The development of polymerized small-molecule acceptors (PSMAs) offers a promising route toward high-performance and stable organic solar cells (OSCs). Herein, we designed two isomeric PSMAs, PAS1 and PAS2, based on an asymmetric A1-DAD-A2 Y-shaped molecular backbone, incorporating indandione (A1) and 3-dicyanomethylene-1-indanone (A2) as distinct terminal groups. Structural isomerism has been shown to significantly influence the physical, chemical, and optoelectronic properties of the two PSMAs. Moreover, isomerism markedly influences their dielectric constants, with the PAS2-based active layer exhibiting a higher value (3.10 vs. 2.59). This enhancement reduces the charge-transfer state binding energy by approximately 16

In order to obtain naphthalimide-based polymer cathode materials with high discharge voltage, two conjugated polymers PNIT-Th and PNIT-DTh were designed and synthesized using naphthalimide-thiophene (NI-Th) or naphthalimide-dithiophene (NI-DTh) as the electrochemically active backbone and 2,2,6,6-tetramethylpiperi-dine-1-oxo radical (TEMPO) units with high redox potential as N-position substituents. As expected, the average discharge voltages of PNIT-Th and PNIT-DTh are both relatively high, at 3.12 V (vs Li/Li+) and 3.20 V (vs Li/Li+), respectively, which are higher than the N-alkyl-substituted polymer PNI-DTh (2.35 V (vs Li/Li+)). Benefiting from the electroactive main chain and side groups, PNIT-Th and PNIT-DTh both exhibited high initial discharge specific capacities at 0.1C, with 222.2 mAh g-1 and 240.5 mAh g-1, respectively. The high discharge voltage and discharge specific capacities of the two polymers result in high energy density. At 0.1C, the specific energy densities of PNIT-Th and PNIT-DTh are 711.2 Wh kg-1 and 794.6 Wh kg-1, respectively. It is satisfactory that these two polymers also exhibit excellent long-cycle and rate performance. At 5C, the capacity retention rate remained above 90% after 4000 cycles. The experimental results indicate that polymers containing TEMPO groups are a class of potential cathode materials for lithium-ion batteries.

In this study, the creep tests of three PM Ni-based superalloys with different Zr contents were carried out at 700 °C/780 MPa, 750 °C/550 MPa and 800 °C/400 MPa, respectively. The effect of Zr on creep deformation behaviors was studied by OM, SEM, EBSD and AC-STEM. The results show that the addition of appropriate Zr (0.1 wt.

Nickel-based powder metallurgy superalloys with high W and high gamma ' content exhibit excellent high-temperature properties, but their high deformation resistance poses significant challenges for hot processing. In this study, the hot compression behaviour of an extruded nickel-based powder superalloy FGH4109 with high W (6.1%) and high gamma ' phase contents (60%) was systematically investigated at temperatures ranging from 1060 degrees C similar to 1140 degrees C, strain rates from 0.001 s(-1) similar to 1 s(-1), and maximum true strains of 0.7. Combined with the hot working map and the microstructure evolution in different hot working zones, the optimal hot working window for the alloy was determined to be in the temperature range of 1060 degrees C similar to 1140 degrees C and strain rates of 0.001 s(-1) similar to 0.012 s(-1), where the power dissipation efficiency eta was greater than 0.5, and the dominant deformation mechanism was discontinuous dynamic recrystallisation.

Benzoquinone (BQ) electrode is regarded as next generation energy storage material for lithium ion batteries (LIBs) because of its advantages of high theoretical specific capacity, abundant source, environmental friendliness. However, the two key challenges, the dissolution of BQ in organic electrolyte and the low discharge plateaus, impede practical application of BQ as cathode. Here, triphenylamine (TPA) with high working voltage and BQ with high theoretical capacity are used to synthesize triphenylamine-benzoquinone monomer (TPA-BQ) and its polymer (poly triphenylamine-benzoquinone (PTPA-BQ)) as cathodes for LIBs. The charge/discharge results reveal that the discharge plateaus of TPA-BQ and PTPA-BQ increase from similar to 2.5 V to similar to 3.5 V, and PTPA-BQ exhibits high discharge capacity and remarkable cyclic stability compared with TPA-BQ. The electrochemical mechanism shows that the redox peak potential of similar to 2.3 V/similar to 2.2 V are assigned to the insertion/extraction of lithium ion in C=O groups of BQ, while at high potential of similar to 3.6 V/similar to 3.5 V corresponds to the de-dope/dope of the PF6- anion in TPA unit. The results demonstrate TPA was introduced BQ into small molecule to form PTPA-BQ polymer that can improve discharge plateaus and charge/discharge performance of BQ small molecule, which provide guides for solving the dissolution and discharge platforms of the other organic electrode materials.

