[en] A calculation code (HBDC) for the parameters of core reflector is encoded based on the one-dimensional transport equivalent method and the discrete ordinates method ANISN. This code is applied to calculate the Zion-1 benchmark problem and iron-water reflector problem for verification. Numerical results demonstrate that this method is flexible for both the baffle reflector and iron-water reflector, and it can achieve high accuracy. (authors)

[en] Highlights: • A green route is developed for synthesis of water-soluble and fluorescent Fe:ZnSe quantum dots. • Tunable luminescence intensity can be realized with different ligand-to-Zn molar ratios. • The obtained quantum dots are in the so-called “quantum confinement regime”. -- Abstract: Here, we report a synthetic route for highly emissive Fe:ZnSe quantum dots in aqueous media using the mercaptoacetic acid ligand as stabilizing agent. The structural, morphological, componential, and optical properties of the resulting quantum dots were explored by the X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, photoluminescence and UV–visible absorption spectroscopies. The average crystallite size was calculated to be about ca., 4.0 nm using the Scherrer equation, which correlates well with the value obtained from the transmission electron microscopy analysis. The obtained water-soluble Fe:ZnSe quantum dots in the so-called “quantum confinement regime” are spherical shaped, possess the cubic sphalerite crystal structure, and exhibit tunable luminescence properties. The presence of mercaptoacetic acid on the surface of Fe:ZnSe quantum dots was confirmed by the Fourier transform infrared spectroscopy measurements. As the ligand/Zn molar ratio increases from 1.3 to 2.8, there is little shift in the absorption peak of the Fe:ZnSe sample, indicating that the particle size of the obtained quantum dots is not changed during the synthetic process. The photoluminescence quantum yield of the as-prepared water-soluble Fe:ZnSe quantum dots can be up to 39%. The molar ratio of ligand-to-Zn plays a crucial role in determining the final luminescence properties of the resulting quantum dots, and the maximum PL intensity appears as the ligand-to-Zn molar ratio is 2.2. In addition, the underlying mechanism for the resulting tunable luminescence properties of the obtained Fe:ZnSe quantum dots was also elucidated

[en] The NQR signal is very weak, only in the order of ten nanovolts, while the noise and interference are several orders higher than the NQR signal. The processing methods commonly used such as maximum likelihood algorithm, subspace algorithm, wavelet transform and so on have advantages, but their disadvantages are also obvious. In this paper, starting with the sample data of signals, the colored noise is simulated as Yule-Walker model by using adaptive Kalman filter algorithm, and then the whitened signal is filtered by using traditional Kalman filter. The experimental results show that the algorithm greatly reduces the noise interference, and the extracted FID signal frequency is relatively single, the amplitude of resonance frequency is unchanged, and the signal-to noise ratio is greatly improved. (authors)

[en] Highlights: • Effects of molecular structures (chain/ring) on combustion and emission are tested. • Effects of cetane number and oxygen on combustion and emission are isolated. • Soot reduction effects of different oxygen fundamental groups are compared. • The sequence of soot reduction is alcohols < ketones < ethers. • 2,5-Dimethylfuran is more effective to realize high efficiency and clean combustion. - Abstract: The effect of oxygenated additives with different oxygen functional groups and different carbon chain structures on the combustion and emissions was investigated on a single-cylinder diesel engine. Three different oxygenated hydrocarbons with ring molecular structure including cyclohexanone, cyclohexanol and 2,5-dimethylfuran and other three oxygenated hydrocarbons with chain molecular structure including 2-hexanone, n-hexanol, and isopropyl ether were blended with diesel fuel separately to formulate 6 blended fuels with the same oxygen content (4 wt%). A wide range of exhaust gas recirculation rates (from 0 to misfire) were employed to cover both conventional diesel combustion and low temperature combustion. The results indicate that the effect of oxygenated fuels on combustion and emission get larger at high rates of exhaust gas recirculation. For chain structure oxygenated additives, although n-hexanol presents much longer ignition delay at high rates of exhaust gas recirculation, it exhibits the highest soot peak due to its high boiling point. And isopropyl ether has the lowest soot emission attributing to its better volatility. The ring structure oxygenated additives present more significant difference in combustion than chain structure ones, and the sequence of ignition delay is 2,5-dimethylfuran > cyclohexanol > cyclohexanone > diesel. The soot emissions show a close relation with the ignition delay of the fuel, i.e., the fuel with longer ignition delay always exhibits lower soot emissions. And the lowest soot emission can be obtained with 2,5-dimethylfuran companied with apparent improvement in combustion efficiency and thermal efficiency. For the soot reduction ability of different oxygen functional groups, the sequence is alcohols < ketones < ethers. The oxygenated fuels with ring molecular structure tend to produce more soot compared with the ones with chain structure if only the oxygenated effect is considered, while the soot emissions is also influenced by the position of oxygen functional group. Taking all the effects together, 2,5-dimethylfuran is more effective in realizing high efficiency and clean low temperature combustion.

