中国产区苹果越冬冻害的风险评估

越冬期冻害是影响苹果种植分布和质量形成的主要气象灾害之一。论文利用1961-2014年2 084个气象站点资料和冻害调查数据,基于二分类Logistic回归分别建立了越冬期初冬冻害和极端低温冻害发生的概率预测模型,并按照风险极低、低、中度、高、极高等5个等级进行了空间划分。结果表明：建立的初冬冻害和极端低温冻害风险概率预测模型均通过了Hosmer-Losmer检验,独立样本的预测准确率分别达到了83.6%和91.4%。中国产区苹果的越冬冻害主要以初冬冻害为主,覆盖了除黄河故道和云南产区外的大部分果区,而极端低温冻害主要分布在纬度或海拔较高的环渤海湾北部产区、黄土高原西北部和北疆。两种冻害的高风险区域面积基本相当,中度以上风险面积较大的省份依次为甘肃、辽宁、河北和山西,但苹果种植面积最大的陕西和山东遭遇两种冻害特别是极端低温冻害的风险概率总体较低。     

我国10城市冬季大气颗粒物中多环芳烃污染及呼吸暴露风险评价

大气中颗粒物和多环芳烃对环境与人体健康危害较大,已引起社会各界的广泛关注。以我国10个城市2013年12月和2014年1月大气中空气动力学直径小于10μm的颗粒物(PM10)为研究对象,采用硅胶-氧化铝层析柱净化分离、气质联用仪分析的方法测定了27种多环芳烃(PAHs)的浓度水平,分析其谱分布及空间分布,并通过呼吸暴露途径估算了癌症病发增量(ILCRs)和人群归因危险度百分比(PAF)。结果表明,27种物质的总浓度为13.72~2 002 ng·m-3;在10个城市中晋中总浓度最高,厦门最低。PAHs空间污染水平呈现北方高于南方、东部沿海城市浓度相对较低的趋势。温度与总浓度有相关性。在27种PAHs中,占主导地位的单体为荧蒽(FLA,7.56%~19.8%),芘(PYR,6.72%~13.8%),艹屈(CHR,12.8%~19.6%)和苯并(k)荧蒽(Bk F,8.59%~15.5%),4者占到多环芳烃总浓度的42.1%~64.3%。根据研究区域苯并[a]芘(Ba P)人口加权浓度估算ILCRs范围为8.94×10-6~4.77×10-4,据此计算的PAFs为0.487%~13.2%,均值为3.44%,高于全国平均水平1.6%。上述研究结果为大气颗粒物中PAHs的研究提供重要的数据基础。     

Effect of preozonation on improvement of settleability of solid in highly concentrated organic wastewater of Japanese wheat and sweet potato spirit-distillery

Solid-liquid separation of the wastewater is very difficult because of high viscosity and high SS concentration. In this study, the effectiveness of preozonation on improving the settleability of the solids in wheat and sweet potato wastewaters was investigated using a bench-scale system and pilot treatment system respectively. Results showed that solid-liquid separation in the wheat wastewater was greatly improved by the decanter in the system(SS reduction from 24100 mg/L to 100 mg/L). However, preozonation practice did not show a significant effect on solid-liquid separation of the sweet potato wastewater. Effect of preozonation on solid-liquid separation between wheat and sweet potato wastewater showed different.     

Relationship between AtPase activity and conjugated polyamines in mitochondrial membrane from wheat seedling roots under osmotic stress

The effects of osmotic stress on the ATPase activity, the contents of —SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [ Triticum aestivum L. cv. Yumai No. 18 (drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and --SH group content decreased with polyethylene glycol(PEG) 6000( - 0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine (NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine (CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidine(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, --SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No. 18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin ( o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd / NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, --SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of --SH group, NCC-Spd and CC-Put in mitochondrial membrane.     

气候变暖对中国夏热冬冷地区居住建筑采暖降温年耗电量的影响

20世纪80年代中期以来的气候变暖,尤其是90年代中期以来的气候显著变暖带给社会经济发展的利与弊,一直以来受到广泛关注。气候变暖对于建筑耗能,尤其是对采暖和降温总耗能的影响很值得研究。论文以主要使用电能进行空间调节的中国夏热冬冷地区为对象,以《夏热冬冷地区居住建筑节能设计标准JCJ134-2001》中所规定的采暖、降温耗电量限值为依据,研究了气候变暖对该区居住建筑单位面积采暖年耗电量、降温年耗电量及采暖降温年耗电总量的影响。结果表明,1986年以来的气候变暖,尤其是1996年以来的气候显著变暖,理论上使夏热冬冷地区居住建筑单位面积采暖年耗电量降低;同时增加了相当一部分地区居住建筑单位面积降温年耗电量;除个别地区外,气候变暖理论上使中国夏热冬冷地区居住建筑单位面积采暖降温耗电总量普遍下降。     

无机离子SO42-对小麦幼苗积累稀土的影响

采用ＭＩＮＴＥＱＡ 程序计算出在无机离子SO₄^2-存在下,轻（Ｌａ）、中（Ｇｄ）、重（Ｙ）３ 种稀土元素在溶液中的形态分布．研究了在水培条件下ＳＯSO₄^2-对３种稀土元素在小麦幼苗根、茎和叶部的积累规律．热力学实验表明,小麦幼苗在加SO₄^2-的稀土元素溶液中培养３０ｄ 后,小麦根部对Ｌａ、Ｇｄ 的积累受抑制,而对Ｙ的积累却明显提高;加入SO₄^2-后茎叶部对Ｌａ、Ｙ积累值改变不明显,但对Ｇｄ的积累有所增加．生长动态实验表明,在SO₄^2-存在下,小麦幼苗根部对稀土的积累随时间增加而增加,其积累值符合线性递增函数方程,相关系数ｒ＞ ０．９４;而茎叶部最初积累能力较强,SO₄^2-的加入对小麦植株动态吸收稀土规律无明显影响．     

