Subjects: Materials Science >> Materials Science (General) submitted time 2022-10-26 Cooperative journals: 《桂林电子科技大学学报》
Abstract： To adopt a low energy consumption and short time-consuming method, high-performance silver selenide (Ag2Se)
based thermoelectric materials was prepared. The different silver-selenium molar ratios (nAgNO3/nSe) silver selenide powder
was synthesized by solvothermal method using ethylenediamine as the solvent, silver nitrate (AgNO3) and elemental selenium
(Se) as raw materials. After spark plasma sintering (SPS) process, the block was obtained. X-ray diffraction (XRD)
and scanning electron microscope (SEM) were used to conduct phase analysis and microscopic morphology observation of the
sample. The thermoelectric performance test system was used to test the pyroelectric performance of the sample. The performance
of the sample was verified by simulation calculation and actual output voltage test of thermoelectric power generation
device. The results shows that with the increase of nAgNO3/nSe, the diffraction peak of the second phase Ag element in
the silver selenide powder increases, which is beneficial to optimize the carrier transport characteristics of the sample. The
highest thermoelectric figure of merit (zT) about 0.74 at room temperature is obtained when the nAgNO3/nSe is 2∶1. A maximum
zT of 1.07 is achieved at 393 K and its average zT value (zTavg) during 303 K~393 K is about 0.82 when the
nAgNO3/nSe is 1.9∶1. Simulation calculation and actual output voltage test of thermoelectric power generation show that the experimentally
prepared silver selenide bulk thermoelectric material is promising to replace N-type Bi2Te3 based thermoelectric material.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-07-20 Cooperative journals: 《广西植物》
Abstract： To identify the molecular mechanisms of on sugarcane (Saccharum officinarum ) responding to cold stress, and find the miRNAs and target genes related to cold tolerance，the leaves of different sugarcane genotypes with different cold tolerance treated for 24 h at 4 ℃ were sampled as the materials for high-through transcriptome sequencing with IlluminaHiSeqTM 2000, and 18 sRNA libraries before and after cold stress were constructed. The results were as follows:（ 1）Total 322 known miRNAs of 84 families were discovered, 110 new miRNAs were predicted. 100 differentially expressed miRNAs were screened out from the known miRNAs (61 up-regulated, 39 down-regulated) and 37 differentially expressed miRNAs (15 up-regulated, 22 down-regulated) were screened out from the new miRNAs. （2）1 844 target genes were predicted by using psRNATarget, TargetFinder and Tapirhybrid software. Three main functional categories of these target genes were revealed via the functional analysis of gene ontology, namely molecular function, cellular component and biological process. （3）In order to verify the high-throughput sequencing data, 14 miRNAs and their target genes were selected for qRT-PCR analysis, which showed that most of the expressions of the 14 miRNAs were detected and consistent with the sequencing results. （4）Some miRNA target genes were identified, which involved in plant growth, development, and cold stress responses. This study shows that miRNA directly or indirectly regulates the expression of target genes in cold-tolerant sugarcane, and plays a key role in regulating the important agronomic traits.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：半蒴苣苔（Hemiboea subcapitata）为苦苣苔科半蒴苣苔属多年生草本植物。该种形态变异幅度大，曾包括多个变种；分布范围广，在多种类型的生境基质上皆有分布。本研究包括典型半蒴苣苔和与之近缘，且曾被归为其变种的翅茎半蒴苣苔(H. pterocaulis)，以及我们新发现的与两者形态上分别最相近的另两种变异类型，对其关键形态、微形态的多样性进行了描述和比较；结合查阅标本、文献资料以及长期的野外追踪调查，统计分析了半蒴苣苔不同类型间的地理和生境分布；此外，通过DNA证据，初步重建各物种及变异类型间的系统发育和单倍型进化关系。研究结果表明：(1)通过茎、叶、花和开花物候等多性状组合能够区分半蒴苣苔复合群各类型。(2)半蒴苣苔复合群四类型间在叶表皮细胞形状和气孔分布等方面无甚区别；而在表皮毛的有无、复表皮层数、维管束数量和排布存上存在差别，或有助于分类。(3)典型半蒴苣苔广泛分布于我国中部至南部，向南延伸至越南北部，在石灰岩、丹霞等生境基质上皆有分布；翅茎半蒴苣苔仅分布于广西桂林市小部分区域的喀斯特山石灰岩基质上；而另两种变异类型则分布更为狭域，仅分布于桂林市永福县一个或相邻的数个喀斯特山石灰岩基质上。(4)DNA单倍型网络图分析表明，半蒴苣苔复合群四类型各自独享单倍型；但重建分子系统发育关系则表明，金钟山居群与翅茎半蒴苣苔聚为一支，两者亲缘关系最近但相互之间不成单系，金钟山居群是否为独立物种还需更多证据加以检验，而半蒴苣苔则与永福半蒴苣苔两者间互为单系，支持两者为独立物种。
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