茉莉酸甲酯对采后赛买提杏冷藏品质的影响

以新疆赛买提杏为试材,研究茉莉酸甲酯对采后赛买提杏冷藏品质的影响.将赛买提杏置于密闭气调箱内用不同浓度茉莉酸甲酯熏蒸处理绿熟期赛买提杏,处理浓度分别为0（CK）,1×10^-4,1×10^-5,1×10^-6 mol/L,处理时间均为24 h,之后放置在（0士0.5）℃条件下贮藏30 d.结果表明,茉莉酸甲酯处理可抑制绿熟期杏果腐烂率的发生,降低呼吸速率,保持较高的维生素C及可溶性固形物含量,有效降低绿熟期杏果实细胞膜透性,浓度1×10^-4 mol/L茉莉酸甲酯处理可以较好保持绿熟期赛买提杏的贮藏品质.     

甲基丙烯酸甲酯改性白炭黑/NR复合材料的研究

在天然胶乳（NRL）和白炭黑（WC）为主的体系中,引入适量的甲基丙烯酸甲酯单体（MMA）和引发剂,利用单体对白炭黑表面发生接枝反应的同时,实现其与橡胶大分子链通过化学键相连接,乳液共沉制备白炭黑填充型天然橡胶复合材料（NR/WC/MMA）。复合材料具有良好的加工流动性、力学性能和耐老化性能。     

茉莉酸甲酯对烟草抗黄瓜花叶病毒的诱导效应

用1 g.L-1茉莉酸甲酯(MJ)处理小十字期烟草幼苗,烟苗移栽后长至10片真叶时再用相同浓度MJ处理一次,并接种烟草黄瓜花叶病毒,研究茉莉酸甲酯对烟草黄瓜花叶病毒(CMV)的诱导效应.结果表明:接种CMV后21 d,MJ处理烟株的病情显著低于对照,诱导效果达到43.24%;MJ处理提高了烟草幼苗叶片内的过氧化物酶、过氧化氢酶及超氧化物歧化酶的活性和过氧化氢的含量;而接种CMV后,MJ处理烟株叶片过氧化氢酶、超氧化物歧化酶活性下降,过氧化物酶活性增强,过氧化氢含量明显升高.     

过氧化氢光催化脱色甲基橙溶液的研究

本文在H2O2存在下用紫外灯照射对甲基橙溶液进行光催化脱色。结果表明,甲基橙溶液的脱色率随着H2O2的增加而增加,但存在一个最佳值。当甲基橙浓度低于25 mg/L时,反应为假一级,当甲基橙浓度高于100 mg/L时,反应为零级;但是不符合Langmuir-Hinshewood动力学模型。脱色率在酸性条件下比碱性条件高。日光照射下对实际染料废水的脱色效果好。     

用茉莉酸甲酯局部喷施长白落叶松苗对落叶松毛虫体内防御酶的影响

为明确茉莉酸甲酯局部处理林木对落叶松毛虫解毒代谢的影响，本研究以3种不同浓度的茉莉酸甲酯(MeJA，0.01、0.10和1.00mmol/L)局部处理长白落叶松苗的侧枝，分析不同处理对取食其针叶的落叶松毛虫3~5龄幼虫体内保护酶和解毒酶活性的影响。研究发现，3个浓度的MeJA局部处理长白落叶松对松毛虫幼虫体内保护酶和解毒酶活性均有显著影响(P < 0.05)，酶活变化趋势一致，但未呈浓度依赖关系。各处理组幼虫体内的SOD和POD活性均在第4龄显著高于CK(P < 0.05)，但3、5龄幼虫体内的SOD和POD活性与CK差异不显著(P>0.05)；而ACP、AKP和GSTs活性先在第3龄低于CK、第4龄均显著低于CK(P < 0.05)，后在第5龄不同程度地高于CK。表明用MeJA局部喷施能诱导提高长白落叶松的系统抗性，且其对食叶害虫具有广谱性，能干扰落叶松毛虫的解毒代谢，抵御其危害；落叶松毛虫能在逐渐适应后，通过提高保护酶和解毒酶的活性去响应诱导抗性造成的毒害。      