长江中下游冬小麦春季湿渍害灾损风险评估

春季湿渍害对南方冬小麦生长发育和产量形成影响很大。选取能较好反映冬小麦湿渍害特征的降雨量、日照和作物需水量构建湿渍害气象判别指数,从春季湿渍害产量实际损失的角度,对受灾频率、因灾减产频率、产量损失风险强度进行分析,基于减产频率和产量灾损风险强度建立风险评估模型,并依据风险值大小进行分区。结果表明:沿江江南地区冬小麦春季湿渍害受灾频率最高,为风险高值区,约占全区台站27%;风险中值区范围较大,约占47%,分布在江淮东部、淮北大部、江汉平原以及鄂东南地区;低风险区约占全区16%,主要分布在湖北北部和淮北局部地区。     

麦秆对水中扑草净的吸附性能研究

农业秸秆富含纤维素、木质素等组分,是良好的吸附材料。采用麦秆作为吸附剂,其对浮油及溶解油具有良好吸附效果。选用麦秆为吸附剂,探究其对扑草净的吸附效果。主要考察麦秆粒径、投加量、振荡频率、扑草净初始质量浓度4种因素对吸附的影响,研究麦秆对扑草净的吸附等温线和吸附动力学过程,并采用正交实验对影响吸附的因素进行优化。结果表明:(1)麦秆可有效降低废水中扑草净浓度,在振荡频率150r/min、麦秆粒径250~500μm、投加量0.500 0g、吸附300min时,扑草净初始质量浓度由5.20mg/L降至3.22mg/L,去除率为38.08%。(2)单因素吸附平衡实验表明,随麦秆粒径增加(150~4 000μm),其比表面积减小,平衡吸附量随之减小,麦秆粒径150~250μm时平衡吸附量为0.192 0 mg/g,显著大于1 700~4 000μm时的平衡吸附量(0.059 3mg/g);随麦秆投加量增加(0.100 0~1.000 0g),去除率随之提高,平衡吸附量与之相反,0.100 0g投加量时平衡吸附量为0.222 0mg/g;随着振荡频率加剧,麦秆在水中扩散增强,与扑草净碰撞几率增加,振荡频率250r/min时平衡吸附量为0.191 0mg/g;随扑草净初始质量浓度增加(1.03~6.18mg/L),平衡吸附量随之增加,初始质量浓度为6.18mg/L,平衡吸附量为0.226 0mg/g。(3)分别以Henry型、Langmuir型、Freundlich型吸附等温式进行拟合,资料表明,以Henry型吸附等温式较适宜描述该吸附过程。(4)采用伪一级动力学方程、伪二级动力学方程、Elovich经验方程、颗粒内扩散方程分析吸附动力学过程,以伪二级动力学方程较符合。(5)在振荡频率为150r/min、初始质量浓度为2.00mg/L、麦秆粒径为250~500μm、投加量为0.700 0g时,扑草净最佳去除率为47.80%。     

Response of non-enzymatic antioxidative mechanisms to stress caused by infection with Fusarium fungi and chemical protection in different wheat genotypes

The aim of this study was to assess the effect of infection with Fusarium fungi and chemical protection on the contents of phenolic acids and antioxidative potential of extracts from grains of 23 wheat genotypes. Based on chemical analyses including abiotic factors such as weather conditions and the location of the plantation, the authors attempted to clarify non-enzymatic antioxidative response mechanisms to two different stressors in 23 wheat genotypes. Based on chemical analysis, it was found that mass infection with fungi from the genus Fusarium induces defence mechanisms of the plant, which results in an increased production of phenolic acids, mainly those, which are substrates for the production of acids exhibiting antimicrobial action. This mechanism is confirmed by the analyses of antioxidant activity, which also increases significantly during fungal infection, connected with the production of mycotoxins. In the course of chemical plant protection, significant changes were observed in the production of phenolic acids. Even if antioxidant activity was not higher in comparison to the control, an increased production of certain phenolic acids was recorded, which suggests stimulation of the resistance system of the plant, at a simultaneous complete response of antioxidative mechanisms, as it takes place during fungal infection.     

地表臭氧浓度升高对冬小麦和大豆生长和产量的影响

我国近地层臭氧污染日趋严重,其不断增加的浓度对农作物的生长造成了严重威胁。以冬小麦和大豆为研究对象,基于大田开顶式气室(OTC)试验,分别设置对照(CK)、100 n L·L~(-1)和150 n L·L~(-1)这3个O3浓度处理组,对2种作物生长指标和产量等参数连续观测,结果表明:O3浓度增加对冬小麦和大豆的株高、叶面积和生物量产生影响,并且对大豆的影响更为明显。与此同时,O3浓度增加使得冬小麦的穗重、穗粒数以及大豆的单株荚数、单株粒数、单株粒重都呈现大幅度下降状态,进而导致其产量降低。在100 n L·L~(-1)臭氧处理下,冬小麦产量较CK降低了12.89%,而大豆产量下降了23.76%。在150 n L·L~(-1)的臭氧处理下,冬小麦产量较对照组降低了29.23%,大豆则比对照组下降了41.57%,与CK相比,大豆产量下降更为明显。上述研究表明,臭氧污染对农作物的生长具有显著影响,且大豆对O3的反应比冬小麦敏感。