Search

Objective—To explore the effect of muscle-enhancing nutrition support on anthropometric indexes after anti-G physical training. Methods—Ten healthy male volunteers were randomly divided into experimental group and control group. Based on anti-G physical training, different muscle-enhancing nutrition support were used for 16 weeks. Anthropometric indexes were measured every two weeks. Results—The neck circumference, chest circumference, armpit upper arm circumference, upper arm circumference, upper arm minimum circumference and upper arm maximum circumference increased, while waist circumference, hip circumference and thigh circumference decreased in the experimental group and the control group. The body weight, fat free mass and muscle mass increased, while body fat percentage and fat mass decreased significantly (p < 0.05) in the experimental group. The body weight, boy fat percentage and fat mass increased while the fat free mass and muscle mass decreased in the control group. Conclusions—The results showed that the nutrition support in the experimental group could help improving muscle mass and reducing fat mass, and the effect was better than that in the control group.

Objective—To observe the effect of different muscle-enhancing supplement programs on muscle strength and guide pilots to carry out reasonable nutritional supplement in anti-G physical training. Methods—Ten healthy male volunteers were randomly divided into the experimental group and the control group. The subjects were trained according to the anti-G muscle strength training program and got different muscle-enhancing supplement programs for 16 weeks. The muscle strength indexes of the subjects were measured before and after the experiment. Results—Compared with before the experiment, the 10RM and 3RM of barbell squat, leg bend and pull, and maximal leg strength in the experimental group and the control group were significantly increased (P < 0.01), and the 10RM and 3RM of barbell push in the experimental group and the control group were significantly increased (P < 0.05). After muscle-enhancing supplement, the proportion of muscle strength improvement in the experimental group was higher than that in the control group. Conclusions—The muscle-enhancing supplement program of experimental group was better than the control group.

Objective—To understand and analyze the prevalence and risk factors of dyslipidemia among flight personnel, so as to provide the basis for aviation health management. Methods—The physical examination data of flight personnel who participated in physical examination in 2020 were collected. The prevalence and risk factors of dyslipidemia in flight personnel were analyzed by statistical methods. Results—The risk of dyslipidemia increased with age and longer flight time. Flight crews with an overweight body mass index are more likely to have dyslipidemia. Conclusions—Comprehensive measures should be taken to prevent and control dyslipidemia from health education, diet and nutrition, and physical training for the key population.

Objective— To investigate the dietary characteristics and nutritional health status of cadets in air force youth aviation school. Methods— The 24-h dietary survey was used to investigate the dietary structure. The body composition index and blood biochemical indexes were measured to evaluate their health status. Results— According to the dietary guidelines for Chinese residents, the intake of fruits was seriously insufficient, reaching only 53.48%–80.23%. The intakes of sodium, potassium and phosphorus were high, calcium, iron, zinc and iodine were low. Folic acid intake reached 50.58% of the recommended amount of Chinese residents. The energy supply for breakfast was 23.97%, which was lower than the recommended amount, while the dinner was higher. Carbohydrate provided 1163.6 kcal (39.80%), which was lower than standard recommended. The proportion of protein intake from animal origin was slightly higher than the upper limit (50%) recommended by military standard. Among the blood biochemical indexes, only VD (25-OH) was low. Conclusions— The dietary structure of the cadets is not reasonable, and the intake of minerals and the energy supply ratio of the three nutrients are unbalanced. The overall nutritional health status was good, individual students had malnutrition.

LiF has potential applications in developing intensive current negative-ion sources and neutral particle detection in space due to its wide band gap. Charge transfer processes on a LiF(100) surface have been studied for 10.5–22.5 keV negative oxygen and chlorine ions under a grazing angle of incidence. In contrast with previous studies, the electron loss of the projectile has been obviously observed. The most striking experimental result is that the positive and negative ion fractions nonmonotonically vary with increasing incident angle in the scattered beam. The positive-ion production is explained by the molecular orbital promotion mechanism. The nonmonotonic positive-ion fraction is well described by the Landau-Zener formula. Besides the complete destruction from the anion sites of the insulator surface, the channel of negative-ion destruction from the cation sites has been suggested and considered in the model calculation to understand the electron loss process. It demonstrates that incident angle is a sensitive parameter for the negative ion conversion during grazing ion surface scattering.

Charge transfer during oxygen negative ion surface scattering is performed to investigate the electronic interaction for the water/Cu system as a function of incident velocity. We find that both positive and negative ion fractions increase with incident velocity for the specular scattering condition. The positive ions produced close to the surface can be understood by the mechanisms of collision-induced ionization and Auger ionization, and they finally survive from the resonant and/or Auger neutralization, which are well described by the exponential scaling. The negative ions are formed through the resonant charge transfer, and the velocity dependence has been explained by the kinematically parallel velocity effect and the surface work function. The modified rate equation taking into account these two factors is in rough agreement with the experimental result.

