Improvement strategy on thermophysical properties of A_(2)B_(2)O_(7)-type rare earth zirconates for thermal barrier coatings applications:A review

The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced thermal conductivity in contrast with the currently used yttria-partially stabilized zirconia (YSZ) in high operating temperature environments.This review summarizes the recent progress on rare earth zirconates for TBCs that insulate high-temperature gas from hot-section components in gas turbines.Based on the first principles,molecular dynamics,and new data-driven calculation approaches,doping and high-entropy strategies have now been adopted in advanced TBC materials design.In this paper,the solid-state heat transfer mechanism of TBCs is explained from two aspects,including heat conduction over the full operating temperature range and thermal radiation at medium and high temperature.This paper also provides new insights into design considerations of adaptive TBC materials,and the challenges and potential breakthroughs are further highlighted for extreme environmental applications.Strategies for improving thermophysical performance are proposed in two approaches:defect engineering and material compositing.

用于构建纳米机器的偶氮苯-β-环糊精包合物——第51届国际化学奥林匹克试题第5题解析

详细分析并解答了第51届国际化学奥林匹克试题第5题。本题以纳米机器为切入点,考察了偶氮化合物的基本性质,以及朗伯-比尔定律、化学平衡、化学动力学等知识的实际运用。

Multicenter phaseⅡstudy of apatinib single or combination therapy in HER2-negative breast cancer involving chest wall metastasis

Objective:Breast cancer(BC)with chest wall metastasis(CWM)usually shows rich neovascularization.This trial explored the clinical effect of apatinib on human epidermal growth factor receptor 2(HER2)-negative advanced BC involving CWM.Methods:This trial involved four centers in China and was conducted from September 2016 to March 2020.Patients received apatinib 500 mg/d[either alone or with endocrine therapy if hormone receptor-positive(HR+)]until disease progression or unacceptable toxicity.Progression-free survival(PFS)was the primary endpoint.Results:We evaluated 26 patients for efficacy.The median PFS(mPFS)and median overall survival(mOS)were4.9[range:2.0-28.5;95%confidence interval(95%CI):2.1-8.3]months and 18(range:3-55;95%CI:12.9-23.1)months,respectively.The objective response rate(ORR)was 42.3%(11/26),and the disease-control rate was76.9%(20/26).In the subgroup analysis,HR+patients compared with HR-negative patients had significantly improved mPFS of 7.0(95%CI:2.2-11.8)months vs.2.3(95%CI:1.2-3.4)months,respectively(P=0.001);and mPFS in patients without or with chest wall radiotherapy was 6.4(95%CI:1.6-19.5)months vs.3.0(95%CI:1.3-4.6)months,respectively(P=0.041).In the multivariate analysis,HR+status was the only independent predictive factor for favorable PFS(P=0.014).Conclusions:Apatinib was highly effective for BC patients with CWM,especially when combined with endocrine therapy.PFS improved significantly in patients with HR+status who did not receive chest wall radiotherapy.However,adverse events were serious and should be carefully monitored from the beginning of apatinib treatment.

Phase Relations in TiAl+Nb System

The microstructures and phases of ternary TiAl+Nb alloys containing 50-60 at.-%Al, 0-21 at.-%Nb have been studied using transmission electron microscopy (TEM) and X-ray powder diffraction. The phases present in the alloys and their distribution were found to be a sensitive function of composition. The phase relations between γ-TiAl and γ1 (a new ordered ternary intermetallic compound based on γ-TiAl) were determined. Essentially single γ phase was determined for alloys with relativety low Nb content (≤10 at.-%Nb). the γ1 phase was determined to exist in the composition range containing higher Nb contents (15-21 at.-%Nb). Between γ and γ1 phases, with intermediate Nb contents there is a transitional phase γ1 (a superstructure of γ-TiAl). As for the influence of Al concentration on the phase relations. the γ1 phase was inclined to form in the alloys with relatively high Al contents. The ordering transformation of γ, to γ1 is a continuous ordering process and the transition may be second order.

Mechanical Properties of Interface between U-0.75Ti Alloy and TiC

The microhardness and modulus changes of the interface between U-0.75Ti alloy and TiC before andafter heat treatment were studied by SEM and Nano Indenter II, and the results show that the hardness and modulusof the interface are greatly increased after 820℃, 2 h water quenching and 450℃, 6 h aging. This result probablycomes from much more U2Ti and U6Ni precipitates along the interface.

