Effect of cooling rate on the magnetic properties of Fe_(53)Nd_(37)Al_(10) alloy

The effect of cooling rate on the magnetic properties of the Fe53Nd37Al10 alloy prepared by different methods, i.e., suction casting and melt spinning at different rates, was investigated. The Fe53Nd37Al10 ribbon at the wheel speed of 5 m.s-1 exhibits the highest coercivity in the samples. Two hard magnetic phases are detected from the hysteresis loops of the 5 m.s-1 ribbon at all temperatures below room temperature. Their appearance is associated with different exchange coupling interactions, which are between the two kinds of hard magnetic phases or between the hard magnetic phase and the soft magnetic phase.

Growth,optical dispersion and magnetic behavior of Dy^(3+) doped yttrium iron garnet crystals

Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.

环硅氧烷阴离子开环均聚及共聚研究进展

聚硅氧烷是一类典型的有机/无机杂化聚合物,具有耐高低温、优异的环境适应性等突出性能,在航空航天、国防科技等领域应用广泛.环硅氧烷单体阴离子开环聚合是制备不同链结构及功能化聚硅氧烷的重要途径,也是推动有机硅聚合物发展的重要研究领域之一.本文以阴离子开环聚合制备聚硅氧烷所涉及的环硅氧烷单体为线索,梳理了与不同化学结构环硅氧烷单体均聚及共聚相匹配的引发体系、聚合条件,以及聚合产物状态,并对相关研究工作做了论述介绍.此外,本文基于此线索对代表性研究体系做了简明罗列,便于高效检索及整体对比认知.

QAAR exploration on pesticides with high solubility:An investigation on sulfonylurea herbicide dimers formed through π–π stacking interactions

Bioactive compounds could form aggregates that influence the bio-interactive processes. In this letter, based on π-π stacking models, quantitative aggregation-activity relationship （QAAR） studies were carried out on a series of sulfonylurea herbicides with good solubility. Four QAAR/QSAR models were constructed, which indicated that the bioactivity may strongly depend on both the characters of the dimeric aggregates and the monomer, The QAAR approach based on dimer-aggregates was also applicable for the highly water-soluble sulfonylurea herbicides that can form π-π stacking interactions. It was expected that the QAAR studies based on molecular aggregation state would be applied to other pesticide systems.

Comparison and Correlation of Magnetic Resonance Imaging and Clinical Severity in Nonhuman Immunodeficiency Virus Patients with Cryptococcal Infection of Central Nervous System

Background:The incidence of cryptococcal meningitis among immunocompetent patients increases,especially in China and imaging plays an important role.The current study was to find the correlation between magnetic resonance imaging (MRI)manifestation and clinical severity in nonhuman immunodeficiency virus patients with cryptococcal infection of central nervous system (CNS). Methods:A total of 65 patients with CNS cryptococcal infection from August 2014 to October 2016 were retrospectively included in this study.All the patients had MRI data and clinical data.The patients were divided into two groups according to whether the patients were confirmed with identifiable underlying disease.Comparison and correlation of MRI and clinical data in both groups were investigated using independent sample t-test,Chi-square test,Mann-Whitney test and Spearman rank correlation analysis. Results:In all 65 patients,41 cases (41/65,63.1%;Group 1)had normal immunity and 24 cases (24/65,36.9%;Group 2)had at least one identifiable underlying disease.Fever,higher percentage of neutrophil (NEUT)in white blood cell (WBC),and increased cell number of cerebral spinal fluid (CSF)were much common in patients with underlying disease (Group 1 vs.Group 2:Fever:21/41 vs.21/24,x^2 =8.715,P =0.003;NEUT in WBC:73.15%vs.79.60%,Z=-2.370,P =0.018;cell number of CSF:19 vs.200,Z=-4.298,P <0.001;respectively).Compared to the patients with normal immunity,the lesions are more common in the basal ganglia among patients with identifiable underlying disease (Group 1 vs.Group 2:20/41 vs.20/24,x^2 =7.636,P =0.006).The number of the involved brain areas in patients with identifiable underlying disease were well correlated with the number of cells and pressure of CSF (r =-0.472,P =0.031,r =0.779,P =0.039;respectively). Conclusions:With the increased number of the involved brain areas in patients with identifiable underlying disease,the body has lower immunity against the organism which might result in higher intracranial pressure and more severe clinical status.

Decoy-state method for quantum-key-distribution-based quantum private query

The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.

Correlation Between Microstructure and Corrosion Behavior of Two 90Cu10Ni Alloy Tubes

Two kinds of 90Cu10 Ni tubes with different service lives（more than 3 years and only 1 year,respectively）under identical working conditions were studied by an immersion test in a 3.5 wt% NaCl solution and the electron backscattered diffraction（EBSD） technique.The morphology after immersion showed severer corrosion attack at the grain boundaries of the tube with shorter service life compared with the tube with longer service life.The grain boundary characterization distributions（GBCDs） of the two tubes obtained by EBSD revealed more Σ3 boundaries and twins,and larger random boundary meshes in the tube with longer service life.A short immersion test in a modified Livingston＇s solution was conducted to evaluate the tendency to corrosion attack of different types of the grain boundaries.SEM and AFM were used to characterize the corrosion morphologies of the boundaries.A strong correlation between varying depths of corrosion grooves and types of the grain boundaries was obtained.The influence of deviation angle of low Σ boundaries on corrosion resistance of the grain boundaries was also discussed.It is concluded that a special ‘‘grain boundary engineering＇＇（GBE） treatment has been performed on the tube with longer service life.It is proposed that the optimized GBCD is responsible for the better service performance of the tube.