Li+ and Na+ ions are scattered from Au(1 1 0) and Au(1 1 1) surfaces in the keV-energy range, respectively. The pronounced Li° and Na° fractions non-monotonically vary with incident energy and exit angle for high work function gold surfaces. In particular, the azimuthal angle dependence of Li° fraction has been observed at low incident energies for a grazing exit angle. The simple calculations are presented to compare with the experimental data. Our findings clearly indicate that both the perpendicular and parallel exit velocity affect the final neutral fraction.

A new structures for efficient AlGaN based deep-ultraviolet light-emitting diode (DUV -LED) with irregular sawtooth hole barrier layer (HBL) and electronic barrier layer (EBL) is proposed in this work. Optical output power and internal quantum efficiency(IQE), the energy band diagrams, radiative recombination rate are investigated by APSYS software. The results indicate that light output power of the DUV-LED with the new structure is enhanced by 131.8%, and internal quantum efficiency is increased by 125.0% at an injection current of 180 mA compared with the conventional AlGaN based DUV-LED structure. Further research shows that irregular sawtooth hole blocking layer(HBL) and electron blocking layer(EBL) can obviously improve the carrier radiation recombination rate, modulate carrier distribution, enhance electron injection efficiency, and confine hole leakage; thus the IQE and optical output power are enhanced.

Energies, E 1 , E 2 and M 1 transition rates and lifetimes are reported for the lowest 134 fine-structure levels of the 3 p 6 3 d 2 , 3 p 6 3 d 4 s , 3 p 5 3 d 3 and 3 p 6 3 d 4 p configurations in all Ca-like ions between Co VIII and Zn XI. The calculations have been performed using the multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods. Important core–valance and core–core electron correlation effects are systematically accounted with large scale configuration interaction expansion. The Breit interaction and leading quantum-electrodynamical (QED) contributions such as the vacuum polarization and self-energy corrections are also included in the RCI calculations. The results are compared with the compiled data from the NIST ASD and other calculations to evaluate the accuracy of the present calculations. Our results have good agreement with previous relativistic many-body perturbation theory (RMBPT) calculations and the data from the NIST ASD, except for Zn XI. Present calculations provide some missing data, especially for Cu X and Zn XI, in the NIST ASD.

A special structure with Al-composition graded barriers in the active region was designed to provide a sawtooth layer for the multiple quantum barriers, which were investigated numerically. The simulation demonstrates that the output power of optimized structure has reached to 50 mW and the efficiency droop also has significantly improved. By detailedly analyzing the results, the advantages of the ultraviolet light emitting diodes with sawtooth barriers are attributed to the design, which could enhance the ability of electrons reservoir, modulate carrier distribution and suppress electron spill out from the active region. As a result, it can enhance the rate of carrier radiation recombination and ameliorate internal quantum efficiency.

The properties of AlGaN-based deep-ultraviolet light-emitting diodes with AlInGaN/AlInGaN superlattices (SLs) electron blocking layer (EBL) were studied numerically. When the common structure of AlGaN EBL is replaced by AlInGaN/AlInGaN SLs EBL, the simulation results show a higher light output power and internal quantum efficiency, which is attributed to higher barrier-suppressing electron leakage and reduced barrier for hole injection due to the alleviated strain force and lattice match. The results also demonstrate that the efficiency drop is slightly decreased from 20.9% to 15.8% when the new structure is used.

The use of nanoporous graphene for separation has attracted increasing interest over the past few years. Nanopore size, temperature, pressure and functionalization are vital for selectivity, but the influence of nanopore density is not known. Thus, we designed a monolayer nanoporous graphene membrane and revealed the influence of nanopore density on its ethylene/acetylene separation performance by employing molecular dynamics (MD) simulations. Our results indicate that an optimal nanopore density exists for permeation flux and selectivity. The MD simulation results were confirmed by density functional theory (DFT) and the kinetic theory of gases. The interactions between ethylene/acetylene and nanopores were also investigated, and van der Waals (vdW) interactions with slight steric repulsion were detected.

In the subsurface environment, colloids play an important role in pollutant transport by acting as the carriers. Understanding colloid release, transport, and deposition in porous media is a prerequisite for evaluating the potential role of colloids in subsurface contaminant transport. In this work, the aggregation, retention, and release of bentonite colloid in saturated porous sand media were investigated by kinetic aggregation and column experiments, the correlation and mechanism of these processes were revealed by combining colloid filtration theory, interaction energy calculation and density functional theory. The results showed that the retention and release of colloids were closely related to the dispersion stability and filtration effect. Multivalent cations with higher mineral affinity reduced the colloid stability, and the dispersion stability and mobility of the colloid were greatly improved by humic acid due to the enhancement of electrostatic repulsion and steric hindrance effects. The primary minimum interaction was found to contribute more to irreversible colloid retention in a Ca2+ system, while the secondary energy minimum was found to be responsible for colloid release with the occurrence of transient solution chemistry. The deposited colloid aggregates could be redistributed and released when the solution chemistry became favorable towards dispersion. These findings provide essential insight into the environmental colloid fate as well as a vital reference for the risk of colloid-driven transport of contaminants in the subsurface aquifer environment.