The thermal stability of zeolitic imidazolate framework-8 (ZIF-8) for poly(vinyl chloride) (PVC) has received attention, but its thermal stabilization mechanism needs further clarification. Herein, the stearic acid-modified ZIF-8 with high specific surface area and large pore volume was effectively synthesized by using zinc stearate as the zinc source for the first time. Modification of stearic acid results in larger adsorption capacity of ZIF-8 for HCl and better thermal stability effect for PVC, especially long-term thermal stability. Moreover, the thermal stability mechanism of ZIF-8 for PVC was demonstrated by experiments and theoretical calculations. In addition to absorbing HCl to eliminate autocatalytic degradation of PVC, ZIF-8 disintegrates and may form 2-methylimidazole-Zn-Cl salt complex instead of free ZnCl2, avoiding the negative zinc burning effect. Furthermore, the Diels-Alder reaction between imidazole ring and degraded PVC prevents the extension of the conjugated double bonds of PVC and delays the deepening of the color of PVC.

The effect of the linking position of the oligo(ethylene oxide) segment on the electrochemical properties of naphthalimide-based polymer cathode materials was investigated. For comprehensive analysis, the influence of the alkyl segment in the main chain on the performance of the polymer was also compared. Polymers with alkyl backbone, oligo(ethylene oxide) backbone, and oligo(ethylene oxide) side chains are termed PNDIB, PNDIO, and PNIOS, respectively. The mobility of lithium ion in polymer PNDIB, PNDIO, and PNIOS electrodes was assessed via the galvanostatic intermittent titration technique (GITT). Relative to the alkyl backbone polymer PNDIB, PNIOS, and PNDIO with oligo(ethylene oxide) chains have a higher mobility of lithium ions because the ether groups are favorable for lithium ion transport. Meanwhile, polymer PNIOS has better electronic conductivity due to the advantage of a conjugated backbone for electron transport. Therefore, PNIOS has the best conductivity of the three polymers, resulting in the highest discharge specific capacity and superior cyclic and rate performance. Specifically, PNIOS delivers an initial discharge specific capacity of 162.9 mAh g-1 at 0.1C, retaining 91.4% of its capacity after 120 cycles. At a high rate of 5C, it maintains a discharge capacity of 130.5 mAh g-1 after 5000 cycles. These findings position PNIOS as a promising candidate for lithium-ion battery cathodes.

The effect of different carboxylic acid substituents on the electrochemical performance of polythiophene anode materials was discussed. In terms of cycle and rate performance, isophthalic acid substituted polythiophene (P3TBDCOOH) outperforms formic and parabenzoic acid substituted polythiophenes (P3-TCOOH and P3-TBCOOH). P3-TBDCOOH has a specific capacity of 681.1 mAh g(-1) after 100 cycles at 50 mA g(-1) and a capacity of 340.8 mAh g(-1) after 1000 cycles at 1000 mA g(-1). According to density functional theory calculations, P3-TBDCOOH and P3-TBCOOH with a benzene ring between the thiophene ring and the carboxyl group have higher conductivity than P3-TCOOH without a benzene ring, and P3-TBDCOOH shows stronger conductivity than P3TBCOOH and P3-TCOOH. The results imply that the pendant isophthalic acid can enhance the electrochemical activity of polythiophene, increasing the reversible capacity.

