The extension of algebra and the automorphism of the extension algebra

代数的扩张是利用一个已知的代数按照一定的规则得到一类新的代数的过程,代数的扩张和扩张代数的相关性质是代数学研究的基本问题.本学位论文主要研究对偶扩张,平凡扩张,单点扩张代数的自同构问题.其中,对偶扩张代数是一个代数与其反代数的张量得到的一类扩张代数;平凡扩张代数是代数$A$与D(A)=\mbox{Hom}(A,k)的半直积得到的一类扩张代数;单点扩张是代数$A$与闭域$k$通过一个$A$-模$M$的扩张代数.本学位论文共分为四章.第一章,我们对与论文有关的研究方向及发展动态进行介绍,并概述了本文的主要工作.第二章,我们研究对偶扩张代数的箭图自同构,Frobenius态射以及固定点代数.第一...Algebra extension is a process of forming a kind of new algebra got according to certain rule from a known algebra, algebra extension and relevant nature of extension algebra have been the basic problem in the study of algebra . Our main research antithesis of academic dissertation is the automorphism of three extension algebras,they are the dual extension algebra ,the trivial extension algebra a...学位：理学硕士院系专业：数学系_基础数学学号：20022300

Generic Sheaves on Elliptic Curves and Interrelated Researches

Grothendieck在上个世纪60年代初提出的概型理论,使代数几何进入一个全新的阶段.概型上的拟凝聚层和凝聚层分别起着环上的模和有限生成模的作用.因此自概型理论建立后,概型上的拟凝聚层和凝聚层一直是代数几何及相关学科的热门研究对象.本学位论文主要研究椭圆曲线上的拟凝聚层以及光滑曲线的凝聚层范畴的单扩张范畴.全文共分为五章. 第一章介绍本学位论文的研究背景及有关方向的发展动态,并阐述本文的主要结论. 第二章给出与本文密切相关的概念及其基本性质,为后面的章节提供必要的理论基础. 第三章讨论椭圆曲线上的generic层.我们给出椭圆曲线上的generic层及generic层的rank,Eu...The theory of schemes was initiated by Grothendieck in early sixties of last century, which marked a new stage of algebraic geometry. Since quasi-coherent sheaves and coherent sheaves on a scheme behave as modules and finite-generated modules on a ring, respectively. Quasi-coherent sheaves and coherent sheaves on a scheme become popular objects to be studied in algebraic geometry and relatedsubjec...学位：理学博士院系专业：数学科学学院数学与应用数学系_基础数学学号：2005140300

加权射影线上的tilting对象和cluster-tilting对象

本文在加权射影线相关的范畴中讨论tilting对象与cluster-tilting对象之间的关系,证明当亏格为1时,向量丛稳定范畴中的tilting对象与相应的cluster范畴中的cluster-tilting对象对应.特别地, cluster范畴中的cluster-tilting对象由加权射影线上凝聚层范畴中的tilting对象诱导.中央高校基本科研业务费专项资金(批准号:2682017ZDPY12和2682018ZT25)资助项

中国近海生态环境变化的同位素示踪研究

同位素在确定物质来源、指示生物地球化学循环路径、定量生物地球化学过程速率等方面具有独特的优势,本文以近海生态环境变化研究中常用的稳定同位素(13C、15N、18O)和放射性核素(14C、234Th、232Th、230Th、228Th、210Po、210Pb、137Cs、226Ra、228Ra、224Ra、223Ra)为对象,介绍它们在揭示海洋有机质来源、食物网结构、水体缺氧机制、氮循环过程、颗粒动力学、海底地下水输入、有机地球化学过程、沉积年代学等方面的应用,侧重于总结我国近海生态环境研究中同位素示踪取得的进展。伴随着我国经济的发展,近百年来我国近海生态环境也发生了明显的变化,基于同位素示踪揭示的近海富营养化和沉积环境的演变规律表明,我国近海生态环境自20世纪50年代起经历持续的变化,特别是在过去2030年时间里,近海生态环境的变化尤为剧烈,反映出人类活动是我国近海生态环境变化的主要驱动力。未来需要通过发展新的同位素技术及拓展更广泛的应用,围绕近海海洋生态环境变化的突出问题,重点揭示近海生态环境变化的响应特征、变化速率和作用机制,从而系统地掌握近海生态环境的时空变化规律。国家重点基础研究计划课题(2015CB452903,2015CB452902);;国家海洋公益性行业科研专项(201505034

Investigation on the iodine status among the population in rural and urban areas of Xiamen in 2013

