Subjects: Biology >> Botany >> Applied botany submitted time 2024-03-26 Cooperative journals: 《广西植物》
Abstract： In this study, the ecological adaptation mechanisms of Anemone shikokiana in two distinct habitats, namely full-light hilltop scrub and shady mixed broadleaved-coniferous forest, were researched by Illumina high-throughput sequencing technology for leaves collected during the flowering stage. Moreover, EST-SSR molecular markers were developed based on SSR locus distribution characteristics. The results were as follows: (1) A total of 53 536 Unigenes sequences were obtained, of which 27 448 were successfully annotated. (2) 5 635 DEGs were obtained after filtering the low abundance genes, 1 600 up-regulated and 4 035 down-regulated genes comparing A. shikokiana in full-light hilltop scrub and in shady mixed coniferous forest. GO classification results showed that 2 460 DEGs were annotated to 2 533 tertiary entries. In addition, 1 051 DEGs were involved in 113 KEGG pathways. (3) The comprehensive analysis of the photosynthesis-antennal proteins pathway related genes revealed that the expression of lhca5 was significantly higher, while the expression of lhca1, lhca2 and lhca3 was significantly lower. Meanwhile, the comprehensive analysis of the flavonoid biosynthesis pathway related genes revealed that the expression of chs, c4h, f3’h, f3h, fls, ans, chi, ccoaomt and hct was significantly higher. (4) A total of 6 006 unigenes containing 7 146 SSRs were identified among 53 536 unigenes by using MISA software from the transcriptome data of A.shikokiana. In the identified SSRs, the dominant repeat motifs were single nucleotide repeats in 106 repetitive motif types. Among the 100 pairs of EST-SSR primers, a total of 68 pairs were effective and 11 pairs with polymorphism, and 24 polymorphic fragments were amplified. Overall, in this paper, the adaptation mechanisms of A.shikokiana in heterogeneous habitats were analyzed at the molecular level, and for the first time EST-SSR molecular markers were developed to fill the gap in this area, which would provide important molecular marker resource for the conservation and utilization of this species.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-26 Cooperative journals: 《广西植物》
Abstract： In this study, the ecological adaptation mechanisms of Anemone shikokiana in two distinct habitats, namely full-light hilltop scrub and shady mixed broadleaved-coniferous forest, were researched by Illumina high-throughput sequencing technology for leaves collected during the flowering stage. Moreover, EST-SSR molecular markers were developed based on SSR locus distribution characteristics. The results were as follows: (1) A total of 53 536 Unigenes sequences were obtained, of which 27 448 were successfully annotated. (2) 5 635 DEGs were obtained after filtering the low abundance genes, 1 600 up-regulated and 4 035 down-regulated genes comparing A. shikokiana in