林芝河谷区苹果园间作牧草对杂草群落组成及多样性的影响

以林芝市巴宜区苹果园杂草群落为研究对象,以清耕后自然生长植物为对照,研究了一年生箭筈豌豆(Avena sativa L.)、燕麦(Vicia sativa L.)和多年生紫花苜蓿(Medicago sativa L.)、鸭茅(Dactylis glomerata L.)牧草单播或混播对苹果园杂草群落组成和多样性的影响。结果显示:(1)调查期间共发现杂草17科31属33种,其中优势科为禾本科、豆科、蓼科和菊科,优势种为白草(Pennisetum flaccidum Griseb.)、画眉草(Eragrostis pilosa(L.)Beauv.)、小头蓼(Persicaria microcephala(D.Don)H.Gross.)、牛膝菊(Galinsoga parviflora Cav.)和蒲公英(Taraxacum mongolicum Hand.-Mazz.);(2)牧草种植可以减少果园中杂草种类,降低优势杂草重要值,改变杂草群落结构,不同类型牧草在不同种植年限对杂草群落的影响存在差异;(3)不同间作牧草模式下杂草群落物种多样性有显著差异,但整体上较对照有所降低,种植年限与种植模式对群落多样性和优势度均有显著影响;(4)间作牧草有良好的杂草抑制效果,其中禾本科牧草的杂草防控效果优于豆科牧草,混播处理的杂草防控效果优于单播处理。研究结果表明,人工牧草的选择应考虑牧草生长年限,一年生牧草在短期内杂草防控效果较好,多年生牧草适宜长期种草的果园。

超高效液相色谱-三重四极杆质谱快速测定地表水中甲萘威、微囊藻毒素-LR、溴氰菊酯

基于超高效液相色谱-三重四极杆串联质谱技术(UPLC-MS/MS),建立了一种经简单过滤即可直接进样测定地表水中甲萘威、微囊藻毒素-LR、溴氰菊酯的分析方法。水样过0.22μm微孔滤膜后,经C18色谱柱(1.8μm,2.1 mm×50 mm),柱温40℃,流速0.3 mL/min,以甲醇和2 mmol/L乙酸铵水溶液(含0.1%甲酸)为流动相进行梯度洗脱;采用电喷雾正离子电离(ESI+),多反应监测模式(MRM)检测,外标法定量分析目标物。方法学验证结果表明3种目标物浓度在0.20~50.0μg/L范围线性关系良好,相关系数(R^(2))>0.9990,方法检出限为0.03~0.08μg/L,目标物平均加标回收率为89.3%~116%,相对标准偏差(RSD)为0.5%~9.6%(n=6)。所建立方法简便快捷、灵敏准确,适用于地表水中3种有机污染物同时快速测定。

5个梨品种在西藏林芝的引种表现及光合特性

为推进西藏林芝梨种植结构合理,对引进的红茄梨、绿宝石梨、翠冠梨、红太阳梨,玉露香梨5个品种的田间生长性状和光和特性进行测定,筛选出适合林芝栽培的梨品种。结果表明:5个梨品种的生长状况不同,其中翠冠梨的苗高、地径、新枝长在不同时期的增长量均较高,翠冠梨生长最好,而红茄梨较差;5个梨品种的净光合速率(Pn)不同,表现为:翠冠梨>绿宝石梨>红太阳梨>玉露香梨>红茄梨;5个梨品种的Pn日变化曲线均呈不对称双峰型;蒸腾速率(Tr)的日变化曲线主要呈现出单峰型和不对称双峰型,其中红茄梨、绿宝石梨和翠冠梨Tr的日变化曲线呈单峰型,红太阳梨和玉露香梨的Tr日变化曲线呈不对称双峰型;水分利用率(WUE)的日变化曲线主要呈不对称双峰型和倒S型;气孔导度(Gs)的日变化曲线较复杂,主要呈单峰型、倒S型、下降型和单谷型;胞间CO2含量(Ci)的日变化曲线主要呈单谷型和双谷型;气孔限制值(Ls)的日变化曲线主要呈单峰型和不对称双峰型。5个梨品种的生长状况和光合特性日变化不同,其中翠冠梨的生长状况和光合性能均优于其他品种,具有在西藏林芝地区大面积推广种植的潜力。

