基于液质联用检测柿子多酚成分的分离与鉴定

柿子中富含多酚类化合物,具有多种生理活性功能。为了获得柿子中的多酚组分,依次采用HP2MGL大孔吸附树脂、Sephadex LH-20凝胶多糖和ODS-A反相填料对柿子多酚进行分离纯化,先后获得了4种不同的柿子多酚组分。通过LC/MS的检测与鉴定,4种组分分别是没食子酸、儿茶素、表儿茶素和咖啡酸,这4种多酚纯度分别为没食子酸95.15%,儿茶素95.04%,表儿茶素87.47%,咖啡酸85.0%。本研究建立了一种从‘磨盘柿’中分离纯化柿子多酚组分的有效方法。     

基于RBF和PSO的双喉道气动矢量喷管优化设计

本文探索了一种能多变量综合优化的方法,即对喷管进行参数化设计后,用均匀试验设计(UED)将试验样本均匀散布在设计区间内,求出各性能参数后,利用径向基神经网络(RBF)对试验样本进行拟合,再用粒子群算法(PSO)对训练好的神经网络进行寻优,找出了更好的双喉道气动矢量喷管设计参数组合。数值模拟结果显示,优化后的双喉道气动矢量喷管的矢量角有了明显提高。试验表明这种优化方法具有很好的优化能力,可以用来对喷管几何外形进行参数优化。      

花鲈皮肤溃疡病病原菌的分离与鉴定

为了确定海水池塘养殖花鲈发生皮肤溃疡病的病原菌及其防治方法。利用莆田市人工饲养的花鲈中挑取具有皮肤溃疡病明显症状的幼鱼,从体表病灶和体内组织中分离出病原菌,通过人工感染试验、细菌形态观察及常规生理生化指标测定对其进行了分类学鉴定,同时进行药敏试验。结果表明：引起该养殖场皮肤溃疡病的病原菌为哈维氏弧菌,该菌对复方新诺明、阿莫西林、哌拉西林、替卡西林、头孢拉定、头孢噻肟、头孢吡肟、头孢他啶、头孢呋辛钠、美罗培南、头孢西丁、卡那霉素、奈替米星、阿米卡星等14种药物敏感,对米诺环素、链霉素等抗生素表现出耐药。在实际生产上采用饲料中添加复方新诺明和维生素C的方法来治疗花鲈皮肤溃疡病,连续用药10天后,取得了较好的疗效。     

分子蒸馏技术拆分陈皮挥发油及其GC-MS分析

以陈皮挥发油为研究对象,将其经过分子蒸馏拆分,得到不同馏分物,并分别对陈皮挥发油及所得馏分物进行气相色谱-质谱(GC-MS)分析。分子蒸馏分为二级,一级条件为:蒸发温度(30±0.2)℃,真空度(0.5±0.1)k Pa,刮膜器转速150~160 r/min;二级条件为:蒸发温度(60±0.2)℃,真空度(0.5±0.1)k Pa,刮膜器转速200~210 r/min;两次进样温度25℃,冷凝管温度10℃。结果表明,陈皮挥发油经二级分子蒸馏后总回收率为98.80%,其中一级轻组分(DF1)回收率为40.20%,二级轻组分(DF2)回收率为58.06%,二级重组分(RF2)回收率为0.53%。陈皮挥发油和各馏分物经过GC-MS分析后,确定25种化合物,主要为右旋萜二烯、α-萜品烯、萜品油烯等,但陈皮挥发油及各馏分物成分种类及相对含量差异明显,说明分子蒸馏技术能有效对陈皮挥发油成分进行拆分,可用于陈皮等挥发油的加工利用。     

蝴蝶兰‘大辣椒’(Phalaenopsis ‘Big chili’)和‘0436’(P. ‘Red swan’)杂交后代花部性状分离研究

为研究红色蝴蝶兰花性状遗传规律,解决国内蝴蝶兰主流品种‘大辣椒’易患煤污病的问题,以‘大辣椒’(Phalaenopsis‘Big chili’)和‘0436’(P.‘Red swan’)为亲本,进行正反交。研究结果表明：（1）蝴蝶兰‘大辣椒’和‘0436’正反交后代花色性状出现了显著的分离,花底色玫红色的深度出现了梯度变化,正反交后代的分离规律基本一致。花底色应是由多对基因控制的复杂遗传,且红色由显性基因控制,显性基因越多,花色越深。（2）蝴蝶兰花心颜色、花纹颜色和叶片性状可能为显性遗传。‘大辣椒’和‘0436’正反交后代的花心颜色、花瓣纹路、花期和叶片性状表现均倾向于‘0436’,可有效解决‘大辣椒’叶片易患煤污病的问题,杂交后代因分泌蜜露造成的煤污病发病率降低至25%以下。（3）‘大辣椒’和‘0436’正反交后代的花径、花朵数和花序长度平均值均低于双亲,中亲或超亲优势不明显。     

单细胞转录组测序技术及其在植物研究中的应用

为探究单细胞转录组测序技术(scRNA-seq)在植物研究中的应用,本综述对单细胞转录组测序技术的发展状况进行了总结,介绍了其在胚胎发育、免疫细胞、肿瘤领域以及植物研究的运用.其次,就单细胞转录组测序技术中的要点技术(单细胞分离技术、单细胞全转录组cDNA扩增技术、高通量测序技术)进行了总结分析.最后,本文根据植物细胞...     