目的了解碘盐新标准实施后农村和城市人群的碘营养现况,为有效落实科学补碘防控策略提供依据。方法在农村和城市调查点各抽取1个镇的1个村,在每个村采集自来水厂出厂水和末梢水各2份;抽取30户以上居民,采集各户家庭食用盐,用3日称量法测算各户居民人均食盐摄入量;抽取18-45岁成人50名以上,采集尿样。在抽中的镇随机选择8-10岁儿童(男女各半)、孕妇和哺乳期妇女各50名以上,采集尿样。测定盐碘、尿碘和水碘含量。结果农村和城市自来水末梢水水碘含量均值分别为4.5μg/L和6.0μg/L;居民人均每日食用盐摄入量中位数分别为7.0和5.6g;8~10岁儿童尿碘中位数分别为152.0和181.2μg/L;哺乳妇尿碘中位数分别为108.3和107.7μg/L;18-45岁成人尿碘中位数分别为121.1和147.4μg/L;孕妇尿碘中位数分别为116.0和112.2μg/L,尿碘含量低于150μg/L的比例分别达67.9%和64%;除农村人均每日食用盐摄入量高于城市,农村18-45岁成人尿碘水平低于城市外,其他指标农村和城市间差异无显著性。结论厦门市仍是缺碘地区,在现有碘盐标准下,8-10岁儿童、18-45岁成人、哺乳期妇女的碘营养处于适宜水平,但孕妇的碘营养不足,要开展针对孕期人群的碘营养监测和指导,杜绝碘缺乏所造成的危害。Objective To gain knowledge of the iodine status among the population in rural and urban areas after the implement of new standard for edible salt and to provide scientific evidence for the initiative of the iodine supplement strategy. Method 1 village / community was selected randomly from rural and urban area as research site respectively. 2 samples of treated water and tap water were collected respectively in both sites, 30 + houses were enrolled randomly and edible salt samples were collected. 3days weighed record was employed to estimate average salt daily intake. Urine sample was collected from 50 + adults aged from 18 to 45. Identical sample was also collected from 50 + children aged from 8 to 10( same amount of subjects in both genders),pregnant women, and lactating women respectively. Iodine level of water, salt, and urine was determined by laboratory assay.Results The iodine concentration of tap water in rural and urban areas was 4. 5 μg / L and 6. 0 μg / L,respectively. The median of average iodine intake in rural and urban areas was 7. 0 g and 5. 6 g, respectively. The median in urine iodine was 152. 0 μg / L and 181. 2 μg / L,respectively. This measurement in lactating women was 108. 3 μg / L and 107. 7 μg / L,respectively. And it was121. 1 μg / L and 147. 4 μg / L in adults aged 18 to 45, respectively. As for the pregnant women, the iodine level reached 116. 0μg /L and 112. 2 μg /L,respectively. The proportion of subjects has urine iodine level less than 150 μg /L reached 67. 9 % and 64 %, respectively. The average salt intake in rural area was higher than urban significantly, and the urine iodine level in adults aged 18 to 45 from rural area was significantly lower than urban. No significance was found in other comparison. Conclusion Through our investigation,Xiamen is still an iodine deficiency area. Under the implement of new edible salt standard, the iodine status in children aged 8 to 10, adults aged 18 to 45 and lactating women was adequate, however, we found that pregnant women enrolled in our study have iodine deficiency in some degrees. Therefore the iodine surveillance and dietary guidance should be performed among pregnant women to eliminate the harm caused by iodine deficiency

Treatment System of Ballast Water in Oceanic Ships Using Hydroxyl Radical(·OH) Based on Strong Electric-field Discharge