Heteroatom-doped nanopores graphene has great potential as emerging energy storage materials, but the complex synthetic routes and disordered structure limit the improvement of supercapacitance performance. Herein, we develop a one-step synthesis strategy to obtain nitrogen/sulfur doped nanopores graphene (NS-NG). Graphene oxides absorbed with dyes are burned in a confined interlayer to obtain porous hydrotalcite for preparing NS-NG. Interestingly, the NS-NG retains the morphology of multilayer graphene oxides coated with fiber rods before combustion, so it exhibits the annual ring -shaped structure, larger surface area, and highly porosity. Importantly, the NS-NG not only shows a high specific capacitance of 325 F g-1, and also has a high energy density of 25 Wh kg-1 at a high power density of 1906 W kg-1 with an excellent capacity retention of 86% after 10,000 cycles applied in the two-electrode symmetric supercapacitor at a current density of 2 A g-1 in 0.5 M Na2SO4 aqueous solution.

Efficient and cost-effective removal of radioactive iodine anions from contaminated water has become a crucial task and a great challenge for waste treatment and environmental remediation. Herein, we present hexadecylpyridinium chloride monohydrate modified bentonite (HDPy-bent) for the efficient and selective removal of iodine anions (I

Accurate prediction of the colloid-driven transport of radionuclides in porous media is critical for the long-term safety assessment of radioactive waste disposal repository. However, the co-transport and corelease process of radionuclides with colloids have not been well documented, the intrinsic mechanisms for colloids-driven retention/transport of radionuclides are still pending for further discussion. Thus the controlling factors and governing mechanisms of co-transport and co-release behavior of Eu(III) with bentonite colloids (BC) were discussed and quantified by combining laboratory-scale column experiments, colloid filtration theory and advection dispersion equation model. The results showed that the role of colloids in facilitating or retarding the Eu(III) transport in porous media varied with cations concentration, pH, and humic acid (HA). The transport of Eu(III) was facilitated by the dispersed colloids under the low ionic strength and high pH conditions, while was impeded by the aggregated colloids cluster. The enhancement of Eu(III) transport was not monotonically risen with the increase of colloids concentration, the most optimized colloids concentration in facilitating Eu(III) transport was approximately 150 mg L

The dynamical transmission of intermediate-energy protons through a polycarbonate (PC) conical capillary with taper angle from 0.48° to 2° are simulated. The results show that for small taper angle of 0.48°, the transmission of 100 keV protons is dominated by the deposited-charge-assisted specular reflection. This reflection effect decreases with the increase of the taper angle. When the taper angle is increased to 2°, the transmission of the protons is mainly influenced by small angle scattering, which is consistent with the experimental data. The asymptotic transmission rate decreases with the increase of the capillary taper angle. These results suggest that the deposited-charge-assisted specular reflection is significant in focusing several-hundred-keV protons.

In the scattering and stopping of heavy ions on a few surface layers in solids, contributions of the electronic and nuclear energy losses can become comparable. In this work we present a study of 0.6--5-keV Ar ion scattering on a Cu (100) surface. Energy-loss spectra were measured and displayed some changes as the incident ion energy changes. Thus, a structured spectrum is observed at the higher energies. We analyze the characteristics of the spectra and contributions from the nuclear and electronic energy-loss components using both a Monte Carlo kinetics simulation assuming an averaged electron density and a semiclassical deterministic simulation with an inhomogeneous electron density in the solid. The general features of the experimental spectra were well reproduced, and semiclassical simulations allow us to identify contributions from trajectories coming from below and on top of the surface atomic layer. The relative contribution of nuclear energy loss and electronic energy loss (EEL) were delineated and a more refined analysis of the EEL for different trajectories is presented.

The jellium model of free electron gas and its extended version have been widely used to understand the neutralization of alkali-metal ions on metal surfaces. We report an unexpected deviation from its prediction that we observed in the neutralization of $\mathrm{N}{\mathrm{a}}^{+}$ ions scattering from an Al(111) surface. We find that the neutralization probability decreases monotonically with increasing ion velocity for the specular scattering condition, which is consistent with the well-known parallel velocity effect. However, the neutralization probability exhibits an unexpected bell shape with the variation of outgoing angle for a given incident energy. Calculations based on the jellium model using the rate equation and including the dynamic parallel velocity effect are presented. Their results agree with the velocity dependence of the neutral fraction, but completely fail in reproducing the angle dependence. This anomalous angle dependence could be due to the appearance of inelastic processes, corresponding to inner $2p$ electron promotion in hard encounters with Al atoms for large incidence angles, when the interatomic distances become small. This can lead to the formation of autoionizing Na states that result in the formation of extra $\mathrm{N}{\mathrm{a}}^{+}$ ions, not accounted for in the jellium model.