不同品质类型小麦籽粒淀粉粒度的分布特征

选用小麦强筋品种德丰3号、德99-3和弱筋品种滨育535和鲁麦21,研究了籽粒中淀粉粒度、淀粉粒的体积、数目和表面积的分布特征,及其与小麦籽粒蛋白质和淀粉含量的相关性。结果表明,成熟期小麦籽粒含有A (＞9.8 μm)、B (＜9.8 μm)两种类型淀粉粒,其粒径为0.37~52.60 μm。淀粉粒的体积和表面积均表现为双峰分布;淀粉粒的数目表现为单峰分布,其中B型淀粉粒数目占总数的99%以上。在强筋品种中,B型淀粉粒所占体积和表面积百分比相对较高,而弱筋品种中A型淀粉粒体积、表面积百分比相对较高。籽粒直链淀粉和总淀粉含量与2.0~9.8 μm和＜9.8 μm的淀粉粒体积百分比分别呈显著和极显著负相关,与9.8~18.8 μm的淀粉粒体积百分比呈极显著正相关。籽粒蛋白质含量与2.0~9.8 μm和＜9.8 μm的淀粉粒体积百分比呈显著正相关,而与9.8~18.8 μm的淀粉粒呈极显著负相关。籽粒淀粉和蛋白质含量均与其他粒径范围的淀粉粒体积无显著相关性。     

集约化猪场粪污处理工艺的研究

根据我国集约化猪场排粪方式和粪水的特性，提出了采用人工清粪方式、固液分离机+沉淀+UASB+SBR+水生植物塘的污水处理工艺和猪粪（渣）堆沤发酵生产有机肥新的粪污处理工艺。经上海市嘉定种畜场污水处理工程实践证明：在保证污水全面达标排放和猪粪（渣）无害化处理的前提下，新工艺比常规工艺节约工程投资35%、节约运行电费65%左右，经济效益好。     

Urban sediment particle size and pollutants in Southern Brazil

Background, aim and scope

Studies of particulate-associated pollutants, or PAPs, in urban areas have become necessary due to their potentially deleterious effects on the environment. However, it is not just the sediments themselves which are problematic but also their particle size composition, which has a great influence on their capacity to adsorb and transport pollutants. This paper presents the particle size distributions and concentrations of five metals (Cr, Cu, Ni, Pb and Zn) of urban sediments collected from paved streets and gully pots from 20 cities in southern Brazil. The cities have different characteristics and hence sources of PAPs associated with differing geologies, soil types and type of urbanisation. Studies of this nature enable elucidation of the relationship between diffuse sources such as streets and gully pots and the likelihood of PAPs to subsequently pollute the urban aquatic environment.

Materials and methods

Sediment samples were taken at random from paved streets and gully pots in 20 cities in Rio Grande do Sul state, southern Brazil by means of a portable vacuum cleaner to avoid loss of finer particles. The particle sizes of the samples were measured using a Cilas® 1180 laser particle analyzer, and the concentrations of five metals (Cr, Cu, Ni, Pb and Zn) were determined by wet acid digestion (HCl–HF–HClO₄–HNO₃) followed by inductively coupled plasma atomic emission spectroscopy on the <63-µm fraction.

Results

It was found that in comparison to sediments collected from the streets, gully pot sediments were more heterogeneous in terms of particle size and also that sediment samples from the gully pots were predominantly coarser than those originating on the streets. From the gully pot results, analysis of the modal particle diameter enabled the cities to be divided into three categories. The concentrations of metals in the street sediments were similar across all 20 cities, with all concentrations above background values.

Discussion

The fact that concentrations of metals in the street sediments were above statutory guideline values and that the coarser material was deposited in the gully pots suggests that the finer, more polluted sediment is not retained in the gully pots but is transported to the nearest local receiving watercourse. This finding has implications for management strategies for reducing pollution in urban environments.

Conclusions

High concentrations of Cr, Cu, Ni, Pb and Zn in the <63-µm fraction of street sediments, in combination with coarse material retained in the gully pots, indicate that metals could be transferred quite rapidly from the diffuse source of pollutants, on impermeable street surfaces, to receiving watercourses.

Recommendations and perspectives

Studies of urban sediment particle size and geochemistry enable predictions to be made of sediment behaviour in urban environments. This will inform management strategies such as the possibility of including sustainable urban drainage systems in future management plans, in which it is useful to know how efficient the drainage system is from the point of view of sediment deposition in the urban aquatic environment and the potential for pollution of receiving waters.     

Laser diffraction analysis of the disintegration of aeolian sedimentary aggregates in water

A new method for the analysis of aggregate disintegration in water was tested using aeolian sediment samples. The response of aeolian sedimentary aggregates to wetting and mechanical energy has important implications for the immobilization of aeolian sediments by rainfall and their susceptibility to post-depositional erosion by water. Repeated laser diffraction analysis of a single sample circulating in deionized water provides a detailed view of the changes in particle size distribution as aggregates disintegrate. This methodology also allows experiments on the effects of water chemistry, exchangeable cation chemistry, and prewetting. Results presented here suggest that aggregates of widely varying stabilities can occur in a wide range of particle size classes; that is, aggregate stability may to some extent be independent of the hierarchy of aggregate sizes emphasized in earlier research. The methods described here are broadly applicable to a variety of soils and sediments, but experiments are needed to relate the results more specifically to aggregate behavior under field conditions.