Over-the-Air Testing for Dual-Polarized MIMO Devices: Setup Design and Validation

Over-the-air(OTA)testing is considered as the only feasible solution to evaluate radio performances of the fifth-generation(5G)wireless devices which feature two important technologies,i.e.,massive multiple-input multiple-output(MIMO)and millimeter-wave(mmWave).The multi-probe anechoic chamber(MPAC)based OTA setup is able to emulate realistic multipath propagation conditions in a controlled manner.This paper investigates an MPAC OTA setup which is capable of evaluating the performances of 5G base stations as the devices-under-test(DUTs)which are equipped with dual-polarized antennas.Both end-to-end setup and probe configuration for the considered MPAC setup will be elaborated.Furthermore,since building a practical MPAC setup is expensive,time-consuming,and error-prone,an endto-end software testbed is established for validation purpose to avoid technical risks before finalizing an MPAC setup.The architecture of the testbed is presented,which can emulate both the channel profiles perceived by the DUT and the physical-layer behaviors of the considered link conforming to 5G new radio(NR)specifications.Results show that the performances under the emulated channel agree well with those under the target channel,validating the accuracy and effectiveness of the MPAC method.

Spatio-temporal pattern and changes of evapotranspiration in arid Central Asia and Xinjiang of China

Accurate inversion of land surface evapotranspiration (ET) in arid areas is of great significance for understanding global eco-hydrological process and exploring the spatio-temporal variation and ecological response of water resources.It is also important in the functional evaluation of regional water cycle and water balance,as well as the rational allocation and management of water resources.This study,based on model validation analysis at varied scales in five Central Asian countries and China's Xinjiang,developed an appropriate approach for ET inversion in arid lands.The actual ET during growing seasons of the study area was defined,and the changes in water participating in evaporation in regional water cycle were then educed.The results show the simulation error of SEBS (Surface Energy Balance System) model under cloud amount consideration was 1.34% at 30-m spatial scale,2.75% at 1-km spatial scale and 6.37% at 4-km spatial scale.ET inversion for 1980-2007 applying SEBS model in the study area indicates:(1) the evaporation depth (May-September) by land types descends in the order of waters (660.24 mm) > cultivated land (464.66 mm) > woodland (388.44 mm) > urbanized land (168.16 mm) > grassland (160.48 mm) > unused land (83.08 mm);and (2) ET during the 2005 growing season in Xinjiang and Central Asia was 2,168.68×10 8 m 3 (with an evaporation/precipitation ratio of 1.05) and 9,741.03×10 8 m 3 (with an evaporation/precipitation ratio of 1.4),respectively.The results unveiled the spatio-temporal variation rules of ET process in arid areas,providing a reference for further research on the water cycle and water balance in similar arid regions.

Evaluation of the ischemic risk in triple-vessel artery patients undergoing stent implantation

Objective Coronary artery disease(CAD) is a global problem.Every year, there was millions of patients suffered from CAD. With the fast development of coronary revascularization therapy, the mortality has decreased dramatically, while there still some forts needed to be conquered, such as multi-vessel coronary artery disease(MVD).

Nano-Ferric Oxide Promotes Watermelon Growth

With the rapid growing of nanotechnology, the effects of nanomaterials released into the environment on plants have drawn more and more attention. Iron is an element essential for plant growth and development. Iron is involved in chlorophyll formation;iron deficiency will cause a plant disorder known as chlorosis. However, whether iron in nano-ferric oxide can be absorbed by plants were rarely concerned. Nano-ferric oxide might promote the growth and development of plants in a suitable concentration. An experiment was designed to evaluate whether nano-ferric oxide can be used to treat chlorosis and the physiological changes of plants in nano-ferric oxide environment. Watermelon was chosen as the experimental plant. Seedlings of watermelon plants were grown in full nutrient solution without iron for 2 weeks until the leaves got yellow. Then the seedlings were treated with different concentrations of nano-ferric oxide (0, 20, 50, 100 mg/L) and 50 mmol/L of EDTA-Fe(II) for a month. The control group seedlings were still grown in full nutrient solution without any iron. Indicators such as activity of antioxidase like superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and content of malondialdehyde (MDA) and soluble protein were studied to measure the physiological effects nano-ferric oxide might have on watermelon. It was observed that the leaves reverted green. Experimental data showed that watermelon absorbed iron from nano-ferric oxide, and nano-ferric oxide promoted watermelon growth in some ways in a suitable concentration.