Objective—When the pilot's function status is low, he can't complete the task effectively, which may cause the whole system to malfunction or even cause serious accidents. So, in order to provide scientific basis for maintaining and improving pilot functional state, this paper studies the concept, connotation and influencing factors of pilot's functional state. Methods—Qualitative research methods were used, including literature analysis, questionnaire survey and expert interview. And 30 pilots were recruited to an in-depth interview. Results—There are three main factors that affect pilots’ functional status: special flying environment, physiological factors and psychological factors. Among these three factors, the perception ability, information processing ability, comprehensive cognitive ability and social psychological state of psychological factors are particularly important for flight function. Conclusions—The pilot's functional state directly affects flight safety. It is necessary to pay attention to the factors that may affect flight functional state, and to monitor the characterization of functional state regularly. Therefore, corresponding preventive measures can be formulated to reduce the potential risk of threat to flight safety.

Objective: To study the sensory quality of six kinds of instant rice by fuzzy mathematics method. Methods: Adopted the method of fuzzy mathematics with color, status, smell, texture and taste as evaluation factors and carried out fuzzy mathematics judgment of the sensory quality of six kinds of instant rice: rice, five grains rice, coix seed rice, mung bean rice, highland barley rice and black rice. Results: The fuzzy comprehensive sensory evaluation scores of six kinds of instant rice from high to low were black rice, coix seed rice, five grains rice, mung bean rice, highland barley rice and rice. Conclusions: The fuzzy mathematics method can reflect the sensory quality of military instant rice objectively, which provided a reference method for the comprehensive sensory quality evaluation of military food.

Objective—To evaluate the dietary quality of aircrew by using military diet balance index (DBI) and provide basis for their dietary guidance and nutritional intervention. Methods—Dietary survey was carried out by weighing method. The dietary quality of aircrew was evaluated by using military DBI. Results—The intakes of red meat and egg met the standard, the intake of vegetable oil was over the standard, the intakes of other kind of food did not meet the standard. The intakes of calcium, iodine, vitamin A, vitamin B1 and vitamin B2 did not meet the standard. The energy supply ratio of protein, fat and carbohydrate was 16%, 46% and 38%, respectively, showing a “high protein, high fat and low carbohydrate” pattern. The food quantitative results were basically consistent with the military DBI scores, showing a slight nutritional imbalance. Conclusions—The dietary pattern of the investigated aircrew was unreasonable; part of the food and nutrients intake was insufficient; the military DBI score showed that the dietary pattern was slightly unbalanced. The dietary pattern should be further adjusted.

Objective To understand the nutritional status of air force pilots and explore its changing trend, so as to provide scientific basis for guiding reasonable nutrition and improving operational performance of the air force pilots. Methods 125–147 male pilots were included in the study. The energy intake was estimated by weighing method. The energy consumption was assessed by life observation method. The body mass index (BMI) was calculated by height and weight. Serum total cholesterol (TC) and triglyceride (TG) were determined by double reagent enzyme method. The results were compared with that of nutrition survey for air force pilots in 1997 and 2007. Results The average daily energy intake and consumption was 3375.2 kcal and 3091.5 kcal, respectively. Protein, fat, and carbohydrate provided 17.4%, 43.9%, and 38.7% of the daily energy intake, respectively. The incidence of underweight, overweight, and obesity was 4.8%, 16.8%, and 4.0%, while the prevalence of hypertriglyceridemia and hypercholesterolemia was 31.2% and 36.1%, respectively. The nutritional status of air force pilots changed a lot compared with that of 1997. However, the situation seemed to be improved compared with that of 2007. Conclusions The dietary pattern of air force pilots was not reasonable and the incidence of overweight, obesity, and dyslipidemia was high. Nutritional intervention and guidance should be strengthened.

Objective—This paper verifies a sensory evaluation method that adds fuzzy mathematical evaluation on the basis of preference evaluation. Methods—Four kinds of ready-to-eat meatballs with different flavors were used as sensory evaluation objects. Based on the preference evaluation, fuzzy mathematics was added to evaluate the sensory quality of meatballs. Results—The results showed that among the four kinds of ready-to-eat meatballs, cumin meatballs, beef meatballs, onion meatballs and spicy meatballs ranked in order of popularity. Conclusions—On the basis of preference evaluation, fuzzy mathematical method can be added to improve the objectivity of food sensory evaluation.

