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[en] Vertical profiles of O_3 and SO_2 concentrations were monitored at the Borden Forest site in southern Ontario, Canada from May 2008 to April 2013. A modified gradient method (MGM) was applied to estimate O_3 and SO_2 dry deposition fluxes using concentration gradients between a level above and a level below the canopy top. The calculated five-year mean (median) dry deposition velocity (V_d) were 0.35 (0.27) and 0.59 (0.54) cm s"−"1, respectively, for O_3 and SO_2. V_d(O_3) exhibited large seasonal variations with the highest monthly mean of 0.68 cm s"−"1 in August and the lowest of 0.09 cm s"−"1 in February. In contrast, seasonal variations of V_d(SO_2) were smaller with monthly means ranging from 0.48 (May) to 0.81 cm s"−"1 (December). The different seasonal variations between O_3 and SO_2 were caused by the enhanced SO_2 uptake by snow surfaces in winter. Diurnal variations showed a peak value of V_d in early morning in summer months for both O_3 and SO_2. Canopy wetness increased the non-stomatal uptake of O_3 while decreasing the stomatal uptake. This also applied to SO_2, but additional factors such as surface acidity also played an important role on the overall uptake. - Highlights: • Application of a modified gradient-method for quantifying dry deposition is demonstrated. • A five-year dry deposition database is developed for O_3 and SO_2 over a mixed forest. • Canopy wetness enhances non-stomatal O_3 uptake while inhibits stomatal uptake. • High surface acidity reduces SO_2 dry deposition. - Capsule: A five-year dataset of O_3 and SO_2 dry deposition velocities was generated from concentration gradient measurement data using a modified gradient method.
[en] Highlights: • A coupled transient model for parabolic trough receiver was developed. • Detailed temperature of parabolic trough receiver is obtained. • Temperature difference change inversely with HTF velocity. • Stagnation temperature of parabolic trough receiver increase linearly with time. - Abstract: Parabolic trough receivers are the key component of parabolic trough solar plants, and they typically account for 30% of the cost of the construction of a solar field. The receiver’s reliability is still a major item which affects the plant’s cost. The temperature distribution of the parabolic trough receivers is required to identify the causation of parabolic trough receiver’s failure, and is the prerequisite to design and optimize the parabolic trough receiver’s structure. In this study, the detailed temperature distribution of a parabolic trough receiver is successfully simulated by combining a MCRT code and FLUENT software. The heat transfer fluid flow, conduction and radiation heat transfers are jointly considered. Temperature-dependent properties of the heat transfer fluid, the wavelength-dependent optical properties of the receiver surfaces and the glass envelope’s absorption of the solar radiation energy are also taken into account. Comparison with indoor experimental results show the average difference is within 6%. In addition, the transient behaviors of parabolic trough receiver under direct concentrated solar irradiance are investigated. The information from this study is of great importance to the design and the optimization of the structure of parabolic trough receiver, as well as to identify the causation of parabolic trough receiver’s failure
[en] Objective: To investigate the safety and efficacy of rotational atherectomy with small burr together with subsequent drug-eluting stent implantation in treating patients with heavily calcified coronary lesions. Methods: During the period from January 2009 to April 2013 a total of 12 patients with heavily calcified coronary lesions were admitted to authors' hospital. The diagnosis was confirmed by angiography in all patients. Rotational atherectomy with small bun combined with subsequent drug-eluting stent implantation were carried out. The clinical data, including angiography success rate, procedure success rate, complications and postoperative main adverse cardiovascular events such as death, myocardial infarction and target lesion revascularization, etc. were retrospectively analyzed. Results: A total of sixteen heavily calcified lesions of Type C in 12 patients were successfully treated with rotational atherectomy and drug-eluting stent placement. After rotational atherectomy the stenosis degree of the coronary artery decreased from preoperative (82.7±7.6)% to postoperative (35.2±10.3)%, the difference between the two was statistically significant (P<0.05), and a total of 22 drug-eluting stents were successfully implanted. The angiography success rate was 100%. The average burr-to-artery ratio used in the procedure was (0.50±0.02), the bun with the diameter ≤1.50 mm was employed in treating 93.7% of lesions (15/16). The success rate of the procedure was 91.7% (11/12). During the procedure stasis of blood flow was observed in one patient, and the patient developed perioperative myocardial infarction. No acute vascular occlusion, coronary perforation, dissection or death occurred, and no patient needed to receive emergency coronary artery bypass grafting. All the patients were followed up for (7.1±2.5) months, and no recurrence of angina pectoris or major cardiovascular event was observed. Conclusion: For the treatment of heavily calcified coronary lesions, rotational atherectomy using small burr combined with subsequent drug-eluting stent implantation is safe and effective with satisfactory short-term results. (authors)
