The Dynamic Volt-Ampere Characteristics of a Vacuum Arc at Intermediate-Frequency Under a Transverse Magnetic Field

In this study, the changes of a vacuum arc＇s appearance were observed and the volt-ampere characteristics of the vacuum arc at intermediate frequency were analyzed under a transverse magnetic field （TMF）. The TMF and phase shift time were calculated by using the TMF contact model and the large phase shift of the magnetic field at a higher frequency was conductive to the dispersion process of residual plasma. The arc velocity was higher at 800 Hz than at 400 Hz. It can be inferred that TMF will encourage arc movement at 800 Hz. Moreover, the arc movement has an impact on the arc voltage. Because of the increasing length of the arc column with a high arc velocity, the elongated arc causes the arc voltage to increase. Specifically, the volt-ampere characteristics of the vacuum arc are divided into three stages in this paper. The higher the frequency, the greater the initial rate of rise in the arc voltage and the larger the area surrounded by arc volt-ampere characteristics. The correlations between the arc voltage and the amplitude and frequency of the current are also presented.

VOLT-AMPERE CHARACTERISTICS OF CIS-POLY(PHENYL ACETYLENE)

The volt-ampere (Ⅰ-Ⅴ) characteristics of the c/s-poly (phenyl acetylene) (PPA) of cis-transoidal structure has been studied in the temperature range of 253-288K. An ITO/ PPA/ Au sandwich configuration was used for the measurements. Under an applied field of less than 10~5V/ cm it showed ohmic behavior, while the space charge limited current (SCLC) was observed at applied fields above 5×10~5V/ cm. In the ohmic region a conductivity of 1.37×10^(-16)S/ cm was obtained at room temperature with an activation energy of 0.5eV. These data indicate that the conduction is not intrinsic one but is the result of thermal release of trapped carriers. In fact the data in the SCLC region treated according to the theory for a single Gaussian distribution of traps gave a mean trap energy of 0.48 eV with a half-width of 0.4 eV and a total density of trapping states of 5×10^(16)/cm^3.

Co-localization of two-color rAAV2-retro confirms the dispersion characteristics of efferent projections of mitral cells in mouse accessory olfactory bulb

The accessory olfactory bulb(AOB), located at the posterior dorsal aspect of the main olfactory bulb(MOB), is the first brain relay of the accessory olfactory system(AOS), which can parallelly detect and process volatile and nonvolatile social chemosignals and mediate different sexual and social behaviors with the main olfactory system(MOS). However, due to its anatomical location and absence of specific markers, there is a lack of research on the internal and external neural circuits of the AOB. This issue was addressed by singlecolor labeling and fluorescent double labeling using retrograde rAAVs injected into the bed nucleus of the stria terminalis(BST), anterior cortical amygdalar area(ACo), medial amygdaloid nucleus(MeA), and posteromedial cortical amygdaloid area(PMCo) in mice. We demonstrated the effectiveness of this AOB projection neuron labeling method and showed that the mitral cells of the AOB exhibited efferent projection dispersion characteristics similar to those of the MOB. Moreover, there were significant differences in the number of neurons projected to different brain regions, which indicated that each mitral cell in the AOB could project to a different number of neurons in different cortices. These results provide a circuitry basis to help understand the mechanism by which pheromone information is encoded and decoded in the AOS.

Experimental study on the jet characteristics of a steam plasma torch

Thermal steam plasma jet is promising for applications in environmental industries due to its distinctive characteristics of high enthalpy and high chemical reactivity. However, the performance of the steam plasma torch for its generation is limited by the problems of the large arc voltage fluctuation and serious erosion of the electrodes. In this study, a gas-stabilized steam plasma torch which can operate continuously and stably was designed. Experiments were conducted to reveal the effect of the different working parameters, including the anode diameter, the cooling water temperature, the arc current and the steam flow rate, on its Volt-Ampere characteristics, arc voltage fluctuation, thermal efficiency, jet characteristics and electrodes erosion. Results showed that the use of hot water to cool the electrodes can effectively prevent the condensation of steam on the inner wall of the electrodes, thus significantly reducing the arc voltage fluctuations and electrodes erosion. This is crucial for increasing the working life of the electrodes and ensuring long-term stability of the steam plasma torch. In addition, suitable anode diameter can greatly reduce the arc voltage fluctuation of the steam plasma torch and effectively improve the stability of the steam plasma jet. Furthermore, high arc current can effectively reduce the fluctuations of the arc voltage and increase the length and the volume of the steam plasma jet. Finally, using steam as the plasma forming gas can achieve higher thermal efficiency compared to air. An ideal thermal efficiency can be achieved by properly reducing the arc current and increasing the steam flow rate.