Molecular dynamics simulation of Ni_3Al melting

With the Voter-Chen version of embedded-atom model （EAM） potential and molecular dynamics, the melting of Ni3Al alloy was simulated by one-phase （conventional） and two-phase approaches. It is shown that the simulated melting point is dependent on the potential and the simulation method. The structures of the melts obtained by different simulation methods were analyzed by the pair correlation function, the coordination number, and the distribution of atom pair type （indexed by the Honeycutt-Andersen pair analysis technique）. The results show that the structures are very similar.

Densification behavior of high Nb containing TiAl alloys through reactive hot pressing

Densification behavior of high Nb containing TiAl alloys through reactive hot pressing was investigated. The results showed that the density of the sample hot pressed at 1400°C could reach a near full density of 98.37%. However, the densification abnormality was observed at 1500°C. The diffusion of elemental Nb during microstructural evolution is an important aspect affecting densification, which will form pore nests. With the increase of hot pressing temperature, the diffusion of Nb becomes more adequate. HIP （Hot isostatic pressing） treatment can only decrease porosity to some extent, but cannot eliminate it completely.

Crystallization of Pd_40Cu_30Ni_10P_20 bulk metallic glass with and without pressure

The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal CuaPd-like, rhombohedral, fcc-Ni2Pd2P, fcc-（Ni, Pd） solid solution, and body-centered tetragonal （bct） NiaP-like phases. The onset crystallization temperature increases with pressure having a slope of 1 1 K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure.

肛管直肠黑色素瘤10例临床分析并文献复习

目的探讨肛管直肠恶性黑色素瘤(ARMM)的临床病理特征及诊治方法。方法回顾性分析苏州大学附属第一医院2011~2021年间收治的ARMM10例并结合文献复习,对其临床资料、病理特点、治疗结果和预后情况进行探讨并总结诊治经验。结果10例ARMM患者中,男性4例,女性6例;年龄50~79岁,平均发病年龄(61.4±7.6)岁。患者临床表现多样,但以便血为主,缺乏特异性,所有患者术前行CEA,CA19-9定量检测结果均正常;10例患者中,9例行免疫组化染色,其中主要指标有S-100、HBM、MelanA、Ki-67,9例患者S-100均为阳性;HBM8例阳性;MelanA除4例未查外,4例阳性,1例阴性。9例患者Ki-67均为阳性,其中5例阳性区>50%。6例接受腹会阴联合肿瘤切除术(Miles术),4例接受经肛门直肠肿物切除术;5例术后接受综合治疗,1例术后因泌尿系转移行尿道切除术,4例术后未行辅助治疗。患者总体生存期5.5个月~108个月,平均生存(30.6±29.5)个月,中位生存期28.0个月。结论ARMM是一种临床上罕见且恶性程度极高的恶性肿瘤,临床表现不典型,主要通过病理活检来确诊,对于确诊患者行腹会阴联合切除是主要的手术方式,术后可以辅助放化疗和免疫治疗。

PRECONDITIONED HSS-LIKE ITERATIVE METHOD FOR SADDLE POINT PROBLEMS

A new HSS-like iterative method is first proposed based on HSS-like splitting of non- Hermitian （1,1） block for solving saddle point problems. The convergence analysis for the new method is given. Meanwhile, we consider the solution of saddle point systems by preconditioned Krylov subspaee method and discuss some spectral properties of the preconditioned saddle point matrices. Numerical experiments are given to validate the performances of the preconditioners.

A parallel computing framework for big data

大数据在研究和申请收到了大注意。然而，大多数当前的努力集中于系统和应用程序处理卷和速度的挑战，并且不很在理论基础上并且到被做了处理变化的挑战。基于公制空间的索引和 computationalcomplexity 理论，我们为大数据建议一个并行计算框架。这个框架由三个部件组成，即，由提炼各种各样的数据类型直到公制的空格的大数据的通用表示，与 NC 班计算理论在大数据的公制的空格，和并行计算基于对明智的距离大数据划分。

Sensitizing effect of Nd^(3+) on Tb^(3+) activated ZrP_(2)O_(7) long persistent phosphor materials