full-light hilltop scrub and in shady mixed coniferous forest. GO classification results showed that 2 460 DEGs were annotated to 2 533 tertiary entries. In addition, 1 051 DEGs were involved in 113 KEGG pathways. (3) The comprehensive analysis of the photosynthesis-antennal proteins pathway related genes revealed that the expression of lhca5 was significantly higher, while the expression of lhca1, lhca2 and lhca3 was significantly lower. Meanwhile, the comprehensive analysis of the flavonoid biosynthesis pathway related genes revealed that the expression of chs, c4h, f3’h, f3h, fls, ans, chi, ccoaomt and hct was significantly higher. (4) A total of 6 006 unigenes containing 7 146 SSRs were identified among 53 536 unigenes by using MISA software from the transcriptome data of A.shikokiana. In the identified SSRs, the dominant repeat motifs were single nucleotide repeats in 106 repetitive motif types. Among the 100 pairs of EST-SSR primers, a total of 68 pairs were effective and 11 pairs with polymorphism, and 24 polymorphic fragments were amplified. Overall, in this paper, the adaptation mechanisms of A.shikokiana in heterogeneous habitats were analyzed at the molecular level, and for the first time EST-SSR molecular markers were developed to fill the gap in this area, which would provide important molecular marker resource for the conservation and utilization of this species.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-27 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] To investigate and analyze the influencing factors of individuals' health information source selection, helps to provide targeted basis for the construction of medical health information resources in China. It also helps to provide efficient service for the public health information acquisition. [Method/process] This study applied grounded theory to analyze the interview texts of 38 individuals' health information source selection behavior, including four stages: open coding, axis coding, selective coding and theoretical model construction. [Result/conclusion] The results indicate that the influence factors of health information source selection of individuals are related to individual conditions-motivation factors, perceived quality factors, relationship and structure factors and information source operation level. Finally, a theoretical framework of influence factors of individual's health information source selection is constructed.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Topic evolution analysis plays an important role in detection the technology frontier detection and innovation strategy deployment. [Method/process] In this paper, the topic evolution analysis process was divided into several steps: topic representation, similarity correlation and intensity evolution calculation. The LDA model was used to represent the topic; content, co-occurrence, and trend similarity were proposed for topic correlation