Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：媒体融合和全媒体传播是当前社会发展的一个重要趋势,同时也是中央政治局第十二次集体学习的主要内容。在人类传播不断改变、传播基础技术日益成熟的背景下,全媒体传播格局的形成是必然的结果。从系统建设的角度来说,需要打造一个包容所有媒体形式、实现传播效果最大化和传播结构最优化的体系,以此来建立起与用户之间的新连接。从制度的角度来说,全媒体传播格局的构建需要数字转化制度、市场运作制度、媒体普及制度的辅助。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] To explore the influencing factors of user's purchase intention for knowledge of virtual community, will help to understand the knowledge payment behavior of users in virtual community, and help knowledge creators and virtual community service providers to understand user's needs. This paper aims to improve the quality of knowledge and optimize the allocation of resources to provide reference.[Method/process] Based on the theory of perceived value, this paper studies the knowledge payment behavior of virtual community users, constructs the structural equation model of knowledge payment, reveals the key factors and the mechanism that affect the user's knowledge payment, and uses the questionnaire survey method to collect 321 valid samples Data. Then it uses partial least squares structural equation model method to analyze the data.[Result/conclusion] The perceived value of virtual community users significantly affects their purchase intention. Perceived benefit (perceived usefulness and perceived trust) significantly affect perceived value. Perceived sacrifice (perceived risk and perceived cost) has a significant negative impact on perceived value. The perceived value is completely mediated by perceived gains and perceived benefit and sacrifice. The word of mouth negatively moderates the perceived value to the purchase intention.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Comparing users' perceptions of data intelligence and expert knowledge from the perspective of trust will help to understand the user's current trust status and differences between these two types of typical decision-making information sources, and then provide suggestions for the further application of data intelligence and the effective integration of data intelligence and expert knowledge. [Method/process] Based on the classic two-dimensional classification of trust, namely cognitive trust and emotional trust, a measurement scale including two pairs and four potential variables was designed. A total of 342 valid samples were collected by questionnaire survey. Descriptive statistics and paired sample t-test were employed for data analysis. [Result/conclusion] The study found that users' cognitive trust in data intelligence is significantly higher than expert knowledge, while their emotional trust in data intelligence is significantly lowerthan expert knowledge.
Subjects: Biology >> Bioengineering submitted time 2017-11-21 Cooperative journals: 《中国生物工程杂志》