[en] To investigate the role of oncolytic reovirus in breast cancer, a tumor xenograft model of NOD/SCID mice was established using a biopsy sample of a primary infiltrating ductal carcinoma obtained from a breast cancer patient. The result of HE and TUNEL was analyzed after injecting the reovirus peritoneally for 3 days. The results showed that estrogen supplementation was required to establish appropriate human breast cancer xenograft model of NOD/SCID mice. 29.6% of these transplanted tumors grew with supplementation of Estrogen. Otherwise none grew (P<0.01). ER of the xenograft model was positive.After treatment with reovirus for 3 days, breast cancer cells were disrupted and disappeared which induced tissue looseness. The rate of apoptosis increased double than before. The biological characteristics of tumor xenograft model confirm with the primary breast cancer. The oncolytic reovirus can kill breast cancer in short time. (authors)
[en] Ground subsidence is a very common phenomenon in mining areas, especially for those with a long mining period. After nearly half a century of mining activity, the concomitant disasters of Yingshouyingzi mining area gradually accumulated and have frequently occurred in recent years. In this work, the ground disaster situation and ground subsidence range appearing in the survey area were determined using field investigation and D-InSAR monitoring technology. Geophysical exploration technology (seismic prospecting and transient electromagnetic methods) and geological drilling exploration was adopted to ascertain the distribution of the underground goaf. The results show that the No. 4 and No. 6 coal seam goafs and second mining affected area were developed in the study area. Additionally, ten influencing factors were selected to evaluate the ground stability. According to the grading of each evaluation factor, the survey area was divided into four regions: unstable region, basic unstable region, basic stable region and stable region, based on a fuzzy comprehensive assessment method, which respectively occupy 15.57%, 60.28%, 15.17% and 8.98% of the total survey area. Through a comprehensive field investigation, the size and number of ground fissures and the housing damage rate decrease from the unstable region, basic unstable region, basic stable region to stable region, which indicates to us that the division result is consistent with the actual ground disaster situation. This, in turn, verified the rationality and validity of this evaluation method. Therefore, this study will provide help in forecasting and controlling the ground surface subsidence disasters caused by underground mining in the Yingshouyingzi mining area or other analogous areas. (paper)
[en] Since porous anodic alumina (PAA) is a frequently-used optical waveguide material, accurate characterization of its structure parameters and optical properties is in urgent need. To characterize PAA, spectroscopic ellipsometry is preferred due to its undamaged detection, no sample pretreatment, and having a coverage area relatively larger than that of scanning electron microscopy. For spectroscopic ellipsometric data fitting, previous studies usually adopted a four-layer model, which displays a large bias from the raw data. Here, a modified six-layer model is built in consideration of the more elaborate porous layer that is the dominating contributor for the optical property of a PAA film. By using this six-layer model, PAA films with different thicknesses and under different oxidation voltages were analyzed, and the disperse curves of the porous layer were provided. This study will be helpful for learning the subtle structure of PAA and widen its applications for optical purposes. (paper)
