摘要：The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical *** hydrogenation poses a significant challenge,which requires the rational design of the catalysts with proper hydrogenation ability for nitro group and simultaneously preventing dehalogenation of halogen ***,a highly effective Rh@Al_(2)O_(3)@C single-atom catalyst(SAC)was developed for the hydrogenation of m-chloronitrobenzene(m-CNB)to m-chloroaniline(m-CAN),through an in-situ grafting of metal during the assembly of MIL-53(Al),followed by confined *** characterizations reveal an exquisite structure of the Rh@Al_(2)O_(3)@C,containing atomically dispersed Rh sites onto Al_(2)O_(3) confined by the amorphous *** five-coordinated aluminum(Al^(Ⅴ))species are essential for achieving the atomic dispersion of Rh atoms,providing the unsaturated coordinative sites for *** to the benchmark Rh/γ-Al_(2)O_(3) and Rh/C nanocatalysts,the Rh@Al_(2)O_(3)@C SAC affords an excellent turnover frequency of 2317 molm-CNB·molRh^(–1)·h^(–1),the highest value to date in heterogeneous catalyst systems for the hydrogenation of m-CNB at 313 K and 20 bar H2,together with a sustained selectivity to m-CAN(~98%)during five consecutive *** superior catalytic performance of the Rh@Al_(2)O_(3)@C is attributed to a proper modulation of electronic structure of hydrogenation metal by forming SAC,together with an enhanced accessibility of acid function sites.

摘要：本研究旨研制一款南瓜沙棘复合果泥。以板栗南瓜和大果沙棘原浆为原料,配合使用白桃浓缩汁,采用单因素与正交试验设计,以色泽、香味、质地、口感为指标,通过模糊数学感官评价法,优化南瓜沙棘复合果泥工艺,并测定优化后南瓜沙棘复合果泥的味觉特征和相关指标。结果表明,南瓜沙棘复合果泥最佳工艺为:板栗南瓜蒸煮时间为30 min,制泥时间为4 min,沙棘原浆添加量为10%,白桃浓缩汁添加量为4%。在此工艺条件下制备的南瓜沙棘复合果泥,色泽鲜亮、酸甜可口、香味浓郁、营养丰富。

摘要：Si C nanowires are excellent high-temperature electromagnetic wave (EMW) absorbing materials. However, their polymer matrix composites are difficult to work at temperatures above 300℃, while their ceramic matrix composites must be prepared above 1000℃ in an inert atmosphere. Thus, for addressing the abovementioned problems, SiC/low-melting-point glass composites were well designed and prepared at 580℃ in an air atmosphere. Based on the X-ray diffraction results, SiC nanowires were not oxidized during air atmosphere sintering because of the low sintering temperature. Additionally, SiC nanowires were uniformly distributed in the glass matrix material. The composites exhibited good mechanical and EMW absorption properties. As the filling ratio of SiC nanowires increased from 5wt%to 20wt%, the Vickers hardness and flexural strength of the composite reached HV 564 and 213 MPa, which were improved by 27.7%and 72.8%, respectively, compared with the low-melting-point glass. Meanwhile, the dielectric loss and EMW absorption ability of SiC nanowires at 8.2–12.4 GHz were also gradually improved. The dielectric loss ability of low-melting-point glass was close to 0. However, when the filling ratio of SiC nanowires was 20wt%, the composite showed a minimum reflection loss (RL) of-20.2 dB and an effective absorption (RL≤-10 dB) bandwidth of2.3 GHz at an absorber layer thickness of 2.3 mm. The synergistic effect of polarization loss and conductivity loss in SiC nanowires was responsible for this improvement.

摘要：生物炭是在缺氧或限氧环境下利用生物质废弃物裂解而成的一类富炭物质。作为一类可资源再生的富炭材料,生物炭的功能化改性成为近年来研究的热点方向。通过改性技术设计出特定的炭基界面结构、转换生物炭的性质,以增强生物炭在固碳、改良土壤肥力、环境污染修复等方面的应用潜力。生物炭改性涉及到多重方法,包括物理改性和化学改性。改性方法的适用性取决于改性生物炭的使用目的,如应用的环境条件或污染物类型(无机/有机物、亲/疏水性污染物、分/离子型污染物)等。为帮助评价改性生物炭用于土壤和水体系统的污染物阻控效果,本文概述了生物炭基于孔隙演化、基团修饰、电荷涂覆和赋磁的四重改性方法,并归纳了改性生物炭吸附环境污染物(重金属和有机物)的机制,以及针对改性生物炭的功能性、稳定性及其环境风险进行了展望。改性生物炭在环境修复领域的应用将为污染物的管理策略提供强有力的技术支撑。

摘要：焦平面阵列是光学读出非制冷红外成像系统的重要部分。在理论分析的基础上设计了一个显微数字全息系统,测量了一种FPA的热机械灵敏度,结果为0.199deg/K。实验还发现FPA反光板上不同位置处热机械灵敏度是不同的,实验给出了热机械灵敏度随到反光板固定端距离的变化函数关系式。

摘要：平稳入学是孤独症儿童融入社会的一次重大转折和挑战,厘清孤独症儿童的入学困境及支持需求,对促进特殊教育普惠发展和社会公平具有重要现实意义。基于“家庭—教育—社会”的综合性视角,采用元人种志方法,对9篇代表性文献进行深度集成和建构,发现孤独症儿童平稳入学存在“断层、污名化、权力失衡和支持缺失”四大困境,具有“多方协作、信息共享、提前规划和提供支持”四项需求。进而形成了以“入学支持”为核心,涵盖公共态度、制度设计和社会实践三个层面的概念框架,系统揭示了为何孤独症儿童难以平稳入学,并构建了全过程的孤独症儿童平稳入学支持实践路径。

摘要：提出了一种双向DC/DC变换器双闭环控制策略以及主电路参数设计方法,在此基础上,通过仿真实现了一种基于DC/DC变换器的直流组网系统稳定性分析方法,仿真测试验证了基于该策略的正确性,以及直流组网系统在负载频繁突变以及故障恢复下的稳定性,具有动静态响应小,电能品质优良的特点,同时对基于该双向变换器的蓄电池充放电模式切换进行仿真验证,结果同样表明了本文设计方法的有效性,对直流组网系统设计具有一定的参考意义和实用价值。

摘要：目的制备具有过氧化物酶活性的钯纳米粒子,并初步探讨其应用于尿酸检测的可行性。方法通过简单的一步法化学反应合成具有氢键超分子结构的钯纳米粒子复合物(MCA-Pd NPs),应用比色分析方法检测其过氧化物酶活性。再设计一系列的试验寻找到纳米粒子应用于尿酸检测体系的最佳反应时间、温度、试剂用量等,并通过制作尿酸标准曲线、检测临床血清标本来探索其临床应用的可行性。结果成功合成性质稳定、具有强过氧化物酶活性的MCA-Pd NPs,并能取代辣根过氧化物酶应用到尿酸检测体系中,检测体系的最佳试剂用量为100μL MCA-Pd NPs(0.105 mg/mL)和50μL ABTS2-(90 mmol/L),最佳反应温度为37℃,最佳反应时间为20 min。纳米粒子比色法检测的5份临床血清标本与日立7600生化分析仪检测结果相一致,与临床诊断相符合。结论钯纳米粒子制作过程简单、性质稳定、类过氧化物酶活性强,并基于该纳米粒子和尿酸酶建立了一种可初步应用于临床血清标本尿酸检测的比色分析方法。