[en] This paper aims to investigate the effect of Cr doping on the magnetic properties of Zn_1-xCr_xO (0 ≤ x ≤ 0.026) thin films deposited using a magnetron co-sputtering method under Ar+O₂ growth atmosphere. All of the films are highly c-axis-oriented wurtzite structures. The x-ray photoelectron spectroscopy results revealed that some Cr ions have substituted into Zn sites, showing the Cr²⁺ signal, in all of the Cr-doped ZnO films. The remaining Cr ions are in a 3+ valence state. A distinct paramagnetic response, as well as weak ferromagnetic signal persisting up to RT, has been observed for the pure ZnO film, while only a distinct paramagnetic response is present for the Zn_1-xCr_xO films with x = 0.026. The variation in ferromagnetic signals seems to coincide with that in the surface morphology features for the films. The results suggest that ferromagnetism in the Zn_1-xCr_xO films can be rationalized in terms of surface defect states, and the substituted Cr²⁺ ions would contribute only to paramagnetism or show an antiferromagnetic coupling.

[en] Aim: To examine extratemporal abnormalities of the cerebral parenchyma in young adult temporal lobe epilepsy (TLE) patients using diffusion tensor imaging (DTI). Materials and methods: The study comprised 20 adults with unilateral TLE and 20 controls. The fractional anisotropy (FA), apparent diffusion coefficient (ADC), parallel eigenvalue (λ_∥), and perpendicular eigenvalue (λ_⊥) were calculated in the regions of interest (ROIs) using a 3 T MRI system. ROIs included the anterior/posterior limb of the internal capsule (AIC/PIC), external capsule (EC), head of caudate nucleus (HCN), lenticular nucleus (LN), thalamus (TL), and genu/body/splenium of the corpus callosum (GCC/BCC/SCC). Results: Compared to controls, TLE patients showed lower FA in all ROIs; higher ADC in bilateral ECs, HCNs, TLs, and BCC; lower λ_∥ in the ipsilateral LN and bilateral AICs, TL, and GCC; and higher λ_⊥ in all ROIs except the bilateral PICs. In TLE patients, the ipsilateral TL had decreased FA compared with the contralateral TL. Pearson correlation analysis revealed a negative correlation between the ADC of the GCC and the age at onset of epilepsy; the λ_∥ of the ipsilateral PIC and age at onset of epilepsy; the λ_⊥ of the contralateral AIC and duration of epilepsy, respectively; and a positive correlation between the ADC of the GCC and the duration of epilepsy and the λ_⊥ of the GCC and the duration of epilepsy, respectively. Conclusion: The study revealed bilateral extratemporal abnormalities in young adult TLE patients compared with controls. In addition, TLE patients with younger age at onset or longer duration of epilepsy may have more serious extratemporal changes

[en] As part of a cooperative research project on migration behavior of TRU in near surface and safety assessment methodology for TRU disposal between the China Institute for Radiation Protection (CIRP) and the Japan Atomic Energy Research Institute (JAERI), a field tracer migration test of radionuclides was conducted in a weak phreatic aquifer at CIRP's Field Test Site from 1997 to November 2000. The radionuclides involved in the test were ³H, ⁹⁰Sr, ²³⁷Np and ²³⁸Pu. The test consists of 1-D, 2-D, and 3-D test. It can be seen from the results of the tests that loess has stronger capacity to sorb the radionuclides. The order of migration velocity is ⁹⁰Sr> ²³⁷Np> ²³⁸Pu, retardation coefficient, R_d, of ⁹⁰Sr, which migrates at fastest velocity among them, is about 502. Also it can be seen that humus retards migration of ⁹⁰Sr. Expands of ⁹⁰Sr are near to each other on the X, Y and Z coordinate

[en] A high-frequency charge-biased CMOS-MEMS resonant gate field effect transistor (RGFET) composed of a metal–oxide composite resonant-gate structure and an FET transducer has been demonstrated utilizing the TSMC 0.35 μm CMOS technology with Q > 1700 and a signal-to-feedthrough ratio greater than 35 dB under a direct two-port measurement configuration. As compared to the conventional capacitive-type MEMS resonators, the proposed CMOS-MEMS RGFET features an inherent transconductance gain (g_m) offered by the FET transduction capable of enhancing the motional signal of the resonator and relaxing the impedance mismatch issue to its succeeding electronics or 50 Ω-based test facilities. In this work, we design a clamped–clamped beam resonant-gate structure right above a floating gate FET transducer as a high-Q building block through a maskless post-CMOS process to combine merits from the large capacitive transduction areas of the large-width beam resonator and the high gain of the underneath FET. An analytical model is also provided to simulate the behavior of the charge-biased RGFET; the theoretical prediction is in good agreement with the experimental results. Thanks to the deep-submicrometer gap spacing enabled by the post-CMOS polysilicon release process, the proposed resonator under a purely capacitive transduction already attains motional impedance less than 10 kΩ, a record-low value among CMOS-MEMS capacitive resonators. To go one step further, the motional signal of the proposed RGFET is greatly enhanced through the FET transduction. Such a strong transmission and a sharp phase transition across 0° pave a way for future RGFET-type oscillators in RF and sensor applications. A time-elapsed characterization of the charge leakage rate for the floating gate is also carried out. (paper)

