甲酸钠热分解行为的实验研究

用差热—热重方法对甲酸钠的热分解过程进行了实验研究,采用滴定分析技术分析了甲酸钠在不同条件下热分解产物的组成。研究发现：在甲酸钠脱氢制草酸钠的工艺中,加热速率和反应温度是影响草酸钠收率的重要因素。纯甲酸钠在253℃熔融,在330℃左右缓慢分解为碳酸钠、氢气、一氧化碳和少量草酸钠;高于400℃发生激烈的放热反应,甲酸钠脱氢转化为草酸钠;高于440℃,草酸钠分解生成碳酸钠。因此,为了高收率的获得目的产物草酸钠,需要快速升温,生成草酸钠的最佳温度为400～420℃,过度加热将导致草酸钠深度分解。     

Experimental validation of inter-subspecific genetic diversity in rice represented by the differences between the DNA sequences of ‘Nipponbare’ and ‘93-11’

The pedigrees of three sequenced rice cultivars were analyzed to show that a majority of the genetic composition of 'Nipponbare' originates from japonica cultivars while the minority originates from indica cultivars. In contrast, '93-11' is derived mainly from indica cultivars with a smaller contribution from japonica cultivars. All ancestors of 'Guang lu ai 4' appeared to be indica lines. A set of molecular markers (46 InDels and 53 SSRs) polymorphic between 'Nipponbare' and '93-11' were examined in 46 typical indica and 47 typical japonica cultivars selected from 443 accessions according to Cheng's index. All cultivars were divided into indica and japonica groups without overlapping when clustered by Cheng's index, InDels and SSRs. Much higher InDel and SSR diversity between groups than within groups implies that the marker polymorphisms between 'Nipponbare' and '93-11' represent a large proportion of inter-subspecific diversity. About 85% of indica cultivars and more than 90% of japonica cultivars were confirmed to have the same PCR banding patterns as '93-11' and 'Nipponbare', respectively. Some polymorphic loci between 'Nipponbare' and '93-11' cannot be validated in other indica and japonica cultivars, either as subspecies-specific but not predominant alleles, or alleles not specific between the two groups. It was concluded that molecular markers developed from sequence polymorphism between 'Nipponbare' and '93-11' often represent inter-subspecific diversity, although some exceptions were sensitive to either particular marker loci or particular cultivars.     

巴马水与其他地区水的生命动力元素比较及与巴马人长寿关系的考察

分析了世界首位长寿地区——巴马地区长寿村井水和其他一些地区水中生命动力源相关元素,并根据第四统计力学群子统计参数理论,证实巴马地区长寿村饮用井水的生命动力元素群子参数与人体中胸腺、骨骼肌的很相近,其阴阳性属为（+）（+）（-）（+）高阳性水,具有良好的免疫作用及极佳壮阳、补气功能,而其他地区水的群子参数与胸腺相差较大,不能很好地作用于人体。巴马井水中所含有的锌、锰等生命动力源元素含水络合离子,对世界首寿的巴马人的长寿起到了决定性作用。     

Mapping of genetic modifiers of <Emphasis Type="Italic">Plcd1</Emphasis> in scant hair mice (<Emphasis Type="Italic">snthr</Emphasis><Superscript><Emphasis Type="Italic">1Bao</Emphasis></Superscript>)

The scant hair mutant mouse (locus symbol: snthr ^1Bao ) is a recessive mutation that originated in an ethylnitrosourea chemical carcinogenesis study using the DBA/2J inbred strain. The gene responsible for the mutation was previously determined to be phospholipase C, delta 1 (Plcd1; mutant allele symbol Plcd1 ^snthr1Bao ). To map the modifiers of Plcd1, an intercross (DBA/2J-snthr ^1Bao /snthr ^1Bao × C57BL/6J+/+) was conducted. The F2 mutant progeny exhibited a variety of alopecia phenotypes; all F2 mutants (n=507) were classified into 3 groups (mild, moderate, and severe alopecia) and genotyped based on 96 microsatellites. A major QTL was identified on mouse chromosome (mChr) 15 at 12 cM with an LOD score greater than 7 (P < 0.0001). Three minor QTLs were detected on mChr 2, 5, and 7 at 40, 84 and 48 cM, respectively. The QTLs on mChr 7 and 15 were associated with minor alopecia while the QTLs on mChr 2 and 5 were associated with moderate to severe alopecia. No antagonistic or synergistic effects among or between the 4 QTLs were found. Integrating the functions of the 4 potential regulatory QTLs and mutant Plcd1 ^snthr1Bao , we found that these QTLs might contribute to variations of scant hair severity by altering the Ca²⁺ signal pathways in mouse skin.     

