Research and Application on Financial Due Diligence of Investment

从众多历史经验来看，有相当多的投资者因为对被投资企业（也称作目标企业）的财务、资产和经营情况知之甚少，对其复杂性预计不足，最终导致投资失败。失败原因主要都是因为没有对尽职调查引起足够的重视，使得尽职调查往往只是流于形式。 尽职调查又被称作谨慎性调查，由财务尽职调查和法律尽职调查组成。在企业风险投资过程中信息不对称风险已成为重要的风险之一，而财务尽职调查是降低风险投资过程中信息不对称风险的最主要手段，是风险投资过程中的重要环节。财务尽职调查从资产、债务、内部控制、经营情况、历史沿革、法律规范、潜在风险等角度，对目标企业进行系统性的深入调查和核实；判断目标企业资料信息的合规性、完整性和有效性，了...A number of historical experiences told us, there are a lot of investors failed to invest, because of less know of financial, assets and management about the target enterprise, lack of complexity understanding and risk predicting. The main reason which leads to investment failure is ignoring financial due diligence. Due diligence is also known as cautious investigation, which is composed of f...学位：会计硕士院系专业：管理学院_会计学学号：X201215701

6,12-二(三乙基硅乙炔基)二苯并苯并二噻吩的合成、表征及性能研究

合成了6,12-二(三乙基硅乙炔基)二苯并[d,d’]苯并[1,2-b;4,5-b’]二噻吩,并通过熔点测定、元素分析、核磁共振谱、质谱及X-单晶衍射分析对其进行了表征,同时对其作为有机场效应管(OFET)材料的性能进行了测试。结果表明,该材料在器件中载流子迁移率高达0.53 cm2/Vs,开关比为105。广西壮族自治区自然科学基金项目(013005)资助;广西民族大学重大项目基金资

Synthesis of Thieno［2，3-b］thiophene-diketopyrrolopyrrole-based

设计并合成了一种交叉共轭的(cross-conjugated)缺电子型聚合物单体——二溴代噻吩[2,3-b]并噻吩-吡咯[3,4-c]并吡咯(DPPTTZ)二酮,并将其分别与噻吩(T)、硒吩(Se)和N-甲基吡咯(Py)的双锡试剂进行共聚反应,获得了一类新的供体-受体(D-A)型共轭聚合物光电材料.这类材料分子的最高占有轨道(HOMO)能级较低,因此其光电器件具有较高的开路电压(Voc),稳定性好.此外,它们在紫外-可见光区有较宽的吸收,最大吸收位于波长620 nm附近;能带隙(band gap)小,分别为1.86 e V(p DPPTTZ-T)、1.83 e V(p DPPTTZ-Se)和1.85 e V(p DPPTTZ-Py).器件初步测试结果表明,上述聚合物与PC71BM组成的本体异质结聚合物太阳能电池Voc在0.68~0.81 V之间,能量转化效率(PCE)最高达3.05%(p DPPTTZ-T).Abstract Thieno［2，3-b］thiophene-diketopyrrolopyrrole ( DPPTTZ ) ，a novel cross-conjugated electrondeficient unit，has been synthesized． This unit was brominated and then copolymerized with 2，5- bis( trimethylstannyl) thiophene，2，5-bis ( trimethylstannyl) selenophene and 2，5-bis ( trimethyl-stannyl) -Nmethylpyrrole respectively，via Stille polymerzation， to form three donor-acceptor ( D-A) type copolymers， poly{ 2，5 -bis ( 2-octyldodecyl) -3-［5-( thiophen-2，5-yl) thieno［2，3-b］thiophen-2-yl］- 6-( thieno［2，3-b］ thiophen-2，5 -yl) pyrrolo［3，4 -c］pyrrole-1，4 ( 2H，5 H) -dione} ( pDPPTTZ-T) ，poly{ 2，5 -bis( 2-octyldodecyl) - 3-［5-( selenophen-2，5 -yl) thieno［2，3-b］thiophen-2-yl］-6-( thieno［2，3-b］thiophen-2，5-yl) pyrrolo［3，4-c］ pyrrole-1，4 ( 2H，5 H) -dione} ( pDPPTTZ-Se) and poly{ 2，5-bis( 2-octyldodecyl) -3-［5-( N-methylpyrrole-2， 5-yl) thieno［2，3 -b］thiophen-2-yl］-6-( thieno［2，3 -b］thiophen-2，5 -yl) pyrrolo［3，4 -c］pyrrole-1，4 ( 2H，5 H) - dione} ( pDPPTTZ-Py) ． These polymers exhibit deep HOMO energy levels ( － 5． 26 ～ － 5． 37 eV) ， leading to high open-circuit voltage ( 0． 68 ～ 0． 81 V) in OPV devices，and good stability of the devices towards atmospheric oxygen． The UV-Vis spectra show broad features with long-wavelength absorption maximum around 620 nm and optical band gap of 1． 86 ，1． 83 and 1． 85 eV for pDPPTTZ-T，pDPPTTZ-Se and pDPPTTZ-Py respectively，which give polymers a good overlap of solar spectrum． Bulk heterojunction solar cells were fabricated by blending these polymers with ［6，6］-phenyl-C71-butiric acid methyl ester ( PC71MB) ，and the power conversion efficiency ( PCE) reaches 3． 05% for the as cast pDPPTTZ-T∶ PCBM-based device without optimization，under simulated AM 1． 5 G irradiation of 100 mW/cm2 ．国家自然科学基金(基金号21367004);广西高校人才小高地建设创新团队项目(项目号GJR201147-12)资