Nickel-based powder metallurgy（PM）superalloy FGH4107 with five varied Zr contents were prepared by the high-throughput preparation,including vacuum induction melting（VIM）,electrode induction-melting gas atomization（EIGA）,and hot isostatic pressing（as-HIPed）processes.The effects of Zr content（mass fraction 0～0.50%）on the equilibrium phases thermodynamics,kinetic behavior and γ/γ′lattice misfit degree were studied by the calculation and simulation of JMatPro 6.5 software,combined with differential scanning calorimetry（DSC）and X-ray diffraction（XRD）.The results show that in the range of 600-1 400℃,the Zr content has little effect on the types of equilibrium phases,which are mainly composed of L,γ,MC,MB 2 ,γ′,M 3 B 2 ,M 23 C 6 ,μandσphases,Zr atoms enter γ,γ′,MC and Ni 7 Zr 2 phase in turn.With the increasing of Zr content from 0 to 0.50%,the initial melting temperature is greatly reduced but the final melting temperature is slightly decreased,and the temperature range of the solid-liquid two-phase region is enlarged.However,the Zr content has little effect on the solvus temperature of the γ′phase.With the addition of Zr from 0 to 0.50%,γ′/γ lattice misfit degree increases from 0.215%to 0.265%,indicating that Zr enters γ′phase and enhances the precipitation strengthening effect.

Peryleneimide and its derivatives have excellent thermal and chemical stability and have been extensively studied as cathode materials for lithium-ion batteries. In this paper, an isophthalic acid-functionalized peryleneimide (PI-COOH) anode active material is provided, the capacity storage mechanisms of PI-COOH electrodes are explored, and the cycling performance and rate capability of PI-COOH/Li batteries are investigated. In the total capacity storage of the PI-COOH electrode, the diffusion process provides about 69%. The PI-COOH electrode exhibits good cycling stability and rate capability, with a specific capacity of 580 mAh g-1 after 100 cycles at a current density of 50 mA g-1 and a specific capacity of 286.6 mAh g-1 after 1000 cycles at a current density of 1000 mA g-1. The results suggest that PI-COOH is a potential anode material for Li-ion batteries.

蒽醌类有机材料是一类具有理论比容量大、氧化还原活性高、电化学可逆性强、结构可设计等优点的低成本、高能量密度的电极活性材料,其在储能方面表现出巨大的潜力.然而,蒽醌小分子在常用的有机电解液中易于溶解,以蒽醌为电极活性材料的二次电池存在容量易衰减、电池寿命短、电池循环可逆性低、倍率性能较差等问题.随着研究手段的进步,可以通过分子设计对其电化学性能进行调节,蒽醌类有机材料作为具有广阔应用前景的电极活性材料被广泛研究.旨在总结近年来蒽醌类有机电极材料在二次电池方面的研究进展,分析了几类典型的蒽醌类小分子化合物、聚合物以及化合物(聚合物)-复合材料的合成方法及其电化学性能,并对部分电化学反应过程机制进行分析.最后对蒽醌类有机电极材料日前面临的问题和未来的发展方向进行了总结和展望,提出可通过引入活性基团、掺杂含碳材料、优化合成路线等方法,将实验与理论计算相结合,设计出综合性能更加优异的蒽醌类有机电极材料.

本文研究了新型第四代粉末高温合金FGH4102在等温热模拟压缩过程中的组织演变,对γ'相在动态再结晶过程中的作用进行了探讨.结果 表明,热等静压态合金在1060～1120℃温度范围变形时,热加工性能较好.1140℃变形后试样容易发生开裂,合金热加工性能较差.合金在γ+γ'两相区变形时均发生了不同程度的动态再结晶,再结晶晶粒尺寸远小于热等静压态的晶粒尺寸.变形过程中,尺寸较大的γ'相起到促进动态再结晶的作用.变形参数对动态再结晶的影响非常显著.低温高应变速率变形时,γ'相促进动态再结晶形核占主导地位,再结晶晶粒比较细小;高温低应变速率变形时,晶粒长大逐渐占据主导地位,再结晶晶粒尺寸较大.