Abstract：肉桂酰辅酶A还原酶（cinnamoyl-CoA reductase, CCR）是催化木质素合成特异途径的第一个限速酶，对木质素的合成起关键作用。本文从中间锦鸡儿中克隆了两个CCR基因，CiCCR2和CiCCR3，其中CiCCR2基因开放阅读框为897bp，编码299个氨基酸，CiCCR3基因开放阅读框为966bp，编码322个氨基酸。过表达CiCCR2和CiCCR3转基因拟南芥株系幼苗期和成熟期木质素含量均高于野生型，组织化学染色也表明转基因株系木质素积累较野生型拟南芥多，且转基因株系鲜重和干重显著高于野生型。
Subjects: Biology >> Bioengineering submitted time 2017-11-21 Cooperative journals: 《中国生物工程杂志》
Abstract：肉桂酰辅酶A还原酶（cinnamoyl-CoA reductase, CCR）是催化木质素合成特异途径的第一个限速酶，对木质素的合成起关键作用。本文从中间锦鸡儿中克隆了两个CCR基因，CiCCR2和CiCCR3，其中CiCCR2基因开放阅读框为897bp，编码299个氨基酸，CiCCR3基因开放阅读框为966bp，编码322个氨基酸。过表达CiCCR2和CiCCR3转基因拟南芥株系幼苗期和成熟期木质素含量均高于野生型，组织化学染色也表明转基因株系木质素积累较野生型拟南芥多，且转基因株系鲜重和干重显著高于野生型。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-10-20 Cooperative journals: 《中国生态农业学报》
Abstract：安徽省从一个灾害频发的穷省, 经过60 多年的艰苦奋斗, 目前具有350 亿kg 的粮食生产能力, 是解放初期63.9 亿kg 的5.5 倍, 已经成为我国五大粮食调出大省之一, 粮食总产到2020 年有望达到400 亿kg, 在我国农业区域发展和粮食安全保障中占有重要地位。但安徽省农田水利建设薄弱、多数地区靠雨养农业, 中 低产田面积占耕地面积的60%左右; 农业机械化发展缓慢, 农业管理粗放, 单产普遍较低; 远远没有发挥其自然资源禀赋的生产潜力, 是我国未来中低产田重点改造的地区。本文提出安徽省粮食安全和现代农业的发展战略是: 在绿色提质增产增效的总体方针指导下, 在区域治理方面, 重点改造淮北砂姜黑土中低产田面积, 扩大建设淮河流域吨粮县市; 在区域发展模式方面, 主抓沿江淮(水稻-小麦)和淮北平原(小麦-玉米)粮食生产及深加工主体功能区农业现代化建设, 拓展江淮丘陵发展经济林果业和特色养殖业, 加快发展皖南及皖西大别山区绿色生态产业; 在农业基础建设方面, 突出农田水利工程建设, 加快投资大中型农业机械化普及, 创建绿色提质增效防灾减灾体系; 在种植业结构调整方面, 继续坚持水稻提升, 小麦高产、玉米振兴, 兼顾油料作物(油菜、大豆)调节; 在作物品种优化布局方面, 淮南地区减籼稻扩粳稻稳定油菜, 沿淮和淮北地区是减弱冬小麦扩半冬性优质小麦, 改中晚熟玉米为中早熟籽粒脱水快优质品种。创建出具有安徽省特色、水热资源高效利用(800~1 000 mm 降水)、投入少、快速改造大面积中低产田、延伸绿色优质高效农产品产业链, 是保障粮食安全的现代农业发展之路。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：皖北、苏北、鲁西南和豫东南的4 省交界地区, 有以淮北平原为主的砂姜黑土、黄泛区为主的风沙盐碱地等易旱易涝中低产田面积400 万hm2 以上, 虽然处于南北过渡带的黄淮南片, 温热降水等自然资源条件较好, 但因地理偏远、交通不便, 科技文化和社会经济发展相对落后, 农业高产潜力还未发挥。加快黄淮南片中低产田改造, 建设黄淮南片第二粮仓, 可以新增粮食50 亿kg, 在区域现代农业发展和保障我国粮食安全中具有重要作用。根据气候变暖和绿色提质增产增效的现代农业发展态势, 提出以下黄淮南片粮仓现代农业发展战略: 在种植业方面, 第1 是培育抗赤霉病的小麦品种, 利用综合防治措施减轻小麦赤霉病的危害; 第2 是培育耐旱耐涝、脱水快适合机械化粒收的玉米新品种并快速示范推广; 第3 是扩大吨粮田建设, 确保黄淮南片和国家粮食安全。在区域治理方面, 重点改造淮北砂姜黑土、黄泛区的风沙盐碱地等易旱易涝区的中低产田, 加强农田排灌系统基础投入, 建设旱涝保收、林网路、渠井电配套的高标准农田。在现代科技装备方面, 要加大农机补贴, 增加大中型农机的数量, 加强深翻深松农机的示范推广, 普及农作全程机械化。在绿色提质增效方面, 积极推行化肥农药减施, 扩大环境友好型的绿色生物肥料制剂等应用, 加强秸秆还田和生物资源等循环高效利用。在科技教育方面, 要扩大职业教育规模, 培养知识农民, 专业服务工人, 打造社会化服务的专业队伍。在区域经济发展方面, 在皖北做强做大粮食品牌化生产, 在苏北做大粮食规模化生产和培育现代新型产业,在鲁西南做好农林牧协同高效发展, 在豫东南打造中国食品深加工的旗舰。在农业信息化建设方面, 加大“互联网+”农业的普及, 带动订单农业、外销农业、观光农业等的快速发展。建议国家及早启动黄淮南片第二粮仓重点科技专项, 将黄淮南片粮食主产区和经济塌陷区建设成为国家主体粮仓和农业经济新兴区及环境优美的可持续发展区。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-07 Cooperative journals: 《中国生态农业学报》
Abstract：酞酸酯(PAEs)又称邻苯二甲酸酯, 是环境激素类有机化合物, 作为增塑剂在塑料、树脂和橡胶制品中的添加量一般为20%~60%。土壤中PAEs 的主要来源有农用化学品、污水灌溉和大气沉降。PAEs 在土壤中有较强的富集作用, 并能通过一系列的环境地球化学过程进入不同的环境介质, 引起环境污染和人类健康风险。本文结合国内外土壤PAEs 的相关研究成果, 综述了我国土壤PAEs 的污染现状, 分析了PAEs 在土壤-大气界面(挥发、沉降)、土壤-植物系统(植物吸收、植物修复)、土壤-水界面下的环境行为(吸附-解吸)及土壤PAEs污染的环境健康风险, 并指出国内土壤PAEs 研究中存在的不足。研究结果显示, 我国土壤环境总体上已遭受不同程度的PAEs 污染; 同时, 土壤PAEs 通过不同界面之间的迁移转化过程, 也面临较高的生态环境健康风险。提出今后土壤PAEs 研究应以区域土壤污染与环境行为为重点, 深入研究土壤PAEs 的时空传输与演变规律、多介质迁移转化机制和风险削减与修复措施, 为保障土壤生态环境与健康提供理论依据。
Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-30 Cooperative journals: 《广西植物》