森林生态系统粗木质残体研究进展

粗木质残体(Coarse woody debris,CWD)是森林生态系统的重要组成部分,包括枯立木、倒木、大枝和树桩等,可为许多物种提供栖息地,是森林和林地恢复的重要考虑因素。在森林生态系统中,CWD代表大量有机质,有助于森林生态系统的碳、氮循环,在全球范围内,森林每年吸收约30%全球人为排放的CO2,因而成为重要的碳汇。CWD作为森林生态系统中一个重要的生态单元,在生产力、养分循环、碳固存、群落更新和生物多样性等方面发挥着重要作用。研究认为,在森林生态系统中留下大量CWD有助于提高森林碳汇强度。在全球气候变化的大背景下,世界森林正在面临大面积非正常死亡的威胁,并在林内形成大量CWD。自然环境因子(烈火和暴风雪等)是造成CWD产生的主要原因,不同森林类型、不同干扰环境CWD会表现出不同特征,对全球可持续发展与经营等方面具有重要意义。从CWD的国内外研究概况及研究热点、形成、来源、分类依据和特征(储量和分解)等方面重点阐述森林生态系统中CWD的研究进展。采用国际上统一的分类标准对CWD进行分类,利于研究结果在全球尺度进行比较,使研究内容纳入统一范畴进行资料整合,完善世界CWD数据库。

膜式壁焊缝图像处理及其识别方法

提出一种基于新的单目视觉线性结构光的膜式壁焊缝识别方法,克服了焊接过程中的飞溅、烟雾等干扰,快速地提取了膜式壁角焊缝特征点。首先,根据激光条纹图像与背景的显著性差异,采用灰度级频率法提取了激光条纹图像;其次,基于骨架抽取提取了激光条纹中心线,并对中心线坐标应用Takagi Sugeno模糊算法进行滤波;最后,应用动态ROI搜寻法快速找到含有焊缝特征点的区域,结合快速排序算法找到焊缝特征点坐标。经实验证明,该算法能够快速准确地提取焊缝特征点,结合控制算法,能够准确跟踪焊缝。

5种牧草芽期耐盐性评价

为评价5种牧草芽期耐盐性。以青引1号、青海444、青燕1号、绿麦草、黑麦草为试材,对5种草种进行1.5%浓度盐胁发芽试验测定。并对测定指标进行相关性分析、主成分分析,结果表明:在1.5%NaCl条件下,供试草种子的发芽势、发芽率、发芽指数、芽长、根长与对照相比均呈下降趋势,各发芽指标耐盐系数间呈正相关,但未达到显著水平;各耐盐系数除芽长外,其余指标与颜色亮度Y呈负相关;主成分分析得出发芽势、发芽率、发芽指数负载耐盐性信息最多,种子颜色次之;综合评价得出青引1号的耐盐性最好,绿麦草的耐盐性最差。

结构光在阴极板焊缝自动跟踪系统中的应用

针对阴极板自动焊接尚无可靠实用的焊缝自动跟踪系统的问题,研制了一种基于结构光的阴极板焊缝自动跟踪系统。该系统以结构光作为光源,以CCD摄像头为传感器件,由工控机对获取的焊缝图像进行实时分析处理,计算得出的焊枪偏差值,反馈给伺服系统驱动执行机构从而实现焊缝自动跟踪。现场实际应用表明,系统实时性好,跟踪精度高,满足阴极板焊缝成型质量要求。