[en] Turbo-expander is the core machinery of the helium refrigerator. Bearing as the supporting element is the core technology to impact the design of turbo-expander. The perfect design and performance study for the gas bearing are essential to ensure the stability of turbo-expander. In this paper, numerical simulation is used to analyze the performance of gas bearing for a 500W helium refrigerator turbine, and the optimization design of the gas bearing has been completed. And the results of the gas bearing optimization have a guiding role in the processing technology. Finally, the turbine experiments verify that the gas bearing has good performance, and ensure the stable operation of the turbine. (paper)

[en] In this study, the biodegradable materials N-2-hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) and N, O-carboxymethyl chitosan (CMC) are used as delivery carrier for the pVAX I -F(o)-C3d6. The optimal preparation condition is as follows: concentration of N-2-HACC is 1.0 mg/ml, concentration of CMC is 0.85 mg/ml, concentration of pVAX I -F(o)-C3d6 is 100 μg ml. The results show that the prepared N-2-HACC-CMC/pFDNA NPs have regular round shape, smooth surface and good dispersion, the particle size is 310 nm, Zeta potential is 50 mV, the entrapment efficiency is 92 %, the loading capacity is 51 % (n=3). (paper)

[en] Aiming at studying the dynamic performances of herringbone-grooved gas bearings, a model is built to analysis the relationship between herringbone-grooved gas bearings parameters and its performances such as friction torque, stiffness, stamping, etc. In this model, the hydrodynamic effect of compressible fluid and the shunting effect of herringbone groove are taken into account, and the partial derivative method which based on local integral finite difference method is used to calculate the modal at the same time. The result shows that when the average gap and the length-diameter ratio are decreasing, the rotate speed and eccentricity ratio will be increasing and the hydrodynamic effect of the gas bearing will be enhanced. Increasing groove angle, decreasing width-ridge ratio or aggrandizing length-groove ratio can improve its load capacity. The parameters such as rotate speed and eccentricity ratio are the most important factors which affect the dynamic characteristics of herringbone-groove gas bearing greatly. Then the analysis method is verified through an experiment systematically. In the experiment, the moment balance method is used. The experiment result shows that the result of model is correct s and reliable. (paper)

[en] Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)

[en] A diode end-pumped continuous wave and acoustic-optical Q-switched YVO₄/Nd:Y_0.9La_0.1VO₄ crystal lasers are first demonstrated at 1064 nm with a compact planar-planar cavity. The continuous and acoustic-optical Q-switched output characteristics have been investigated with different output couplers. The maximum continuous wave power of 12.26 W is obtained at the incident pump power of 21.7 W, corresponding to optical to optical conversion efficiency of 56.5%. For Q-switching operation, at the incident pump power of 21.7 W, the shortest pulse is 7 ns at 1 kHz and 80% transmission, the maximum average output power is 12.07 W at 100 kHz and 30% transmission, and the highest peak power is 1.076 MW at the 1 kHz repetition rates and 50% output transmission

[en] While a diamond-like carbon (DLC)-coated joint prosthesis represents the implant of choice for total hip replacement in patients, it also leads to concern due to the cytotoxicity of wear debris in the form of graphite nanoparticles (GNs), ultimately limiting its clinical use. In this study, the cytotoxicity of various GN doses was evaluated. Mouse macrophages and osteoblasts were incubated with GNs (<30 nm diameter), followed by evaluation of cytotoxicity by means of assessing inflammatory cytokines, results of alkaline phosphatase assays, and related signaling protein expression. Cytotoxicity evaluation showed that cell viability decreased in a dose-dependent manner (10–100 μ g ml⁻¹), and steeply declined at GNs concentrations greater than 30 μ g ml⁻¹. Noticeable cytotoxicity was observed as the GN dose exceeded this threshold due to upregulated receptor of activator of nuclear factor kB-ligand expression and downregulated osteoprotegerin expression. Meanwhile, activated macrophage morphology was observed as a result of the intense inflammatory response caused by the high doses of GNs (>30 μ g ml⁻¹), as observed by the increased release of TNF- α and IL-6. The results suggest that GNs had a significant dose-dependent cytotoxicity in vitro , with a lethal dose of 30 μ g ml⁻¹ leading to dramatic increases in cytotoxicity. Our GN cytotoxicity evaluation indicates a safe level for wear debris-related arthropathy and could propel the clinical application of DLC-coated total hip prostheses. (paper)