[en] In this paper the authors have reached a metric containing five arbitrary functions of time which degenerates, respectively, into Kinnersley metric and Reissner-Nordstroem metric in special case, and further into Schwarzschild metric under more special condition. This metric describes the field of an arbitrarily accelerating charged point mass. (Auth.)

[en] This study aimed to quantify dosimetric effects of weight loss for nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Overall, 25 patients with NPC treated with IMRT were enrolled. We simulated weight loss during IMRT on the computer. Weight loss model was based on the planning computed tomography (CT) images. The original external contour of head and neck was labeled plan 0, and its volume was regarded as pretreatment normal weight. We shrank the external contour with different margins (2, 3, and 5 mm) and generated new external contours of head and neck. The volumes of reconstructed external contours were regarded as weight during radiotherapy. After recontouring outlines, the initial treatment plan was mapped to the redefined CT scans with the same beam configurations, yielding new plans. The computer model represented a theoretical proportional weight loss of 3.4% to 13.7% during the course of IMRT. The dose delivered to the planning target volume (PTV) of primary gross tumor volume and clinical target volume significantly increased by 1.9% to 2.9% and 1.8% to 2.9% because of weight loss, respectively. The dose to the PTV of gross tumor volume of lymph nodes fluctuated from −2.0% to 1.0%. The dose to the brain stem and the spinal cord was increased (p < 0.001), whereas the dose to the parotid gland was decreased (p < 0.001). Weight loss may lead to significant dosimetric change during IMRT. Repeated scanning and replanning for patients with NPC with an obvious weight loss may be necessary

[en] A wind measurement Doppler Lidar system was developed, in which injection seeded laser was used to generate narrow linewidth laser pulse. Frequency stabilization was achieved through absorption of iodine molecules. Commands that control the instrumental system were based on the PID algorithm and coded using VB language. The frequency of the seed laser was locked to iodine molecular absorption line 1109 which is close to the upper edge of the absorption range,with long-time (>4 h) frequency-locking accuracy being ≤0.5 MHz and long-time frequency stability being 3.55×10"−"9. Design the continuous light velocity measuring system, which concluded the cure about doppler frequency shift and actual speed of chopped wave plate, the velocity error is less than 0.4 m/s. The experiment showed that the stabilized frequency of the seed laser was different from the transmission frequency of the Lidar. And such frequency deviation is known as Chirp of the laser pulse. The real-time measured frequency difference of the continuous and pulsed lights was about 10 MHz, long-time stability deviation was around 5 MHz. When the temporal and spatial resolutions were respectively set to 100 s and 96 m, the wind velocity measurement error of the horizontal wind field at the attitude of 15–35 km was within ±5 m/s, the results showed that the wind measurement Doppler Lidar implemented in Yanqing, Beijing was capable of continuously detecting in the middle and low atmospheric wind field at nighttime. With further development of this technique, system measurement error could be lowered, and long-run routine observations are promising. - Highlights: • In this Doppler Lidar system, the frequency of the seed laser was locked to iodine molecular absorption line 1109 which is close to the upper edge of the absorption range, with long-time frequency-locking accuracy being ≤0.5 MHz and long-time frequency stability being 3.55 ×10"−"9. • Design the continuous light velocity measuring system, which concluded the cure about Doppler frequency shift and actual speed of chopped wave plate, the velocity error is less than 0.4 m/s. The experiment showed that the stabilized frequency of the seed laser was different from the transmission frequency of the Lidar. • Design of the pulsed light Chirp real-time monitoring system for monitoring laser output . And such frequency deviation is known as Chirp of the laser pulse. The real-time measured frequency difference of the continuous and pulsed lights was about 10 MHz , long-time stability deviation was around 5 MHz. • Our results showed that the wind measurement Doppler Lidar implanted in Yanqing, Beijing was capable of continuously detecting in the middle and low atmosphere wind field at nighttime, providing the foundation for the future to achieve routine observations.

[en] Our aim was to evaluate the volumetric and dosimetric changes of target volumes and organs at risk (OARs) during intensity-modulated radiation therapy (IMRT) for locoregionally advanced nasopharyngeal carcinoma (NPC) and the necessity of replanning. Twenty locoregionally advanced NPC patients treated by concurrent chemotherapy and IMRT were included. CT and MR images were acquired before treatment and at weeks 2, 3, 4, 5 and 6 during treatment. The target volumes and OARs were contoured based on the fused CT-MRI images and hybrid plans were generated. The changes of volume and dosimetry were measured by comparing original plan and hybrid plans. Significant volumetric changes of target volumes and parotid gland were observed. The primary nasopharyngeal tumor (GTVnx), clinical target volume 1 (CTV1), involved lymph nodes (GTVnd) and left and right parotid glands, shrank at a mean rate of 14.7, 11.56, 11.40, 6.54 and 6.78% per treatment week, respectively. There were no significant dosimetric changes in GTVnx, GTVnd, CTV1, spinal cord and brain stem while the differences of dose to left and right parotid glands were significant (F=6.73, P=0.007; F=7.43, P=0.007). Remarkable volumetric changes were observed. However, the dosimetric changes were inconspicuous except for the parotid. Replanning might contribute to protect the parotid gland. (author)

