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CdMgTe crystal is a hopeful room temperature radiation detection material because of some potential advantages. The Cd0.95Mg0.05Te ingot with free of inclusion was successfully grown by a modified Bridgman method in this paper. This results was achieved by using a significant excess cadmium and in situ annealing during the growth process. The grown ingot was about 30 mm in diameter and 120 mm in length. The CdMgTe crystal had a cubic zinc-blende structure. The distribution of Mg element along growth direction was homogeneous. In the whole ingot, no inclusions were observed in IR images and as high IR transmittance as above 60% was measured. Raman scattering spectroscopy showed a good crystal quality for CdMgTe crystals. Moreover, the resistivity with 109 Ω cm order of magnitudes for the ingot could be useful for the fabrication of room temperature radiation detector.

A novel and sensitive method for ascorbic acid (AA) determination utilizing Ag+–3,3′,5,5′-tetramethylbenzidine (TMB) as a colorimetric probe was proposed. In a weak acidic medium, Ag+ could oxidize TMB to oxidized TMB (ox-TMB) and cause a blue color solution with an absorption peak centered at 652 nm. However, the addition of AA could induce the reduction of ox-TMB, leading to shallower blueness and lower absorbance. Under the selected experimental conditions, there was a good linear relationship between the decrease of absorbance (ΔA) and AA concentration in the range of 0.5–60 μM, and the detection limit was as low as 0.23 μM. The feasibility of this method was verified in commercial beverages with recoveries of 95.8–104.1%. The method has the advantages of simplicity and practicability. More importantly, no nanomaterials need to be prepared.

In order to investigate the passivation effects of hydrogen, high-resistivity indium doped cadmium manganese telluride (CMT:In) single crystals were annealed in H2 atmosphere. The results indicated the concentration of Mn element and the density of Te inclusions did not change after annealing. Both the resistivity and IR transmittance increased because of the reduction of the carrier concentration. The intensity of (D0,X) peak and (D0,h) peak decreases remarkably because of the passivation of the indium donor. The donor–acceptor pair peak (DAP) peak disappeared, which was due to the dissociation of [VCd − InCd] complexes and the passivation of the impurities by hydrogen. Moreover, Dcomplex peak consisted of two peaks. The intensities of D1 peak increased and D2 peak decreased because the passivation of hydrogen on the donor and dislocation, respectively. The best condition of passivation for H2 atmosphere annealing is 573 K for 30 h.

Since the existing satellite thermal infrared (TIR) land surface temperature (LST) is susceptible to cloud contamination and other factors, surface urban heat island (SUHI) studies based on TIR LST are limited to clear-sky conditions and are not representative of SUHI under all-weather conditions, which result in a possible clear-sky bias for SUHI. This study introduces a newly released 1-km all-weather LST product (TRIMS LST), which is spatiotemporally seamless, to investigate the real SUHI under all-weather conditions for five megacities (i.e. Harbin, Beijing, Shanghai, Guangzhou, and Chengdu) in China. Firstly, this study compares TRIMS SUHI with MODIS SUHI under clear-sky, partial-cloudy, and cloudy conditions. Secondly, the extent of the influence of cloudiness on SUHI is quantified. Finally, the monthly TRIMS SUHI is used to analyze the clear-sky bias that is caused by using only clear-sky data for the SUHI. Results indicate that (i) the absence of pixel data leads to negative offsets in the SUHI intensities calculated by MODIS LST, and these offsets expand gradually with increases in the number of missing-pixel data, causing the maximum offset to reach −1.83 °C under cloudy conditions in Chengdu; (ii) cloud can mitigate the SUHI for most cities: when the cloud coverage in Guangzhou reaches 90–100%, the daytime SUHI intensity decreased from 2.66 °C for clear-sky conditions to 1.70 °C; the mitigating effect differs at daytime and nighttime; and (iii) clear-sky bias varies significantly across climate zones and seasons, with a varying range of −1.6–1.2 °C for the five selected cities.

