高熵氧化物的制备及应用研究进展

高熵氧化物作为近几年发展起来的新型氧化物体系，打破了传统掺杂氧化物的设计理念，由五种及以上氧化物以等摩尔或近等摩尔构成，因其具有简单的结构和优异的性能等受到国内外研究人员的广泛关注。高熵氧化物由于多主元且主元之间混乱排列，易形成岩盐型、氟化钙型、尖晶石型或钙钛矿等固溶体结构，从而表现出优异的性能，尤其在能源存储材料和磁性材料方面有十分广阔的应用前景，但目前对高熵氧化物应用研究较少。本工作介绍了国内外高熵氧化物的制备方法，主要包括固相法、热解法、共沉淀法、水热合成法和液相燃烧合成法等，比较了各方法的优缺点和发展前景；归纳了高熵氧化物作为锂离子电极材料、巨介电材料、磁性材料和催化材料等方面的应用；指出了高熵氧化物目前研究存在的问题，讨论了解决措施，展望了高熵氧化物未来的发展趋势。     

H13钢等离子堆焊Ni60A/Cr3C2覆层的磨损及热疲劳性能

采用等离子堆焊技术在H13钢基体表面上制备了Ni60A/Cr₃C₂堆焊覆层,研究了覆层的磨损行为和热疲劳性能。在600 ℃下销盘试验的结果表明,镍基碳化铬复合覆层的耐磨性是Ni60A堆焊覆层的2.8倍和基材H13钢的11.6倍。镍基覆层可以显著降低H13钢的摩擦因数,加入碳化铬则会削弱覆层的摩擦性能。随着磨损的进行,主要磨损机理从氧化磨损演变为磨粒磨损和粘着磨损。在800 ℃到室温下的热疲劳测试结果表明,镍基碳化铬复合覆层在48个热循环后疲劳裂纹达到200 μm,早于镍基覆层的62次。这说明高温氧化促进热疲劳裂纹的产生。碳化铬增强相从镍基上剥离,导致镍基复合覆层热疲劳性能下降。     

Allosteric p97 Inhibitors Can Overcome Resistance to ATP-Competitive p97 Inhibitors for Potential Anticancer Therapy

Abstract : A major challenge of targeted cancer therapy is the selection for drug-resistant mutations in tumor cells leading to loss of treatment effectiveness. p97/VCP is central regulator of protein homeostasis and a promising anticancer target because of its vital role in cell growth and survival. One ATP-competitive p97 inhibitor, CB-5083, has entered clinical trials. Selective pressure on HCT116 cells dosed with CB-5083 identified five different resistant mutants. Identification of p97 inhibitors with different mechanisms of action would offer the potential to overcome this class of resistance mutations. Our results demonstrate that two CB-5083 resistant p97 mutants, N660 K and T688 A, were also resistant to several other ATP-competitive p97 inhibitors, whereas inhibition by two allosteric p97 inhibitors NMS-873 and UPCDC-30245 were unaffected by these mutations. We also established a CB-5083 resistant cell line that harbors a new p97 double mutation (D649 A/T688 A). While CB-5083, NMS-873, and UPCDC-30245 all effectively inhibited proliferation of the parental HCT116 cell line, NMS-873 and UPCDC-30245 were 30-fold more potent in inhibiting the CB-5083 resistant D649 A/T688 A double mutant than CB-5083. Our results suggest that allosteric p97 inhibitors are promising alternatives when resistance to ATP-competitive p97 inhibitors arises during anticancer treatment.     

Combined constant speed control method for a wind generator equipped with hydraulic energy storage

A wind generator equipped with hydraulic energy storage (WG‐HES) uses hydraulic transmission systems instead of gearbox transmissions, thus eliminating high‐power converters and reducing the tower‐top cabin weight. When there is no wind or the wind speed is extremely low, the pressured oil released by accumulators is used to drive a motor to operate at a constant speed, thereby generating constant‐frequency power. However, few studies have examined the constant speed control characteristics for generating electricity using only an accumulator group. In this study, a combined constant speed (CCS) proportional–integral–derivative (PID) control method based on “variable displacement and throttling” is proposed, which includes two closed loops and one regulating loop. First, a simulation model of the CCS PID control method for a variable motor was established in the Simcenter Amesim program. The influence of different PID parameters on the anti‐interference ability of the constant speed control of the motor was analyzed under a given load step. Then, we obtained the range of control parameter values and a set of optimal values. Second, the effectiveness of the CCS control method and the accuracy of the simulation results were verified on a 600‐kW WG‐HES system prototype. The results verified that the CCS control method has good anti‐interference ability and can meet the requirements of constant speed control for a variable motor under the best PID parameters. These results can provide a basis for developing control strategies for WG‐HESs when there is no wind or at low wind speeds.     

二层沟槽织构对机床导轨表面润滑特性的影响

通过构建二层沟槽织构模型，仿真研究沟槽织构表面的流体动力效应。结果表明：沟槽容积相同时，与单层沟槽相比，二层沟槽的平均油膜压力可以达到单层沟槽的2.31倍；保持二层沟槽的量纲一总深度[β]1、第一层沟槽量纲一宽度[α]1不变时，随着第二层量纲一深度[β]2的增大，平均油膜压力先增大后减小，[β]2为4.4时，平均油膜压力达到最大值；第二层沟槽的量纲一宽度[α]2从0.25增大到0.45时，沟槽内的旋涡区也随之增大，平均油膜压力逐渐减小。     

下荆江熊家洲至城陵矶弯曲型河段河床调整规律

三峡水库运用后, 坝下游水沙过程发生了较大调整, 对下荆江熊家洲至城陵矶弯曲型河段河床冲淤演变造成较大影响, 从而对本河段河势稳定、防洪、航运等可能造成不利的影响, 基于此, 根据最新实测资料分析水沙条件变 化及其对本河段河床调整规律的影响。研究成果显示: 三峡水库运用后, 水流含沙量大幅减小, 且水库调蓄导致熊 家洲至城陵矶河段在枯水期径流量明显增加, 使弯道主流长期偏向于凸岸, 引起凸岸边滩大幅冲刷, 这是近期该河段发生“撇弯切滩”的主要原因之一; 随着三峡上游干支流水库群陆续建成运用, 坝下游河道将会长期遭受清水冲 刷, 河床仍将呈单向冲刷下切的趋势, 弯顶段主流平面摆动仍将较大, 弯道顶冲点也将相应下移, 导致主流贴岸距离 进一步下延, 引起河道岸线的崩退, 未来一段时期内典型弯曲型河道的局部河势变化仍将明显。     

Headspace fingerprinting approach to identify the major pathway influencing volatile patterns of vinasse-cured duck processed by high pressure,as well as its impact on physicochemical and sensory attributes

As a decisive attribute, flavour could be influenced by HP treatments through multiple physical and chemical pathways within the high pressure (HP)-assisted meat curing process. This investigation aimed to identify the major pathway influencing volatile flavour patterns of two representative vinasse-cured duck (VCD) products with HP treatments (150–300 MPa/15 min), including wet and dry types, by employing headspace fingerprinting as an untargeted approach. Results suggested that HP treatments greatly lowered moisture contents and increased Warner-Bratzler shear force and thiobarbituric acid reactive substances of the cured samples. According to multivariate models, the volatile flavour patterns of the HP-processed VCD could be clearly separated from the unprocessed samples, but the VCD pressurised at different intensities represented similar volatile fingerprinting, which was validated by e-nose analysis. The discriminant analysis (OPLS-DA) model outlined vinasse-derived ethanol, acetic acid, 3-methyl-1-butanol, 2-methyl-1-butanol, phenethyl alcohol and 2-methyl-3-octanone as the major discriminant aromas across the unpressurised and pressurised samples.     

Stochastic processes in renewable power systems: From frequency domain to time domain

With the increasing penetration of renewable energy resources(RESs), the uncertainties of volatile renewable generations significantly affect the power system operation. Such uncertainties are usually modeled as stochastic variables obeying specific distributions by neglecting the temporal correlations. Conventional approaches to hedge the negative effects caused by such uncertainties are thus hard to pursue a trade-off between computation efficiency and optimality. As an alternative, the theory of stochastic process can naturally model temporal correlation in closed forms. Attracted by this feature, our research group has been conducting thorough researches in the past decade to introduce stochastic processes within renewable power systems. This paper summarizes our works from the perspective of both the frequency domain and the time domain, provides the tools for the analysis and control of power systems under a unified framework of stochastic processes, and discusses the underlying reasons that stochastic process-based approaches can perform better than conventional approaches on both computational efficiency and optimality. These work may shed a new light on the research of analysis, control and operation of renewable power systems.Finally, this paper outlooks the theoretic developments of stochastic processes in future's renewable power systems.     

碱度对熔剂性球团生球性能的影响

 熔剂性铁矿球团具有优良的高温冶金性能，是高炉炼铁的优质炉料。为探明生产熔剂性铁矿球团时碱度对生球性能的影响规律，以某钢厂赤铁精矿为原料，通过添加石灰石粉调节碱度，进行了造球及生球干燥特性试验研究。结果发现，提高碱度，生球落下强度呈提高趋势，抗压强度变化不明显，适宜膨润土配比略有下降，生球爆裂温度明显提高，生球干燥速率则没有明显变化。与基准自然碱度（R＝0.14）相比，当碱度提高到0.6以上时，适宜膨润土配比由1.2%下降到1.1%，生球爆裂温度提高近50 ℃以上。     

Covalent Linkage of an R-ω-Transaminase to a d-Amino Acid Oxidase through Protein Splicing to Enhance Enzymatic Catalysis of Transamination

R-ω-Transaminases (RTAs) catalyse the conversion of R-configured amines [e.g., (R)-1-phenylethylamine] into the corresponding ketones (e.g., acetophenone), by transferring an amino group from an amino donor [e.g., (R)-1-phenylethylamine] onto an amino acceptor (e.g., pyruvate), resulting in a co-product (e.g., d -alanine). d -Alanine can be deaminated back to pyruvate by d -amino acid oxidase (DAAOs). Here, through in vivo subunit splicing, the N terminus of an RTA subunit (RTA^S) was specifically ligated to the C terminus of a DAAO subunit (DAAO^S) through native peptide bonds (RTA&DAAO). RTA^S is in close proximity to DAAO^S, at a molecular-scale distance. Thus the transfer of pyruvate and d -alanine between RTA and DAAO can be directional and efficient. Pyruvate→d -alanine→pyruvate cycles are efficiently formed, thus promoting the forward transamination reaction. In a different, in vitro noncovalent approach, based on coiled-coil association, the RTA^S N terminus was specifically associated with the DAAO^S C terminus (RTA#DAAO). In addition, the two mixed individual enzymes (RTA+DAAO) were also studied. RTA&DAAO has a shorter distance between the paired subunits (RTA^S–DAAO^S) than RTA#DAAO, and the number of the paired subunits is higher than in the case of RTA#DAAO, whereas RTA+DAAO cannot form the paired subunits. RTA&DAAO exhibited a transamination catalysis efficiency higher than that of RTA#DAAO and much higher than that of RTA+DAAO.