Background In view of the current difficulty of clinically diagnosing osteoarticular tuberculosis, our aim was to use mass spectrometry to establish diagnostic models and to screen and identify serum proteins which could serve as potential diagnostic biomarkers for early detection of osteoarticular tuberculosis. Methods Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was used to select an osteoarticular tuberculosis‐specific serum peptide profile and establish diagnostic models. Further, liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) was used to identify potential serum biomarkers that could be used for auxiliary diagnosis of osteoarticular tuberculosis, and then clinical serum samples were used to verify these biomarkers by enzyme‐linked immunosorbent assay (ELISA). Results We established four diagnostic models that can distinguish osteoarticular tuberculosis from rheumatoid arthritis, ankylosing spondylitis, osteoarticular infections, and healthy adults. The models were osteoarticular tuberculosis‐rheumatoid arthritis, osteoarticular tuberculosis‐ankylosing spondylitis, osteoarticular tuberculosis‐osteoarticular infections, and osteoarticular tuberculosis‐healthy adult, and their accuracy was 76.78%, 79.02%, 83.77%, and 88.16%, respectively. Next, we selected and identified 18 proteins, including complement factor H‐related protein 1 (CFHR1) and complement factor H‐related protein 2 (CFHR2), which were upregulated in the tuberculosis group only. Conclusions We successfully established four diagnostic models involving osteoarticular tuberculosis, rheumatoid arthritis, ankylosing spondylitis, osteoarticular infections, and healthy adults. Furthermore, we found that CFHR1 and CFHR2 may be two valuable auxiliary diagnostic indicators for osteoarticular tuberculosis. These results provide reference values for rapid and accurate diagnosis of osteoarticular tuberculosis.

Hydrogen storage in solids is becoming an ever more important technology. We theoretically design a completely new material for hydrogen storage, which is quite different from the present materials. This kind of material, base on monolayer graphene, is thought to be extremely flexible. First-principles calculations and kinetic theory of gases are employed to evaluate this material. The results demonstrate that it is promising for hydrogen storage. More than anything, the hydrogen storage capacity of this material is about 4 mmol g−1 at 300 K and 1 atm.

In the 21st century Master of Public Administration (MPA) programs need to meet the challenge of preparing public affairs professionals for an increasingly global and interdependent world in which complex social problems often span national boundaries and cultural differences. In that context, various internationalization strategies can be helpful in developing the necessary global, international, and intercultural (GII) competencies that public affairs professionals need. In this paper, we evaluate a model known as Cultures and Languages Across the Curriculum (CLAC) as an internationalization at home tool which may have potential in public affairs programs. We describe the philosophical and pedagogical approach of CLAC, and compare our experiences with three levels of CLAC integration within graduate-level public affairs classes. Based on feedback from students and observations from faculty we are able to offer preliminary assessments on the effectiveness of the CLAC approach in MPA education, and advice for MPA programs and instructors who may be interested in using CLAC to develop GII competencies among their students.

L-shell X-rays of 48Cd and 49In have been measured for the bombardment of protons in the energy range 75–250 keV in steps of 25 keV. The individual Lι, Lα, Lβ, Lγ and total L X-ray production cross sections were extracted from the yield. The results were compared with theoretical predictions of PWBA, ECPSSR and ECUSAR, as well as with experimental results of other authors. Good agreements were observed for our data with others and ECPSSR or ECUSAR calculations. The influence of using different atomic parameter databases is also discussed.

Carbon particle therapy has shown great advantages in radiation therapy owing to its high relative biological effectiveness. In-beam positron emission tomography (PET) is an effective method for monitoring and measuring the position and dose of a carbon ion beam. In this paper, we use Geant4 application for emission tomography software to simulate carbon therapy and in-beam PET imaging processes. One hundred pulses of 12C with 100, 200, and 300 AMeV were impacted on a PMMA target. The distributions of positron-emitting nuclides and the radiation dose were calculated. The coincidence data of annihilation photons from positrons were measured via a small animal PET protocol, which uses the same detector size and ring radius as the MicroPET Focus 220. Finally, we reconstructed the 3-D PET image for the distribution of generated positron-emitting nuclides by using a filtered back projection algorithm, and the PET image was used to determine the position of maximum dose deposition. Thus, we demonstrate a comprehensive method to accurately identify the position of maximum dose deposition by using the reconstructed in-beam PET image.

Shifted Fermi sphere model and parallel velocity effects on clean metals have been verified by a number of previous studies. However, for fast F − and Cl − ions scattering on dissociated water covered Cu(110) at grazing incidence, the negative-ion fraction is projectile dependent and monotonically increases with the increase of impact velocity, which cannot be explained by the conventional parallel velocity effect. The positive-ion fraction increases with the increase of perpendicular velocity, which can be well described by the exponential scaling. Positive ions efficiently formed at large perpendicular velocities strongly suppress the negative ion yield at short distances from the surface, so that negative ions are only formed at large distances. In addition, the large surface work function further promotes a transition between two kinds of parallel velocity effects. The calculation taking into account these contributions is in rough agreement with the experimental data.

