Heat Treatment for High Manganese Steel

本文介绍了入炉温度、升温速度、保温温度、保温时间、冷却速度、摆放位置等热处理工艺参数对高锰钢力学性能的影响。This paper introduces the effect of heat treatment parameters including charging temperature,heating rate,holding temperature,holding time,cooling rate,putting position etc on the mechanical properties of high manganese steel

Ansamycins Produced by Streptomyces sp. LZ35

目的对海洋放线菌STrEPTOMyCES SP.lz35固体发酵提取物的化学成分进行研究。方法采用SEPHAdEX lH-20,硅胶等色谱柱及重结晶进行分离纯化,用波谱技术鉴定化合物的结构。结果从14 l固体发酵提取物中分离得到7个安莎霉素类化合物,分别鉴定为gEldAnAMyCIn(1),17-O-dEMETHylgEldAnAMyCIn(2),HErbIMyCIn b(3),rEblASTATIn(4),17-O-dEMETHylrEblASTA-TIn(5),AuTOlyTIMyCIn(6),HygrOCIn A dErIVATIVE(7)。结论化合物1~7均为首次从该菌株中分离得到,且首次从一株链霉菌中分离到2种类型的安莎霉素。OBJECTIVE To study the chemical constituents of Streptomyces sp.LZ35.METHODS The constituents were isolated and purified by Sephadex LH-20 column,silicagel column and recrystallization,and their structures were identified by NMR and ESI-MS techniques.RESULTS Seven compounds were isolated and identified as geldanamycin(1),17-O-demethylgeldanamycin(2),herbimycin B(3),reblastatin(4),17-O-demethylreblastatin(5),autolytimycin(6),hygrocin A derivative(7),respectively.CONCLUSION Compounds 1-7 were obtained from the strain for the first time.Two types of ansamycins were isolated for the first time from Streptomyces sp.国家杰出青年科学基金(30325044);教育部科学技术研究重点(重大)项目(306010);山东大学自主创新基金(2010TB016;2010TS072

Innovation and Practice on the Construction of Marine Biological and Ecological Field Practice Base in the Yangtze Estuary and Adjacent Sea

文章以国家自然科学基金委首个海洋科学类野外实践基地——长江口及邻近海域海洋生物与生态野外实践基地的建设为背景,从充分利用区位优势、突出综合实践功能、有效整合校际资源、积极筹措建设经费、创新基地管理体制、加强基地开放共享、促进科教有效融合、提升平台建设水平等八个方面进行了创新与实践,并对建设过程中的体会与问题进行了探讨。Based on the background of the construction of marine biological and ecological field practice base in the Yangtze estuary and adjacent sea which is the first field practice base of marine science supported by the National Natural Science Foundation of China,we try to make some innovation and practice from the following eight aspects： taking full advantage of location,highlighting the comprehensive practical function,integrating universities＇ resources effectively,raising funds for construction actively,innovating management system of field,strengthening open sharing of bases,promoting effective integration of science and education,and improving the level of platform construction. At last,this paper discusses the experience and problems in the construction process.国家自然科学基金野外实践能力提高项目（项目编号：J1310037）; 浙江省高等教育教学改革项目（项目编号：jg2015090

Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25

阿尔茨海默病（Alzheimer’s disease, AD）是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征（Down’s syndrome, DS）是早发型阿尔茨海默病的一个重要风险因素，作为最常见的智力障碍遗传疾病，厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点，并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能，缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成，厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作，王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持，清华大学董晨教授提供了Usp25基因敲除小鼠，厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao). 该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

SNX14 deficiency-induced defective axonal mitochondrial transport in Purkinje cells underlies cerebellar ataxia and can be reversed by valproate

共济失调是一类以运动协调性紊乱为主要特征的神经系统症状，临床表现包括步态不稳、丧失平衡、吞咽困难、眼球运动异常、肌张力受损等。厦门大学医学院神经科学研究所王鑫教授团队首次从轴突线粒体运输这一全新视角揭示了一类遗传性共济失调的发病机制，并发现抗癫痫药--丙戊酸大幅度减缓模型小鼠的疾病进程，具有较强的转化应用价值，有望为共济失调提供新的治疗手段。 该研究工作由王鑫教授指导完成，厦门大学医学院助理教授张洪峰和博士生洪育娟共同完成主要实验工作。Loss-of-function mutations in SNX14 cause autosomal recessive spinocerebellar ataxia 20, which is a form of early-onset cerebellar ataxia that lacks molecular mechanisms and mouse models. We generated Snx14-deficient mouse models and observed severe motor deficits and cell-autonomous Purkinje cell degeneration. SNX14 deficiency disrupted microtubule organization and mitochondrial transport in axons by destabilizing the microtubule-severing enzyme spastin, which is implicated in dominant hereditary spastic paraplegia with cerebellar ataxia, and compromised axonal integrity and mitochondrial function. Axonal transport disruption and mitochondrial dysfunction further led to degeneration of high-energy-demanding Purkinje cells, which resulted in the pathogenesis of cerebellar ataxia. The antiepileptic drug valproate ameliorated motor deficits and cerebellar degeneration in Snx14-deficient mice via the restoration of mitochondrial transport and function in Purkinje cells. Our study revealed an unprecedented role for SNX14-dependent axonal transport in cerebellar ataxia, demonstrated the convergence of SNX14 and spastin in mitochondrial dysfunction, and suggests valproate as a potential therapeutic agent.We thank Tim Huang for helpful discussion, Wei Mo for sharing mouse lines, Li Zhong for sharing reagents, Aidong Han, Luming Yao, Caiming Wu, Mingxia Zhu, Qingfeng Liu, Lin Zhu, Shuo Zhang, Haiping Zheng, and Changchuan Xie for technical assistance, and Cui Li for providing bioinformatics software. We also thank Novogene Co., Ltd. and PTM Biolab Co., Ltd. for technical assistance in the transcriptomic and proteomic analyses, respectively. 厦门大学医学院许华曦、赵颖俊、张云武、杜丹教授在研究过程中给予大力帮助和支持。本研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

基于多源卫星遥感的黄海绿潮多尺度观测与变化研究

自2007年以来，我国黄海连年暴发由漂浮浒苔聚集而成的绿潮，对山东半岛沿岸城市造成经济损失，绿潮的实时监测成为当务之急。遥感技术以分辨率高、监测范围大、观测频次高等优势，在黄海绿潮监测中发挥了重要作用。由于卫星影像监测的绿潮像元大多为混合像元，而不同分辨率影像受混合像元影响不同，绿潮监测面积差异显著，这给绿潮覆盖面积估算带来不确定性。因此，本研究对比了不同分辨率影像监测的绿潮覆盖面积和影响面积，揭示了绿潮信息提取的影响因素，进而实现绿潮多尺度观测和年际季节变化监测。 基于多源遥感卫星影像（包括MODIS、GF-WFV、HJ-CCD、Sentinel-2 MSI、Landsat、HY-1C CZI和Tiangong-2 MWI），本研究首先以同步卫星影像，分析了绿潮覆盖面积、影响面积和聚集度随分辨率的变化趋势，并评估了低分辨率卫星影像的绿潮漏检现象，探究了空间分辨率和动态阈值设定对于绿潮提取结果的影响。通过构建不同分辨率的绿潮覆盖面积的尺度转换模型，实现不同分辨率的绿潮覆盖面积尺度转换，同时多源遥感数据应用于绿潮监测，可以提升绿潮的观测频次。在此结果上，本研究获取了2007—2021年黄海绿潮的时空分布和年际季节变化特征，并分析了近年来绿潮规模与紫菜养殖筏架收割进程的关系。主要结论如下： （1）通过同步卫星影像，获取了绿潮覆盖面积、影响面积和聚集度随卫星影像空间分辨率的变化趋势。结果显示，随空间分辨率的提高，绿潮覆盖面积和聚集度降低，而绿潮影响面积增大；随分辨率的降低，绿潮漏检率增加，且绿潮聚集度较低区域的漏检率高于较高区域的结果。不同分辨率的卫星影像的空间分辨率的差异，及其所引起的混合像元效应，是多源遥感绿潮监测结果差异的主要原因。 （2）本研究分析了动态阈值设定对绿潮监测结果的影响，发现除卫星影像的空间分辨率外，动态阈值设定也是绿潮覆盖面积估算的重要因素。本研究中，提出了Linear和Equalization两种识别方法，并探究了不同分辨率影像的不同识别方法的绿潮覆盖面积。结果发现，不同分辨率影像获取的绿潮覆盖面积整体变化趋势较为一致，且发现Equalization监测的绿潮覆盖面积，比Linear方法多识 别20%-50%左右。 （3）在绿潮年际变化方面，本研究以250 m分辨率的MODIS影像，获取了2007-2021年黄海绿潮的年际变化。结果显示，不同识别方法的年度日最大覆盖面积的变化趋势大致相同，且以不同指数（DVI、NDVI和RVI）获取的绿潮覆盖面积，结果相差10%以内。2007-2021年黄海绿潮年际规模变化显著，绿潮年际规模变化存在三个峰值，即2009年、2016年和2019年，绿潮年度日最大覆盖面积均为2500 km²以上。 （4）在绿潮季节变化方面，以WFV、CCD和CZI影像，补充MODIS数据，获取了2007-2021年黄海绿潮的时空分布和覆盖面积季节变化，发现各年度的绿潮出现时间、消亡时间和年度规模差异显著，但整体趋势相似：5月前后发源于苏北浅滩附近海域，随盛行风向山东半岛沿岸漂移，绿潮覆盖面积迅速增加。达到年度日最大覆盖面积后，绿潮覆盖面积迅速降低，一般于7月底8月初消亡于山东半岛沿岸海域。 （5）本研究以WFV光学和Sentinel-1 微波数据，提取了2019-2021年度紫菜养殖面积，并分析了5月的紫菜养殖设备回收进程。结果显示2019和2021年度紫菜养殖设备回收较早，基于CZI的绿潮年度日最大覆盖面积达到2290 km²和1949 km²，而2020年度年度日最大面积面积仅为336 km²。本研究进一步证实了推迟紫菜养殖筏架回收进程，可控制绿潮年度日最大覆盖面积的结论。 本研究以多源遥感卫星数据，获取了2007-2021年度黄海绿潮的年际和季节变化，为绿潮灾害的尺度转换和定量观测提供了依据