前刀面槽型结构对D型刀片车削球墨铸铁性能的影响

通过切削力、磨损和冲击切削试验,研究了前刀面槽型结构对D型刀片车削球墨铸铁切削性能的影响。试验结果显示,刀具的第一前角对切削力的影响最大;在10°~15°范围内,刀具前角越大,切削力越低;棱带宽度大的刀片具有更加优异的耐磨损性能;具有正刃倾角的刀片显示出更优异的耐冲击性能。

Water Holding Characteristics of Coarse Woody Debris of Abies fabri Forest on the East Slope of Tibet Sygera Mountain

Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD in subalpine forest of southeast Tibet,CWD reserve of primitive A. fabri forest in Sygera Mountain was investigated by sample plot method,and water absorption and storage capacity of CWD was studied by using soaking method. The results showed that decay grade was positively related to water storage potential,that is to say,the higher the decay grade,the larger the water storage potential. Saturated water holding capacity,saturated water holding rate,effective water holding capacity and effective water holding rate of A. fabri CWD all rose with decay grade increased,and the order was Ⅴ>Ⅳ>Ⅲ>Ⅱ>Ⅰ. CWD reserve was 51.555 t/hm^2,and the maximum water storage capacity was 71.601 t/hm^2,while effective water storage capacity was 60.861 t/hm2,which was equivalent to 6.086 mm of rainfall.

西藏水果产业发展现状问题及对策建议

西藏是我国果树资源最为丰富的地区之一。通过分析西藏果园发展现状,认为西藏水果产业发展缓慢的原因包括果园管理粗放,缺乏技术指导;生产成本高,销售困难;品种结构不合理及产业化水平低等,结合西藏生产实际,提出引进技术人才,科学管理果园;政府出台优惠政策,降低生产成本;引进、培育新品种及提高水果产业化水平等建议,为西藏自治区水果产业发展提供参考。

秦巴山区蜜环菌新菌株“陕蜜2009”选育研究

秦巴山区拥有独特的地理环境和气候,成为中国最大的天麻主产区之一,为保障天麻、猪苓产业稳步发展,课题组从不同生态环境条件的天麻种植区采集蜜环菌资源进行分离纯化,获得资源菌株18个,经过系统选育,筛选出优良菌株ZY-17,命名为“陕蜜2009”。该品种在秦巴山区多年多点的区域试验和生产试验中,表现出伴栽天麻产量高、菌种适应性强、稳定性好的特点。栽培试验表明,该品种伴栽天麻无性繁殖生产,比对照菌株(京-234)增产28.22%;伴栽天麻有性繁殖生产,比对照菌株(京-234)增产28.71%。

Short-term Effects of Nitrogen Deposition on Soil Physical and Chemical Properties of Tibetan Forest-Grassland Landscape Boundary

[Objective] The paper was to study the effects of nitrogen deposition on soil nutrients and soil dissolved organic carbon in forest-grassland landscape in Linzhi, Tibet, and to provide scientific basis and basic data for understanding and assessing the effect of atmospheric nitrogen deposition on soil nutrients and soil dissolved organic carbon. [Method] From July 2014 to August 2015, in situ nitrogen deposition （CK0 kg· hm^2/a, LN25 kg·hm^2/a, MN 50 kg·hm^2/a, HN 150 kg· hm^2/a） was simulated in the forestgrassland boundary of Zhuqudeng village, Bujiu Township, LinzhiCounty, Tibet. The soil samples were collected for analyzing nutrient and dissolved contents in the soil layer of 0-20 and 20-40 cm. The effects ofdifferent nitrogen deposition levels on soil nutrients and dissolved organic carbon （DOC） were studied. [Result] Nitrogen deposition had significantimpacts on soil organic matter, total N, total P, total K, available N, available P, available K, exchangeable Ca, exchangeable Mg, pH, and DOC（P〈0.05）. （2） With the deepening of nitrogen deposition from CK, LN, MN to HN in the 0-20 cm boundary soil, the contents of organic matter, total N,total P, available P, exchangeable Ca, exchangeable Mg and DOC kept decreasing, and the content of total K and available N increased continuously. The pH increased in LN treatment and decreased in HN treatment, while the available K content was decreased in LN and HN treatment, butincreased in MN treatment. （3） The contents of organic matter, total N, total P, available N, available P, exchangeable Ca, exchangeable Mg andDOC all decreased at the soil layer of 20-40 cm under the same nitrogen deposition. The pH increased in LN treatment, but decreased in HN treatment; the content of total K decreased in LN treatment and increased in MN and HN treatments; the content of available K decreased in LN andHN treatments, but increased in MN treatment. （4） With the deepening of boundary soil layer （0-20 to 20-40 cm）, the organic matter, total N, totalP, available P, available K, exchangeable Ca, exchangeable Mg, DOC showed the same response to simulated nitrogen deposition, while the available N and total K responded differently. [Conclusion] Different levels of N deposition had certain impact on soil nutrient, and the variation of soilnutrients was not the same at different levels.