Abstract： To explore the effects of land use and ecological restoration on soil enzyme activities and C:N:P ratios in the karst ecosystem, three land use types [disturbed land, pasture grassland, and orchard forest (Loquat)] and four restoration types (evergreen forest, deciduous forest, evergreen-deciduous mixed forest, and natural restoration forest), which are long-term positioning observation experimental plots of the Huanjiang Observation and Research Station for Karst Ecosystems, were selected. We measured the activities of four soil enzymes [β-1,4-glucosidase (βG), β-1,4-N-acetylglucosidase (NAG), leucine aminopeptidase (LAP), and alkaline phosphatase (ALP)], and analyzed the relationship between activities level and the C:N:P ratios and soil-associated physical and chemical factors. The results were as follows: (1) Enzyme activities were higher in the three land use types than in the restoration types. In addition, the activities of the four enzymes, enzymatic N:P, and enzymatic C:P of pasture grassland were higher than those in the other restoration types. The βG and ALP activities in the evergreen-deciduous mixed and deciduous forests were significantly higher than those in the natural restoration and evergreen forest, and NAG activity in the evergreen forest was significantly higher than that in the other three restoration types. The enzymatic N:P ratios of the evergreen-deciduous mixed forests were significantly lower than those in the other restoration types, as was the enzymatic C:P ratio of the deciduous forest. In addition, vector analysis of the enzyme activity measurement ratio showed that all land use and restoration types were limited by P. (2) The activities of the four enzymes were positively correlated with organic C, ammonia N (NH4+-N), and nitrate N (NO3--N), whereas negatively correlated with total P (TP). βG activity was positively correlated with available P (AP) and ALP activity was positively correlated with total N (TN). (3) Redundancy analysis showed that the levels of TP, NH4+-N, NO3--N, and AP explained 38.3%, 9.5%, 9.3%, and 8.0%, respectively, of the changes in soil enzyme activity and C:N:P ratios. Based on these results, the different land use and restoration types in karst areas were shown to generally exist under the limitation of soil P, which implies that the fixation and transformation of P should be the focus of soil quality improvement in the land use development and restoration process. Furthermore, soil enzyme activities, C:P ratios, and AP contents in pasture grassland, evergreen-deciduous mixed forest, and deciduous forest were higher than those in the other land use and restoration types. The result indicates that forage and deciduous plants are important for soil nutrient cycling and should be considered in the process of karst land use and restoration.