[en] Magnetic hydrophilic polymeric microspheres containing oxirane groups were prepared by inverse suspension polymerization of glycidyl methacrylate (GMA), N, N′-methylene bisacrylamide (MBAA) and N-vinyl pyrrolidone (NVP) in the existence of formamide, which were denoted as magnetic poly(GMA-MBAA-NVP) microspheres. The magnetic poly(GMA-MBAA-NVP) microspheres were characterized by scanning electron microscopy (SEM), FT-IR spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and so on. The results showed that poly(GMA-MBAA-NVP) microspheres possessed well spherical shape, narrow size distribution, abundant porous structure, reactive oxirane groups and superparamagnetic properties. Formamide used in the present work served as a modifier, a dispersant and a porogen to form final porous polymer microspheres. The penicillin G acylase (PGA) was covalently immobilized onto the magnetic microspheres through the reaction between the amino groups of enzyme and the oxirane groups on the microspheres for producing 6-aminopenicillanic acid (6-APA). The effects of GMA/NVP ratio and crosslink density on the activity of immobilized PGA were investigated. The highest apparent activity, enzyme loading and coupling yield of immobilized PGA were 821 IU/g, 65.3 mg/g and 42.3% respectively when the mass ratio of GMA/NVP was 1:1 and crosslink density was 60%. Compared with the free PGA, immobilized PGA showed a wider range of pH value and reaction temperature. The relative activity and reaction rate of immobilized PGA remained almost constant after 20 recycles. The magnetic poly(GMA-MBAA-NVP) microspheres would be very promising carriers for immobilizing enzymes in industrial application. - Highlights: • The magnetic poly(GMA-MBAA-NVP) microspheres were successfully synthesized. • Formamide served as a modifier, a dispersant and a porogen to form microspheres. • The magnetic microspheres were highly efficient carriers for immobilizing PGA. • Immobilized PGA showed a wider range of pH value and reaction temperature

[en] An introduction of a new method of time-digital convert circuit based on digital delay line is given. High precision and good reliability can be realized when it is combined with traditional counting convert method in the measurement of large scale pulse width and low frequency self-excitation oscillator. (authors)

[en] Highlights: • Two-stage injection using diesel blended fuel at high EGR (46%) was studied. • Blending fuels induce retarded pilot heat release and have less effect on MPRR. • Effects of injection parameters of blended fuels on emissions are similar to diesel. • Different fuels have little influence on post combustion heat release. • Small quantity post injection close to main results in better efficiency and emissions. - Abstract: The effect of two-stage injection on combustion and emission characteristics under high EGR (46%) condition were experimentally investigated. Four different fuels including pure diesel and blended fuels of diesel/gasoline, diesel/n-butanol, diesel/gasoline/n-butanol were tested. Results show that blending gasoline or/and n-butanol in diesel improves smoke emissions while induces increase in maximum pressure rise rate (MPRR). Adopting pilot injection close to main injection can effectively reduce the peak of premixed heat release rate and MPRR. However, for fuels blends with high percentage of low cetane number fuel, the effect of pilot fuel on ignition can be neglected and the improvement of MPRR is not that obvious. Pilot-main interval presents more obvious effect on smoke than pilot injection rate does, and the smoke emissions decrease with increasing pilot-main interval. A longer main-post interval results in a lower post heat release rate and prolonged combustion duration. While post injection rate has little effect on the start of ignition for post injection. The variation in fuel properties caused by blending gasoline or/and n-butanol into diesel does not impose obvious influence on post combustion. The smoke emission increases first and then declines with retard of post injection timing. Compared to diesel, the smoke emissions of blended fuels are more sensitive to the variation of post injection strategy