The Effect of Nitrogen Deposition on Soil Microorganisms in the Woodland-Grassland Border of Tibet

Nitrogen deposition was simulated from July 2014 to August 2015 in the grassland, woodland, and woodland-grassland border in Zhuqudeng Village, Bujiu Township, Linzhi County,(CK, 0 kg·hm^2·a^(-1); LN, 25 kg·hm^2·a^(-1), MN, 50 kg·hm^2·a^(-1); HN, 150 kg·hm^2·a^(-1)). NH_4NO_3 was used as nitrogen source to analyze the number of microorganisms in soil layers of 0–20 cm and 20–40 cm and explore the effect of different degrees of nitrogen deposition on soil microorganisms in grassland, woodland, and woodlandgrassland border. The results showed that: the number of bacteria in the grassland increased significantly under the treatment of LN, and the number of bacteria in the woodland-grassland border and woodland had a rising response under the influence of nitrogen deposition; the number of actinomycetes in the grassland increased in MN and HN treatment, and significantly increased in the border and woodland under LN treatment; the number of molds decreased sharply in the grassland, woodland, and woodland-grassland border.

产后营养护理联合乳房穴位按摩对初产妇产后泌乳及生活质量的影响

目的 探究给予初产妇产后营养护理联合乳房穴位按摩对产后泌乳与生活质量的影响。方法 遴选我院2020年12月-2021年5月分娩的80初产妇为探究对象,随机抽取营养护理依从性差的初产妇40例作为对照组,抽取依从性好的40例作为研究组。干预过程中两组均进行产后营养护理联合乳房穴位按摩,将对营养护理依从性差的列入对照组,将对营养护理依从性高的列入研究组,对于组间产后泌乳情况、乳房胀痛情况、生活质量以及护理满意度进行分析。结果 对比对照组数据显示,研究组产后24 h内、24~48 h及48~72h的乳房充盈率较高、泌乳量和喂养有效次数较多,各项生活质量评分较高,护理后VAS评分较低,组间存在明显差异(P<0.05)。结论 给予初产妇实施产后营养护理联合乳房穴位按摩的效果较为理想,可促进产后泌乳、减轻乳房胀痛,同时还可促进生活质量提升,具有理想的应用价值。

