Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：随着国内经济发展的速度持续加快,广播电视行业进入到繁荣发展时期。现阶段,广播发射机的应用较为普遍,其操作相对简单,而且具有较强的功能,可以保证广播活动的实际需要得到切实满足。相较于电子管板调发射机,1kW中波广播发射机的优势更为明显,其具有良好的稳定性,体积不大,而且重量较轻。此种发射机虽然拥有较大优势,然而在应用时出现的问题较多,这就要求技术人员履行好自身的职责,切实做好维护工作。本文主要对1kW中波发射机使用过程中出现的各种故障展开深入探析,在此基础上寻找切实可行的处理之策,并要保证维护工作能够切实做到位。
Subjects: Biology >> Botany submitted time 2022-12-01 Cooperative journals: 《广西植物》
Abstract：
Quercus gilva is a precious timber tree species in middle subtropical China. In order to investigate the phenotypic diversity, phenotypic variation pattern and the major geographic and climatic factors influencing phenotypic variation of Q. gilva populations, 15 growth and leaf traits of 115 individuals from 14 natural populations were measured and then the phenotypic diversity, variation pattern and the correlation between phenotypic variation and geographic and climatic factors were studied using nested analysis of variance, phenotypic differentiation coefficient, correlation analysis, principal component analysis and cluster analysis. The results were as follows (1) The average variation coefficient and the average Shannon-Wiener index of 15 phenotypic traits were 35.07% and 1.998, respectively. Variation coefficient and Shannon-Wiener index of 14 populations ranged from 14.94% (Dongkou) to 35.56% (Longshan) and from 1.127 (Songyang) to 1.980 (Changning), respectively. These results indicated that Q. gilva showed a relatively high level of phenotypic diversity. (2) Significant differences in 15 phenotypic traits were found among and within populations (P<0.01), with an average phenotypic differentiation coefficient of 41.49%. This elucidated that the phenotypic variation within populations was greater than that among populations. (3) Correlation analysis showed that there were significant correlations among parts of the traits, whereas no correlation was found between phenotypic traits and geographic factors. Precipitation was the major factor that influenced the phenotypic traits of Q. gilva. (4) Principle component analysis indicated that the first four principal components explained 82.96% of total phenotypic contribution rate of Q. gilva. (5) Cluster analysis revealed that 14 Q. gilva populations were divided into three groups according to their different leaf and petiole size, which was not related to the geographic distribution of populations. This study provides scientific basis for the protection and utilization of Q. gilva germplasm resources, and lays an important foundation for 基金项目：国家自然科学基金（32201589）；湖南省自然科学基金（2021JJ41069）；湖南省林业科技创新 资金项目（XLKY202218）；福建省公益类科研院所专项（2022R1010007）[Supported by National Natural Science Foundation (32201589); Natural Science Foundation of Hunan Province (2021JJ41069); Forestry Scientific and Technological Innovation Project of Hunan Forestry Department (XLKY202218); Public Research Institutes Special Project of Fujian Province (2022R1010007)]。
Subjects: Biology >> Botany >> Applied botany submitted time 2021-12-19 Cooperative journals: 《广西植物》