calculations, and the prophet-based pre-train fine-tuning model was used to predict the topic trends. An empirical analysis was conducted using the stem cell field as an example. [Result/conclusion] Experiments show that the Logistic growth model has a R2Score of more than 0.90 for each topic. It shows that the Logistic growth model in Prophet is consistent with the growth trend of topics, and can fit the evolution trend of the topic intensity. The topic evolution model proposed in this paper has certain reference to topic distribution and evolution analysis in specific fields.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The extreme environment of the deep sea has shaped special life processes with great resource potential, and its detection and research are the frontier of international earth science. While the harsh high-pressure environment of the deep sea greatly limits the application of deep-sea sampling and detection technology, the deep-sea in situ detection technology can obtain the component and content information of deep-sea samples without changing the location and state of the measured object, hence it is more and more widely used in the research of deep-sea extreme environment. The deep-sea extreme environment in situ detection technology has a broad prospect. However, as an emerging detection technology, many scientific problems still need to be solved. This study summarizes the international and domestic research progress of deep-sea extreme environment in situ detection technology, and puts forward the future development strategies for the research of deep-sea extreme environment in situ detection technology in China.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-19 Cooperative journals: 《中国科学院院刊》
Abstract： Resource and environmental monitoring have always been an important part of land sustainable management which ground survey and remote sensing monitoring are two fundamental ways. The crowd sourcing geographic data (CSGD) brought by smart phones provides new opportunity for the ground investigation of resources and environment. Meanwhile, the rapid development of cloud computing makes it possible to allow people to process massive remote sensing data much more efficient and accurate. Compared with traditional data acquisition methods, data in the cloud is easier to acquire and process. Based on this, a big data method for environment monitoring is introduced based on CSGD and cloud-based resource data. The large amount of human resources required for traditional resource environment monitoring are no longer needed as the professional services of cloud computing are proposed. It will gradually replace the traditional governmental business on resource survey. The participation of the public avoids a large amount of investment. This approach ultimately leads to efficient and crowd-sourced resource management.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2022-05-18 Cooperative journals: 《计算机应用研究》