Design and fabrication of superconducting HEB mixer

This paper describes the design and fabrication of superconducting hot electron bolometer （HEB） mixer based on ultra-thin superconducting NbN films. The high quality films were epitaxially grown on high resistance Si substrates. The device was fabricated by magnetron sputtering, electron beam lithography （EBL）, reactive ion etching （RIE）, lithography, and so on. The device＇s resistance-temperature （R-T） curves and current-voltage （I-V） curves were studied. The results of THz response of the device are presented. Y-factor technique was used to measure the device＇s noise temperature. When the device was irradiated with a laser radiation of 2.5 THz, the obtained lowest noise temperature of the device was 2213 K.     

Detection of infrared photons with a superconductor

A superconductor single photon detector based on NbN nanowire was fabricated using electron beam lithography （EBL） and reactive ion etching （RIE） for infrared photon detection. When biased well below its critical current at 4.2 K, NbN nanowire is very sensitive to the incident photons. Typical telecommunication photons with a wavelength of 1550 nm were detected by this detector. Data analysis indicates the repeating rate of the device with 200 nm NbN nanowire may be up to 100 MHz, and the quantum efficiency is about 0,01% when biased at 0.95/c.     

{VO3}nn- 和{M(bpp)(H2O)2}n2n+ 链编织的三维配位聚合物的合成、结构及电化学性质

在水热条件下, 合成了2 个Ni(II)和Co(II)的配位聚合物: [M(bpp)(H₂O)₂V₂O₆]·0.4H₂O(bpp = 1,3-二(4-吡啶)丙烷; M = Ni (1)和Co (2)). 单晶X 射线衍射分析结果表明, 配合物1 和2 是同晶异质体, 是由无限的一维{VO₃}_n^n- 和{M(bpp)(H₂O)₂}_n²ⁿ⁺ 链构筑的三维结构,{M(bpp)(H₂O)₂}_n²ⁿ⁺ 链沿着a 和b 轴方向伸展, 编织成互相穿插的三维结构, 而{VO₃}_n^n- 螺旋链沿c轴方向穿插在{M(bpp)(H₂O)₂}_n²ⁿ⁺ 链编织所形成的孔道中, 并与M(Ⅱ)形成配位键. 电化学测试表明, Li⁺能够可逆地在配合物1 和2 中进出.     

《土力学》网络课件的设计与开发

根据土力学教学大纲的要求，应用计算机网络技术，设计开发了《土力学》多媒体网络课件，课件采用文本、图像、动画等多种形式，形象直观地表现了土力学中难以描述的抽象内容。本文论述了课件的设计原理和方法以及课件系统开发的全过程。     

Acid etching process for fabrication of Bi2Sr2CaCu2O8＋x stack

We adopted a new method, acid etching process, to fabricate the intrinsic Josephson junctions based on the Bi2Sr2CaCu2O8 x single crystals. By soaking the crystals into the dilute hydrochloric acid, we fabricated a junction stack successfully, and meantime made the surrounding area insulated. A certain concentration of hydrochloric acid was used to maintain the roughness of the modified layer. The cur-rent-voltage characteristic was achieved through the four terminal measurement. We could control the junctions' number by changing the concentration and the soaking time. We also found that the thick-ness of the stack was equal to the average height of the insulation layer. Such a simple, convenient and controllable fabrication method with a high yield might widen the applications of the intrinsic Joseph-son junctions.     

光电化学免疫分析研究进展

光电化学分析是近年建立起来的一种基于物质的光电转换特性而进行检测的新型分析方法,它具有灵敏度高、设备简单、易于微型化等特点.光电化学免疫分析则是光电化学分析与免疫反应的结合,体现了光电化学传感的高灵敏度和免疫反应的高特异性.其基本方法原理是,在光照条件下,光电活性物质将免疫反应转变为电信号,从而实现对待测物的定量测定.在过去10年中,伴随着光电化学分析技术的进步,光电化学免疫分析经历了快速发展的过程.本文介绍了光电化学免疫分析的方法原理和特点,对其代表性的研究工作进行介绍和评述,并展望其未来的发展趋势.