摘要：利用精密绝热热量仪测定了配合化合物Zn(Met)_3(NO_3)_2·H_2O(s)(Met=L-α-蛋氨酸)在78-371 K温区的摩尔热容.通过热容曲线解析,得到了该配合物的起始脱水温度为T_D=325.10 K.将该温区的摩尔热容实验值用最小二乘法拟合得到了摩尔热容(C_p)对约化温度(T)的多项式方程,由此计算得到了配合物的舒平热容值和热力学函数值.基于设计的热化学循环,选择100 mL 2 mol·L^(-1)HCl溶液为量热溶剂,利用等温环境溶解-反应热量计,得到了298.15 K配合物的标准摩尔生成焓Δ_f H_m^0[Zn(Met)_3(NO_3)_2·H_2O,s]=-(1472.65±0.76)J·mol^(-1).

摘要：相比于传统的风洞设备,低温风洞可以生成更高雷诺数的气流,而风洞降温过程中残留的痕量水蒸气可能会影响试验件气动参数的测量。痕量水结冰的热力学过程复杂,实验测试较为困难,其机理仍需深入研究。针对该问题,本文基于欧拉方法建立了空气⁃过冷水滴⁃冰晶多相流模型,仿真结果与文献中的实验数据吻合度较高,进一步采用该模型获得了低温风洞中水蒸气凝结液滴/冰晶撞击翼型的结冰过程,探究了气流中总的水含量、融化比、气流温度、压力、马赫数等参数对结冰过程的影响,并定量分析了结冰现象对翼型气动参数的影响,可为低温风洞的实际运行提供一定的理论参考。

摘要：Lithium carbon dioxide(Li-CO_(2))batteries deliver a theoretical energy density of 1876 W h kg^(-1) in terms of effective utilization of greenhouse *** battery system is considered to be an encouraging electrochemical energy storage device and a promising alternative to Li-ion ***,the main drawback of Li-CO_(2) batteries is their accumulative discharge product of Li_(2)CO_(3)/C,which leads to large overpotential and poor cycling ***,specific and efficient catalysts must be explored to enhance the decomposition of Li_(2)CO_(3)/***-atom catalysts(SACs)are regarded as promising heterogeneous catalysts owing to their maximized utilization of metal atoms and strong interfacial electronic ***,single-metal atoms of Fe,Co,and Ni uniformly anchored on N-doped reduced graphene oxide(rGO),designated as Fe_(1)/N-rGO,Co1/N-rGO,and Ni_(1)/N-r GO,respectively,are designed and fabricated to investigate their catalytic activity toward the decomposition of Li_(2)CO_(3)/*** them,Fe_(1)/N-rGO delivers a high discharge capacity of 16,835 mA h g^(-1) at 100 mA g^(-1) and maintains stability for more than 170 cycles with a discharge voltage of 2.30 V at 400 mA g^(-1).Therefore,this catalysts are overwhelmingly superior to other *** work reveals the advances of SACs in Li-CO_(2) batteries and offers an effective method for realizing high-performance Li-CO_(2) batteries.

摘要：Gel polymer electrolytes(GPEs)has been considered as a promising candidate for the development of lithium metal batteries(LMBs)with high energy density and high safety,yet most reported GPEs is flammable,making the LMBs still facing great safety ***,we used dimethyl methylphosphate(DMMP)as the functional flame retardant and plasticizer for poly(vinylidene fluoride)(PVDF)matrix to develop a novel nonflammable PVDF-DMMP GPEs for *** DMMP not only highly enhances the flame resistance of PVDF-DMMP GPEs,the efficient dissociation of lithium salt and the rapid transport of lithium ions,but also helps to form stable and robust CEI/SEI *** a result,the ultrathin PVDF-DMMP GPEs(∼20µm)present superb flame resistance,high ionic conductivity(1.34×10^(−3) S cm^(−1) at 30℃),fast lithium ion transport(t_(Li^(+))=0.59at 30℃),high electrochemical stability voltage window(over 4 V)at 30–80℃ and uniform lithium *** used in Li∥Li symmetric cells,Li∥LiFePO_(4)(LFP)and Li∥LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) full cells,the nonflammable PVDF-DMMP GPEs could endow these cells with long-term cycle stability,high rate capability,wide-temperature operation ranges(from−20 to 80℃)and high safety *** when suffering from harsh deconstructive tests,the Li∣PVDF-DMMP GPEs∣LFP pouch cells still work normally without any safety *** actual energy density of the packed pouch cell is as high as 508 Wh kg^(−1).Therefore,our work can provide a promising strategy for the design of high safety and high-energy-density LMBs.

摘要：为了建立一个面向用户、设计师、工程师和决策者的产品设计知识协同信息管理平台,有效利用案例中的设计知识,提出一种案例驱动的协同设计知识管理模型,该模型通过分析新产品开发中用户、决策者、设计师和工程师之间的设计知识流通模式,建立了基于案例的知识协同与信息交互过程的映射模型,提出了基于Markov模型的设计知识提取方法,构建了案例驱动的协同设计知识管理框架,并以软件形式实现。案例驱动的协同设计知识管理模型将已有领域案例的设计知识引入新项目设计问题的设计求解中,新产品设计开发和过程管理所需的所有设计信息均可通过领域案例设计知识库进行实时地设计知识获取、重用和进化,直至完成整个设计项目。以某品牌起重机造型设计方案在案例驱动协同设计知识管理软件平台上的具体应用为例进行验证,证明了所提模型的可行性和合理性。

摘要：The exchange bias is of technological significance in magnetic recording and spintronic *** a large bias field is a long-term goal for the research field of magnetic shape memory *** this work,a large bias field of 0.53 T is achieved in the Ni50Mn34In16-xFex(x=1,3,5)system by tuning the magnetic ground state(determined by the composition x)and the magnetic-field history(determined by the magnetic field HFCduring field cooling and the maximum field HMaxduring isothermal magnetization).The maximum volume fraction of the interfaces between the ferromagnetic clusters and antiferromagnetic matrix and the strong interfacial interaction are achieved by tuning the magnetic ground state and the magnetic-field history,which results in strong magnetic unidirectional anisotropy and the large exchange ***,two guidelines were proposed to obtain the large bias ***,the composition with a magnetic ground state consisting of the dilute spin glass and the strong antiferromagnetic matrix is preferred to obtain a large bias field;secondly,tuning the magnetic-field history by enhancing HFCand reducing HMaxis beneficial to achieving large exchange *** work provides an effective way for designing magnetically inhomogeneous compounds with large exchange bias.

摘要：Micro-supercapacitors（MSCs） have emerged as one competitive candidate of high-performance, flexible, safe,portable and wearable energy storage devices. However, improving their electrochemical performance from electrode materials to assembled devices still remains huge ***, we for the first time synthesized two-dimensional（2D）,ultrathin, mesoporous polypyrrole-based graphene nanosheets uniformly anchored with redox polyoxometalate（mPPy@rGO-POM） by soft template approach. Further, using a layer-by-layer deposition and mask-assisted technique, the compactly stacked and sandwich-like hybrid film（mPGM）based on pseudocapacitive mPPy@rGO-POM nano sheets and electrochemically exfoliated graphene was directly fabricated as binder-and additive-free interdigital electrodes for all-solid-state planar micro-supercapacitors（mPGM-MSCs）. Notably, the resulted mPGM-MSCs exhibited outstanding areal capacitance（115 mF cm^-2）, remarkably enhanced volumetric capacitance（137 F cm^-3 at 1 mV s^-1） in comparison with MSCs based on the films of mPPy@rGO without POM anchoring（95 F cm^-3）, and non-porous polypyrrole-graphene（68 F cm^-3）.Further, mPGM-MSCs disclosed robust mechanical flexibility with ～96% of capacitance retention at a highly bending angle of 180°, and impressive parallel or serial interconnection for boosting capacitance or voltage output. As a consequence, our proposed strategy of filling the redox species into mesoporous graphene and other 2D nanosheets will open up new ways to manufacture high-compact and flexible energy storage devices ranging from supercapacitors to batteries.

摘要：CRISPR-Cas12a系统的反式切割活性在其识别特定的DNA激活序列后被激活,这不仅能实现特定DNA靶标的直接定量分析,同时也为构建针对多种生物标志物的体外传感体系带来了新的思路。然而,已有文献中所采用的双链DNA(dsDNA)和单链DNA(ssDNA)激活序列结构多种多样,缺乏全面、系统的设计指导原则。针对该问题,该文系统研究了不同结构的DNA激活序列对LbaCas12a反式切割活性的影响。通过对比研究,得出以下结论:(1)前间区序列邻近基序(PAM)位点有助于LbaCas12a更高效地靶向结合dsDNA激活序列和ssDNA激活序列;(2)PAM近端区域缺少序列片段会降低Cas12a-crRNA定位激活序列的效率;(3)删除PAM远端序列片段有利于增强LbaCas12a的反式切割活性;(4)由于省略了dsDNA解链过程,ssDNA激活序列在激活LbaCas12a的反式切割活性方面普遍比dsDNA激活序列产生的效果更好。根据这些发现,该文提出了一种LbaCas12a所青睐的高效激活序列结构,其激活的LbaCas2a反式酶切活性较采用含PAM位点的标准dsDNA激活序列高出3.7倍。研究结果为构建基于CRISPR-Cas12a的高效体外生物传感系统提供了重要支撑。

摘要：由人工结构组成的超材料具有传统材料不具备的卓越性能.通过设计和排列具有特殊物理性质的单元结构可制备用于高效电磁波吸收的吸波超材料.这些亚波长尺度的单元结构是吸波超材料超越传统材料性能极限的基础,因此制造工艺的匹配尤为重要.快速发展的3D打印技术在制造具有复杂结构的材料方面展现出巨大的优势和潜力,为研究和制备吸波超材料提供了一种简单、快速、高效的方法.在这篇综述中,我们介绍了吸波超材料的概念和发展,重点介绍了利用3D打印技术制造吸波超材料的研究现状.此外,还简要介绍了超材料的典型应用,讨论了当前超材料发展的不足和3D打印技术制备吸波超材料的局限性,并提出了超材料和3D打印技术结合的发展前景.

摘要：An approach to design multi-channel cylinder dryer was proposed. The heat transfer performance and flow characteristic under various structural parameters were analyzed. First, an experiment was designed and set up to measure the condensing heat transfer coefficient and the pressure drop in order to ,~erify the applicability of the Cavallini＇s correlation. Then, the relationship among the count of channels, aspect ratio, spacing ratio, width, height and hydraulic diameter of a channel was given. Finally, the correlation of condensing heat transfer and the homogeneous model was introduced in order to observe the heat transfer performance and flow characteristic of the multi-channel cylinder dryer affected by different structures. The study reveals that the structural parameters including count of channels, aspect ratio, spacing ratio of a channel dramatically influence the condensation heat transfer coefficient and frictional resistance of the steam. Based on the selected paper machine, it is suggested that the overall performance of the multi-channel cylinder dryer is best if the count of channels is 150-200, the aspect ratio is 1 ： 3 and the spacing ratio is 1 ： 1-1 ： 3.