Tibetan Plateau vortices (TPVs) are mesoscale cyclones originating over the Tibetan Plateau (TP) during the extended summer season (April–September). Most TPVs stay on the TP, but a small number can move off the TP to the east. TPVs are known to be one of the main precipitation-bearing systems on the TP and moving-off TPVs have been associated with heavy precipitation and flooding downstream of the TP (e.g., in Sichuan province or over the Yangtze River Valley). Identifying and tracking TPVs is difficult because of their comparatively small horizontal extent (400–800 km) and the limited availability of soundings over the TP, which in turn constitutes a challenge for short-term predictions of TPV-related impacts and for the climatological study of TPVs. In this study k](i) manual tracking (MT) results using radiosonde data from a network over and downstream of the TP are compared with (ii) results obtained by an automated tracking (AT) algorithm applied to ERA-Interim data. Ten MT-TPV cases are selected based on method (i) and matched to and compared with the corresponding AT-TPVs identified with method (ii). Conversely k]ten AT-TPVs are selected and compared with the corresponding MT-TPVs. In general k]the comparison shows good results in cases where the underlying data are in good agreement k]but considerable differences are also seen in some cases and explained in terms of differences in the tracking methods k]data availability/coverage and disagreement between sounding and ERA-Interim data. Recommendations are given for future efforts in TPV detection and tracking k]including in an operational weather forecasting context.

Based on a variety of ground-based and satellite-derived observational data, we studied a flood-rainstorm event that occurred over northeastern Sichuan, China, from the 8th to the 14th of September 2014. Four periods of mesoscale convective system (MCS) activity were found during a mutual evolution process of an 850-hPa basin inverted trough (BIT) and 850-hPa basin low vortex (BLV). Among them, the first three periods occurred in an alternating evolution of the BIT and BLV (called the first stage), and then, the fourth period was stimulated by continuous activity of the BLV (called the second stage). During the first stage, MCSs enhanced (weakened) under the situation of the BIT (BLV), and then during the second stage MCSs developed to their strongest levels. Further analysis of the reasons behind the enhancement and weakening of MCSs revealed an obvious characteristic of upper level (lower level) positive (negative) divergence in the BIT situation of the first stage and BLV situation of the second stage. By comparison, under the BLV situation of the first stage, the vertical helicity was larger in the upward airflow of the zonal circulation, and the direction of the wet Q-vector was toward the ascending airflow in the vertical direction. In the horizontal direction, the negative divergence of the wet Q-vector corresponded to the position of water vapor flux convergence. In addition, in the early development of convection, sounding data showed a humidity profile of dry upper and wet lower levels, as well as a larger value of convective available potential energy, which triggered convective activity under the favorable dynamic conditions of atmosphere. When the above characteristics weakened, the convective activity also weakened. Therefore, the formation of multiple convective systems was closely related to the adjustment in atmospheric conditions around the BIT and BLV.

Radiation detectors with different thickness are needed to detect gamma rays with various energies. In this paper, a post-growth annealing method was used to improve the properties of CdMnTe:In (CMT:In) crystals with different thickness for gamma-ray detectors. The results indicated that Te inclusions in CMT:In crystals with different thickness were reduced remarkably after annealing. Both the resistivity and IR transmittance of annealed CMT:In crystals with different thickness increased obviously, which suggested that the crystal quality was improved. For the detectors fabricated by annealed CMT:In slices with 1 mm, 2 mm and 5 mm thickness, the energy resolutions were enhanced about 252%, 193% and 141%, respectively. And ( μτ ) e values were enhanced about 80%, 80% and 76%, respectively. The performance of the detectors was greatly improved after annealing.

An abnormal heavy rainfall that occurred on 27 October 2014 in the Sichuan Basin (SB), China, is analyzed. An inverted trough at 850 hPa evolved into a Southwest China Vortex (SWCV), and strong upward motion caused by interaction between the low-level jet (LLJ) at 850 hPa and the upper-level jet (ULJ) at 200 hPa triggered the rainstorm process. Under a large-scale circulation system featuring a westerly trough and subtropical high, there were two cloud bands over the northeast side and south side of the Tibetan Plateau, respectively. Influenced by the eastward-moving trough, the inverted trough, LLJ, and the SWCV, a Mesoscale Convective System (MCS) was generated near the intersection of the two cloud bands, and it was the direct rainstorm system. The MCS strengthened under the situation of the 850 hPa inverted trough, but weakened when the inverted trough evolved to into the SWCV. Eventually, it formed the phenomenon known as “existing vortex without cloud.” Through analysis of the possible reasons why precipitation strengthened (weakened) under the situation of the inverted trough (SWCV), it was found that the strengthening of precipitation was due to a strong tilting updraft in the area of the ULJ and LLJ intersection. On one hand, the upward motion was related to the vorticity advection variation with height and the low-level warm advection forcing; while on the other hand, the dew-point front near the LLJ also played a lifting role in the upward flow of the lower-layer vertical circulation. Meanwhile, the LLJ “head” was a high-value area of water vapor convergence, which provided sufficient water vapor for the rainstorm. During the SWCV, the weakening of precipitation was due to the SWCV weakening gradually; plus, the ULJ was interrupted over the SB, the upper airflow presented downdrafts, and its superposition with the ascending branch of low-level vertical circulation. This airflow structure inhibited the development of strong upward motion, whilst at the same time, the LLJ retreated toward the south and the dew-point front ultimately weakened and disappeared. Subsequently, water vapor convergence weakened and no longer supported the occurrence of heavy rainfall. Therefore, the strong upward motion caused by the ULJ-LLJ intersection and the lower-level dew-point front were the key reasons for the occurrence of this late-autumn rainstorm.

