北极星爵士：“启蒙运动”时期中、欧 建筑与园林艺术交流的文化使者——纪念 威廉·钱伯斯300周年诞辰

2023年是北极星爵士——威廉·钱伯斯300周年诞辰。这位生于瑞典的苏格兰裔英国新古典主义建筑大师出身于海员,在追求个人兴趣的因缘际会下开启了中欧建筑、园林艺术在专业层面交流的先河。通过回顾这位文化使者生平的同时,尝试提出“‘英-华园’范式”概念,并指出其成为欧洲“启蒙运动”时期那一代“开明君主”青睐的王家园林摹本而风靡一时,亦因多处实践成果列入世界文化遗产而影响至今。同时,作为一篇纪念文章,在写作上通过对历史大背景下的相关事件联想式地展开,希望能够跳出就事论事的考据,以引发之外的一些思考。     

用MBR工艺处理印染前处理废水的试验研究

棉纺织印染前处理废水成分复杂、水质较差、处理难度较大。采用膜生物反应器(MBR)处理经过简单预处理的印染前处理废水,可使废水水质大为改善、后续处理压力大大减轻。在近100 d的现场试验中,得出了MBR的最佳操作参数为:温度25℃,HRT 18 h,MLSS 8 g/L,DO 2.8 mg/L,pH 7.5～8.5。在最佳工艺条件下,SS、色度、NH_3—N和COD_(Cr)去除率分别约为90%、30%、72%、72%。该工艺运行成本约为1.643元/m~3。     

基于欠驱动原理的5指残疾人假手设计

采用欠驱动自适应原理设计了与成年人手大小相仿的5指残疾人假手,所设计的假手结构简单,质量轻,适应性强。假手主控制器采用TMS320F2810来实现对传感器信号的采集,步进电机的控制。并利用所设计假手进行了多种抓握实验,表明该假手可对多种形状物体进行抓、握、捏等多种操作。     

国内乳化蜡的研究及应用进展

介绍了乳化石蜡的类型及制备方法,讨论了乳化剂、乳化温度、乳化时间及搅拌速率对乳化蜡稳定性的影响;评述了乳化蜡在国内纺织工业、人造板工业、造纸工业、上光剂、农业及乳化炸药等行业的研究及应用进展;分析了国内乳化蜡的市场前景,指出中国发展乳化蜡的方向是实现产品的系列化和规模化。     

利用磷肥副产含氟硅胶制δ型层状结晶二硅酸钠

磷肥副产含氟硅胶经氨洗、水洗至中性后,与片状烧碱反应,制得模数为2．0的水玻璃,然后加3％的KCI作晶型转化剂,经煅烧制备δ型层状结晶二硅酸钠。实验得出制取中间产物水玻璃的最佳工艺条件是：反应温度720-800℃、反应时间40min;水玻璃煅烧制d型层状结晶二硅酸钠的最佳工艺条件是：煅烧保温温度600℃、保温时间30．50min。在最佳条件下,可得到钙离子交换量大于4A沸石的优质δ型层状结晶二硅酸钠。     

臭氧预处理-常规处理-深层过滤组合工艺的生产性试验

针对广东饮用水源的水质特点,采用臭氧预处理—常规处理—深层过滤组合工艺对微污染水源水进行生产性试验,结果表明:当进水浊度、CODMn、氨氮、铁、细菌总数和大肠菌群等分别为8.44～112.09NTU,1.13～2.98mg/L,0.07～0.31mg/L,0.65～9.74mg/L,3.2×103～3.6×103CFU/mL和1.6×103CFU/100mL时,出水各指标分别为0.09～0.68NTU,0～0.79mg/L,小于0.02mg/L,小于0.01mg/L,未检出和小于3CFU/100mL;年平均去除率分别为99.15%,80.33%,84.89%,94.17%,100%和近100%。该工艺出水水质好,抗冲击负荷能力强,运行平稳。     

Construction of Dual-Shell Mo2C/C Microsphere towards Efficient Electromagnetic Wave Absorption