Electrical and Optical Characteristics of Electrodeless Lamp

In order to study the methods to enhance the efficacy of electrodeless lamp,volt-ampere characteristics,illuminance and emission spectrum have been investigated in home-built electrodeless lamp experimental system with an electrodeless lamp in shape like QL 85 lamp.The results show that lamp current increases as lamp voltage increases in non-discharge,the current decreases first and then increases as the voltage increases in discharge.The illuminance of electrodeless lamp increases linearly with discharge power increasing,and it decreases linearly with power decreasing.The emission spectrum is different for different bulb and lighting time.The spectrum of Ar 811.5 nm,76.5 nm,750.4 nm and Hg 313.2 nm decrease with lighting time.While the intensity of Hg 407.8 nm increases with lighting time.

1980~2019年成都夏季极端高温事件与其干湿热的时空分布特征

基于1980~2019年成都14个国家气象观测站的逐日气温、气压和相对湿度等数据,统计5类极端高温指标分析成都夏季极端高温的变化,并将成都夏季极端高温分为极端干热型和极端湿热型,利用经验正交函数和傅里叶分解等方法对比分析两者的时空分布特征。结果表明:1980~2019年成都夏季极端高温主要呈西北少、东南多,由西北向东南递增的空间分布;极端高温的强度、频次和持续性在空间分布上有一定差异,成都的西北部和中西部虽有高温天气出现但不易形成持续性的热浪,西部和北部的高温天气更易以持续性的热浪发生,东部和南部则是较强高温热浪的频发区;40年里成都夏季极端高温呈增长趋势并多出现在7月和8月,2006年和2016年为成都夏季极端高温较强的年份。同时,成都夏季的极端高温以极端湿热型为主,且呈增长趋势;过去40年成都极端湿热的增幅整体大于极端干热;极端干热存在2种模态的空间分布型,分别为全区一致型和纬向“三极子”型,相应的时间系数分别在90年代中期和2000年以后出现年际和年代际变化特征;极端湿热主要呈现全区一致的变化特征,对应的时间系数呈增长趋势并有明显的年际和年代际变化特征。

Construction of a broadband impedance spectrum and synchronous DC voltammetry measurement system for solar cells

The current impedance spectroscopy measurement techniques face difficulties in diagnosing solar cell faults due to issues such as cost,complexity,and accuracy.Therefore,a novel system was developed for precise broadband impedance spectrum measurement of solar cells,which was composed of an oscilloscope,a signal generator,and a sampling resistor.The results demonstrate concurrent accurate measurement of the impedance spectrum(50 Hz-0.1 MHz)and direct current voltametric characteristics.Comparative analysis with Keithley 2450 data yields a global relative error of approximately 6.70%,affirming the accuracy.Among excitation signals(sine,square,triangle,pulse waves),sine wave input yields the most accurate data,with a root mean square error of approximately 13.3016 and a global relative error of approximately 4.25%compared to theoretical data.Elevating reference resistance expands the half circle in the impedance spectrum.Proximity of reference resistance to that of the solar cell enhances the accuracy by mitigating line resistance influence.Measurement error is lower in high-frequency regions due to a higher signal-to-noise ratio.

重庆某项目蒸发冷却式热泵机组节能运行研究

分析了某项目全年空调运行的负荷特性,干湿球温度特性对SCOP的影响,从而制订出蒸发冷却式热泵机组的高效运行策略。与传统风冷热泵比,制冷季运行的节能效益优势以及在制热季低温环境下,蒸发冷却式热泵机组制热量高于风冷热泵制热量,可降低设备容量的特点。

泸定百合转录组测序与特性分析

泸定百合是非常优良的种质基因资源,鳞茎研究是其科研和生产的关键环节,然而泸定百合鳞茎的分子生物学研究尚属空白。为揭示泸定百合鳞茎的分子机制,应用高通量测序技术对泸定百合的鳞茎进行转录组分析。原始数据经过生物信息学分析后,共获得4.9G有效数据,43 412条Unigene;所获得的Unigene与NR,GO,COG和KEGG等数据库进行搜索比对后,发现有30 225条和21 531条Unigene分别获得NR和GO注释,14 069条Unigene得到COG注释,GO注释中获得374条Unigene可能作为转录因子参与泸定百合鳞茎的形成与发育;共有10 822条Unigene参与了KEGG代谢途径,其中有571条Unigene注释到次生代谢合成途径,其中66条和23条Unigene分别参与了萜类和生物碱的合成。研究结果为采用生物技术手段提高百合的药用成分的含量及改善其园艺性状积累了基本资料。