Energy researchers believe that by storing energy the frequency and voltage of renewable energy systems can be better controlled and increases the use of renewable electricity by providing sustainable energy. Hence, the use of renewable solar energy coupled with an energy storage technology can be fruitful for urban areas in achieving sustainable development and reducing environmental crises. This study presents and investigates a new energy system for energy production and storing. The energy generation unit is a Linear Fresnel Reflector (LFR)-based hybrid system coupled to a Stirling engine and a thermoelectric generator. Two different scenarios are considered for the generated energy: 1) the available electrical energy is consumed to produce hydrogen fuel by an alkaline electrolyzer, and 2) the available electrical energy is stored by a storage system. Solar energy is converted into thermal energy by LFRs. Thermal energy then enters the Stirling engine and according to the Stirling cycle, thermal energy is converted into electrical energy. To prevent heat loss of the engine, a thermoelectric generator is thermally coupled to the engine to generate electrical energy. Results indicate that the proposed system can produce 11.73 kWh of electrical energy with an overall efficiency of about 43.6%. In addition, the solar system embedded in the cycle must be able to produce 2.96 kW of thermal energy per hour. To store generated electrical energy, the storage system should be about 7.8 m3 in size. Furthermore, 100.8 moles of hydrogen fuel can be produced during the working hours of the energy system. Finally, a comparison is made between the performance of the PTC and the LFR in supplying the heat required by the Stirling engine.

Heteroatom-doped nanoporous graphene has great potential as emerging energy storage materials, but the complex synthetic routes and disordered structure limit the improvement of supercapacitance performance. Herein, we develop a one-step synthesis strategy to obtain nitrogen/sulfur doped nanoporous graphene (NS-NG). Graphene oxides absorbed with dyes are burned in a confined interlayer of porous hydrotalcite for preparing NS-NG. Interestingly, the NS-NG retains the morphology of multilayer graphene oxides coated with fiber rods before combustion, so it exhibits the annual ring -shaped structure, larger surface area, and highly porosity. Importantly, the NS-NG not only shows a high specific capacitance of 325 F g−1, and also has a high energy density of 25 Wh kg−1 at a high power density of 1906 W kg−1with an excellent capacity retention of 86% after 10,000 cycles applied in the two-electrode symmetric supercapacitor at a current density of 2 A g−1 in 0.5 M Na2SO4 aqueous solution.

The two-dimensional (2D) materials provide an excellent platform for the study of the dimensional effect. The richer the types of 2D materials, the broader the unknown field we can explore. However, among the large number of 2D materials manufactured by humans, true single-crystalline (SC) atomically thin 2D metals are rare. The instability of SC 2D metal materials puts high demands on its fabrication process. By implementing molecular dynamics (MD) simulations, we proved that the SC biatomic-layer (BL) gallium film can be formed at the interface between two graphene layers. The Ga atoms deposited on the surface of the graphene on the copper substrate will spontaneously evolve into independent liquid nano-islands, and then cover the nano-island with a monolayer graphene. When the Ga nano-islands confined under the graphene layer are heated to 500 °C, they will expand into a BL Ga film, and finally, the entire system is cooled to room temperature to obtain the SCBL Ga film. It is found that these nano-islands are in the liquid state at ∼400 °C, but they undergo a phase transition and evolve into the solid state at ∼500°C. At the same time, the nano-islands also drop from 3D to 2D. In addition, the vertical heterostructure with moire superstructure is formed between the SCBL Ga and the top layer graphene. The calculations of the electronic properties show that the Dirac conical point of the graphene in the heterostructure is shifted below the Fermi level, which proves that SCBL Ga is able to induce semimetallic to metallic conversion in graphene, indicating SCBL Ga can be used for metal contacts in 2D devices.

Nanoporous graphene membrane (NGM) has enormous potential and excellent properties in practical applications. But almost all of the previous studies were based on the assumption that the nanopores were symmetric along the normal vector of the graphene plane. Asymmetric nanoporous graphene membrane (A-NGM), a promising membrane material in energy, environment and bionic, was seldom researched until now. A kind of graphene membrane with asymmetric semisphere nanopore embedded in it is designed. Such a membrane is provided with the properties of A-NGM. Its electron properties and van der Waals surface are analyzed by quantum chemistry approach. Permeation mechanism of helium, neon and argon across this graphene membrane is analyzed by employing Langmuir adsorption isotherm. Molecular dynamics simulations are used to characterize the asymmetric performance of A-NGM for gas permeance. The driving force of these dynamical processes is revealed by implementing noncovalent interaction analysis. These results are considered not only assist in the designing of asymmetric membrane material, but also pave the way toward the realization of unidirectional graphene membrane in the future.