Abstract： Bone age assessment is a common method to detect endocrine and growth abnormalities in children. But in deep learning methods, low-quality hand X-ray images reduce the final evaluation accuracy. To solve this problem, this paper proposed an alignment network that increases the area of interest in hand X-ray images. This network uses the Swin Transformer structure as the backbone network to learn image hand similarity and obtain affine coefficients and does not require large-scale hand annotation during the training process. In the bone age assessment network, for the improvement of efficient channel attention and spatial attention mechanism. This paper proposed dual-pool efficient channel attention and asymmetric convolution spatial attention method and combines these two methods in the form of dual attention and Xception network proposes DA-Xception. This paper tested the RSNA dataset, which achieved a mean absolute error of 5.37 months for this bone age assessment method. Compared with other deep learning methods, this method can fully extract features and optimize the evaluation results.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2021-04-13 Cooperative journals: 《干旱区地理》
Abstract：利用 1961—2017 年北疆 37 个地面气象站逐日最低气温观测资料，结合常规气象统计方 法，分析北疆地区初、终霜日和霜期的时空演变特征。结果表明：（1）北疆平均初霜日以 2.2 d·（10a）-1 速率推迟；平均终霜日以 1.7 d·（10a）-1 速率提前；平均霜期以 3.9 d·（10a）-1 速率缩短；初、终 霜日和霜期的主周期均为 2 a 左右。（2）北疆霜期缩短趋势较大（小）的地区，能较好的对应其初霜 日推迟、终霜日提前较强（弱），伊犁州、塔城地区北部及东天山东北部霜期的缩短趋势最为显著， 博州至天山北坡一线居中，阿勒泰地区霜期的缩短趋势最弱。（3）北疆大部分地区初霜日的变 化趋势与海拔高度有很好的相关性，其初霜日的推迟速度随海拔高度的增加而减小，垂直递减率 为-0.077 d·（a·km）-1；秋季气候变暖是初霜日推迟的主要原因，春、秋季气候变暖同时影响霜期缩 短，且秋季的影响更大。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-10 Cooperative journals: 《干旱区研究》
Abstract：人类活动和自然环境的胁迫加速了中亚地区新疆野苹果〔Malus sieversii (Ledeb.)Roem.〕种群栖息环境的丧失，新疆野苹果种群面积和生存力趋于下降。本文以第三纪孑遗植物新疆野苹果为研究对象，野外系统调查新疆野苹果种群的生存现状，比较新疆伊犁和哈萨克斯坦分布的新疆野苹果种群年龄结构及果实产量，对两地当前新疆野苹果种群变化进行了分析。研究结果显示：当前伊犁地区和20世纪70年代哈萨克斯坦新疆野苹果种群的龄级结构主要以中龄(15~50 cm)树为主，而幼龄(0~15 cm)与老龄(50~75 cm)树较少。1969年和1970年哈萨克斯坦的新疆野苹果种群生存力最弱，种群为衰退型(Deevey Ⅲ)，但其产量较高；2016年和2017年伊犁的新疆野苹果种群生存力相对较弱，种群趋于衰退(Deevey Ⅲ)，产量较低；2013年哈萨克斯坦新疆野苹果种群生存力相对最强，种群最稳定(Deevey Ⅱ)；幼龄个体的缺乏是新疆野苹果种群趋于衰退的关键因子。目前，在哈萨克斯坦新疆野苹果保护区内需进行适当放牧干扰，以扩大种子的传播，提高种子的萌发；新疆地区以建立保护区为主，杜绝新疆野苹果的采收和降低野果林内的割草强度，以保护幼苗的生存数量，提高新疆野苹果的种子库，加快新疆野苹果种群更新。
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2019-03-05 Cooperative journals: 《电气工程学报》
Abstract：智能电网技术的发展给高压开关设备智能化提出了新的要求和挑战。本文 依据高压开关智能化要求，自监测、自诊断和自控制能力，设计真空断路器智能化过 程中触头系统电磨损在线监测装置。该装置触头系统磨损量计算采用改进的开断电流 累计加权方法，其中权值的选择和磨损总量的计算依据电寿命曲线采用最小二乘法拟 合得到，该法具有通用性，可应用于不同型号的真空断路器；加权积分系数 K，采用 训练好的 LM-BP 神经网络，进行动态预测，使 K 值的选择更加符合工程实际；采用 燃弧时间感应器对燃弧时间进行采集，且给出燃弧时间感应器的安装位置和采用的屏 蔽措施；硬件处理核心采用 TMS320F2812 微处理芯片，主要负责算法处理、上位机通 信和 CAN-BUS 控制器局域网通信；短路电流采用罗氏线圈进行采集，且设计电流处 理电路，并给出 2812AD 采样校正办法；最后给出触头系统磨损量在线监测软件流程 和设计时应注意的关键技术。
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2019-03-05 Cooperative journals: 《电气工程学报》