Abstract： Sect. Chrysanthae have high ornamental value, but their classifications are controversial. In order to study the morphological characteristics and taxonomic significance of pollen in sect. Chrysanthae, we observed morphological shape, exine ornamentations and perforation characteristics of 10 species of sect. Chrysanthae pollen grains by scanning electron microscope, and the polar axis, equatorial axis and germination ditch length were analyzed by cluster. The results were as follows: (1) The pollen of sect. Chrysanthae was single, medium size and most of them were subspherical, only C. indochinensis var. tunghinensis was oblate sphere and C. impressinervis was prolate; The extine ornamentation of pollen could be broadly divided into three types: ornate, verrucate and tuberculate-baculate, and the size and density of various surface perforation were obviously different. (2) Cluster analysis showed that the pollen morphology of C. perpetua, C. petelotii var. grandiflora, C. petelotii and C. euphlebia were proximity ; C. flavida, C. micrantha and C. indochinensis var. Tunghinensis had similar characteristics. However, C. pubipetala and C. impressinervisare were clearly different from the others. The extine ornamentation and perforation of pollen were different, but it was still necessary to combine the polar axis, equatorial axis and the length of germination groove to clearly distinguish the 10 species of sect. Chrysanthae. From the perspective of palynology, the pollen of sect. Chrysanthae has the general characteristics of Camellia without specificity, and this group of plants may not be an independent group, but the pollen morphology of this group of plants has obvious inter-specific differences, which can be used as the basis for taxonomy. The results of this study provide the basis for the taxonomic status among species of Camellia.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-08-27 Cooperative journals: 《广西植物》
Abstract：本研究采用聚乙二醇（PEG-6000）模拟干旱胁迫，测定了发芽率、发芽势和胚根长度等指标，运用相关性分析、聚类分析和隶属函数法综合评价梓树6个种源种子萌发期的抗旱性大小，初步筛选出抗旱性较强的种源，以期为我国楸树嫁接繁育选出良种砧木，促进我国楸树良种繁育，为其规模化应用奠定物质基础。结果表明：随着溶液水势的降低，6个种源种子的发芽率、发芽势、相对发芽率、发芽指数、活力指数表现出持续下降趋势；除河南洛阳种源的胚根、胚轴长度以及甘肃正宁种源的胚根长度外，其余种源胚根、胚轴长度均表现为逐渐下降趋势；溶液水势为-1.0 MPa时，河南洛阳种源失活，其余种源各指标趋于一致。将各种源种子发芽特性与原产地地理环境因子进行相关分析表明，种子活力指数与经、纬度呈显著正相关（0.903和0.871），经纬度较大的种源活力更强，抗旱性更佳；年均气温越高，种子发芽率和活力均降低；年降雨量与种子的发芽率和活力指数呈中偏弱的负相关，但与胚根和胚轴的生长呈中等正相关。温度和降雨量对梓树种子的抗旱性有一定影响，主要体现在年均温和年降雨量越低，种子的发芽率越低。初步发现处于干旱和寒冷等相对恶劣环境下的梓树种源表现出以提高种子发芽率，降低种子胚生长活性的调节机制来适应不良环境。鉴于相关分析具有一定局限性，运用聚类分析及隶属函数法对6个种源梓树种子萌发期抗旱性进行抗旱性综合评价，辽宁恒仁种源种子抗旱性最强，而河南洛阳种源种子抗旱性最弱。综上所述，梓树6个种源抗旱性差异明显，温度和降雨量在一定程度上影响了种子萌发的抗旱性。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-12-19 Cooperative journals: 《广西植物》
Abstract：为研究金花茶组植物花色与细胞内重要环境因子的关系，以花色不同的8个金花茶组物种的9个居群为试材，测定了其花瓣的颜色、总黄酮含量、含水量、细胞pH, 7种金属离子浓度。结果表明，所测金花茶组植物的花色平均值明度L为80.82、色相a‘为一2.88、色相b‘为53.97、彩度C为54.10、色相角h为93.19，故金花茶花色为明度较亮的黄色，其中色相b‘为描述黄色的主要指标，据此可将所测植物分为金黄、黄、浅黄3类。花瓣总黄酮含量为20.17%，花瓣含水量为88.14%，物种间均达到差异显著，且均与花色呈弱相关，对黄色呈现影响较小。花瓣细胞偏弱酸性，pH平均值为6.19，不同物种间差异显著，细胞pH与花色呈显著正相关，即中偏弱酸性细胞环境有利于金花茶花瓣黄色的呈现。金属离子浓度中，K+含量最高(12.61 mg "g-1)，依次为Cat+(3.91 mg "g-1), Mgt+(1.28 mg "g-1), A13+(0.98mg·g-1), Na+(0.17 mg·g-1), Fe3+(0.07 mg·g-1) } Cu2+含量最低(0.0038 mg·g-')} 7种金属离子在所测植物间均存在显著差异，其中A13+, Fe3+和Cat+}IJ对金花茶黄色花色的形成具有不同程度的干扰作用，随着这3种金属离子浓度升高，黄度降低，花色变淡，因此较低浓度的A13+, Fe3+, Ca2+可能更有利于金花茶黄色花的呈现。
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