Initial research of cord blood leptin, adiponectin and IGF-I with fetus growth and development

Objective:In order to reveal the relationship between cord blood leptin,adiponectin and insulin-like growth factor-I(IGF-I)and the fetus growth and development,and discuss the interaction and clinical significance on fetus growth and development.Methods:The levels of cord blood leptin,adiponectin,IGF-I in 86 newborns were examined by radio immunoassay,according to gestation age and birth weight percentile relation,the objects were divided into the SGA group(n=16),the AGA group(n=41),the LGA group(n=29),meanwhile,neonatal birth weight,body length,head circumference,foot length,and placental weight were measured,and body mass index(BMI)was computed.Dependability analysis was taken.Results:The levels of cord blood leptin,adiponectin and IGF-I were as follows:LGA group>AGA group>SGA group.The level of cord blood adiponectin was positively correlated with birth weight,placental weight and BMI(p<.05).Cord blood leptin and IGF-I concentrations were positively correlated with their birth weight,body length,head circumference,foot length,placental weight and BMI,respectively(p<.01),cord blood leptin was positively correlated with adiponectin and IGF-I(p<.01).The levels of cord blood leptin and adiponectin had no statistical significance with neonatal sexuality and deliver style(p>.05);the levels of cord blood IGF-I had no statistical significance with neonatal sexuality(p>.05),but had statistical significance with deliver style(p<.05).Conclusions:Cord blood leptin,adiponectin and IGF-I played an important part in adjusting fetus growth and development as well as participating in the process of fetus growth and development,and could be regarded as one of the clinical indexes to evaluate fetus growth and development or state of nutrition.The abnormal level of cord blood leptin and IGF-I might be one of the reasons to cause intrauterine growth retardation and fetal macrosomia.

Ether chain functionalized fullerene derivatives as cathode interface materials for efficient organic solar cells

The electron transport layer (ETL)plays a crucial role on the electron injection and extraction, resulting in balanced charge transporting and reducing the interracial energy barrier.The interface compatibility and electrical contact via employing appropriate buffer layer at the surface ofhydrophobic organic active layer and hydrophilic inorganic electrode are also essential for charge collections.Herein,an ether chain functionalized fullerene derivatives [6,6]-phenyl-C61-butyricacid-(3,5-bis (2-(2-ethoxyethoxy)-ethoxy)-phenyl)-methyl ester (C60- 2EPM)was developed to modify zinc oxide (ZnO)in inverted structure organic solar cells (OSCs).The composited ZnO/Cr0-2EPM interface layer can help to overcome the low interface compatibility between ZnO and organic active layer.By introducing the C60-2EPM layer,the composited fullerene derivatives tune energy alignment and accelerated the electronic transfer,leading to increased photocurrent and power conversion efficiency (PCE)in the inverted OSCs.The PCE based on PTB7-Th: PC71BM was enhance from 8.11% on bare ZnO to 8.38% and 8.65%with increasing concentrations of 2.0and 4.0 mg/mL,respectively.The fullerene derivatives C60-2EPM was also used as a third compound in P3HT:PC61BM blend to form ternary system,the devices with addition of Cro-2EPM exhibited better values than the control device.