Abstract：智能电网技术的发展给高压开关设备智能化提出了新的要求和挑战。本文 依据高压开关智能化要求，自监测、自诊断和自控制能力，设计真空断路器智能化过 程中触头系统电磨损在线监测装置。该装置触头系统磨损量计算采用改进的开断电流 累计加权方法，其中权值的选择和磨损总量的计算依据电寿命曲线采用最小二乘法拟 合得到，该法具有通用性，可应用于不同型号的真空断路器；加权积分系数 K，采用 训练好的 LM-BP 神经网络，进行动态预测，使 K 值的选择更加符合工程实际；采用 燃弧时间感应器对燃弧时间进行采集，且给出燃弧时间感应器的安装位置和采用的屏 蔽措施；硬件处理核心采用 TMS320F2812 微处理芯片，主要负责算法处理、上位机通 信和 CAN-BUS 控制器局域网通信；短路电流采用罗氏线圈进行采集，且设计电流处 理电路，并给出 2812AD 采样校正办法；最后给出触头系统磨损量在线监测软件流程 和设计时应注意的关键技术。
Subjects: Dynamic and Electric Engineering >> Electrical Engineering submitted time 2019-03-05 Cooperative journals: 《电气工程学报》
Abstract：本文采用 Matlab 软件的动态仿真工具 Simulink 及其电力系统工具箱 PSB 对小电流接地系统进行故障仿真，论述了模型的搭建步骤。主要分析了接地类故障零 序电压、零序电流的波形特征；分析了两相短路、三相短路短路电流的波形特征；分 析了两相接地短路系统零序分量以及故障相电压的波形特征。对系统的主要故障线路 始端以及故障区段两端波形进行仿真，观察波形更易于识别各故障的主要特征，了解 不同故障波形特征的差异，进而便于后续故障检测以及故障识别的研究，为小电流接 地系统故障规律分析提供了依据，对于小电流接地系统故障检测算法与检测设备的研 制具有重要意义。
Subjects: Biology >> Zoology submitted time 2018-12-25 Cooperative journals: 《动物营养学报》
Abstract：胃饥饿素（Ghrelin）又称作生长激素释放肽，作为脑肠肽，其可促进鱼类摄食。有研究报道禁食或摄食前可提高鱼类Ghrelin表达水平，中枢或外周注射Ghrelin可增加鱼类的摄食量。本文根据Ghrelin在哺乳动物和鱼类上的研究进展，阐述了Ghrelin结构、组织分布和对鱼类摄食的调控及相关机制，为今后鱼类摄食调控和生长的研究和生产实践提供理论依据。
Subjects: Astronomy >> Astrophysical processes submitted time 2018-07-23 Cooperative journals: 《天文研究与技术》
Abstract： 图像模拟在天文学研究中已经发挥越来越重要的作用，其重要性主要表现在以下几个方面：通过模拟可以为准备研制的天文观测设备评估提供重要的依据；通过对模拟数据的处理可以验证数据处理的算法。本文对图像模拟的整个过程进行描述，并在计算上对图像模拟的局部方法进行优化，使模拟结果能够高效准确的生成。本文所做的主要工作包含以下几个方面：对天体的形态的模拟，包括点源（如恒星）和展源（星系），而这里主要是对展源建模；模拟观测条件，主要是仪器和天光背景等产生的噪声；模拟点扩散函数（PSF）；从计算和程序上的方法对计算流程进行优化；对结果进行分析。本文中所采用的数据是哈勃超深空场（HUDF）ACS WFC i(F775)波段的数据，其极限星等达到
Subjects: Mechanical Engineering >> Other Disciplines of Mechanical Engineering submitted time 2018-06-15 Cooperative journals: 《电气工程学报》
Abstract： Vacuum circuit breakers (VCBs) are widely used in power systems to control and protect power lines and power equipments under the conditions of normal, overload, short circuit and other faults. Once a VCB is unable to interrupt or make a current as designed, especially for the short circuit current, heavy losses would be brought about to both the power system and the consumers. In order to reduce the number of accidents and prevent possible troubles due to the failures of VCBs, one valid way is to monitor their performance and condition on-line. Based on the understanding and development of condition based maintenance (CBM) of high-voltage circuit breakers, the authors give some general introduction to electrical endurance on-line condition monitor for VCBs, in which the stress put on the non-intrusive method and device for determination of the arcing duration. The principle and configuration for arcing duration detect are emphatically expounded in our research, in which the electromagnetic induction theory is adopted for the arcing initialization and duration detect. The simulation and experimental results of the arcing detect device are provided in detail. The accuracy and stability of the arcing detect device have been demonstrated and it can distinguish co-existing arc