 1.5 V, switch-off voltage of ~ 3.4 V, and a high ON/OFF ratio almost of 10⁵. The rewritable behavior of the FTO/PMMA + CNTs/Ag device has been investigated by the endurance test, retention test, and the write-read-erase-reread multiple-cycle tests. The FTO/PMMA + CNTs/Ag device exhibited good retention performance for 2 × 10⁵ s and underwent 10⁴ read pulses. The conduction mechanism in ON state obeys Ohmic conduction; simultaneously, for OFF state, trap-limited space-charge limited conduction was discovered to be the dominant conduction mechanism.