Under the background of the novel coronavirus pneumonia epidemic, based on the involvement theory, this paper explores the impact of destination involvement based on empathy from anti-epidemic music video on potential tourists' behavioral intention. The results of an analysis of 945 questionnaires indicate that: empathy from anti-epidemic music video has a significant positive effect on attraction, centrality, sign and risk in destination involvement, but has no significant effect on tourists' behavioral intention; that attraction, centrality and risk in destination involvement have a significant positive effect on behavioral intention, and attraction, centrality, sign and risk in destination involvement have a full mediating effect between empathy from anti-epidemic music video and behavioral intention; and that travel experience plays a role of negative moderating variable between empathy from anti-epidemic music video and attraction, and has a positive moderating effect between empathy from anti-epidemic music video and risk. This study introduces destination involvement into the situation of novel coronavirus pneumonia epidemic and provides a new perspective for music video research in tourism through empathy. Thus, the study expands the theoretical mechanism of tourist decision-making and provides advice for tourism destination marketing under the background of the epidemic.
Based on the family investment model, a study was made to test if psychological suzhi and its dimensions mediate between the family socioeconomic status (SES) of middle school students and their class peer status. The participants, 1801 students from the first grade of junior middle school to the third grade of senior middle school, were asked to complete the questionnaires which measured their psychological suzhi as well as SES and peer status. Significant positive correlations were found to exist between SES and peer status (r= 0.10, p < 0.01), SES and psychological suzhi (r=0.15, p < 0.01), and psychological suzhi and peer status (r=0.20, p < 0.01). The psychological suzhi was found like a mediator between SES and peer status, its mediating effect being 0.03 (95% CI: [0.02, 0.04]). An analysis of multiple intermediary effects on the three dimensions of psychological suzhi showed that only the adaptability dimension played a significant mediating role in the process of SES influence on peer status, the mediating effect being 0.04 (95% CI: [0.03, 0.06]), that is to say, good family SES promotes higher peer status, mainly through its positive impact on the adaptability of adolescents. This finding has deepened, to a certain extent, the study of family investment model and improved the researchers' understanding of the role and function of psychological suzhi.
凤凰县旅游产业前景广阔,具有相当巨大的竞争力,虽然部分地区在旅游业发展上取得了显著成效,但还存在旅游产业中的经济基础与上层建筑,资源开发与合理利用之间的矛盾,设施建设薄弱、旅游人才队伍欠缺、区域合作有待加强等一系列问题.针对这些问题,凤凰县文化旅游发展必须采取加强区域合作、强化政府主导型管理与引导、加快景区景点建设、打造旅游公共服务中心、强化营销合作联动、加大人才培养等旅游业的发展决策,完成凤凰县资源的充分挖掘以及结构性供给侧发展的战略目标.
为阐明紫花苜蓿新品系MS-LM01的抗旱性,采用盆栽断水法模拟土壤干旱胁迫,设置三个水分梯度,研究不同紫花苜蓿品种响应干旱的形态和生理特征.结果表明:随着胁迫程度的增加,各品种的株高、根粗、生物量、叶片相对含水量、叶绿素含量、净光合速率都呈明显的下降趋势,而脯氨酸含量呈增加趋势.与其他4个品种相比,MS-LM01在轻度干旱(LS)和重度干旱(SS)处理下株高、生物量、根粗、叶片相对含水量、脯氨酸含量、净光合速率等对干旱胁迫的敏感程度较小.隶属值综合分析显示抗旱能力大小依次为陇东＞ MS-LM01＞甘农3号＞金皇后＞中苜1号.表明新品系MS-LM01具有较强的抗旱性以及优良的农艺性状,这对干旱地区紫花苜蓿品种的选择以及抗旱性紫花苜蓿品种的选育具有重要意义.