基于正交试验不同处理对藏川杨生根质量的影响

本研究试图寻求科学培育藏川杨苗木的方法,以解决苗木供不应求的现状,为西藏造林绿化,生态系统稳定,生态环境的保护和可持续发展作出一份贡献。选用1 a生萌蘖条为材料,采用3因素3水平的L9(34)正交设验设计方案,研究插穗类型、ABT浓度和浸泡时间对藏川杨无性扦插繁殖生根质量的影响。结果表明,各试验因子对藏川杨生根率和生根质量有极显著(P<0.01)影响,且上述不同实验因子间存在正相关关系;ABT浓度、插穗类型和处理时间3个因素中,插穗在ABT溶液中浸泡时间对藏川杨扦插生根质量影响最大,其次是ABT浓度和插穗类型。基于总根系生物量,藏川杨扦插生根质量的最优组合为A_(3)B_(2)C_(1)(插穗部位基部,ABT浓度200 mg/L,浸泡时间2 h),其生根质量指数为50.19,远高于其他8种试验组合。结果表明,以1 a生萌蘖条的基部作为插穗,用200 mg/L的ABT溶液中浸泡2 h可以大大提高藏川杨硬枝扦插生根质量。

Effect of Fallen Wood of Abies fabri Forest on Seedling Recruitment in Tibet Sygera Mountain

The impact on seedling recruitment by fallen wood of A. fabri forest in Tibet Sygera Mountain was studied. The results showed that regenerated seedlings on fallen wood roughly showed normal distribution,and there were more regenerated seedlings in the middle of fallen wood,while regenerated seedlings were fewer at two ends. Fallen wood at level IV had the most regenerated seedlings,followed by level-III fallen wood,and regenerated seedlings were the fewest on fallen wood at level V. The number and species of regenerated seedling on and around fallen wood on the west slope were more than that on the east slope. With the improvement of decomposition level,regenerated seedling per unit area firstly increased and then decreased,but the number of regenerated seedling on and around fallen wood was far more than that in woodland.

Short-term Effects of Nitrogen Deposition on Soil Enzyme Activities in Tibet Grasslands

[Objective] The paper was to study the effects of nitrogen deposition on enzyme activity in different layers of soil. [Method] With grass-land located in Zhuqudeng Village, Bujiu Township, Linzhi City, the Tibet Autonomous Region, as the object, nitrogen deposition was simulated from July 2014 to August 2015. Four N addition treatments were established： control （0 kg·hm^2/a）, low N （LN, 25kg·hm^2/a）, medium N （MN, 50 kg·hm^2/a） and High N （HN, 150 kg·hm^2/a）, aiming at measuring enzyme activity （invertase, catalase, urease, amylase, cellulase, polyphenol oxidase and β-glucosi- dase） in different layers of grassland soil （0 -20 cm and 20-40 cm）. [Result] （1） Different levels of simulated nitrogen deposition had significant impact on invertase and β-glucosidase at the soil depth of 0-20 cm （P〈0.05）, but no significant impact on catalase, urease, amylase, cellulase and polyphenol oxidase（P〉0.05）; invertase, polyphenol oxidase and β-glucosidase had significant response to nitrogen deposition at the soil depth of 20- 40 cm （P〈0.05）, while catalase, urease, amylase and cellulose had no significant response （P〉0.05）. （2） The activities of invertase and polyphenol oxidase were enhanced at the soil depth of 0-20 cm, and that of β-glucosidase was inhibited. （3） With the deepening of nitrogen deposition, the ac- tivities of invertase and cellulose were enhanced at the soil depth of 20-40 cm; the activity of polyphenol oxidase was reduced in LN treatment, but increased in HN treatment; the activity of β-glucosidase was increased in LN treatment, but decreased in MN treatment. （4） With the deepening of soil layers, invertase and polyphenol oxidase responded similarly to simulated nitrogen deposition. [Conclusion] The results provide certain scientific basis and fundamental data for better understanding and evaluating the effects of nitrogen deposition on enzyme activity in grassland soil.

