遵义臭氧时空变化特征及与气象条件的关系

为了研究云贵高原城市遵义O_3分布特征及与气象条件的关系,通过对遵义市城区2014—2017年连续4年环境监测站和气象站观测数据的分析。结果表明:(1)遵义市O_3浓度超标率较之前增长较快;(2)遵义市O_3浓度基本呈现夏、秋季高,春、冬季低的季节特征,O_(3-8h)浓度最高月份一般出现在5月,峰值为52.71μg/m~3,谷值出现在11月为26.18μg/m~3。这与夏、秋季平均日照时间长、平均气温高有很大的关系;(3)遵义市O_3浓度日变化曲线呈单峰型分布,白天浓度明显高于夜间,峰值一般出现在16:00左右;(4)城市大气污染主要源自局地排放和化学转化,太阳辐射、气温、风速、日照和相对湿度是影响城区O_3浓度的主要气象因素,复杂地形下降水量和气压对O_3浓度传输能力影响相对较弱。     

臭氧与其他环境因子及其复合作用对植物的影响

综述了臭氧（O₃）浓度升高、太阳辐射减弱、UV-B辐射、CO₂浓度升高及其与O₃复合作用对植物形态特征、光合作用、干物质累积及作物产量等生理生化机制的影响。交互作用的试验条件可以更好地模拟自然环境条件。O₃和UV-B辐射对植物几乎没有积极作用。太阳辐射减弱、CO₂浓度升高都会促进植物营养生长。但太阳辐射减弱降低干物质累积和产量,CO₂浓度升高对其有促进作用。CO₂浓度升高在与O₃复合条件下,可部分缓解太阳辐射减弱对植物造成的伤害。而UV-B辐射与O₃复合对植物造成的伤害更大。     

不同厚度聚乙烯薄膜对韭薹低温贮藏品质的影响

为建立冷藏条件下韭薹自发气调包装(MAP)保鲜方法,将新鲜预冷的韭薹(200±0.5)g密封包装于25 cm×60 cm的聚乙烯(Polyethylene,PE)薄膜包装袋内,薄膜厚度分别为10、20、25、30、45μm,于(0±0.5)℃下贮藏105 d,研究不同O₂和CO₂透过率的薄膜对韭薹贮藏过程中包装袋内O₂和CO₂体积分数及产品品质的影响。结果表明,不同O₂和CO₂透过率的聚乙烯薄膜包装处理都可以很好地抑制韭薹品质劣变;不同处理组之间袋内O₂和CO₂的体积分数均存在显著差异(P<0.05);45μm PE袋(O₂透过率(4 080±352)cm³·m^-2·d^-1·0.1 MPa^-1、CO₂透过率(16 566±1 415)cm³·m^-...     

3种植物对养殖水体中氮磷净化作用研究

为研究养殖水体中适于净化氮磷的植物,选择凤眼莲(Eichhornia crassipes)、紫背浮萍(Spirodela polyrrhiza)、空心菜(Ipomoea aquatica)等3种植物为试验对象。通过对每种植物设定生物量梯度,每5天取1次水样,测定分析养殖水体的总氮(TN)、硝酸盐(NO₃ ^-)、亚硝酸盐(NO₂ ^-)、氨氮(NH₄ ⁺-N)和总磷(TP)等氮磷指标,进行不同植物、生物量梯度以及试验时间对养殖水体氮磷净化效果的研究。结果显示,3种植物均正常生长,对养殖水体氮磷均有较好净化能力。3种植物对氮净化效果较好的时间在10~15天,对磷的净化效果较好的时间则在15~20天。凤眼莲生物量2000~2500 g/m ³,浮萍生物量150~200 g/m ³,空心菜生物量800~1600 g/m ³对氮磷的净化效果最佳。3种植物均可用于养殖水体的氮磷净化,3种植物对养殖水体中TN、TP、NO₃ ^-去除效果空心菜>浮萍>凤眼莲,对NO₂ ^-、NH₄ ⁺-N去除效果凤眼莲>空心菜>浮萍。凤眼莲更适于养殖水体的氮磷净化。     