Subjects: Biology >> Ecology submitted time 2017-11-29 Cooperative journals: 《中国生态农业学报》
Abstract： Based on a long-term experiment on maize-soybean relay intercropping system in Huanjiang Observation and Research Station for Karst Ecosystem, Chinese Academy of Sciences, the effects of straw in place of chemical potassium on the yield of spring maize and soil potassium balance were investigated, aiming to provide scientific basis for the rational use of straw and fertilizer in karst peak-cluster depression. The experiment was started in 2006, and the data were collected during 2010-2014. Four treatments with four repetitions were discussed in this study, including CK (no fertilizer), NPK (chemical fertilizer), C7S3 (in which 30% K from the straw and 70% K from the chemical fertilizer.), C4S6 (60% K from the straw and 30% from the chemical fertilizer). The results showed that: ⑴ the annual yields of spring maize in fertilization treatments during the 5 years were 4.12 ~ 4.17 times than that in no fertilizer treatment. The corn yields in C7S3 and C4S6 were 98.3% and 98.7% of that in NPK, respectively. The yields of grain and straw increased with time on. ⑵ compared with CK, fertilization application could significantly increase the K amount in maize straw with 2.21 ~ 2.53 times than that in CK. And fertilization application could significantly increase N, P and K absorption amounts in maize grain (P < 0.01), but there was no significant difference among fertilizer treatments (P > 0.05). ⑶ there were no significant differences for recovery efficiency, absorption efficiency, agronomic efficiency and partial factor productivity for potassium during the NPK, C7S3 and C4S6 treatments. ⑷ the annual surplus amount of potassium in NPK was 3.00 kg∙hm-2, which was higher than that in C7S3 (with minus 1.90 kg∙hm-2). The most annual surplus amount of potassium appeared in C4S6, with 8.22 kg∙hm-2, and the Surplus of potassium was 7.4%. ⑸ Compared to the beginning of the experiment(2006), soil rapidly available potassium declined by 15.9% in 2014; The fertilization application significantly increased the amount of rapidly available potassium (P < 0.01). The orders of annual amount of rapidly available potassium during 2010 ~ 2014 in fertilizer treatments were that: NPK > C7S3 > C4S6, with no difference in treatments (P > 0.05).⑹ after eight years of cultivation, soil slowly available potassium declined by 10.9% in CK, slightly declined in C4S6 with no more than 5%, slightly increased in NPK by 1.3%, and increased in C7S3 by 22.4%. Overall, the application of straw returning to replace some potassium fertilizer was suitable for the soil in karst peak-cluster depression, as it could not only maintain the yield of spring maize, but also sustain potassium dynamic balance. And 60% of the straw potassium substitution could be more suitable for sustaining potassium balance, while 30% of the straw potassium substitution could be more beneficial to improve soil slowly available potassium.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：基于自2006 年在广西喀斯特峰丛洼地区开展的长期玉米/大豆套作定位施肥试验, 选择2010—2014 年监测数据, 探讨等氮量投入条件下, 不同比例有机肥替代无机氮肥对喀斯特峰丛洼地玉米/大豆套作系统作物产量及土壤养分的影响, 为喀斯特峰丛洼地农田作物高效施肥及提高土壤肥力提供理论依据。试验选取4 个处理:对照(不施肥, CK)、平衡施用化肥(NPK)、有机粪肥替代30%化肥氮(C7M3, 按氮素计算, 不z30%的PK 用无机肥补充, 肥料总量与NPK 处理相同, 有机粪肥为牛粪, 下同)、有机粪肥替代60%化肥氮(C4M6, 按氮素计算, 不足60%的PK 用无机肥补充), 每个处理4 次重复。于2010 年、2012 年、2014 年大豆收获后采集土壤样品, 测定土壤养分状况。结果表明: 1)施肥处理土壤有机质、全氮、速效磷及速效钾含量均高于CK 处理, 其中C4M6 处理有机质含量显著高于NPK 处理(PNPK>C7M3, 但施肥处理间差异不显著(P>0.05)。3)长期不施肥CK 处理玉米产量随着试验年限推移呈下降趋势, 降幅为5.45 g·m2·a1, 大豆产量却表现出增加趋势, 增幅为1.50 g·m2·a1。长期施肥处理中, 玉米和大豆产量总体呈增加趋势。4)施肥处理中, 玉米季表现为钾素亏缺(NPK 处理除外), 大豆季表现为氮素亏缺。综合两季作物, 只有C4M6 钾素表现亏缺, 亏缺量为7.9 kg·hm2。磷素在各施肥处理中盈余量较大, 分别为81.2 kg·hm2(NPK)、83.4 kg·hm2 (C7M3)和74.8 kg·hm2 (C4M6)。综上, 在喀斯特峰丛洼地玉米/大豆套作制度下, 基于作物产量及土壤养分表观平衡特征提出有机粪肥可以代替部分化肥施用, 在玉米季适当“减氮、稳磷和增钾”, 大豆季“稳氮、减磷和减钾”的施肥措施。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-06 Cooperative journals: 《中国生态农业学报》