Electrochemical Capacitance of MnO_2 /PANI Composite

以P123为模板剂,软模板法制备出纳米MnO2.酸性条件下引入苯胺并聚合,得到了MnO2/聚苯胺复合材料.X射线衍射(XRD)、红外光谱(IR),扫描电子显微镜(SEM)表征观察样品的结构、形貌.循环伏安、交流阻抗、恒电流充放电等测试MnO2/聚苯胺电极的电化学性能.结果表明:引入苯胺改变了样品纳米MnO2的形貌.MnO2/聚苯胺电极比容量高达190.8F·g-1,500次循环电极比容量仅衰减4.7%,库仑效率均保持在97%以上.Nano-MnO2 was prepared by using P123 as a soft template.The MnO2 /polyaniline composite was further prepared by polymerization of aniline with the nano-MnO2 in acidic conditions and was investigated by XRD and IR.The morphology of nano-MnO2 observed by SEM was changed with the introduction of aniline.The electrochemical properties of MnO2 /PANI electrode were investigated using cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopy.The specific capacitance of MnO2 /PANI electrode could reach as high as 190.8 F·g-1,which decayed only 4.7% over 500 cycles.And the coulombic efficiency has been maintained at above 97%.作者联系地址：中南大学化学化工学院;Author's Address: College of Chemistry and Chemical engineering,Central South University,Changsha 410083,Hunan,Chin

Electrochemical Performance of 1-ethyl-3-methylimidazolium Trifluoroacetic to the Electrolyte of Electrochemical Double Layer Capacitor

应用循环伏安法和直流恒流充放电研究了以离子液体1-乙基-3-甲基咪唑三氟乙酸盐([EMIm]CF3COO)和高比表面活性炭电极构成的电化学双电层电容器的电化学性能.实验表明,[EMIm]CF3COO具有高的比电容、良好的循环特性以及高的充放电效率.在离子液体稳定的电化学窗口内,比电容随电化学窗口的增加而增大.能量密度随电流和电化学窗口的增加逐渐提高,功率密度随电流的增加而减小、随电化学窗口的增加而增加,是一种优良的电化学双电层电解液.The electrochemical performance of an Electrochemical Double Layer Capacitor consisted of higher specific surface area activated carbon and ionic liquid CF3COO was investigated by constant current charge/discharge and cyclic voltammegrams(CV) methods.The results indicated that the CF3COO had High specific capacitance,excellent cyclic characteristics and high charge/discharge efficiency.Specific capacitance of the EDLC increased with electrochemical window increase at the range of steady electrochemical window.Energy density increased with current and voltage increase,power density deduced with current increase but increased with electrochemical window increase.These conclusions revealed that the CF3COO was very suitable for the electrolyte of EDLC.作者联系地址：中国科学院山西煤炭化学研究所炭材料重点实验室,中国科学院山西煤炭化学研究所炭材料重点实验室,中国科学院山西煤炭化学研究所炭材料重点实验室,中国科学院山西煤炭化学研究所炭材料重点实验室,中国科学院山西煤炭化学研究所炭材料重点实验室 山西太原030001,中国科学院研究生院,北京100039,山西太原030001,山西太原030001,中国科学院研究生院,北京100039,山西太原030001,山西太原030001Author's Address: 1.Key Laboratory for Carbon Materials,Shanxi Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,Shanxi,China, 2.Graduate School of the Chinese Academy of Sciences,Beijing 100039,Chin

福建梅花山圈养华南虎幼虎与成年虎肠道菌群结构的比较研究

通过对华南虎3只幼虎和5只成年虎粪便微生物16S rRNA基因V4区域进行高通量测序，分析华南虎幼虎和成年虎肠道菌群组成和差异。结果表明，8份样品共检测到501个OTUs，包含17个门和176个属。华南虎幼虎肠道细菌物种Beta多样性显著高于成年虎（P4）。幼虎与成年虎肠道菌群组成的多样性与差异，可为不同年龄阶段华南虎的食物选择提供理论依据

高速列车的关键力学问题

在过去10年时间,中国和谐号系列高速列车经历了一系列速度上的飞跃.在最初引进消化吸收基础上,研制了新一代高速列车并大规模投入运营,伴随这一过程的大量试验与工程实践,大大促进了对高速铁路这样一个车-线-网-气流强耦合的复杂大系统中的关键力学问题的深入理解和全面研究.该文将从6个方面对高速列车研制和运行过程中的典型力学问题的研究进展以及未来的研究方向做一个梳理.考虑到这样一个大系统的复杂性,同时也为了使对高速列车感兴趣的技术与科研人员对这些力学问题有一个比较全面的认识,文中将分别就高速列车的空气动力学、弓网关系、车体振动与车体模态设计、车体运行稳定性、高速轮轨关系、关键结构的运行可靠性和列车噪声

Current research progress in the mechanics of high speed rails

在过去10年时间,中国和谐号系列高速列车经历了一系列速度上的飞跃.在最初引进消化吸收基础上,研制了新一代高速列车并大规模投入运营,伴随这一过程的大量试验与工程实践,大大促进了对高速铁路这样一个车-线-网-气流强耦合的复杂大系统中的关键力学问题的深入理解和全面研究.该文将从6个方面对高速列车研制和运行过程中的典型力学问题的研究进展以及未来的研究方向做一个梳理.考虑到这样一个大系统的复杂性,同时也为了使对高速列车感兴趣的技术与科研人员对这些力学问题有一个比较全面的认识,文中将分别就高速列车的空气动力学、弓网关系、车体振动与车体模态设计、车体运行稳定性、高速轮轨关系、关键结构的运行可靠性和列车噪声

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements