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We demonstrated electrical spin injection into an AlGaAs/GaAs-based high-mobility two-dimensional electron gas (2DEG) system using Co2MnSi as a spin source. A non-local spin-valve signal was observed from 4.2 K to room temperature. Interestingly, the spin-valve signal does not show a monotonic decrease with increasing temperature and reaches a peak at about 80 K. This contrasts with the result observed in bulk GaAs, in which a monotonic decrease in spin-valve signals with increasing temperature was observed. Moreover, the spin-valve signal decreases by a factor of about 5.6 with increasing temperature from 4.2 K to 294 K, and this factor is smaller than those values reported in bulk GaAs devices. This result suggests that the spin-valve signal in a 2DEG device is less sensitive to temperature than that in a bulk device, which is promising for realizing future spin transistors that can operate at room temperature. [ABSTRACT FROM AUTHOR]

Source-based calibration methods used for photon attenuation and coincidence summing corrections are time consuming and require multiple certified standards that match sample geometry with varying densities. Three programs which are capable of simulating a variety of sample geometries, matrix compositions, and sample densities have been examined as alternatives. LabSOCS, ANGLE 3 and GESPECOR are effective at generating efficiency curves for food matrices with a range with different densities. The curves generated have been successfully used to determine activity in food samples. [ABSTRACT FROM AUTHOR]

Pu isotopes in various foods were detected using a quadrupole ICPMS and Aridus II desolvation nebulizer. The method has ability to detect 239 Pu and 240 Pu at concentrations of ~52 pg/kg (0.12 Bq/kg) and ~9.5 pg/kg (0.08 Bq/kg) as well as 240 Pu/ 239 Pu ratio in <8 h after receiving the samples. Foods were wet-ashed followed by DGA extraction for eliminating matrix, isobaric, and polyatomic interferences. A UH + formation rate <10 −5 and a 5-fold enhanced sensitivity for Pu was achieved after system optimization. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a practical radioanalytical method suitable for screening for beta- and alpha-emitting radioactive contamination in a large number and wide variety of foods in the event of a nuclear or radiological emergency. Simple and rapid solid-phase extraction was used to overcome matrix and radiometric interferences that occurred during food analysis. Benefiting from discriminative liquid scintillation counting, simultaneous detection of alpha and beta radioactivity was achieved with negligible quench effects and ~95 % counting efficiencies. Method limits of detection were ~0.06 Bq/kg for alpha and ~0.4 Bq/kg for beta radioactivity and the results were within ±20 % of the known values. [ABSTRACT FROM AUTHOR]

• A self-centering brace with controllable initial stiffness is proposed. • The frame with different parameters of braces along with the intensity is considered. • Proposed acceleration assessment method is applicable to most structures. • Less initial stiffness of self-centering brace reduces the severe floor acceleration. • Self-centering and buckling restraint braced frame dissipate similar seismic energy. The self-centering brace (SCB) generally exhibits higher initial stiffness than the buckling-restrained brace (BRB), which has great effects on structural performance. In this work, a stiffness control SCB (S-SCB) is proposed to overcome the difficult adjustment of the initial stiffness of the existing SCB. Via the simulation of the S-SCB, it is found that a higher initial stiffness increases the energy dissipation capacity and has no influence on the residual deformation. Four 9-story S-SCB frames (S-SCBFs) with different stiffnesses are simulated, and the influences of the energy dissipation capacity and intensity on the structural response are also considered. It is found that the increase of the initial stiffness can reduce the displacement response, but the serious amplification of the peak absolute floor acceleration (PAA) appears on the middle or lower floors, namely the self-centering adverse effect (SAE). The SAE can be reduced by the lower initial stiffness, high activated stiffness, and greater energy dissipation capacity of the S-SCB. An assessment method including two indices is proposed to describe the degree of acceleration amplification and the floor distribution characteristics. The indices of the S-SCBF are found to exhibit significantly different characteristics from those of the BRB frame (BRBF) and the moment-resisting frame (MRF). The maximum PAA of the S-SCBF is found to be 1.5 times less than that of the BRBF with the same skeleton curve. The feasibility of the acceleration assessment method is verified by a set of frames with 4-, 8-, and 16-story. [ABSTRACT FROM AUTHOR]