Converting small organic molecules to their lithium salts or polymerization effectively solves the capacity fading caused by the dissolution of small organic molecules in electrolytes. While polymer lithium salts have the characteristics of small molecular lithium salts and polymers and can obtain good cycle stability and rate performance. The 3-carboxylithium substituted thiophene (3-TCOOLi) and polymer (P3-TCOOLi) anode materials for lithium-ion batteries were synthesized, and their electrochemical properties were compared. Compared with the small-molecule lithium salt 3-TCOOLi electrode, the polymer P3-TCOOLi electrode exhibits superior cycling and rate performance. The P3-TCOOLi electrode still has a specific capacity of 390 mAhg(-1) after 100 cycles at a current density of 50 mAg(-1). During the rate charge and discharge process, when the current density increased to 1000 mAg(-1), the specific capacity was 305 mAh g(-1). It shows that the idea of small molecule lithium salt polymerization is feasible.

Two poly(arylamine-imide)s, poly(N,N,N′,N′-tetraphenyl-1,4-benzenediamine naphthalenediimide) (PDDP-NI) and poly(N,N,N′,N′-tetraphenyl-1,4-benzenediamine perylenediimide) (PDDP-PI), were successfully prepared by condensation polymerization of an amine monomer N,N,N′,N′-tetraphenyl-1,4-benzenediamine (DDP) with dianhydride monomer 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) or 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). The DDP units in the polymer can reversibly dope/dedope the PF 6 − anion, while the naphthalenediimide (NI) unit or perylene diimide (PI) unit can reversibly insert/extract the lithium cation. The lithium ion half-cells based on the polymer cathode and the lithium anode are assembled and the electrochemical properties are tested. Due to the high voltage of the DDP unit in the polymer backbone, lithium-ion half-cells based on PDDP-NI and PDDP-PI cathodes provide a high average discharge voltage of about 3.2 V. Moreover, the as-prepared polymer materials exhibit long-cycle performance, PDDP-NI remains 89% capacity after 500 cycles at 10 C and PDDP-PI maintains 98% capacity after 1000 cycles at 10 C, furthermore, their coulombic efficiency close to 100% at all current rates tested, which shows that these organic cathode materials have potential applications in long-cycle lithium-ion batteries.

A 3-anthraquinone substituted polythiophene (poly[3-(2-anthraquinone)-2,5-thiophene], P3-AQT)) was synthesized by chemical oxidation polymerization using FeCl3 as oxidant. The structure and thermal stability of P3-AQT were characterized by infrared spectroscopy and thermogravimetric analysis. Due to its electrochemical activity in the range of 0-3.0 V, P3-AQT can be used as an anode material for lithium-ion batteries. The P3AQT/Li batteries were assembled and their electrochemical properties were studied. P3-AQT electrodes can deliver an initial charge capacity of 791 mAh g-1 at a current density of 50 mA g-1 and show good cycle stability at high current density. When the current density is 1000 mA g-1, the initial charge specific capacity is 710 mAh g-1, and the specific capacity remains at 505 mAh g-1 after 100 cycles. The results indicate that the introduction of anthraquinone at the 3-position of polythiophene can increase the reversible capacity of polythiophene and P3-AQT is a potential anode material for lithium-ion batteries.

Conjugated polymers have been proven to be full of promising application in photoacoustic (PA) imaging. Generally, the absorption spectra of PA contrast agents lying in the near-infrared (NIR) II window are requisite to eliminate the light absorption and scattering of tissue, skin, and blood. In this concise study, strong acceptor acrylate-substituted thiadiazoloquinoxaline (ATQ) was developed and used to copolymerize with different donors, yielding three NIR II polymers. Results show that (i) ATQ-based polymers can reach an ultralow optical band gap of 0.56 eV; (ii) the ATQ-based polymer nanoparticles have good biocompatibility and high PA signal intensity with a tissue penetration depth up to 10 mm; and (iii) under NIR II laser irradiation, the signal-to-noise ratio of mouse cerebrovascular during in vivo PA imaging enhanced by 10 times after injecting ATQ-based nanoparticles. This work reveals that acrylate-substituted ATQ-based polymers, which can be easily synthesized and functionalized, extend the absorption spectra to longer wavelengths, and decrease the radiative decay rate (kr), are a promising class of NIR polymers for developing efficient PA contrast agents.