The long persistent phosphors of Zr_(0.97)P_(2)O_(7):0.018 Tb^(3+),0.012 Nd^(3+)with Nd^(3+)as sensitized ions and Tb^(3+)as emission centers were synthesized using high temperature solid state reaction.The crystal structure and defects,excitation and emission spectra,decay curves and thermoluminescence(TL) curves of the phosphors were investigated.The synthesized Zr_(0.97)P_(2)O_(7):0.018 Tb^(3+),0.012 Nd^(3+)is essentially in line with the standard card PDF#49-1079.The emission band with main peak at 548 nm exhibits the characteristic transitions of ^(5)D_(3)-^(7)F_(j)(j=5,4) and ^(5)D_(3)-^(7)F_(j)(j=6,5,4,3) of Tb^(3+).The analysis of excitation and emission spectra shows that there exists the overlap between the emission peaks of Nd^(3+)at 466 and 485 nm and the excitation of Tb^(3+)at 443 and 485 nm,and the energy transfer from Nd^(3+)to Tb^(3+)plays an important role in the improvement of luminescence properties.The decay curves shows that Zr_(0.97)P_(2)O_(7):0.018 Tb^(3+),0.012 Nd^(3+)has longer afterglow time than ZrP_(2)O_(7) and Zr_(0.982)P_(2)O_(7):0.018 Tb^(3+).Additionally,the TL curves indicate that the trap depth at 0.72 eV in Zr_(0.97)P_(2)O_(7):0.018 Tb^(3+),0.012 Nd^(3+)is to the benefit of the afterglow time.The possible luminescence mechanism of ZrP_(2)O_(7):Tb^(3+),Nd^(3+)is proposed on the basis of the XPS spectra,EPR spectra,excitation and emission spectra,decay curves,TL curves and the analysis of defect equations.

Structure-guided discovery of potent and oral soluble epoxide hydrolase inhibitors for the treatment of neuropathic pain

Soluble epoxide hydrolase(sEH) is related to arachidonic acid cascade and is over-expressed in a variety of diseases, making sEH an attractive target for the treatment of pain as well as inflammatory-related diseases. A new series of memantyl urea derivatives as potent sEH inhibitors was obtained using our previous reported compound 4 as lead compound. A preferential modification of piperidinyl to 3-carbamoyl piperidinyl was identified for this series via structure-based rational drug design. Compound A20 exhibited moderate percentage plasma protein binding(88.6%) and better metabolic stability in vitro. After oral administration, the bioavailability of A20 was 28.6%. Acute toxicity test showed that A20 was well tolerated and there was no adverse event encountered at dose of 6.0 g/kg. Inhibitor A20 also displayed robust analgesic effect in vivo and dose-dependently attenuated neuropathic pain in rat model induced by spared nerve injury, which was better than gabapentin and sEH inhibitor(±)-EC-5026. In one word, the oral administration of A20 significantly alleviated pain and improved the health status of the rats, demonstrating that A20 was a promising candidate to be further evaluated for the treatment of neuropathic pain.

Self-aligned fiber-based dual-beam source for STED nanolithography

A fiber-based source that can be exploited in a stimulated emission depletion(STED) inspired nanolithography setup is presented.Such a source maintains the excitation beam pulse, generates a ring-shaped depletion beam, and automatically realizes dual-beam coaxial alignment that is critical for two beam nanolithography.The mode conversion of the depletion beam is realized by using a customized vortex fiber, which converts the Gaussian beam into a donut-shaped azimuthally polarized beam.The pulse width and repetition frequency of the excitation beam remain unchanged, and its polarization states can be controlled.According to the simulated point spread function of each beam in the focal region, the full width at half-maximum of the effective spot size in STED nanofabrication could decrease to less than 28.6 nm.

A visibly transparent radiative cooling film with self-cleaning function produced by solution processing

Daylighting structures,including solar cells and building windows,utilize sunlight whilst suffering from undesired solar heat and outdoor dust contamination.A radiative cooling system that is transparent to sunlight and has a superhydrophobic surface would cool and clean the daylighting structures in a sustainable manner.However,the majority of the current daytime radiative cooling systems were designed to fully reflect the incident sunlight to maximize the cooling power.In this work,we optimized both the sunlight transmission and infrared thermal irradiation by modeling the size-dependent scattering and absorption of light by SiO_(2)spheres embedded in a polymer matrix,we found that the use of nanospheres(20 nm)enabled both high sunlight transmittance(>90%)and infrared emissivity(-0.85).This theoretical prediction was confirmed by experimental measurements of a solution-processed nanocomposite film.When coated on a solar cell,the as-prepared film not only preserved the power conversion efficiency of the cell(14.71%,uncoated cell has an efficiency of 14.79%)but also radiatively cooled the cell by up to 5℃under direct sunlight.This reduction of the operating temperature of the solar cell further enhanced its electrical power output,evidenced by an increase in the equilibrium temperature of the LED load by about 14℃.The nanoscale textured surface formed by the nanospheres further led to superhydrophobicity and thus excellent self-cleaning performance(efficient removal of dust by wind and/or water droplets).

ON THE NONLINEAR MATRIX EQUATION Xs ＋ A＊F（X）A = Q with s ≥ 1

This work is concerned with the nonlinear matrix equation Xs ＋ A＊F（X）A = Q with s ≥ 1. Several sufficient and necessary conditions for the existence and uniqueness of the Hermitian positive semidefinite solution are derived, and perturbation bounds are presented.