L x rays of Nd have been measured for the bombardment of protons with the energies of 100–250 keV. It is found that Lγ 2 (abbreviation of Lγ 2,3,4,4 ′) x-ray emission is largely enhanced by proton impact, compared to the case of photon radiation. It is proposed that is caused by the multiple-ionization of outer-shell electrons. To verify this explanation, the enhancement for relative intensity ratio of Lι and Lβ 2 to Lα x ray and the energy shift of various L-subshell x rays are discussed. In addition, the production cross sections of Lι, Lα, Lβ and Lγ x ray are obtained and compared with theoretical calculations of PWBA, ECPSSR and ECUSAR, along with various atomic parameter databases.

In this work, we present negative-ion fractions as a function of exit velocity and angle after keV-energy negative oxygen and carbon ions scattering on a highly oriented pyrolytic graphite (HOPG) surface, at a scattering angle of 38°. The negative-ion fractions increase monotonously with the increase of exit velocity for specular scattering, while negative-ion fractions present a bell-shaped dependence on exit angle. In order to gain further insight into the nature of charge transfer on HOPG, a modified charge transfer model involving the contribution of positive ions has been proposed and roughly reproduced the velocity and angle dependences of negative-ion fractions.

We have measured the electron and X-ray emission of tungsten bombarded with proton in the energy range of 50–250 keV. It is found that the total electron yield mainly consists of kinetic electron emission, which results from the excited valence electrons, and presents a similar trend to the curve of stopping power. The ratio between electron yield and electronic energy loss is not constant, but decreases with increasing incident energy. The behavior is interpreted by an expected competitive mechanism of ionization between different shell electrons of target atom. The explanation is verified by the experimental increase of M-shell X-ray emission yield, and the measured and calculated ionization cross section of core and valence electrons.

The experiment of 6.5-22.5 keV C-, O- and F- ions scattering on water covered Si(111) surface has been performed. It is found that the positive-ion fraction is very low and increases monotonically as a function of perpendicular exit velocity and exit angle. In particular, the negative-ion fraction increases monotonically with perpendicular exit velocity for specular scattering, and for a given incident energy the angle dependence of the fraction is nonmonotonic. We interpret the observed positive ions in terms of inelastic binary collision, and adopt a modified resonant charge transfer model to calculate the bell shaped negative-ion fraction. We find that the neutral yield at short ion-surface distance is nonzero and obeys well an exponential dependence. It strongly indicates that a dynamical equilibrium for negative ion formation is never achieved at short distances, and the band gap effect on charge transfer can be neglected to a large extent in this relatively high energy region. (C) 2016 Elsevier Ltd. All rights reserved.

Water–Cu(110) interaction is of particular importance during the routine use of graphene-based devices. In this work, water adsorption, dissociation, and desorption at elevated temperatures have been well studied using the time-of-flight ion scattering technique. It is found that water adsorption meets the first-order Langmuir adsorption model at room temperature. The variation of the ratio between residual O and H on the surface with temperature has been well determined, which profoundly reveals the dynamical process of surface composition. Furthermore, the change in the surface electronic properties has been probed by measuring negative-ion fractions as a function of the annealing temperature for fast ion scattering. It suggests that charge transfer is a very sensitive method for studying specific electronic processes in real time.

Doping has significantly affected the characteristics and performance of semiconductor electronic devices. In this work, we study the charge transfer processes for 8.5–22.5 keV C− and F− ions scattering on H2O-terminated p-type Si(100) surfaces with two different doping concentrations. We find that doping has no influence on negative-ion formation for fast collisions in this relatively high energy range. Moreover, we build a model to calculate negative ion fractions including the contribution from positive ions. The calculations support the nonadiabatic feature of charge transfer.

Acetamiprid is a neonicotinoid insecticide used worldwide that has caused environmental pollution and adverse effects on ecosystems. Here, a novel bacterium, Pseudaminobacter salicylatoxidans CGMCC 1.17248, was isolated to rapidly degrade acetamiprid to IM-1-2 via hydration. Gene cloning and overexpression demonstrated that two nitrile hydratases, AnhA and AnhB, converted acetamiprid to IM-1-2. Escherichia coli overexpressing AnhA and AnhB degraded 98.1% and 94.0% of acetamiprid (1.0 mmol L−1) in 5 min and 8 h, respectively. The pure AnhA and AnhB had a Vmax value of 14.12 and 1.20 μmol mg−1 min−1, respectively, and a Km value of 1.02 mmol L−1 and 2.95 mmol L−1, respectively. Compared with AnhA, AnhB had broad pH stability, as well as metal ions and organic solvents tolerance. Expression of AnhA and AnhB was induced by decreasing the nutrient concentration of culture broth and addition of urea and therefore significantly enhanced acetamiprid degradation of CGMCC 1.17248. qPCR indicated that the expression of AnhA and AnhB under the cultured conditions of 1/15 lysogeny broth or 0.5% urea addition was improved by from 2.2 to 5.3 times. The results presented herein will facilitate development of bioremediation agents for acetamiprid pollution and understanding of the functional role of bacterial nitrile hydratase.