The Effect of Nitrogen Deposition on Soil Enzyme Activity in the Forest Grassland Landscape Boundary of Tibet

The simulated nitrogen deposition [control check(CK), 0 kg·hm^2/a; low nitrogen(LN),25 kg·hm^2/a; medium nitrogen(MN), 50 kg·hm^2/a; high nitrogen(HN), 150 kg·hm^2/a] was performed from July 2014 to August 2015 in the forest-grassland boundary in Zhuqudeng Village, Bujiu Township,Linzhi City, Tibet Autonomous Region to analyze the activity of enzymes(invertase, catalase, urease,amylase, cellulase, polyphenol oxidase, and β-glucosidase) in soil layers of 0-20 cm and 20-40 cm and explore the effect of different levels of nitrogen deposition on enzyme activity different layers of soil.The results showed that: ① different levels of simulated nitrogen deposition had remarkable effects on sucrase, amylase, cellulase, polyphenol oxidase and β-glucosidase in the soil layer of 0-20 cm(p < 0.05) and unremarkable effects on catalase and urease(p > 0.05); in the soil layer of 20-40 cm, the response made by sucrase, catalase, urease, amylase, cellulase, polyphenol oxidase and β-glucosidase to nitrogen deposition reached a significant level(p < 0.05). ② In the soil layer of 0-20 cm, the activity of urease and poyphenol oxidase reduced under LN treatment and enhanced under HN treatment, and the activity of invertase,catalase, amylase, cellulose, and β-glucosidase was inhibited by nitrogen deposition. ③ In the soil layer of20-40 cm, the activity of polyphenol oxidase and β-glucosidase reduced under under LN treatment and enhanced under HN treatment, and the activity of invertase, catalase, urease, amylase, and cellulase was inhibited by nitrogen deposition. ④ With the deepening of the boundary soil layer(from 0-20 cm to20-40 cm), urease and β-glucosidase made different responses to the different levels of nitrogen deposition,while invertase, catalase, amylase, cellulose, and polyphenol oxidase showed the same response to nitrogen deposition.

Effects of Different Afforestation Techniques on Soil Nutrients in Populus alba Woodland

[Objective] The research aimed to study the influence of different afforestation technology measures on soil nutrients of P. alba wood-land in arid valley region of Rikaze, Tibet. It aimed to improve afforestation technology measure in arid valley region of Rikaze, Tibet, and provide theoretic basis for restoring the degraded ecosystem at upper reaches of the Yarlung Zangbo River. [ Method] In arid valley region of Duojiao Vil-lage, Nanmulin County, Rikaze City, the planted land using rooting powder, egg shell, leaves, mud and water retention agent was taken as re-search object, while the land without any afforestation measures was taken as the control, to determine soil nutrients under different afforestation measures. [Result] Under different afforestation measures, the contents of various soil nutrients were all obviously higher than control, in which available potassium, available phosphorus, alkali hydrolysable nitrogen and organic matter in soil obviously increased than control, but there was no similar rule among different measures. [Conclusion] Vegetation restoration in dry valley belt of Rikaze by different afforestation measures is favorable for improving physical-chemical properties of soil and increasing soil fertility.

林芝云杉林粗木质残体持水特性研究

粗木质残体(CWD)是森林生态系统的重要组成部分,在水土保育、维持生物多样性和生态平衡等方面起着重要作用。林芝云杉(Picea likiangensis var.linzhiensis)是藏东南亚高山暗针叶林的主要建群树种之一,为了解藏东南亚高山森林中粗木质残体的持水特性,以岗乡自然保护区原始林芝云杉林为研究对象,采用浸泡模拟法研究粗木质残体的分解程度、密度与持水性能的关系。结果表明:CWD密度随着分解程度加深而减小;吸水率随浸泡时间增加而增加,可用方程y=clnx-d拟合;吸水速率随分解等级加深而减小,可用方程y=ax^(-b)进行拟合;标准地内CWD最大持水量为41.25t·hm^(-2),相当于降雨4.12mm,有效持水为33.93t·hm^(-2),相当于降雨3.39mm。林芝云杉林内不同分解等级粗木质残体持水性能差异明显,其中Ⅴ级密度最小,持水量最高,证实了CWD分解程度对森林生态系统粗木质残体储水能力和吸收能力的影响,该研究有利于后续开展林芝云杉粗木质残体的生态功能研究。