遮阴对不同大小种球大百合生长与光合特性的影响

[目的]研究不同程度遮阴对不同种球大小的野生大百合(Cardiocrinum giganteum)生长发育和光合特性的影响,探讨野生大百合的引种驯化机制。[方法]将不同大小野生大百合按周径等级分类进行不同程度(0、45%、70%)的遮阴处理,处理13 d后进行各植株株高、叶片数的测量。处理46 d时进行光合指标如净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)的测定并同步测定光合有效辐射(PAR)及叶温(TL)。[结果]在45%遮阴处理下大百合具有较高的相对生长率、净光合速率、蒸腾速率和气孔导度,胞间CO2浓度较低。70%遮阴处理下大百合生理特性普遍优于全光照,但过度遮阴使光合速率降低,不利于其生长。此外,种球周径越大的大百合生长发育及生理特性相对更优。因此,生产上应用周径相对大的种球和适当调控光照强度,是大百合引种驯化的重要措施。[结论]该研究可以为大百合在城市园林中的应用提供理论依据。

基于CFD的贯流式水轮机叶片改型及性能研究

采用改型和CFD方法,对一贯流式水轮机转轮叶片进行改型优化。采用15条叶高方向从叶片头部到尾部的B样条曲线来对叶片进行参数化,通过调整B样条的控制参数来达到修改叶片几何形状的目的。结果表明,通过对叶片的改型优化,尾水管的水力损失明显有所降低,水轮机在最优工况和额定工况点的效率和空化性能都有所提高。同时也对优化前后的流场进行了详细的分析和比较,模型试验的结果也验证了改型和数值仿真的正确性。

4种球根盆花的生育特性·植物学性状及花期调控研究

[目的]对4种球根花卉郁金香、风信子、洋水仙及朱顶红的生育特性、园艺学性状及花期调控进行研究。[方法]以不同方法栽培郁金香、风信子、洋水仙及朱顶红球根,观察生育特征;通过冷藏、去皮及赤霉素处理,调控花期。[结果]4种球根花卉品种的生育期差异较大,但在昆明地区种植均表现优良,成花率达98%以上。用2℃低温冷藏盆花,可有效地延迟郁金香、风信子、洋水仙的花期;赤霉素处理和去皮处理,可提早郁金香的花期。[结论]该研究可为郁金香、风信子、洋水仙及朱顶红的大规模推广应用提供理论依据。

中国石蒜鳞茎中淀粉粒的分布特征

以中国石蒜为材料,用软件Motic Images Advanced 3.2测量了其鳞茎淀粉粒的形态特征,并统计了不同部位淀粉粒的数目和大小。结果表明：中国石蒜鳞茎的淀粉粒面积范围为10.095-1 993.649μm^2,且随着面积增大淀粉粒出现的频率表现为单峰分布。不同大小的中国石蒜鳞茎中大、小淀粉粒的比例没有显著差异。石蒜鳞茎的上部、中部、下部的大、小淀粉粒的比例无显著差异,但同一个部位的内层、中层、外层鳞片的大、小淀粉粒的比例差异极显著。鳞茎盘中的淀粉粒面积在10.095-296.035μm^2之间。中国石蒜所有的鳞叶均着生在鳞茎盘上,鳞叶间的营养物质运输需要通过鳞茎盘来转运。在鳞茎发育过程中,外层鳞叶的营养物质被消耗供中层鳞叶发育,以满足叶片生长和形态建成,中层鳞叶所积累的光合产物供内层鳞叶的生长发育。

郁金香引种及露地越冬后生长发育性状研究

以从荷兰引种到沈阳地区的16个郁金香品种为试材,对露地越冬后的生物学性状进行观察和统计,研究郁金香生长发育的性状。结果表明:在沈阳地区大多数的郁金香品种在3月下旬萌发,4月中旬前后各品种基本能用肉眼观察到花蕾,始花期集中在4月15—22日。品种‘Senora’、‘Cum Laude’、‘Ravani’、‘Canasta’、‘Mount Tacoma’和‘Black Parrot’的花期较长,达到15d或以上,是布展和城市绿化的理想品种。品种‘Golden Apeldoom’、‘Triumph Blue’和‘Purpled Dream’株高都超过了40.0cm,可以用作切花生产。品种‘Red Baby Doll’、‘Uncle Tom’和‘Canasta’的植株高度均在20.0cm以下,是理想的盆栽品种。品种‘Blue Parrot’的繁殖能力最强,总繁殖率达到620.0%,品种‘Crystal Beauty’和‘Crystal Star’,开花球繁殖率最高,分别为220.0%和200.0%。

不同成熟度东方百合籽球冷藏后的生理生化特性及活力

以生长期为4.0、4.5、5.0、5.5、6.0个月不同成熟度的东方百合籽球为材料,研究(2±0.5)℃下冷藏0、30、60、90、120、150、180 d籽球的生理生化特性及其活性的变化情况.结果显示,成熟度高(生长期5.5、6.0个月)的籽球,其淀粉含量高,水分含量低,可溶性蛋白合成能力强,此时籽球的休眠程度深,冷藏过程中呼吸速率低,能有效清除丙二醛(MDA)的累积,降低膜透性,营养消耗少.表明在培育东方百合小籽球时,其植株在田间的生长期需超过5.5个月,以保证籽球的成熟度,籽球在冷藏过程中的生理衰变慢,活性强,其发芽率和活力指数可满足生产要求.