[Objectives] To provide a theoretical basis for the establishment of the best suitable nitrogen application forms and proportion in the cultivation of Isatis indigotica Fort., the effect on the dry matter, apparent quality and photosynthesis of I. indigotica was explored. [ Methods] Field experiment was going to analyze the growth, chlorophyll content and photosynthetie parameters of I indigotica from five different areas by using seven nitrogen treatment with three repeats, which were nitrogen control, N0-3-N,NH+4-N, NH+4-N/NO-3-N = 75/25,NH+4-N/N0-3-N = 50/50, NH+4-N/NO-3-N = 25/75 and CO ( NH2 )2, respectively. [Results] I. indigotica from Shaanxi Shangluo in ammonium nitrate mixed fertilizer( NH+4-N/NO-3-N = 75/25 and NH+4-N/NO-3-N = 50/50) ,grew well; While the group from Gansu Zhangye in the ammonium nitrogen and amide nitrogen processing conditions, underground biomass and total biomass had a larger accumulation. The treatment of amide nitrogen could improve the dry weight of roots of Anhui Bozhou, Gansu Zhangye, Anhui Fuyang and Shanxi Yuncheng. The main root diameter and the number of lateral root in the group of Gansu Zhangye and Shaanxi Shangluo all reached maximum in NH+4-N/NO-3-N = 25/75 and NH+4-N/NO-3-N = 50/50, respectively. Nitrogen treatment could effectively improve the chlorophyll content of I, indigotica, especially the Anhui Fuyang with nitrate nitrogen. Meanwhile, nitrogen treatment was also beneficial to improving its photosynthetie rate, stomatal conductance, transpiration rate and intercellular CO2 concentration, which significantly affected on the I. indigotica from Shaanxi Shangluo. [Conclusions] These results indicated that there are many differences between the response of nitrogen treatment in different areas. Therefore we could improve the yield of the I. indigotica by applying suitable nitrogen forms and proportions according to the different responses to nitrogen forms and proportion in different areas. [ABSTRACT FROM AUTHOR]

The threat to global security from terrorist attack does not solely arise from illicit use of firearms, explosives or weapons of mass destruction. Terrorist threats will inevitably become more subtle as information and expertise is acquired by terrorist groups, and one vulnerable area is food and the food supply chain. Many laboratories, especially in countries with nuclear programmes, are involved in the routine monitoring of foodstuffs, and will be required to respond with increased food monitoring necessary for ensuring food safety and protecting public health after real (or perceived) contamination of food by either accidental or illicit means. This paper examines the needs for reference and performance testing materials that were identified at an international workshop to discuss this matter held at NIST in 2008, and further refined at a follow-up workshop in 2009. [ABSTRACT FROM AUTHOR]

A pre-pressed spring self-centering energy dissipation (PS-SCED) bracing system has significant energy dissipation and re-centering abilities, although many welds result in a lengthy manufacturing process and reduce the machining accuracy to an unacceptable level. An assembled pre-pressed spring self-centering energy dissipation (A-PS-SCED) bracing system that uses disc spring groups to provide a re-centering ability and a friction device to dissipate energy, is presented in this paper to simplify production and maintenance. A novel force method-based (FMB) hysteretic analysis model governing the distribution of the internal force is proposed and verified by a numerical model of the A-PS-SCED brace and tests of the PS-SCED brace specimen. The simulation results indicate that the A-PS-SCED brace exhibits sufficient and steady energy dissipation and re-centering capacities. The FMB model agrees well with the numerical model with a maximum bearing force difference of 2% and has steady hysteretic responses under random excitations. The FMB model is used to determine the mechanisms of the stiffness and contact status change during a typical loading process. Additionally, the FMB model accurately predicts the cyclic loading test results of an existing PS-SCED brace specimen, and the average bearing force differences are 6% and 2% at friction force of 200 kN and 300 kN, respectively. [Display omitted] • An assembly bracing system that is easy to repair after earthquake is proposed. • A force method based (FMB) model is proposed to predict hysteretic response of braces. • Mechanisms of stiffness and contact status change during loading process are revealed in detail. • FMB model can effectively predict test results of self-centering bracing specimen. [ABSTRACT FROM AUTHOR]