青稞与牛奶搭配制作青稞牛奶饮品的研究尚未见报道.本研究以青稞和鲜牛奶为原料,通过感官评价及稳定性指标确定了青稞牛奶饮品制作工艺中青稞粉最佳粒度及添加量、乳化剂及增稠剂最佳使用量和适宜均质压力,并通过正交试验筛选了乳化剂及增稠剂的最佳复配组合.结果表明:添加2％过80目筛的青稞粉于牛乳中,再加入0.06％蔗糖脂肪酸酯、0.08％单硬脂酸甘油酯、0.07％黄原胶,经30 MPa压力均质,制备的青稞牛奶饮品的风味、口感较好,且能够确保青稞牛奶饮品的乳化体系具有良好的稳定性.
为揭示人工林土壤有机碳组分的稳定性维持机制,以云南松人工林为研究对象,利用土壤有机碳化学分组方法,结合元素分析和傅里叶变换红外光谱分析等多种研究手段,研究土壤三种稳定有机碳组分化学结构特征的差异.结果表明,云南松人工林地土壤三种有机碳组分(胡敏酸HA、富里酸FA和胡敏素HM)具有相似的化学结构和官能团组成,主要含有酚羟基、少量脂族烃基、羧基、酮型羟基、酰胺基团和少量碳水化合物.但随土壤剖面深度增加,土壤有机碳组分的官能团特征存在差异.剖面深层土壤HA中富含脂肪族基团,至亚表层土壤中HA脂肪族基团含量减少,表层土HA中未显示含有脂肪族基团.研究表明,脂肪族基团与土壤有机碳组分稳定性的维持有密切关系.该结果从官能团结构特征角度为揭示人工林土壤有机碳化学稳定机制提供了科学依据.
关于超声波腌制对牦牛肉品质影响的研究尚未见报道,试验目的在于探讨不同超声波腌制条件对牦牛肉蒸煮损失、剪切力、色差、感官评价等影响.用普通腌制方法对牦牛肉分别腌制6、12、18、24或48 h作为对照,采用超声波腌制方法分别对牦牛肉进行30、45、60、75和90 min腌制处理.结果表明:超声波腌制能够在较短时间内达到腌制效果,显著降低蒸煮损失、提高a*、减少剪切力和增加感官品质得分(p＜0.05).研究认为超声波腌制法应用于生鲜肉的腌制,其效果优于普通腌制法.
在全球变化的背景下,内蒙古草原生态系统的降水量可能增加或者减少.迄今,降水量的改变对该区域草地生态系统碳交换的影响我们还知之甚少.为此,本研究通过完全控水防雨棚,开展了降水梯度实验,探究该生态系统碳交换（ecosystem carbon exchange）随降水量变化的响应轨迹.结果表明:随着生长季降水量从100mm增加到500mm,净生态系统碳交换（net ecosystem exchange,NEE）、生态系统呼吸（ecosystem respiration,ER）和生态系统总生产力（gross ecosystem productivity,GEP）均显著提高,这些过程均表现为明显的非线性响应.NEE、ER和GEP的饱和点对应的降水量分别为350mm,200mm和275mm.从响应率的变化斜率看,降水量减少（＜275mm的处理）的效应显著强于降水量增加（＞275mm的处理）的效应.变异来源分析说明,随着降水量的改变,群落生物量是草原生态系统碳交换的首要影响因素,可以解释NEE、ER和GEP变异的30.89%、41.90%和40.60%,而土壤含水量和土壤温度只能解释NEE、ER和GEP变异的11.51%、7.78%和9.28%.上述结果为我们理解和预测未来降水变化对内蒙古温带典型草原生态系统碳交换的影响提供了依据.
水体溶解氧含量是水环境质量的重要参数.本研究将室内模拟实验和疏浚工程相结合,探讨了疏浚对沉积物-水界面耗氧能力、微剖面溶解氧分布的环境效应.研究结果显示,疏浚具有降低溶解氧消耗能力的潜在长期效应,但是由于还原性物质的暴露,疏浚后新生表层沉积物短期耗氧能力很强;疏浚没有改变到氧气在沉积物-水界面中的传质深度.结果暗示疏浚可能显著提高重度富营养化湖泊夏季溶解氧含量.