5-氨基乙酰丙酸和乙烯利复配剂对东北春玉米光合特性及产量的影响

以中单909为材料,设置5-氨基乙酰丙酸（5-ALA）和乙烯利（ETH）不同浓度复配组合,于拔节期（V6）进行叶面喷施。研究5-ALA—ETH复配剂对缓解东北春玉米生育期内低温冷害、提高叶片光合作用、增加干物质积累、保障春玉米稳产增产的技术机理。结果表明,22.50g/hm ² 5-ALA配合450mL/hm ² ETH处理（A2E1）可显著提高玉米产量,比对照提高4.8%。该处理下玉米生育期内功能叶净光合速率（P_n）、气孔导度（G_s）、胞间CO₂浓度（C_i）和蒸腾速率（T_r）比对照平均分别提高2.7%、3.6%、2.2%和1.4%,且在灌浆期比对照分别提高3.2%、15.7%、8.2%和3.6%。此外,A2E1处理玉米收获期（R6）相对绿叶面积增加16.9%,全生育期内功能叶SPAD值和地上部分干物质积累量比对照平均分别增加2.9%和8.6%。因此,5-ALA—ETH（22.50g/hm ²—450mL/hm ²）复配剂能够有效改善东北春玉米灌浆期光合特性,提高该区域春玉米生育中后期抗耐低温冷害的能力,对保障该区域春玉米的高产稳产具有重要意义。     

CO2浓度对大豆叶片气孔特征和气体交换参数的影响

利用可精准控制CO₂浓度的大型气候箱设置7个CO₂浓度处理(400、600、800、1000、1200、1400和1600 μmol mol ^-1), 对大豆进行CO₂浓度富集的室内培养试验。结果表明, CO₂浓度升高显著减小大豆叶片近轴面的气孔密度和远/近轴面的气孔面积指数。当CO₂浓度为400 μmol mol ^-1时, 远轴面气孔分布最规则, 提高CO₂浓度导致远轴面气孔的不规则分布; 与远轴面相反, CO₂浓度升高导致近轴面气孔的空间分布更加规则, 即在较高CO₂浓度处理下的Lhat(d)最小值均低于对照组。不同叶面(远/近轴面)气孔特征对大气CO₂浓度变化的响应存在明显差异, 但大豆可以通过调整气孔形态特征和气孔空间分布格局进一步改变叶片的气体交换参数。研究结果有助于从气孔特征响应的角度深入理解CO₂浓度对大豆叶片气体交换过程产生的影响。     

NO对损伤诱导的豌豆幼苗叶片抗氧化系统的影响

为了明确损伤后豌豆幼苗叶片内NO产生的途径及NO对其诱导的抗氧化系统的作用,以豌豆幼苗为试材,研究损伤胁迫下其内源NO含量、NR和NOS活性的变化,以及只有NO供体SNP处理和NO清除剂PTIO、NOS抑制剂L-NAME、NR抑制剂NaN₃喷施后损伤处理过24 h 时对豌豆幼苗叶片内H₂O₂和O₂ ^-·含量变化及对抗氧化酶SOD、POD、CAT、APX等的活性影响。结果表明,损伤处理后0~60 h 内豌豆幼苗叶片内NO含量呈双峰曲线;其中损伤处理早期（第1 峰值）NO的主要来源是NOS酶促途径,而后期（第2 峰值）NO的主要来源是NR酶促途径;损伤处理24 h 豌豆幼苗叶片内NO含量最高,此时H₂O₂和O₂ ^-·含量接近对照水平,而SOD、POD、CAT、APX等的活性显著高于对照,NO供体SNP处理时有类似的结果,NO清除剂PTIO 处理后H₂O₂和O₂ ^-·含量升高,SOD、POD、CAT、APX等的活性降低。以上研究结果表明,NO可能通过增强保护酶的活性来降低损伤诱导的膜脂过氧化程度。     