基于国产高分环境卫星的南黄海绿潮监测对比研究

Based on the domestic satellites WFV images of GF-1 with 16m resolution and CCD images of HJ with 30m resolu tion, the monitoring capability about Enteromorpha of two kinds of data in different stages in southern Yellow Sea was compared, and we analyzed the reasons of differences between the monitoring results of two kinds of data. The results show that: 1) During the growth 8 海 岸 科 学 2020 年 and outbreak of Ulva prolifera, its own shape and patch composition changed significantly, which would lead to changes in the number of mixed pixels. 2) The coverage area of Enteromorpha of HJ satellite monitored from 6. 18% to 49. 86% more than that of GF-1, and the monitoring results of different stages were significantly different, while little differences in the same stage and different periods. 3) Through the comparison of the monitoring area of the two kinds of synchronous satellite data and the analysis of the composition of Enteromorpha patches, it was found that the changes of Enteromorpha patches would lead to changes in the mixed pixels, which could result in certain differences in the monitoring results of the two kinds of data. In addition, satellite imaging data, cloud cover and other external factors will also have an impact on the monitoring results

B族链球菌疫苗研究现状及展望

B族链球菌(group B streptococcus,GBS)主要危害新生儿、孕妇以及免疫力低下人群,能够引发早产、死产,还能引起脓毒症、菌血症和脑膜炎等多种疾病。使用抗生素是预防GBS的主要手段,但随着抗生素耐药性的逐渐增强,急需发展一种安全、有效的GBS疫苗,用于预防GBS感染。目前已有部分GBS候选疫苗进入临床试验阶段,同时也有部分疫苗处于临床前研究阶段。本文就这些具有临床使用潜力的GBS疫苗的研究现状进行综述。国家基金(81471934);;分子疫苗学和分子诊断学国家重点实验室自主研究课题资助项目(课题编号:2016ZY005

基于倍四元数的缝纫机器人运动学分析

针对传统D-H法以及旋量法进行机器人运动学分析过程中存在运算效率低、奇异性的问题，采用倍四元数求解了缝纫机器人的运动学参数。建立倍四元数形式的缝纫机器人的运动学方程，应用消元法构造Dixon结式，实现运动学参数求解。在受限工作范围内进行运动学分析仿真，结果表明，该方法运算效率高，较D-H法在速度上提高了10%左右，可为机器人纺织缝纫过程中的运动控制提供理论依据

Removal of methyl orange from aqueous solution by exfoliated graphite/ZnO composites

分别加热醋酸锌和水洗后的可膨胀石墨、干燥后的可膨胀石墨和膨胀石墨(Eg)的混合物,制备了3种不同的膨胀石墨/znO复合材料,分别记为Eg/znO-1,Eg/znO-2和Eg/znO-3。使用X射线衍射分析(Xrd)、扫描电子显微镜(SEM)和brAnAuEr-EMMETT-TEllEr(bET)比表面积等技术对样品结构进行表征。在紫外线(uV)照射下,研究了Eg/znO对水中亚甲基橙的去除效率。结果表明,Eg/znO同时具有膨胀石墨的吸附功能和znO的降解功能。在3种Eg/znO中,Eg/znO-3对水中甲基橙的去除效率最高。使用Eg/znO-3,甲基橙去除率受Eg/znO-3热处理温度和znO含量的影响。在优化工艺条件下,经过3.5HuV照射,水中甲基橙可被完全去除。Three exfoliated graphite (EG) doped with ZnO,marked as EG/ZnO-1,EG/ZnO-2 and EG/ZnO-3 composites,were prepared by heating a mixture of zinc acetate with water-washed expansible graphite,dried expansible graphite and EG,respectively.The composites were characterized by XRD,SEM and Branauer-Emmett-Teller (BET).Under UV irradiation,the removal of methyl orange (MO) from aqueous solution with the composites was investigated.The experimental results showed that the composites could synchronously provide with the adsorption efficiency of EG and decomposition efficiency of ZnO.Among all composites,EG/ZnO-3 was the most effective on removing MO.The MO removal efficiency of EG/ZnO-3 was influenced by the heating temperature and the ZnO content.After selection of desired operation parameters,the complete removal of MO could be achieved after 3.5 h UV irradiation.河北省科技攻关项目(05216701D