[en] A thermostat chip of indium-tin oxide glass substrate for static chip polymerase chain reaction (PCR) is, for the first time, introduced in this paper. The transparent conductive layer was used as an electro-heating element. Pulse width modulation and fuzzy proportional integration-differentiation algorithm were adopted in the temperature programming of the chip. The temperature distribution was investigated, and a dynamic control precision within ±2 deg. C was achieved. The highest ramping rates were 37 deg. C s-1 for heating and 8 deg. C s-1 for cooling with an electric fan. The PCR reaction vials were constructed with polyethylene tubes or poly(dimethylsiloxane) directly on the thermostat chip; the chip had a typical size of 25 mm x 25 mm and a thickness of 1.1 mm. Static chip PCR was successfully demonstrated either in a single vial or in an up to 8-parallel array vials. In situ real time fluorescence monitoring during PCR of a λ DNA fragments (236 bp) with SYBR Green I was demonstrated using a blue light emission diode as a light source and a photomultiplier as a detector. The method proposed here is characterized by open access, easy fabrication and low cost. This work could be the basis for developing a portable real time PCR system with disposable chips for point of care tests
[en] Three novel copper(II)-oxovanadium(IV) heterodinuclear complexes bridged by dianions of N,N'-oxamidobis(propionato)cuprate, [Cu(obp)], and endcapped with 2,9-dimethyl-1,10-phenanthroline (Me2phen), 4,7-diphenyl-1,10-phenanthroline (Ph2phen) or 5-methyl-1,10-phenanthroline (Mephen), respectively, have been synthesized and identified as [Cu(obp)VO(Me2phen)] (1), [Cu(obp)VO(Ph2phen)] (2) and [Cu(obp)VO(Mephen)] (3). The three dinuclear complexes have not yet been isolated in crystalline form suitable for X-ray structure analysis, but based on elemental analyses, IR and electronic spectra studies, magnetic moments at room temperature and molar conductivity measurements, these complexes are proposed to have an extended oxamido-bridged structure consisting of planar copper(II) and square-pyramidal oxovanadium(IV) ions. The three heterodinuclear complexes were further characterized by variable-temperature magnetic susceptibility (4.2-300K) measurements and the magnetic data have been used to deduce the indicated heterodinuclear structure. The results derived from least-squares fit of the experimental data have confirmed that the operation of a ferromagnetic interaction between the adjacent copper(II) and oxovanadium(IV) ions through the oxamido bridge within each molecule takes place. Based on spin Hamiltonian, H at=-2JS at1.S at2, the exchange integral (J) was evaluated as J=+21.9cm-1 for (1), J=+18.8cm-1 for (2) and +26.5cm-1 for (3). The influence of the symmetry of the magnetic orbitals and different terminal ligands on the nature and magnitude of the magnetic interaction between the paramagnetic centers is also discussed
[en] Regional drought frequency analysis was carried out in the Poyang Lake basin (PLB) from 1960–2014 based on three standardized drought indices: the standardized precipitation index (SPI), the standardized precipitation evapotranspiration index (SPEI) and the standardized Palmer drought index (SPDI). Drought events and characteristics were extracted. A Gumbel–Hougaard (GH) copula was selected to construct the bivariate probability distribution of drought duration and severity, and the joint return periods (Ta) were calculated. Results showed that there were 50 (50 and 40) drought events in the past 55 years based on the SPI (SPEI and SPDI), and 9 (8 and 10) of them were severe with Ta more than 10 years, occurred in the 1960s, the 1970s and the 2000s. Overall, the three drought indices could detect the onset of droughts and performed similarly with regard to drought identification. However, for the SPDI, moisture scarcity was less frequent, but it showed more severe droughts with substantially higher severity and longer duration droughts. The conditional return period (Ts|d) was calculated for the spring drought in 2011, and it was 66a and 54a, respectively, based on the SPI and SPDI, which was consistent with the record. Overall, the SPI, only considering the precipitation, can as effectively as the SPEI and SPDI identify the drought process over the PLB under the present changing climate. However, drought is affected by climate and land-cover changes; thus, it is necessary to integrate the results of drought frequency analysis based on different drought indices to improve the drought risk management.
[en] This paper presents an analysis of the modern state of studies of the thermophysical properties of nanofluids and the heat-transfer mechanism in them. The results of experimental studies of obtaining and determining the dynamic viscosity of the nanofluids (SiO2 + water) with various concentrations of nanoparticles are given. Nanofluids are obtained using a two-stage method in an ultrasonic field with a frequency of 20 kHz. It is shown that, in the SiO2 + water system, nanoparticles with sizes of 7, 12, and 16 nm are most stable. Various SiO2 concentrations in the volume range 0.5–5% were tested, and their thermophysical properties were studied for the purpose of using them as a heat-transfer medium in flat-plate solar collectors.