Charge transfer on graphite, a typical substrate and one of the fusion first wall materials, is of great importance in the plasma–wall interaction, thin-film growth, and surface catalysis. We present an experimental study of 8.5–22.5 keV energy carbon, oxygen, and fluorine negative ions scattering from a highly oriented pyrolytic graphite (HOPG) surface at a scattering angle of 8°. It is found that the positive ion fraction decreases monotonically with the increase of both incident velocity and angle. In particular, these dependences are very different from those presented in previous studies. A molecular dynamics simulation reveals that, around the critical condition for planar surface channeling, a number of projectiles may penetrate into the subsurface and become energetic atoms when they emerge from the surface. Hence, an exponential scaling related to the penetration probability has been proposed to well describe the velocity and angle dependences of positive ion fractions.

Nb2RuB2 and Ta2RuB2 phases were recently predicted by GGA-VASP structure optimization to crystallize in the Nb2OsB2-type structure. Although the Fe-based (Mo2FeB2 type) and Os-based (Nb2OsB2 type, superstructure variant of Mo2FeB2 type) analogues have been synthesized and characterized successfully, the Ru-based phases remained unknown. Crystal structure prediction of Nb2RuB2 and Ta2RuB2 phases, using an evolutionary algorithm, led to the AlMn2B2-type structure in contrast to the aforementioned optimization; however, phonon calculations showed that the Nb2OsB2-type phases are dynamically more stable than the AlMn2B2-type phases. A slightly modified synthetic strategy finally led to the successful preparation of the predicted phases. The extremely quick arc-melting procedure, under argon atmosphere, not only led to a quantitative amount of the phases but also to single crystals suitable for structure determination. Powder and single-crystal X-ray diffraction as well as EDX analysis of the metal ratio have confirmed the GGA-VASP structure optimization: Nb2RuB2 and Ta2RuB2 compounds indeed crystallize isotypically with Nb2OsB2 structure, a superstructure variant of Mo2FeB2 type, in which B-dumbbells and Peierls-distorted Ru-chains are found. Susceptibility measurements on a Ta2RuB2 single crystal reveal no superconducting transition down to 2 K, even though some features in the band structures of both phases, similar to those reported in superconducting NbRuB, hinted at possible superconductivity.

Computational fluid dynamics (CFD) simulation for the sharp-edged nozzle was made using the OpenFOAM source code. Jet dynamics characteristics for the gas stream from a sharped-edged nozzle are then simulated under two-dimensional and axisymmetric steady state condition. Gas and particle velocities in a jet are obtained under different input and boundary conditions to provide an insight into the jet characteristics. For the range of downstream distances considered, the results indicate that a jet is characterized by an initial rapid decay of the axial velocity at the jet center while the cross-sectional flow evolves toward a top-hat profile downstream. Numerical simulation of the free-jet expansion from six types of nozzles indicated that the flow fields had significant differences in the early stages of the expansion. The effects of nozzle geometry on the nanoparticles were investigated. Simulation results indicated that the geometry of nozzle affected the cluster penetration efficiency and beam diameter. The extent to which to the Brownian diffusion can affect the particle extraction from nozzle is investigated. Simulations have shown that the Brownian motion perturbs the clusters from the trajectories dictated by the carrier gas and increases the rate of cluster deposition on the nozzle.

The commercial computational fluid dynamics (CFD) software OpenFOAM was used to simulate the gas flow field in a direct current (DC) magnetron nanocluster source. The density of free metal atoms in the aggregation region influenced the cluster formation and the cluster intensity. In order to improve the density of nanoclusters, two factors should be considered: redeposition of the sputtered atoms within the cathode region and the loss of the nanoclusters on the chamber wall. The angles of the jet and the vortex in the aggregation region have a significant influence on the number of nanoclusters. The extent to which to the Brownian diffusion can affect the particle extraction from source is investigated. Simulations have shown that the Brownian motion perturbs the clusters from the trajectories dictated by the carrier gas and increases the rate of cluster deposition on the source internal wall.

The key technology in “soft landing” for Chang’e 3 is to accurately control the height between shutdown sensor and the lunar surface. gamma shutdown sensor uses a launcher to launch photons to the lunar surface and judges the distance between craft and the moon through the number of received photons . The software of Geant4 is used to simulate the simplified system of the launcher-acceptor. The simulation results show the advantages of the launcher with a certain cone launching angle when the craft is landing to the moon. And we find that the relative position of launcher and acceptor is not decisive factor of selecting the launcher with cone launching angle. By the detailed analysis of the scattering probabilities of the photons from the launcher to the acceptor at different scattering angles, we can get the reason that why we chose the 120° cone launching angle in the mission. The simulation data indicate that the most important scattering areas of the gamma launcher are quite different from the laser method. This work provides a way to optimize the structure of the gamma shutdown sensor to accomplish the mission and reduce the radiation dose.