船舶压载水的交换可能致使海洋中不同海域生物的交互入侵,打破原有海域生态系统的平衡,为此,研究了一种基于强电离放电方法规模化制备羟基自由基技术的新型船舶压载水处理系统。该系统利用大气压下强电场电离放电,将氧气和气态水充分电离,离解产生大量氧活性粒子,并通过高速射流,在管路中完成空化效应,制备高浓度羟基溶液,实现在船舶压载水装载过程中快速、高效的杀灭有害微生物和病原体。实验结果显示,压载水经过质量流量为10 T/H的压载水处理系统处理后,藻和细菌被全部杀灭,致死率达100%。在48 H和120 H两个时间点对处理舱进行检测,未发现有再生现象发生。除此之外,比较处理前后水质参数及生物学指标变化情况,经羟基处理后丙二醛(MdA)浓度有明显升高,而水中bOd、COd质量浓度明显降低。通过对MdA检测,羟基杀灭机制很可能是通过影响细胞脂质过氧化进程来完成。处理后压载水的水质得到了明显改善,减轻了压载水排放过程中对排放水域的环境压力。Exchanging ballast water from ships might cause the interactive bio-invasion of different seawater, and break ecological balance.Therefore, we described a ship ballast water system which generates hydroxyl radical from strong electric field ionization discharge.The discharge at atmospheric pressure could ionize O2 in air and gaseous H2O to form a large amount of oxygen active particles, which were injected into a tube of the ballast water treatment system to generate a high concentration of ?OH solution through the cavitation effect.The ?OH solution could kill harmful micro-organisms in ballast water quickly and efficiently.Test results showed that, after being treated by the system at a flow speed of 10 t/h, the single-cell algae and bacteria in ballast water were almost completely eliminated, and the micro-organisms did not reactivate at 48 h and 120 h.In the treated ballast water, the concentration of malondialdehyde(MDA) obviously increased while BOD and COD decreased significantly.According to the MDA test, ?OH probably kills algae and bacteria though preoxidating their cytolipin.The treatment can effectively lower the pollution from the ballast water.The results indicate that solution of high ?OH concentration significantly improves the quality of ballast water, hence it relieves the environmental threats of the ballast water discharge on local marine system.国家高技术研究发展计划(863计划)(2012AA062609); 国际科技合作项目(2010DFA61470); 国家杰出青年科学基金(61025001)~

土地流转面面观

自2008年10月中共十七届三中全会明确提出允许农地承包经营权“多种形式流转“以来,关于农地流转的讨论有渐成两级分化之势。今年全国“两会“上,吴邦国委员长在工作报告中,将土地管理法的修改和农村土地承包经营纠纷仲裁法的制定,列入本年的工作重点。3月12日,本刊和华

Study on bio-safety for Nano-Ag/HAp as anti-bacterial materials

通信作者:史建陆Tel:(0576)85199572 E-mail: zmfjmu@ gmail．com[中文文摘]目的研究纳米银羟基磷灰石的细胞毒性。方法采用能快速、准确、敏感地评价细胞增殖率和细胞毒性的MTT比色法,以纳米羟基磷灰石为对照组,纳米银羟基磷灰石为实验组,在材料浸提液中,分别检测人牙周膜成纤维样细胞的相对增殖率。另观察细胞在扫描电镜中的形态,从而分析比较涂层表面对细胞的毒性。结果与纳米羟基磷灰石相比,纳米银羟基磷灰石涂层中的纳米银粒子直径在200～400nm时体外细胞培养显示表现出较高的细胞增殖率,细胞毒性趋于0级,显示其具有良好的生物活性。结论纳米银羟基磷灰石涂层无细胞毒性。[英文文摘]Objective To study the cytotoxicity of a Nano-Ag/HAp composite coating on titanium surface.Methods A Nano-Ag/HAp composite coating was deposited on the surface of pure titanium by electrochemical deposition.In vitro celluar responses of the PDLF to the coating were also evaluated by MTT assay.Conventional HAp coatings and commercially pure titanium were taken as control.Results The Nano-Ag/Hap bioceramic coating has good crystallization and homogeneity on nano-scale surface morphology.The PDLF culture exhibits satisfactory bioactivity．Conclusions The Nano-Ag /HAp bioceramic coating on titanium surface has promising prospects in the future clinical application

COTORSION PAIRS IN A RECOLLEMENT OF TRIANGULATED CATEGORIES

National Natural Science Foundation of China [10926041, 11126268]; Fundamental Research Funds for the Central Universities of China [2010121003]In the present article, we study the relationship of cotorsion pairs among three triangulated categories in a recollement. We show that if a triangulated category D admits a recollement relative to triangulated categories D' and D '', we can obtain cotorsion pairs in D from cotorsion pairs in D' and D ''. On the other hand, we prove that certain cotorsion pairs in D can induce cotorsion pairs in D' and D ''. Furthermore, we construct recollements of abelian categories from a recollement of triangulated categories

对偶扩张代数的forbenius态射固定点代数

设A是由箭图Q和关系I所确定的代数,D(A)是代数A的对偶扩张代数,对应的箭图Q*和关系I*由Q和I决定,本文证明:带关系箭图(Q*,I*)的自同构由带关系箭图(Q,I)的自同构决定,D(A) 的forbenius态射由A的forbenius态射完全决定,代数D(A)的固定点代数同构于相应的代数A的固定点代数与Aop的固定点代数的张量积, 特别地, 当Q为单的箭图时, 代数D(A)的固定点代数同构于代数的A固定点代数的对偶扩张代数国家自然科学基