Mid-infrared active metasurface based on Si/VO_(2) hybrid meta-atoms

Active metasurfaces whose optical properties can be tuned by an external stimulus have attracted great research interest recently. Introduction of VO_(2)phase change material in all-dielectric metasurfaces has been demonstrated to modulate the resonance wavelength and amplitude in the visible to near-infrared wavelength range. In this study, we report a mid-infrared active metasurface based on Si∕VO_(2)hybrid meta-atoms. By incorporating VO_(2)thin films in different locations of Si∕VO_(2)all-dielectric nanodisks, we demonstrate different modulation amplitude of the electric or magnetic resonance scattering cross sections, leading to drastically different transmission spectrum upon VO_(2)insulator to metal phase transition. The physical mechanism is originated from the field profiles of the resonance modes, which interact with VO_(2)differently depending on its locations. Based on this mechanism, we experimentally demonstrated a large modulation of the transmittance from 82% to 28% at the 4.6 μm wavelength. Our work demonstrates a promising potential of VO_(2)-based active all-dielectric metasurface for mid-infrared photonic applications such as infrared camouflage, chemical/biomedical sensing, optical neuromorphic computing, and multispectral imaging.

Prognostic nomogram incorporating radiological features for predicting overall survival in patients with AIDS-related non-Hodgkin lymphoma

Background: Acquired immune deficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) is a high-risk factor for morbidity and mortality in patients with AIDS. This study aimed to determine the prognostic factors associated with overall survival (OS) and to develop a prognostic nomogram incorporating computed tomography imaging features in patients with acquired immune deficiency syndrome-related non-Hodgkin lymphoma (AR-NHL).Methods: A total of 121 AR-NHL patients between July 2012 and November 2019 were retrospectively reviewed. Clinical and radiological independent predictors of OS were confirmed using multivariable Cox analysis. A prognostic nomogram was constructed based on the above clinical and radiological factors and then provided optimum accuracy in predicting OS. The predictive accuracy of the nomogram was determined by Harrell C-statistic. Kaplan-Meier survival analysis was used to determine median OS. The prognostic value of adjuvant therapy was evaluated in different subgroups.Results: In the multivariate Cox regression analysis, involvement of mediastinal or hilar lymph nodes, liver, necrosis in the lesions, the treatment with chemotherapy, and the CD4 ≤100 cells/μL were independent risk factors for poor OS (allP < 0.050). The predictive nomogram based on Cox regression has good discrimination (Harrell C-index = 0.716) and good calibration (Hosmer-Lemeshow test,P = 0.620) in high- and low-risk groups. Only patients in the high-risk group who received adjuvant chemotherapy had a significantly better survival outcome.Conclusion: A survival-predicting nomogram was developed in this study, which was effective in assessing the survival outcomes of patients with AR-NHL. Notably, decision-making of chemotherapy regimens and more frequent follow-up should be considered in the high-risk group determined by this model.

Computational Investigations about the Effects of Heteromolecular Aggregation on Bioactivities:a Case of Neonicotinoids and Water

Molecular aggregation state of bioactive compounds plays a key role in bio-interactive procedure.Diverse ag-gregation states of bioactive compounds contribute to different biological or chemical properties.Water-bridge,as the simple hetero-molecular aggregation,has been found bridging the binding between many bioactive compounds and their targets through hydrogen bonding network,e.g.in the recognition of neonicotinoids with insect nAChRs.To better understanding the roles of water-bridge on bioactivities of compounds,an approach of hetero-dimeric ag-gregation with water was proposed.Quantitative structure-activity relationship(QSAR)and pharmacophore mod-eling investigations were applied on 19 neonicotinoids,as well as their aggregates with water.The aggregate-based CoMSIA,PHASE and linear QSAR models presented better statistical significance and predictabilities than the monomer ones,which indicated that the bioactivities correlated with the aggregate properties and water bridged hy-drogen bond of the active site.All results revealed the essential roles of water-bridge in ligand recognition,which should be considered in future ligand design and optimization.

Simplified Programming Design Based on Automatic Test System of Aeroengine

Aeroengine is a highly complex and repairable multi-component system,and operates over a long time under the harsh conditions of high temperature,high pressure,high speed and high load,and any faults threatening the safety of the aircraft.Based on this,through the in-depth analysis of several common automatic fault detection methods used in aeroengines,an automatic test system based on association rules mining technology is proposed to realize automatic test of aeroengine fault.The system used association rule mining algorithm to deal with the database with a large amount of data.By improving the algorithm,the algorithm can reduce the size of the database and the number of programming.The test results show that the hardware design of the automatic test system is reasonable,the signal acquisition is accurate and the error can meet the requirements;the design of the fault detection process is applicable,the search algorithm is fast and accurate,the speed of detection is about twice as high as possible,and the service life of the engine is saved.