Abstract：烟碱含量偏高是我国烤烟的现状。如何有效降低烟叶烟碱含量, 提高烤烟工业可用性是烟叶生产中 的一个难题。根据烟草打顶导致烟碱含量急剧上升和机械损伤造成细胞氧化迸发的的现象, 本试验从打顶创伤引起的一系列生理变化入手, 采取打顶后在伤口涂抹抗氧化剂抗坏血酸+谷胱甘肽(AsA+GSH)和抗坏血酸(AsA)两种方法来抑制活性氧含量的上升, 探究茉莉酸刺激烟碱含量上升和活性氧含量之间的关系, 并比较两种方法在抑制活性氧及烟碱上升的效果。结果发现, 涂抹AsA+GSH 和AsA 处理对烟草叶片超氧阴离子、过氧化氢、丙二醛的上升有抑制效果, 过氧化氢降解速度慢于超氧阴离子, 在烟草内有积累现象。涂抹AsA+GSH和AsA 处理在打顶6 h 时茉莉酸含量低于常规打顶, 对茉莉酸的产生有抑制效果。其中处理96 h 后, 打顶后涂抹AsA+GSH 的处理叶片烟碱含量比常规打顶低21.5%, 打顶后涂抹AsA 的处理叶片烟碱含量比常规打顶低17.5%。且各检测指标之间存在显著或极显著的相关性。另外, 打顶后24 h, 各处理的活性氧含量回到对照(不打顶)的水平。试验表明, 抗氧化型物质(AsA+GSH)涂抹打顶后烟草的伤口能有效抑制活性氧、茉莉酸和烟碱含量的上升, 且活性氧、茉莉酸、烟碱之间存在着密切联系。AsA+GSH 比AsA 有更强的抗氧化性, 能更好地抑制打顶后烟碱的上升。
Subjects: Biology >> Botany submitted time 2023-08-26 Cooperative journals: 《干旱区研究》
Abstract： This study focused on the natural Juniperus rigida population in the loess hilly region of InnerMongolia. The structure and dynamic changes of the population were analyzed using a static life table, survivalfunction, dynamic quantitative analysis, and time series model. The results showed that the population mainlycomprised many individual seedlings, followed by medium and less mature trees. Combined with the dynamicchange index Vpi > 0, the population was a growth type. The survival curve was verified using the curve modeland tended to Deevey-II, indicating that the mortality rate of each age class was stable. Considering the externalinterference, the dynamic index tended to 0, and the population growth is not obvious under the interferencecondition. In the survival function analysis, the population showed a strong survival trend in the early stage,followed by a gradual decline in the middle stage. During the 2-to-8-year period, the number of seedlingsdecreased while middle- aged and adult trees increased. The seedling stage is crucial to the regeneration anddevelopment of the population. Therefore, implementing scientific protection measures for seedlings to promotepopulation regeneration is recommended. Research on the internal mechanisms of the Juniperus rigidapopulation can enrich vegetation construction in arid areas, provide a reference for population management, andprovide a theoretical basis for vegetation protection and restoration in the loess hilly area.
Subjects: Biology >> Botany submitted time 2023-08-26 Cooperative journals: 《干旱区研究》
Abstract： This study focused on the natural Juniperus rigida population in the loess hilly region of InnerMongolia. The structure and dynamic changes of the population were analyzed using a static life table, survivalfunction, dynamic quantitative analysis, and time series model. The results showed that the population mainlycomprised many individual seedlings, followed by medium and less mature trees. Combined with the dynamicchange index Vpi > 0, the population was a growth type. The survival curve was verified using the curve modeland tended to Deevey-II, indicating that the mortality rate of each age class was stable. Considering the externalinterference, the dynamic index tended to 0, and the population growth is not obvious under the interferencecondition. In the survival function analysis, the population showed a strong survival trend in the early stage,followed by a gradual decline in the middle stage. During the 2-to-8-year period, the number of seedlingsdecreased while middle- aged and adult trees increased. The seedling stage is crucial to the regeneration anddevelopment of the population. Therefore, implementing scientific protection measures for seedlings to promotepopulation regeneration is recommended. Research on the internal mechanisms of the Juniperus rigidapopulation can enrich vegetation construction in arid areas, provide a reference for population management, andprovide a theoretical basis for vegetation protection and restoration in the loess hilly area.
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