Highly selective electrocatalytic Cl− oxidation reaction by oxygen-modified cobalt nanoparticles immobilized carbon nanofibers for coupling with brine water remediation and H2 production

Combining the H2 production with brine remediation is regarded as a sustainable approach to achieving clean H2 energy. However, designing stable Cl− oxidation reaction (COR) electrocatalyst is the key to realize this route. Herein, a type of oxygen-modified Co nanoparticles anchored graphitic carbon nanofibers catalyst (Co/GCFs) was synthesized through a two-step strategy of adsorption and pyrolysis. The Co/GCFs-2.4 exhibits high selectivity and stability for COR at neutral electrolyte. It is worth noting that unlike the water oxidation, the chemical valence of cobalt has not changed during the COR. Further results demonstrated that the oxygen-modified Co nanoparticles provide active sites for selective COR, meanwhile, the graphitic carbon gives rise to strong catalytic stability. Thanks to the superior COR and H2 production activity of Co/GCFs-2.4, a two-electrode brine electrocatalysis system employing Co/GCFs-2.4 as both cathode and anode for H2 production exhibited robust stability, efficient and high Faraday efficiency (98%-100%). We propose that this work provides a novel strategy for designing efficient and stable catalysts with electrocatalytic COR and HER activities at neutral brine water for practically coupling with H2 production by water electrolysis and brine water remediation.

An iASPP-derived short peptide restores p53-mediated cell death in cancers with wild-type p53

Background:Inhibitor of apoptosis-stimulating protein of p53(iASPP)is an evolutionarily conserved p53 inhibitor.Mechanistically,iASPP can accelerate tumorigenesis by inhibiting the transactivation function of p53.Targeting the interaction between iASPP and p53 may be a potential therapy for restoring the activity of p53 in tumors.Methods:We constructed an iASPP-derived peptide,called A8,that was derived from the C-terminus of iASPP.Here,we transfected A8 into two wildtype(WT)p53 cell lines,U2OS and A549,and then determined the number of apoptotic cells.The mechanism by which A8 affected apoptosis was further examined by immunoprecipitation(IP),Dual-Luciferase reporter assays,and chromatin IP assays.Real-time polymerase chain reaction and western blots were also used to examine the expression levels of apoptosis-related factors.Results:Our data demonstrate that A8 can increase apoptosis rates in WT p53 cell lines.Functional analysis suggested that A8 restored the transcriptional function and DNA binding activities of p53 toward the Bax and PUMA gene promoters.Moreover,A8 reduced cell proliferation and inhibited tumor growth in xenograft nude mice.Conclusions:These data provide a new approach for restoring the tumor suppressor function of p53 in cancer cells that express WT p53 and therefore may serve as a novel cancer treatment strategy.

钠离子电池合金化负极材料研究及应用进展

钠离子电池凭借钠资源丰富、分布广泛、价格低廉的优势在大规模储能领域具有重要的应用前景,可与锂离子电池形成优势互补.负极材料是电池化学的关键组成,其能量密度、使用寿命等直接影响着电池性能.合金化材料具有理论比容量高、工作电压适宜等优势,被认为是一类有应用潜力的储钠负极.然而,这类材料发生合金化反应时体积膨胀严重,电极材料易粉化脱落,造成电化学稳定性欠佳.目前,主要通过材料微纳结构设计、界面化学调控、碳材料复合、表面包覆、电解液优化等方法来改善其电化学性能.本文综述了合金化负极材料的最新研究进展,探讨了其发展面临的瓶颈以及解决方案,介绍了基于合金化负极的钠离子全电池构筑策略和应用实例,为高性能钠离子电池的发展提供一定参考依据.