signals in three-phase of circuit breakers. In the end, an algorithm for the electrical endurance of vacuum circuit breakers on-line condition monitoring system is proposed, which based on TMS320F2812 one type of DSP281X series produced by texas instruments semiconductor. The universally accepted approach of accumulative breaking current of high voltage circuit breaker contact to diagnose electrical endurance is used in the high-voltage circuit breakers electrical endurance on-line monitor system.
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本文旨在研究颈静脉灌注精氨酸对泌乳中期奶牛血清生化和免疫指标的影响。采用3×3复式拉丁方试验设计，选择6头体重、胎次、泌乳期、泌乳量和体况基本一致的荷斯坦奶牛为试验动物，随机分为3组（每组2头），分别为酪蛋白组（对照组）、精氨酸组[灌注37.66 g/(L·d)]、丙氨酸组[与精氨酸组等氮，灌注77.24 g/(L·d)]；每个试验期为22 d（7 d灌注+15 d间隔），在每个试验灌注期的最后1 d晨饲前采血，测定血清生化和免疫指标。结果表明：精氨酸组的奶牛血清中总蛋白、免疫球蛋白G(IgG)、肿瘤坏死因子α（TNF-α）浓度要显著高于其他2组（P0.05）。综上，灌注精氨酸能够通过提高血清总蛋白、IgG及IL-1、TNF-α的浓度，从而一定程度上增强泌乳奶牛机体的免疫力和胎儿的被动免疫力。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮异亮氨酸水平对肥育猪生长性能、胴体性状和肉品质的影响。选取体重为（77.0±0.1） kg的杜×长×大三元杂交去势公猪72头，随机分为3组，每组6个重复，每个重复4头猪。4组试验猪分别饲喂含0.25%（低异亮氨酸水平，表现为异亮氨酸缺乏，L-Ile组）、0.39%（NRC推荐异亮氨酸水平，N-Ile组，作为对照组）和0.53%（高异亮氨酸水平，表现为异亮氨酸超量添加，H-Ile组）标准回肠可消化异亮氨酸的饲粮。试验期为28 d。结果表明：饲粮异亮氨酸水平对肥育猪的平均日增重和平均日采食量没有显著影响（P>0.05），但L-Ile组料重比较对照组显著增加（P<0.05）；随着饲粮异亮氨酸水平的增加，肥育猪背最长肌肌内脂肪含量线性提高（P<0.05），而剪切力线性下降（P<0.05）；与对照组相比，采食异亮氨酸缺乏饲粮的肥育猪的背膘厚、眼肌面积和肉色评分显著降低（P<0.05），采食异亮氨酸缺乏或超量添加饲粮的肥育猪的热胴体重、屠宰率以及背最长肌滴水损失和黄度值均显著降低（P<0.05）；随着饲粮异亮氨酸水平的增加，血清甘油三酯含量线性提高（P<0.05），血清尿素氮含量线性下降（P<0.05）；与对照组相比，采食异亮氨酸超量添加饲粮的肥育猪的血清葡萄糖含量显著增加（P<0.05），采食异亮氨酸缺乏饲粮的肥育猪的血清中游离的必需氨基酸、非必需氨基酸和总氨基酸的浓度显著降低（P<0.05），而采食异亮氨酸缺乏或超量添加饲粮的肥育猪血清总胆固醇、低密度脂蛋白和高密度脂蛋白含量均显著降低（P<0.05）。由此得出，饲粮中异亮氨酸缺乏对肥育猪生长性能、胴体性状和肌内脂肪含量有负面影响，而超量添加异亮氨酸会显著改善肌肉的剪切力和滴水损失，增加肌内脂肪含量，但会以降低热胴体重、屠宰率为代价。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：调控猪各个阶段的采食量是动物营养研究的热点问题。风味剂主要有香味剂、甜味剂、鲜味剂，可以改善饲粮的适口性，提高猪对饲粮的喜爱程度，也可以缓解因环境变化、饲料原料改变等应激反应导致的采食量下降。猪的嗅觉系统特别发达，灵敏度很高，味觉也要比人类敏感，因此在饲粮中添加风味剂主要通过刺激猪的嗅觉和味觉来使摄食中枢兴奋，进而促进猪采食。本文综述了饲粮中添加风味剂对猪采食量的影响及其作用机理，为相关试验提供理论依据。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本文主要研究颈静脉灌注精氨酸对泌乳奶牛养分消化和氮利用的影响。采用3×3拉丁方试验设计，6头体重、胎次、泌乳期、泌乳量、体况基本一致的荷斯坦奶牛随机分为3组（每组2头）：酪蛋白模式组（颈静脉灌注酪蛋白模式的氨基酸混合物，对照组）、精氨酸组（颈静脉灌注精氨酸）、丙氨酸组（颈静脉灌注与精氨酸组等氮的丙氨酸）；每试验期22 d，包括7 d的灌注期和15 d的间隔期。测定其尿、血清、乳中尿素氮浓度及养分表观消化率指标。结果表明：尿、血清中尿素氮浓度在组间无显著差异（P>0.05），精氨酸组乳中尿素氮浓度显著低于对照组和丙氨酸组（P<0.05）；精氨酸组干物质、有机物、粗蛋白质、中性洗涤纤维的表观消化率皆显著高于丙氨酸组（P<0.05）；乳蛋白氮产量以精氨酸组最高，显著高于其他2组（P<0.05）；乳蛋白氮占摄入氮比例也以精氨酸组最高。综上，灌注精氨酸对泌乳中期奶牛氮的消化、利用有一定的促进作用，可提高乳蛋白氮产量及其占摄入氮比例。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本文旨在研究颈静脉灌注精氨酸对泌乳中期奶牛泌乳性能和牛乳酪蛋白合成的影响。将6头体重、胎次、泌乳期、泌乳量和体况基本一致的荷斯坦奶牛随机分为3组（每组2头）：酪蛋白模式组（对照组）、精氨酸灌注组、丙氨酸等氮组（与精氨酸灌注组等氮），采用3×3复拉丁方试验设计，每期22 d（7 d灌注期+15 d间隔期），测定其泌乳性能、酪蛋白含量以及酪蛋白基因的表达情况。结果表明：1）灌注的第5天精氨酸灌注组的乳蛋白及乳中非脂固形物含量均显著高于酪蛋白模式组（P0.05）；κ-酪蛋白含量则以精氨酸灌注组为最高，显著高于其他2组（P<0.05）。3）精氨酸灌注组αs1-酪蛋白基因（CSN1S1）、αs2-酪蛋白基因（CSN1S2）的表达量显著高于其他2组（P<0.05）。综上，灌注精氨酸提高了乳蛋白中α-酪蛋白和κ-酪蛋白含量，以及CSN1S1、CSN1S2在奶牛乳腺组织的表达量，有利于牛乳中乳蛋白率和乳品质的提高。
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