种植密度对不同株型夏玉米产量和冠层特性的影响

为了指导不同株型夏玉米品种的田间生产,选用平展型品种‘鲁单981’和紧凑型品种‘鲁单818’为供试材料,通过设置30000株/hm ² (D1)、60000株/hm ² (D2)、90000株/hm ² (D3)3个种植密度,研究了密度对不同株型夏玉米产量、叶面积持续期(LAD)、叶面积指数(LAI)、群体净同化率(NAR)的影响。结果表明,‘鲁单981’在D2时产量最高,为11452 kg/hm ²,‘鲁单818’在D3时最高,为13024 kg/hm ²。在D3下,紧凑型品种‘鲁单818’的LAD[452 (m ²·d)/m ²]及花后比例(50%)、穗位叶LAI以及全生育期NAR [6.87 g/(m ²·d)]更高。上述研究结果表明紧凑型品种冠层结构紧凑,中下层受光充足,LAD延长,有利于干物质积累,产量上升,更适合高密度栽培。     

锡林郭勒草地NDVI和牧草估产产量的变化特征

为及时准确了解草地牧草生长状况,利用EOS/MODIS遥感资料结合地面同步调查数据,分析锡林郭勒草原草甸草原、典型草原和荒漠草原3种草地类型NDVI和草地生物量的月际变化特征。结果表明,利用S曲线回归估产模型测算的草地生长季逐月牧草产量能较好地反映其生长状况变化,体现了各类草地地上生物量的分布特征。其中,草甸草原牧草生长季NDVI和牧草平均估产产量变化范围分别为0.208~0.560和39.8~168.6g/m²（干重）,峰值出现在8月;典型草原牧草生长季NDVI和牧草平均估产产量变化范围分别为0.194~0.480和33.7~146.2g/m²（干重）,峰值出现在7月;荒漠化草原牧草生长季NDVI和牧草平均估产产量变化范围分别为0.130~0.185和10.0~29.8g/m²（干重）,峰值出现在7月。     

转小麦铁蛋白基因酵母的抗氧化活性

铁蛋白是广泛存在于动、植物和微生物中的储铁关键蛋白,具有调节铁代谢平衡、消除亚铁离子引起的氧化毒性等作用。本研究克隆了小麦铁蛋白基因,构建其真核表达载体,经筛选、检测得到具有形成活性小麦铁蛋白多聚体能力的转基因酵母。转基因酵母与转空载体的对照酵母相比不仅可有效清除过氧化氢(H₂O₂),而且还具清除羟自由基(^.OH)和超氧阴离子(O₂^?)的能力;×OH、O₂^?和H₂O₂对转基因酵母的半致死浓度(LD₅₀)分别为0.40、1.00和36.91 mmol L^-1,比对照酵母分别提高了37.93%、47.06%和77.03%。不同浓度转基因酵母对×OH、O₂^?和H₂O₂清除能力的回归方程分别为一元三次多项式、对数方程和负指数方程。说明小麦铁蛋白基因的真核表达产物可以有效清除3种活性氧,而且具有较为复杂的互不相同的作用机制。     

嵊州市十大森林休闲养生区空气负离子资源及影响因子分析

本研究旨在评价浙江省嵊州市十大森林休闲养生区春、夏、秋、冬4个季节空气负离子(NAI)浓度及其空气质量状况。从2016年6月到2019年6月期间,用NT-C101A便携式空气正负离子测定仪对嵊州市十大森林休闲养生区30个监测点进行了空气负氧离子测定。结果显示：（1）嵊州市十大森林休闲养生区平均负氧离子浓度6668个/cm³,超过世界卫生组织清新空气标准的6倍多;（2）嵊州市十大森林休闲养生区NAI浓度季节分布特征是夏季>春季、秋季>冬季;（3）不同森林休闲养生区的空气负离子浓度有明显差异,其中紧临跌水的监测点的空气负离子浓度最高,瞬时测定最高值达67800个/cm³;（4）NAI浓度与空气相对湿度、温度呈显著正相关关系、与PM_2.5浓度呈不显著负相关关系。浙江省嵊州市十大森林休闲养生区空气负离子资源丰富,季节变化明显,夏季较高,冬季较低。NAI浓度的变化受空气中的湿度、温度及PM_2.5等环境因素的综合影响,嵊州市茂密森林植被资源和丰富的水资源使其空气清洁、舒适,有益于人体健康的决定因素,发展森林健康产业前景广阔。     