百合鳞茎腐烂病病原菌的鉴定及生物学特性研究

为确定北京市昌平区百合鳞茎腐烂病的病原菌,采用组织分离、致病性测定、形态学及分子生物学方法对病原菌进行鉴定,并利用菌落生长法和血球计数板孢子计量法研究了主要致病菌的生物学特性。结果表明,引起当地百合鳞茎腐烂病的病原菌为尖孢镰刀菌和腐皮镰刀菌,尖孢镰刀菌在分离数量上占优势,腐皮镰刀菌的致病性较强。尖孢镰刀菌的最适培养基为PDA培养基。菌丝生长和产孢的最适温度为25℃,菌丝生长的最适pH值为5,产孢的最适pH值为7。12∶12光暗交替条件下菌丝生长最快,产孢量最高。菌丝生长的最适碳源和氮源分别为乳糖和硝酸钠,产孢的最适碳源和氮源分别为葡萄糖和甘氨酸。

几种荷兰水仙生物学性状与光合特性

在上海气候条件下,对8个品种的荷兰水仙在种球生长、光合特性等方面进行了田间试验。结果表明,8个品种均能正常出苗、生长、开花、繁殖,但不能结籽;品种"头巾"(Mount Hood)繁殖系数最高,种球产量位居8个品种中第2位,表现最好;品种"迷惑者"(Spellbinder)的母球周径增长最小,抗病性最差,种球数量与重量均出现负增长。对早花品种"荷兰船长"(Dutch Master)和晚花品种"郡主"(Sovereign)进行光合指标测定,结果表明,2个品种的净光合速率(Pn)日变化均呈双峰变化曲线,非气孔因素是造成露地栽培荷兰水仙出现光合"午休"现象的主要原因。

朱顶红在南京地区的引种筛选

引进26个朱顶红品种,在南京地区连栋大棚进行引种筛选试验,从花期、观赏性状和种球特性等方面进行对比分析。结果表明:除‘派比奥’种植第2年未能开花,其余25个朱顶红均能正常生长并且开花;‘棉花糖’、‘娇羞新娘’、‘维加斯’、‘初恋’、‘柠檬冰糕’、‘圣诞快乐’、‘花瓶’、‘双龙’等16个品种具有观赏价值高、适应性强、繁殖系数高等优良特性,适宜在南京地区种植推广。

根外施肥对兰州百合植株生长和鳞茎产量的影响

在陇中半干旱区山坡地大田栽培条件下,采用2因素随机区组试验方法,研究了根外施肥对兰州百合植株生长特性及鳞茎产量的影响。结果表明,叶面喷施磷酸二氢钾可显著增大百合植株的茎秆粗度和鳞茎产量,喷施尿素对增大叶面积作用显著。磷酸二氢钾与尿素配合喷施可有效改善百合植株的生长性状,提高百合鳞茎的产量,其中以磷酸二氢钾和尿素的配合喷施次数均为3次时效果最佳,百合田间株高、茎秆粗度、叶面积和鳞茎产量均达到最高值,分别较对照增加16.7%、17.6%、11.6%和12.4%。建议在大田生产中磷酸二氢钾喷施3次,尿素2～3次即可。

成年大鼠嗅球嗅鞘细胞的分离、培养、纯化与生物学特性的研究

目的探讨成年大鼠嗅球嗅鞘细胞(OECs)的分离、培养和纯化方法,并观察其形态学变化及免疫细胞化学特性。方法采用原代培养技术,从成年大鼠的嗅球分离培养OECs,用差速贴壁+Thy1.1抗体及补体等方法纯化培养OECs,并用碱性成纤维细胞生长因子(bFGF)扩增OECs,倒置相差显微镜下观察OECs的形态变化特点及生长情况,采用GFAP、NGFRp75、S100等抗体行免疫细胞化学染色,根据NGFRp75免疫细胞化学染色结果统计培养的OECs的纯度,并计算OECs的增殖率。结果体外培养的成年大鼠OECs主要为双极或三极细胞,其突起细长。差速贴壁+Thy1.1抗体及补体纯化法的纯化效率高于其他两种。免疫细胞化学染色显示,培养的成年大鼠OECs呈现GFAP、NGFRp75、S100蛋白染色阳性。bFGF能明显促进OECs的增殖(P<0.01),对OECs的形态、纯度没有明显影响。结论差速贴壁+Thy1.1抗体及补体纯化法是一种高效率的纯化培养OECs的方法,bFGF能明显促进OECs的增殖。