Carbon-based carbides have attracted tremendous attention for electromagnetic energy attenuation due to their adjustable dielectric properties, oxidation resistance, and good chemical stability. Herein, we reasonably regulate the growth of dopamine hydrochloride on the surface of the Mo-glycerate (Mo-GL) microsphere and then transform the resultant Mo-polydopamine (Mo-PD) microsphere into a dual-shell Mo₂C/C (DS-Mo₂C/C) microsphere in a high-temperature pyrolysis process under an inert atmosphere. It is found that the pyrolysis temperature plays an important role in the graphitization degree of the carbon matrix and internal architecture. The fabrication of a dual-shell structure can be propitious to the optimization of impedance matching, and the introduction of Mo₂C nanoparticles also prompts the accumulation of polarization loss. When the pyrolysis temperature reaches 800 °C, the optimized composite of DS-Mo₂C/C-800 exhibits good EM absorption performance in the frequency range of 2.0–18.0 GHz. DS-Mo₂C/C-800′s qualified bandwidth can reach 4.4 GHz at a matching thickness of 1.5 mm, and the integrated qualified bandwidth (QBW) even exceeds 14.5 GHz with a thickness range of 1.5–5.0 mm. The positive effects of the dual-shell structure and Mo₂C nanoparticles on EM energy attenuation may render the DS-Mo₂C/C microsphere as a promising candidate for lightweight and broad bandwidth EM absorption materials in the future.     

Nicotinamide Mononucleotide Supplementation Improves Mitochondrial Dysfunction and Rescues Cellular Senescence by NAD+/Sirt3 Pathway in Mesenchymal Stem Cells

In vitro expansion-mediated replicative senescence has severely limited the clinical applications of mesenchymal stem cells (MSCs). Accumulating studies manifested that nicotinamide adenine dinucleotide (NAD⁺) depletion is closely related to stem cell senescence and mitochondrial metabolism disorder. Promoting NAD⁺ level is considered as an effective way to delay aging. Previously, we have confirmed that nicotinamide mononucleotide (NMN), a precursor of NAD⁺, can alleviate NAD⁺ deficiency-induced MSC senescence. However, whether NMN can attenuate MSC senescence and its underlying mechanisms are still incompletely clear. The present study herein showed that late passage (LP) MSCs displayed lower NAD⁺ content, reduced Sirt3 expression and mitochondrial dysfunction. NMN supplementation leads to significant increase in intracellular NAD⁺ level, NAD⁺/ NADH ratio, Sirt3 expression, as well as ameliorated mitochondrial function and rescued senescent MSCs. Additionally, Sirt3 over-expression relieved mitochondrial dysfunction, and retrieved senescence-associated phenotypic features in LP MSCs. Conversely, inhibition of Sirt3 activity via a selective Sirt3 inhibitor 3-TYP in early passage (EP) MSCs resulted in aggravated cellular senescence and abnormal mitochondrial function. Furthermore, NMN administration also improves 3-TYP-induced disordered mitochondrial function and cellular senescence in EP MSCs. Collectively, NMN replenishment alleviates mitochondrial dysfunction and rescues MSC senescence through mediating NAD⁺/Sirt3 pathway, possibly providing a novel mechanism for MSC senescence and a promising strategy for anti-aging pharmaceuticals.     

AAV13 Enables Precise Targeting of Local Neural Populations

As powerful tools for local gene delivery, adeno-associated viruses (AAVs) are widely used for neural circuit studies and therapeutical purposes. However, most of them have the characteristics of large diffusion range and retrograde labeling, which may result in off-target transduction during in vivo application. Here, in order to achieve precise gene delivery, we screened AAV serotypes that have not been commonly used as gene vectors and found that AAV13 can precisely transduce local neurons in the brain, with a smaller diffusion range than AAV2 and rigorous anterograde labeling. Then, AAV13-based single-viral and dual-viral strategies for sparse labeling of local neurons in the brains of C57BL/6 or Cre transgenic mice were developed. Additionally, through the neurobehavioral test in the ventral tegmental area, we demonstrated that AAV13 was validated for functional monitoring by means of carrying Cre recombinase to drive the expression of Cre-dependent calcium-sensitive indicator. In summary, our study provides AAV13-based toolkits for precise local gene delivery, which can be used for in situ small nuclei targeting, sparse labeling and functional monitoring.