[en] This paper describes the passive quench protection system selected for the muon ionization cooling experiment (MICE) cooling channel coupling magnet. The MICE coupling magnet will employ two methods of quench protection simultaneously. The most important method of quench protection in the coupling magnet is the subdivision of the coil. Cold diodes and resistors are put across the subdivisions to reduce both the voltage to ground and the hot-spot temperature. The second method of quench protection is quench-back from the mandrel, which speeds up the spread of the normal region within the coils. Combining quench back with coil subdivision will reduce the hot spot temperature further. This paper explores the effect on the quench process of the number of coil sub-divisions, the quench propagation velocity within the magnet, and the shunt resistance

[en] With the analysis of impurities at different locations and spectral transmittance of conventionally and rapid grown KDP crystals, several factors which influence the transmittance of crystals at ultraviolet band are discussed. Also multi-short damage thresholds of crystals induced by pico-second laser pulses at wavelength 1064 nm and 532 nm are reported. Crystal adsorption and the damage threshold correspondent suggest that impurities as well as the lattice defect convert irradiance to heat distinctly and thus reduce the damage threshold of crystals

[en] A cryogenic system for the Muon g-2 Superconducting Magnet was built at Brookhaven National Laboratory, U.S.A.. The g-2 magnet consists of four large superconducting solenoids which are up to 15.1 meters in diameter with a total cold mass of 6.2 tons. The superconducting solenoids are indirectly cooled by using forced two-phase helium in tubes which are up to 200 meters in length. The J-T circuit of a refrigerator is capable of delivering 625 W at 4.5 K. The solenoids are powered through a pair of 5300A multi-tube gas-cooled electrical leads. (author)

[en] The silane coupling agent KH-550 was used to perform surface modification on calcium sulfate whiskers (CSW). Fourier transform infrared spectroscopy and thermogravimetric analysis were used to characterize the effect of surface modification on enhancing the compatibility of CSW with isotactic polypropylene (iPP). Subsequently, the synergetic effect of CSW modified by KH-550 (K-CSW) and aryl amide β-nucleating agent dicyclohexyl-terephthalamide (commercial name: TMB-5) on increasing the relative content of β-crystals and the peak crystallization temperature of iPP was studied. The results showed that KH-550 was a suitable surfactant for surface modification of CSW and K-CSW had certain β-nucleating abilities for iPP. Moreover, for iPP nucleated with the K-CSW/TMB-5, the higher peak crystallization temperature and relative content of β-crystals (K_β = 0.84) were achieved, which were obviously better than those of iPP nucleated with K-CSW or TMB-5 independently, demonstrating that K-CSW/TMB-5 was a novel highly efficient compound β-nucleating agent for iPP and had certain synergistic effect for formation of β crystals.

[en] A highly efficient compound nucleating agent of carboxylated graphene/calcium pimelate (Gra/CaPi) for isotactic polypropylene (iPP) was prepared. The structure of Gra/CaPi was investigated by Fourier-transform infrared spectroscopy. The effects of Gra/CaPi on the crystallization and melting behaviors and crystalline morphology of iPP were investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. The results showed that CaPi and Gra were combined by chemical bonds, improved the dispersibility and nucleation ability of Gra in iPP. When the addition amount of Gra/CaPi in iPP was 0.3 mass%, the crystallization peak temperature was increased by 8.0 °C and the relative content of β-crystal in iPP reached up to 0.868 compared with that of pure iPP.

[en] Octamethylenedicarboxylic dibenzoylhydrazide (TMC-300) was used as a nucleating agent for isotactic polypropylene (iPP) for the first time. The Avrami method and the Caze method were used to analyze the isothermal and non-isothermal crystallization kinetics of iPP incorporated with TMC-300, respectively. During isothermal crystallization, the half crystallization time at 130 °C reduces from 130 s of virgin iPP to 44 s after addition of TMC-300, which reflects that TMC-300 increased the crystallization rate of iPP obviously. The crystallization activation energy decreases from 382.5 kJ mol⁻¹ of virgin iPP to 275.3 kJ mol⁻¹ of iPP/TMC-300. During non-isothermal crystallization, the crystallization peak temperature of iPP nucleated with TMC-300 was increased by 5.1 °C when compared to that of virgin iPP at the cooling rate of 20 °C min⁻¹, and both the reduction of half crystallization time and the increase in peak crystallization temperature also justified that the addition of TMC-300 accelerated the crystallization of iPP.