[en] Cerenkov luminescence imaging (CLI) is a new method of optical molecular imaging, which has been successfully applied in early clinical trials. However, weak signal intensity and limited ability in tissue penetration have impeded its clinical application. Cerenkov radiation energy transfer imaging and radiation excitation fluorescence imaging were adopted to solve these problems by enabling transformation of some of the blue-weighted Cerenkov luminescence (CL) spectra to red-shifted emissions, or by exciting rare earth particles to emit visible and near infrared light. This article reviews the development of Cerenkov signal enhancement by fluorescence excitation effect. (authors)

[en] Highlights: • MIT appears in electron-doped Y_xCa_1−xMnO₃ compounds at high temperature. • ESR was employed to investigate the magnetic behaviors around the MIT temperature. • All the ESR parameters present a jumping around the MIT temperature. • The MIT is correlated with the variation of the magnetism at high temperature. -- Abstract: Electron-spin resonance (ESR) studies have been performed on Y_xCa_1−xMnO₃ (0.05 ⩽ x ⩽ 0.12) compounds in the temperature range from 140 K to 470 K. It is found that with the temperature increasing, the ESR linewidth increases to the maximum at T_max (=200 K, 220 K, and 270 K for x = 0.08, 0.10, and 0.12, respectively), and then decreases for all the compounds except that with x = 0.05 which shows a continuous decrease in the whole temperature range. For x ⩾ 0.08, the change of the ESR linewidth can be described very well by the adiabatic small polaron hopping model in the temperature range from 140 K to T_max. The ESR intensity decreases with temperature increasing for all the compounds between 140 K and 470 K except 300 K ⩽ T ⩽ 330 K in which it increases with temperature increasing. Meanwhile, the g-factor reaches the minimum at about T = 300 K. The characteristics of the ESR linewidth and intensity indicate the appearance of the short-range magnetic correlations and that the spin–lattice relaxation plays an important role for x ⩾ 0.08. In addition, the electronic transport properties of Y_xCa_1−xMnO₃ compounds reveal a metal–insulator transition at T_MI which varies from 254 K to 293 K with Y content increasing. The resistivity versus temperature between 140 K and T_MI can be fitted well by the adiabatic small polaron hopping model. It is suggested that the metal–insulator transition in Y_xCa_1−xMnO₃ compounds is correlated with the variation of the magnetism under high temperature

[en] Objective: To explore the reliability of patients' sensation of the need to urinate, and to investigate the optimal volume and duration of bladder filling and training method for the stability of bladder filling. Methods: From 2014 to 2015, Fifty patients with pelvic tumor were divided into group A and group B, according to whether they had the history of diseases or surgery in the pelvis or urinary system. Both groups received training of the sensation of the need to urinate. The training required patients to drink a fixed volume of water every time they emptied the bladder. The bladder capacity was measured by a bladder scanner (BladderScan BVI 9400), and a rating scale of the sensation of the need to urinate was completed at 30 min, 45 min, 1 h, and over 1 h when the patient sensed the limit for bladder capacity. The optimal volume and duration of bladder filling or optimal frequency for the training were explored. The paired t-test method was performed for the difference between the predictive value and the measured value, Pearson method was performed for correlation between the sensation of the need to urinate and the measured value. Results: In the A and B groups, there was no significant difference between the predicted value and measured value (A: predicted value and measured value P = 0.777, B: predicted value and measured value P = 0.061), suggesting that the measured value could be used to reflect the predictive value. Compared with group B, group A had a higher correlation between the sensation of the need to urinate and the measured value (r_A = 0.812, r_B = 0.762). The correlation between the predictive value and the measured value became the highest at 45 min and 1 h (r = 0.858 and 0.916), and the corresponding bladder filling volume and score of the sensation of the need to urinate were 330-450 ml and 4-6, respectively. The correlation between the predictive value and the measured value increased with the frequency of the training (r₂ = 0.914, r₃ = 0.917, r₄ = 0.930, r₅ = 0.951, r₆ = 0.962). Conclusions: Before radiotherapy, patients with pelvic tumor should received at least 46 rounds of the training of bladder filling. Patients should drink 800-1400 ml of water every time they empty the bladder, and the optimal bladder filling volume and the reliable and stable sensation of the need to urinate will be achieved after 45 min-1 h. For the patients with the history of urinary system diseases or pelvic surgery, the bladder filling volume needs to be measured using a bladder scanner (BladderScan BVI 9400) during the training before radiotherapy. (authors)