WOFOST模型对山东省夏玉米发育期与产量模拟的适用性评价

夏玉米作为山东省最主要的粮食作物,其生长发育与产量变化,对保障地区乃至全国的粮食安全具有举足轻重的作用。不同生育期内气象要素的不同组合对夏玉米发育进程与产量形成等将产生重要影响。WOFOST作物模型机理性较强、定量水平高,且更为高效,能够为客观、定量、动态地评估气象要素对夏玉米生产的影响提供技术支撑。为提高作物模型模拟的准确性,将山东省分为鲁西北、鲁中、鲁西南、鲁东南与半岛5个调参区域,并结合山东省10个夏玉米观测站2012-2014年玉米主栽品种的生长发育数据,开展模型的调参验证与适用性评价。研究结果表明,WOFOST模型对山东省各观测站点所有年份出苗期的模拟误差均不超过4d,决定系数（R ²）在0.43~0.99,归一化均方根误差（nRMSE）为0.3%~1.9%;针对开花期和成熟期,各观测站点绝大多数年份模拟误差均不超过5d,大多数观测站点R ²分别在0.77~0.99与0.51~0.99,各观测站点nRMSE分别在0.4%~2.3%与0.7%~3.2%;绝大多数观测站点产量模拟R ²在0.68~0.99,相对误差为0.8%~16.7%,绝大多数观测站点相对误差小于10%;nRMSE在1.2%~19.5%,均小于30%,大部分观测站点nRMSE小于10%。各评价指标均在可接受的范围内,WOFOST模型能够对山东省夏玉米发育期与产量进行较准确的模拟。     

临汾市雾霾天气的分析和研究

为了进一步提高对临汾市雾霾的预测以及防治效果,从而避免、减轻雾霾天气对人类造成的交通、健康等危害。根据临汾市2013年11月—2014年3月自动气象站对PM_1.0、PM_2.5、PM₁₀、能见度、相对湿度、气温等的观测资料,利用临汾市1954—2014年12—3月的降水日数和静风日数的统计资料,利用数理统计、线性拟合、多元回归等方法,分析临汾市秋冬季雾霾与天气气象要素之间的关联。结果表明：风速、气压、气温都会对空气的能见度产生影响,其中风速的影响最大,风速每增大1 m/s,能见度增加3.3 km;气温、相对湿度、风速、能见度均与PM_2.5呈负相关,风速与PM_2.5浓度值的负相关程度最大,风速每增大1 m/s,PM_2.5的浓度值减少65.2 μg/m³;静风日数以0.98 d/10 a的速率减少,而降水日数以 0.07d /10 a的速率减少。     

Effects of elevated carbon dioxide and ozone on potato tuber quality in the European multiple-site experiment ‘CHIP-project’

Potato (Solanum tuberosum L cv. Bintje) was exposed to ambient and elevated carbon dioxide (CO₂), to ambient and elevated ozone (O₃) and to elevated levels of both gases during two growing seasons, 1998 and 1999. Experiments in open-top chambers (OTC) were carried out in Finland, Sweden, Ireland, United Kingdom, Germany and Belgium and a FACE (Free Air Carbon dioxide Enrichment) experiment was carried out in Italy. In OTCs the plants were grown under ambient CO₂ concentrations or with 550 and 680 μl l⁻¹ CO₂ alone or in combination with ambient or elevated O₃ concentrations (target seasonal mean of 60 nl l⁻¹ 8 h per day). In the FACE systems the plants were exposed to ambient or 550 μl l⁻¹ CO₂. In the OTC experiments the reducing sugar content of potato tubers decreased significantly with increased concentration of O₃. The starch content of potato tubers decreased, with negative impact on tuber quality, but the ascorbic acid concentration increased as a function of the AOT40 (The sum of the differences between hourly ozone concentration and 40 nl l⁻¹ for each hour when the concentration exceeds 40 nl l⁻¹ during a relevant growing season). However, simultaneous exposure to elevated CO₂ counteracted the ozone effect. With increase in the CO₂ exposure, glycoalkaloid and nitrate concentrations decreased yielding improved quality, while the citric acid concentration decreased causing a higher risk for discoloration after cooking. The amount of dry matter and starch increased significantly in the FACE experiment.     