Methyl Jasmonate Counteract UV-B Stress in Barley Seedlings

The role of exogenously applied phytohormone methyl jasmonate (MeJA) in counteracting the ultraviolet B (UV‐B) stress in barley seedlings was investigated. Barley seedlings (Hordeum vulgare L., cv. Alfa) 4 days old were supplied with 5 × 10^?5 m MeJA through the roots for 3 days and then exposed for 2 days for 5 h per day to UV‐B (312 nm, biological effectiveness of UV‐B radiation 28.8 kJ m^?2day^?1). The rate of ¹⁴CO₂ fixation, PSI and PSII activities and chlorophyll content decreased, but flavonoids, H₂O₂, malondialdehyde, proline and UV‐B induced compounds increased after UV‐B treatment. The rate of photosynthetic oxygen evolution was more strongly inhibited by UV‐B‐irradiation than PSI and PSII efficiency. MeJA itself increased the content of free proline, which acts as a stress protector due to its radical scavenging ability. Increased superoxide dismutase, catalase and peroxidase (POX) activities in the leaves and in the roots and the POX isoforms induction revealed the MeJA involvement in plant tolerance to oxidative stress caused by UV‐B irradiation. It was shown that pre‐treatment with MeJA counteracted UV‐B stress. Therefore, it was suggested that MeJA could acts as a mediator in plant defense responses to UV‐B irradiation by enhancing the activity of antioxidant system and free radical scavenging capability of plant cells.     

MEK-石脑油可回收稀释降粘输送工艺

概述了稠油的物性,分析了石脑油中加入MEK(甲基乙基酮)后对稠油的稀释降粘效果。介绍了MEK-石脑油可回收的稠油稀释降粘工艺流程,指出MEK-石脑油回收稀释降粘工艺虽比石脑油回收稀释降粘工艺增设了一套MEK回收装置,投资及运行成本略高,但其降粘效果较好,能够以较小的稀释比提高稠油的输送能力。     

不同浸渍时间对辐照后杨木气干密度、24h吸水率的影响

采用浸渍甲基丙烯酸甲酯（MMA）再经γ射线辐照的方法,研究了不同浸渍时间（8h、24h、48h）对处理材的气干密度和24h吸水率的影响。结果表明：1）处理材的气干密度与浸渍时间呈显著正相关。2）处理材的24h吸水率与浸渍时间呈显著负相关。     

大豆油酸的连续加压酯化方法及动力学的研究

脂肪酸甲酯的制备和生产技术多种多样,常用酯交换方法具有醇酸摩尔比大,反应时间长的缺点.在管式固定床的反应器中,采用自制的同体催化剂,油酸甲酯通过直接酯化方法制得,生产工艺简单.油酸与甲醇在加压的条件下,酯化工艺条件经优化得到其最佳反应条件为:反应温度为100℃,压力0.35 MPa,反应停留时间2.5 h,醇酸摩尔比2:1.在此条件下,经单段反应的转化率可达到93.10%,与传统酯化方法相比,该工艺具有甲醇用量显著降低,无三废产生,可实现连续化生产等优点.反应时间的缩短也降低了能耗.对油酸甲酯的酯化反应进行动力学研究,依据数据采用最小二乘法线性回归模拟酯化反应的宏观动力学方程,结果表明:油酸酯化反应为准二级反应.     

Dielectric relaxation due to heterogeneous structure in moist wood

Dielectric properties in three main directions for hinoki wood (Chamaecyparis obtusa) specimens conditioned at various levels of relative humidity were measured in the frequency range from 20 Hz to 10 MHz over the temperature range from −150°C to 20°C. Three relaxations were observed in the specimens conditioned at high levels of relative humidity. The relaxation in the highest frequency range was ascribed to the motions of adsorbed water molecules. The relaxation in the middle frequency range remained unchanged by the ethanol–benzene extraction of specimens. The relaxation location was independent of measuring directions. The relaxation in the lowest frequency range was not detected in the specimens impregnated with methyl methacrylate (MMA). This result suggested that the relaxation was due to electrode polarization. The Cole-Cole circular arc law applied well to two relaxations recognized in the specimens impregnated with MMA. The relaxation magnitude in the middle frequency range was extremely large, and the distribution of relaxation times was very narrow. These characteristics suggested relaxation of the Maxwell-Wagner type resulting from the interfacial polarization in the heterogeneous structure, which included adsorbed water with large electrical conductivity within the insulating cell walls.