Growth mechanism of CsPbBr3 perovskite nanocrystals by a co-precipitation method in a CSTR system

A co-precipitation method based on supersaturated recrystallization in a continuous stirred-tank reactor(CSTR)system was applied to un cover the growth mecha nism of CsPbBr3 perovskite nano crystals(NCs).The reacti on rate can be controlled by changi ng the reaction conditions in this CSTR system,which helps us to observe importa nt intermediate stages to gain in sight into the growth mecha nism of these NCs.The effects of the temperature,concentrations of the ligands(oleylamine and oleic acid),and precursor concerttrations during the growth process of CsPbBr3 NCs were discussed in detail.Further,the growth mechanism of CsPbBr3 NCs was investigated in terms of the dynamics and thermodynamics on the basis of experimental results.The growth mechanism is a useful guide to large-scale synthesis.The synthesized CsPbBr3 NCs were employed for fabrication of both white light-emitting diodes and quantum-dot light-emitting diodes to test their photoelectric properties;the results show that CsPbBr3 NCs show great promise for optoelectronics applications.

近年来我国非洲教育研究成果综述及趋势展望——基于“非洲高等教育国别研究”评介

近年来,随着中非关系的全面发展,国内关于非洲教育研究的成果越来越多,浙江师范大学开展的'非洲高等教育国别研究'占据相关研究的主体。这些研究主要集中在非洲高等教育的管理体制、高等教育质量问题、性别平等问题、经费投入问题以及私立高等教育发展等方面。但目前在非洲高等教育研究方面尚存在国别的数量需扩大、研究质量需提高、研究力量需加强等关键问题。在研究视阈上,今后应更多关注在华非洲留学生、中国对非教育援助、孔子学院发展等方面的研究。

Anthraquinone acted as a catalyst for the removal of triphenylmethane dye containing tertiary amino group: Characteristics and mechanism

Herein,we found that anthraquinone(AQ)acted as a catalyst for the rapid and effective removal of triphenylmethane dye containing tertiary amino group(TDAG).Results showed that AQ had an enhanced catalytic reactivity towards the removal of TDAG compared to hydro-quinone,which was further proved and explained using density functional theory(DFT)calculations.AQs could achieve a TDAG removal efficiency and rate of approximately 100%and 0.3583 min^(−1),respectively,within 20 min.Quenching experiments and electron paramagnetic resonance(EPR)tests indicated that the superoxide radical(O_(2)^(•−))generated through the catalytic reduction of an oxygen molecule(O_(2))by AQ contributed to the effective removal of the TDAG.In addition,itwas found that the electrophilic attack of the O_(2)^(•−)radical on the TDAG was the driving force for the dye degradation process.Decreasing the pH led to protonation of the substituted group of AG,which resulted in formation of an electron deficient center in the TDAGmolecule(TDAG-EDC+)through delocalization of the π electron.Therefore,the possibility of the electrophilic attack for the dye by the negative O_(2)^(•-)radical was significantly enhanced.This study revealed that the H+and the O_(2)^(•−)generated by the catalytic reduction of O_(2) have synergistic effects that led to a significant increase in the dye removal rate and efficiency,which were higher than those obtained through persulfate oxidation.

A detailed comparison of MYD11 and MYD21 land surface temperature products in China's Mainland

Land surface temperature(LST)is a key parameter in land surface system.The National Aeronautics and Space Administration(NASA)recently released new Moderate Resolution Imaging Spectroradiometer(MODIS)LST products(MOD21 and MYD21).Here,we conducted a detailed comparison between the MYD11 and MYD21 LST data in China's Mainland.The LSTs of MYD21 were approximately 1℃ higher than those of MYD11 averaged for China's Mainland,as MYD21 corrected the cold bias of MYD11.The proportions of the valid value of MYD21 were generally lower than those of MYD11 because the cloud removal method of MYD21 was stricter than that of MYD11.Furthermore,the outliers were less significant in MYD11 than in MYD21 because the outliers in MYD11 were removed using temporal constraints on LST.The outliers in MYD21A2 resulted in a difference of greater than 3℃ in average seasonal surface urban heat island intensity(SUHII)between MYD11A2 and MYD21A2.Finally,using MYD11 may underestimate the slope of long-term trends of SUHII.MYD21 LST data may have some uncertainties in urban areas.This study provided a reference for users for selecting LST products and for data producers to further improve MODIS LST products.