Measurement capability and data comparability are essential for emergency response when analytical data from cooperative laboratories are used for risk assessment and post incident decision making. In this study, the current capability of food emergency response laboratories for the analysis of 210Po in water was evaluated using a proficiency test scheme in compliance with ISO-43 and ILAC G13 guidelines, which comprises a test sample preparation and verification protocol and an insightful statistical data evaluation. The results of performance evaluations on relative bias, value trueness, precision, false positive detection, minimum detection limit, and limit of quantification, are presented. [ABSTRACT FROM AUTHOR]

• A concise and efficient dual-interface passivation strategy was developed with mixed cations at the both interfaces. • Inverted PSC exhibits a peak PCE of 24.20 %. Compared to the control of 21.78 %, An ∼ 11.11 % enhancement is achieved. • After 1440 h of 60 °C and 35 % RH, the PCE still retains an impressive 75.3 % of the initial performance. • The device shows a remarkable improvement of stability (21.2%) compared to the control one (62.1%). The interfacial modification is crucial for achieving high efficiency and stability in perovskite solar cells (PSCs). Here, we have developed a concise and efficient dual-interface passivation strategy by incorporating mixed cations of phenylethylammonium iodide and methylammonium iodide (PEAI and MAI, denoted as PMI) at both the interfaces of the electron and hole transport layers (HTL). The buried interface enhances HTL wettability and improves perovskite crystallinity, thereby enhancing its performance. Simultaneously, modifying the top surface of the perovskite effectively reduces defects and nonradiative recombination losses. As a result, inverted PSCs exhibit improved V OC , J SC , and FF, leading to a peak PCE of 24.20 %. Compared to the control device (PCE max = 21.78 %), there is an ∼ 11.11 % enhancement in PCE. Importantly, the passivated PMI-based devices demonstrate exceptional stability even under harsh conditions of 60 °C and 35 % RH. After 1440 h, their PCE retains an impressive 75.3 % of the initial performance, showcasing a remarkable improvement of 21.2 % compared to the control devices (62.1 %). The observed stability exceeds previous studies on PTAA-based inverted PSCs. [ABSTRACT FROM AUTHOR]

A stable solid‐electrolyte interphase (SEI) is crucial for cycling reversibility of Na‐ion batteries by mitigating continuous side reactions. So far, the severe SEI dissolution leads to low Coulombic efficiency (CE) and short cycle life. Meanwhile, the quantified relationship between SEI components and their solubility remains unclear. In this work, we establish the direct correlation between SEI components and SEI solubility, and quantify that the solubility of organic‐rich SEI is 3.26 times of inorganic‐rich SEI. We further propose a feasible strategy to preform inorganic‐rich insoluble SEI and demonstrate a practical hard carbon (HC)||NaMn0.33Fe0.33Ni0.33O2 full cell in a commercial electrolyte of 1 M NaPF6 in propylene carbonate (PC) with 80.0 % capacity retention for 900 cycles, and achieve a record‐high average CE of 99.95 % for a practical Na‐ion full cell. This study provides an effective strategy of preforming insoluble SEI to suppress its dissolution towards highly reversible Na‐ion batteries. [ABSTRACT FROM AUTHOR]