增效缩节安化学封顶对棉花主茎生长的影响及其相关机制

缩节安(1,1-dimethyl piperidinium chloride, DPC)是棉花生产中广泛应用的植物生长延缓剂。增效DPC (DPC ⁺, 25%水剂)助剂中的成分能对植物幼嫩组织表面形成轻微伤害, 实践证明其可实现棉花化学封顶、起到替代人工打顶的作用。为探究DPC ⁺作用机制, 本试验于2015年在田间条件下研究了棉花盛花期后(7月24日)应用DPC ⁺ (1125 mL hm ^-2)对棉花主茎生长和顶芽解剖结构、氧化还原状态及相关基因表达的影响。结果表明, 与对照(同期喷施清水)相比, DPC ⁺处理后棉花株高降低, 白花以上节位(nodes above the last white flower, NAWF)更早降到5; 处理后3 d即可观察到主茎生长点较对照扁平, 生长点的纵横比显著低于对照; 处理后6 h棉花顶芽的O₂ ^-、H₂O₂和MDA含量高于对照, 而开花相关基因GhSPL3和GhV1及顶端分生组织相关基因GhREV3的表达量则低于对照。化学封顶剂DPC ⁺可引起棉株顶芽的短期氧化应激反应, 降低与主茎生长点发育和花芽分化相关基因的表达水平, 从而延缓棉株生长和花芽的产生, 实现化学封顶。     

圆柏对大气颗粒物的阻滞作用研究

为了研究在单株尺度上林木对大气中不同颗粒物的阻滞作用,选择圆柏作为研究对象,分析3个树冠高度和不同季节中PM_2.5、PM₁₀以及TSP这3种颗粒物的浓度变化规律;对圆柏不同高度上的阻滞效率进行探究,并使用离子色谱对PM_2.5颗粒中的6种水溶性离子成分进行分析。结果表明：不同高度上浓度日变化规律大致相同,浓度差异不大,并均在中午达到最低值;但3个高度的阻滞率差异悬殊,以中部阻滞效果最为明显,尤以PM_2.5为甚,可达47.6%,其次是上部,下部最低;3个季节浓度相差较大,春季最高,夏季次之,秋季最低,且以秋季的波动最为平缓;水溶性离子浓度以Na 、NH₄ 最高,圆柏对F^-、Na 阻滞效果明显,分别为87.62%、68.27%。     

Influence of modified atmosphere packaging on sensory quality of shiitake mushrooms

Shiitake mushrooms (Lentinus edodes) were packaged under air in two macroperforated packages (A—9.0 × 10³ perforations/m², 0.1 mm² surface and B—17 perforations/m², 0.1 mm² surface) and under two gas mixtures (15% and 25% O₂) in polyethylene packages, and stored at 5 °C for 18 d. The sensory quality of the mushrooms was evaluated using a trained assessors panel.

Mushrooms packaged in macroperforated packages A showed the smallest deterioration rate. However, weight loss after 6 d of storage reached 15%, which is unacceptable. Besides, shelf life of shiitake mushrooms in active modified atmosphere was limited by off-odour development. Mushrooms in these packages developed off-odour after 12 d of storage due to the fact that O₂ concentrations fall bellow 5%.

On the other hand, the shelf life of mushrooms packaged in macroperforated packages B was limited by their sensory deterioration, particularly by changes in the colour and uniformity of their gills. In this film, mushrooms could be stored for approximately 10 d with a weight loss lower than 2%.

Results from the present work suggest that during the first 6 d of storage all the evaluated packaging conditions were useful for reducing mushroom deterioration rate.     

Physio-pathological responses of cabbage stored under controlled atmospheres

The response of cabbage to controlled atmospheres (CA) of 1–3% O₂ and 1–10% CO₂; 3% O₂ and 5% CO₂ was studied in relation to the incidence of physiological and pathological disorders. Fungal infections, pepper spot, low oxygen injury, weight loss, colour, odour, flavour and ethanol were evaluated. The findings show that CA did not reduce Botrytis cinerea rot in comparison to low temperature storage in air. PVC film and CA, on the other hand, reduced pepper spot by over 50% with respect to the air control. In particular, pepper spot was eliminated by high CO₂ (10%) levels. Low O₂ (1% O₂ and 1% CO₂) atmospheres caused 33 and 50% injury respectively after 89 and 109 days of storage. CA and PVC film reduced weight loss to 1%, as compared with 11% in the heads in air, which had shrivelled. The combination of 3% O₂/5% CO₂ and PVC film delayed yellowing with respect to air control. Concentrations of 1–3% O₂ and 10% CO₂ resulted in off odours and flavours after 74 days of storage. This result was confirmed by a considerable increase in ethanol concentrations. The most effective concentration tested was 3%O₂/5%CO₂ although, in general, infection by B. cinerea limited the storage life.     