Recently, researchers were interesting in exploring alternative materials for well-studied CdZnTe which was the key material of radiation detection. Cadmium Magnesium Telluride (Cd1-xMgxTe) crystal was regarded as promising one for room temperature X-ray and gamma-ray detectors due to some potential advantages. In this paper, two large-size Cd0.95Mg0.05Te ingots with 30 mm diameter and over 100 mm length were successfully grown by a modified vertical Bridgman method. Two modifications, including Cd excess or Te-rich condition and the accelerated crucible rotation technique (ACRT), were applied in growing process to decrease defects, enhance resistivity and homogenize component distribution. The results indicated that both ingots had a cubic zinc-blende structure. The distribution of Mg element in the ingots along axial direction was very homogeneous. The energy band gap of Cd0.95Mg0.05Te was close to Cd0.9Zn0.1Te. Low density of Te inclusions (103 cm−3 order of magnitudes) and high IR transmittance (over 60%) showed the good crystal quality. Raman scattering spectroscopy also showed a good crystal quality for Cd0.95Mg0.05Te crystals. Thus, Cd0.95Mg0.05Te crystals could be a promising radiation detector material.

Cadmium&ndash, magnesium&ndash, telluride (CdMgTe) crystal was regarded as a potential semiconductor material. In this paper, an indium-doped Cd0.95Mg0.05Te ingot with 30 mm diameter and 120 mm length grown by a modified Bridgman method with excess Te condition was developed for room temperature gamma-ray detection. Characterizations revealed that the as-grown Cd0.95Mg0.05Te crystals had a cubic zinc-blende structure and additionally Te-rich second phase existed in the crystals. From the tip to tail of the ingot, the density of Te inclusions was about 103&ndash, 105 cm&minus, 2. The crystals had a suitable band-gap range from 1.52&ndash, 1.54 eV. Both infrared (IR) transmittance and resistivity were relatively low. Photoluminescence measurement indicated that the ingot had more defects. Fortunately, after annealing, IR transmittance and the resistivity were significantly enhanced due to the elimination of Te inclusions. CdMgTe crystal after annealing showed a good crystal quality. The energy resolutions of the detector for 241Am and 137Cs gamma-ray were 12.7% and 8.6%, respectively. The mobility-lifetime product for electron was 1.66 &times, 10&minus, 3 cm2/V. Thus, this material could be used for room temperature radiation detectors.

The movement of southwest China vortex (SWV) and its heavy rainfall process in South China had been investigated during June 11–14, 2008. The results show that under the steering of upper-level jet (ULJ) and mid-level westerly trough, SWV moved eastward from southern Sichuan Plateau, across eastern Yunnan-Guizhou Plateau to South China, forming an obvious heavy rain belt. SWV developed in the large storm-relative helicity (SRH) environment, as environmental wind field continuously transferred positive vorticity to it to support its development. The thermodynamic structures of distinctive warm (cold) advections in front (rear) of the SWV movement are also important factors for the SWV evolutions with a southwest low-level jet (LLJ) and vertical wind shear. SWV development was associated with the distributions of negative MPV1 (the barotropic item of moist potential vorticity) and positive MPV2 (the baroclinic item of it). The MPV1 and MPV2 played the dominant role in the formation and the evolution of SWV, respectively. The mesoscale convective systems (MCSs) frequently occurred and persisted in water vapor convergence areas causing the severe heavy rainfall. The areas of high moist helicity divergence and heavy rainfall are consistent, and the moist helicity divergence could be a good indicator for heavy rainfall occurrence.

Based on the theoretic study of location of general facilities, this paper makes an attempt to optimize the typical discrete element of the location of aviation rescue base through discrete binary particle swarm (PSO) algorithm in order to find out an optimized location method with more simplified calculation and more optimized result, which will finally provide a solid theoretical foundation for the location of aviation rescue base.