本文研究了新型镍基粉末高温合金FGH4102在750～850℃长期时效过程中γ'相的演变行为.结果 表明:合金长期时效过程中一次γ'相稳定性较好;三次γ'相主要存在于750℃及800℃,析出量达到饱和后随时效时间延长符合Ostwald熟化理论,之后逐渐溶解;二次γ''相在750℃及800℃时效过程中存在分裂导致的反粗化现象,850℃时效时二次γ'相随时效时间增加而持续长大;800℃及850℃时效后期,三次γ'相形态转变为沿<100>方向排列的方形;时效温度及时间对合金硬度的影响较大,时效后期硬度值的变化主要取决于二次γ'相尺寸的变化.

采用Gleeble-3800热模拟试验机研究了热等静压态新型第四代粉末高温合金的热变形行为,变形温度1 060～1 140℃,应变速率0.001～1 s-1,真应变量0.69.结果 表明,热等静压态合金热模拟压缩实验的高温流变曲线呈动态再结晶特征.基于双曲正弦函数型Arrhenius方程和实验数据,采用峰值应力以及应变修正两种方式构建了合金的高温流变本构方程.后者由于包含了应变量的影响,预测的合金热变形流变应力值与实际测试结果比较吻合,平均相对误差绝对值为7.875 38％,能更好的反映合金在热变形过程中的流变行为,为合金热加工工艺的设计优化提供参考依据.

本文总结了我国了21世纪初研制的高合金化γ'相沉淀强化镍基粉末高温合金FGH4097在成分设计、制备工艺、显微组织等方面的研究工作,对于进一步提高FGH4097合金涡轮盘件的材料利用率进行了展望.

Nickel-base powder metallurgy (PM) superalloys are widely used as high temperature components in gas turbine engines owing to their outstanding mechanical properties and workability under intense heat. In order to meet the performance requirements of a new generation aircraft engine with a higher thrust-weight ratio, the fourth generation PM superalloy has been studied at home and abroad. Its operating temperature has been raised to 815-850℃. The alloy in this study was a newly-designed fourth generation PM superalloy, which exhibited excellent high temperature stress rupture and creep properties compared with the previous three generations' PM superalloys, FGH4095, FGH4096, and FGH4098. Based on the performance characteristics of PM superalloys of different grain sizes, dual microstructure heat treatment (DMHT) has been used to produce a turbine disk which has a fine-grained bore and a coarse-grained rim. Therefore, it was first necessary to obtain a uniform fine-grained disk. It has been demonstrated that the fine-grained disk can be gained through hot isostatic pressing (HIP) and multi-steps of high temperature working. In order to study the influence of multiple isothermal forging (ITF) on the grain refinement of the advanced PM superalloy, three steps of ITF were employed; each deformation was about 40%. The effective strain distribution of the alloy during ITF was simulated by using the commercial finite element software DEFORM 2D. Microstructures of those forgings were investigated by means of the electron back scattered diffraction (EBSD) technique. The experimental results show that during ITF, the axial section of the forging is divided into three regions. Region Ⅰ, located in the upper and lower end faces, has the smallest deformation. Region Ⅱ is located at both sides of the section, and its deformation is larger than that of region Ⅰ. And region Ⅲ, located in the center of the section, obtains the maximal deformation. After three steps of ITF, Regions Ⅱ and Ⅲ of the forging are fully recrystallized, and equiaxed fine-grained microstructures with an average grain size of 2-3 μm are generated. Nevertheless, necklace structures form near Region Ⅰ of the forging. A great amount of fine recrystallized grains distribute around the non-equiaxed deformed grains. The deformed grains contain plenty of low-angle grain boundaries (LAGBs), which mean that the dislocation density is very high. Through proper heat treatment, the necklace structure in Region Ⅰ is refined. Meanwhile, grain growth occurs in Region Ⅱ and Ⅲ. These findings suggest that fine-grained disks with uniform microstructures can be achieved, and the average grain size is 6-8 μm.