CO2 and ozone effects on canopy development of potato crops across Europe

This paper describes the effects of elevated CO₂ (550 and 680 μl l⁻¹) and O₃ (60 nl l⁻¹ O₃ as an 8 h mean), alone or in combination, on canopy development and senescence in potato (Solanum tuberosum L. cv Bintje) across a range of European agro-climatic conditions. The assessments were made within the European CHIP project (CHanging climate and potential Impacts on Potato yield and quality) that was conducted for two growing seasons (1998 and 1999) in free air CO₂ enrichment systems (FACE) and open-top chamber facilities (OTCs) at seven European sites. A comparison of chambered and unchambered experimental plots was included to examine the effects of chamber enclosure. Phenological growth stages, plant height, leaf area index (LAI) and the number of green and yellow leaves were recorded non-destructively throughout the growing season and by a destructive intermediate harvest at maximum leaf area (MLA). In the dynamic growth analysis CO₂ and O₃ effects were studied over three developmental stages: canopy expansion, full canopy and canopy senescence. Chamber enclosures promoted potato crop development (taller plants, more leaves) during the initial growth stages and led to a faster decline of LAI and a higher number of yellow leaves. The growth in ambient plots varied between sites and seasons, as did the scale of the treatment responses. Despite the large background variation, some overall treatment effects could be detected across all sites. Both levels of increased CO₂ reduced final plant height in comparison to ambient concentrations, which indicates a premature ending of the active plant growth. At the stage of full canopy and crop senescence the average number of green leaves was significantly (P<0.05) decreased by 680 μl l⁻¹ CO₂ (OTC experiments) and LAI showed the same tendency (P=0.07). As there was however no indication of a decreased leaf formation during initial growth and at full canopy, this must have been due to an earlier leaf fall. In the FACE experiments LAI had already began to decline at the stage of full canopy at 550 μl l⁻¹ CO₂ but not in ambient CO₂ (DAE×CO₂, P<0.05). These observations strongly indicated that elevated CO₂ induced a premature senescence during full canopy. O₃ did not have an overall detrimental effect on crop development during initial growth nor at full canopy, but did induce a faster reduction of LAI during crop senescence (DAE×O₃, P<0.05). Final plant height was not affected by O₃. There were few CO₂×O₃ interactions detected. There was a suggestion (P=0.06) that O₃ counteracted the CO₂-induced decrease of green leaves at full canopy, but on the other hand during crop senescence the decline of LAI due to elevated O₃ was faster at ambient compared to elevated CO₂ (P<0.05). These responses of canopy development to elevated CO₂ and O₃ help to explain the treatment responses of potato yield within the CHIP project at sites across Europe.     

拉萨市空气质量预报方法

利用拉萨市地面气象观测资料、高空观测和数值天气预报产品,挑选了与空气污染物扩散有关的42个气象因子,进行标准化处理后,基于逐步回归方法利用拉萨市区2008—2012年3种主要空气污染物SO₂、NO₂和PM₁₀日平均浓度建立不同季节的污染物浓度回归方程,并对宗教活动和节庆假日的焚香、焰火等人类活动作订正得出污染物浓度预报结果。利用2013年的数据作试报表明该预报方法的效果较好：SO₂平均绝对误差为0.001~0.0022 mg/m³,平均相对误差在15.3%~27.0%之间;NO₂平均绝对误差为0.003~0.005 mg/m³,平均相对误差在17.2%~27.5%之间;PM₁₀平均绝对误差为0.006~0.019 mg/m³,平均相对误差在16.6%~28.6%之间,空气污染指数(API)预报准确率在78.2%~87.8%之间。该预报方法能够满足拉萨市空气污染物浓度预报的需要。