为科学评估青藏高原草地畜牧业生产现状,对四川省、青海省和西藏自治区的13个乡镇的153户牧户进行了入户调研,综合分析了高寒地区各调研户户均饲草供给、家畜生产、基础设施条件及家庭收支情况,提出了阻碍草地畜牧业可持续发展的饲草供给不足、经济效率低下、基础设施落后、生产技术滞后等关键问题,并提出了相应的应对策略.调研结果可为国家相关部门制定政策法规,促进高寒牧区畜牧业可持续发展,实现牧区生态安全和牧民增产增收提供重要参考.
Impulsivity,which may be conceptually divided into traits impulsivity and cognitive impulsivity,is always closely related to addiction.In previous researches,high trait impulsivity and cognitive impulsivity have been found in various substance-use addicts,but the causal relationship between impulsivity and addiction has not been clear yet.Recent studies have pointed out that impulsivity might exist before addiction,thus a potential marker for the addiction susceptibility to potentially intermediate the addiction process.But how it works is still unknown.Some important issues may be worthy deep investigation in future researches,such as the neuron mechanism underlying the influence of impulsivity on addiction or vise visa,and how impulsivity training could help to reduce relapse in addicts or prevent addiction in teenagers.
Taking the mountainous city Chongqing as a case,this paper used the infilling-extension-leapfrog index,the cohesion index and the topographic position index(TRI)to reveal the process and patterns of the urban spatial restructuring,based on land use maps from 1978 to 2011.Chongqing's spatial expansion was shown to be primarily driven by extension growth,being over 50% in all the four periods studied:1978-1988,1988-1997,1997-2006 and 2006-2011.Leapfrog urban growth increased in the early periods,followed by a decline,while infilling urban growth was generally on the rise.From 1978 to 2011,the change of cohesion index for urban clusters exhibited different trends,such as decreasing,increasing and U-shape fluctuation.Urban development occurred mostly at middle slopes,followed in sequence by ridges,gentle slopes,steep slopes,flat slopes and valleys.
Using the density functional theory ,the authors study lithium niobate (LN) and Mg doped lithi‐um niobate crystals with inevitable introduction hydrogen ions .Through structural optimization ,the posi‐tion of the H ion is considered to occupy the lithium site ,offset from this position and unite with one oxy‐gen atom to form an OH structure .For LN ,Mg∶LN and H∶Mg∶LN samples ,they find that the ab‐sorption line edge of each crystal displaces in different directions ,and propose the formation of O H2 - and O H - structures and the mechanism of their influence upon absorption line .
The degradation of carbon resistors was simulated under different current conditions in laboratory.The results of the experiment were analyzed according to the nonlinear characteristics of the carbon resistor and the double Schottky barrier theory.In direct current degradation,forward and reverse varistor voltage and leakage current were asymmetric,and the temperature showed a linear increase.In alternating current degradation,forward and reverse varistor voltage and leakage current were symmetric,and the temperature changed in an increasing-stability-dropping pattern.In impulse current degradation,the varistor voltage showed an increasing-stability-dropping trend and the leakage current exhibited a stability-rocketing trend,while the nonlinear coefficient steadily declined.The above conclusion should be of reference significance in the application and testing of carbon resistor surge protective devices.
The purpose of this study was to understand the present status and changing trend of the fish community structure and fishing in Yibin section of the upper Yangtze River ,and to provide information for species and resources conservation .Investigations of catch per unit effort ,catch composition and fish‐ing size of different fishing gears including drift‐trammel‐net and baited hook were carried out and the data collected were analyzed statistically .Altogether ,49 fish species ,belonging to 29 genera ,10 families and 3 orders ,were collected in this section of the Yangtze River .Most of them belonged to Cypriniformes and Siluriformes .Coreius guichenoti , Pseudobagrus v achelli , Gobiobotia boulengeri , Gobiobotia filifer and Saurogobio dabryi dominated the fish community .Eleven endemic fish species were recorded ,accounting for 22.4% of the total ,and more than half of them were rare species .The fishing size in Yinbin section was small in general ,and most of the individuals caught were smaller than 100 g in weight and 150 mm in length .The catch was low ,and the catch per unit effort of drift‐trammel‐net and baited hook was only 1-2 kg per boat per day .In conclusion ,the fishery resources in Yibin section of the upper Yangtze River have been declining seriously with low catch and small fishing size ,and lots of endemic species have become rare .Measures such as fishing closures are suggested to be taken to improve the species and resources con‐servation .
On the basis of defining the concept ofproducer services industry,we use the revised data of Chongqing after the second economic census to estimate the TFP(total factor productivity),technical progress and pure technical efficiency of the producer services industry segments of Chongqing in 1998-2012,using the DEA-Malmquist productivity index method.The results show that the TFPof producer services declined in 1998-2002 and was on a rise in 2005-2012,that the development of producer services experienced a change from the extensive pattern to the intensive pattern,and producer services were no longer the main contributing factor to the declining efficiency of the service industry,and that TFPchange of producer services sub-classification had a considerably large industry heterogeneity which was owed to the different changes of technical efficiency.
A field investigation was conducted in Zhongxian county of Chongqing city to identify the factors influencing the development of the rural land assets market and to analyze the driving factors of the rural land assets market so as to provide a theoretical reference for the construction of the rural land assets market.The research methods adopted in this study were the Delphy method and generalized grey incidence analysis.The results showed that the development of the rural land assets market in China was driven mainly by the government policies of the rural reform and development,the changes in rural reform and development,and the changes in the livelihood of farmer households.In conclusion,in order to accelerate rural reform,to realize the large-scale production,industrialization and specialization of agriculture and to promote the sound development of the rural land assets market,we should make great efforts to develop the leading enterprises of modern agriculture with a market orientation,to improve and put into practice the agriculture preference policies related to revenue and financial credit with the support from the government,and to enhance the farmers' market consciousness,ecological consciousness and science and technology consciousness with the farmer households as the basis.
The pole changing multi‐speed three phase induction motor is smartly combined with the electro‐magnetic slip clutch in this study ,and thus an electromagnetic slip speed control device is developed .This device can automatically convert the number of the magnetic poles of the motor stator winding based on the requirement of the load speed ,and can regulate smoothly and cost‐effectively the speed in a broad range because of its good starting performance .
The data about temperature and precipitation recorded at 19 meteorological stations in Guizhou Province during the period from 1960 to 2009 is chosen ,and Guizhou Province is divided into two regions‐South Area and North Area‐by the latitude 26?876°N of Weining Station .Meanwhile ,the geographic fac‐tors such as latitude ,normalized altitude ,normalized slope and aspect are analyzed in order to build the prediction models between temperature and precipitation in each region based on DEM (digital elevation model) in 1 km spatial resolution and polynomial regression .Finally ,the refined calculation of climate ele‐ments is carried out in one particular area of each region .The results show that of the geographical factors studied ,latitude contributes most to temperature and precipitation ,that the temperature model in South Area is correlatively significant , but the precipitation model fails to pass the statistical test , that the effects of temperature and precipitation models in North Area are both relatively favorable ,and that zonal difference exists in the distribution of temperature and precipitation of the calculated area .
Effects of soil turnover depth and application of amendments on the physico‐chemical properties of tobacco‐planting soils were studied through a two‐year field experiment , conducted in Pengshui , Chongqing from April ,2012 to September ,2013 ,and the suitability of soils for tobacco cultivation after consolidation was evaluated .The results indicated that turnover of soil ameliorated its physical properties :soil bulk density was reduced by 1.38% -15.17% and soil porosity increased by 1.68% -18.68% ;how‐ever ,it decreased the contents of soil organic matter and reduced the availabilities of nitrogen ,phosphor‐us ,iron ,manganese and copper .These negative effects increased with the increase in soil plough depth . Lime ,biochar and compost showed different roles in ameliorating soil physico‐chemical properties :liming increased soil pH but reduced the availabilities of most nutrients ,biochar promoted the accumulation of soil organic matter and enhanced the role of lime in acid soil improvement ,while compost had positive roles both in improvement of soil physical properties and balanced supply of nutrients .Combined applica‐tion of the soil amendments tested showed a synergistic effect for improving soil physico‐chemical proper‐ties ,resulting in better suitability for tobacco cultivation .Topsoil application of amendments showed bet‐ter effects than application to the w hole soil profile .
