蒸汽爆破过程麦秆木质纤维素的转化

采用低压蒸汽爆破技术处理小麦秸秆木质素。通过单因素试验,考察蒸汽爆破过程汽爆压力、液固比、物料粒度、维压时间对木质纤维素降解的影响,木质素的降解率达到22.67%。设计L9(34)正交试验,上述因素影响主次顺序为汽爆压力＞液固比＞维压时间＞物料粒度,优化条件为汽爆压力0.6 MPa,液固比为20︰1,维压时间为30 min,物料粒度为20～60目,且对优化结果进一步验证。红外光谱分析表明,经汽爆后麦秆木质素结构受到了一定程度的破坏;扫描电镜观察,麦秆的纤维束受到了破坏,发生了断裂,且出现了多孔的结构。     

Comparison of Antioxidant Components and Activity of Buckwheat and Wheat Flours

Plant phenolics and tocopherols content were determined in light and wholegrain buckwheat and wheat flour. Antioxidant activity of flours were comparatively assessed by scavenging activity on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH^•), hydroxyl (^•OH), and superoxide anion (O₂^•–) radicals, reducing activity, and chelating activity on Fe²⁺. Rutin, quercetin, and ferulic acid were quantified in both buckwheat flours, while ferulic acid was quantified in wholegrain wheat flour. Significantly higher content of phenolics and tocopherols was found in buckwheat than in wheat flours. Tocopherols in buckwheat flours were present in the order: γ‐ > α‐>> δ‐tocopherol, and in wheat flours: α‐ > γ‐ >> δ‐tocopherol. Buckwheat flours possessed better scavenging abilities on DPPH^•, ^•OH and O₂^•– radicals, as well as better reducing activity, while wheat flours showed better chelating activity on Fe²⁺, according to IC₅₀ values. Results suggest the possibility of improving the antioxidant properties of wheat‐based food products through addition of buckwheat flour.     

黄土高原水土保持世行贷款项目区局地气候变化初步分析

对黄土高原水土保持世界银行贷款项目实施前后的监测数据和有关气象资料进行分析表明 ,大规模林草、梯田等坡面措施和沟道坝库工程的实施 ,影响了当地小气候特性 ,较好地起到了调节温度、提高湿度、增加降水和雾日、减少冰雹等作用 ,项目区与参照站比较 ,相对湿度提高了 5～ 10个百分点 ,平均每年有雾日相对增加了 6 7d ,年降水量相对增加 5 %～ 10 %。     

Olive processing wastes for weed control

The herbicidal effect of olive processing wastes (OPW) on some weed species in wheat, maize and sunflower was investigated in the Aegean region of Turkey. In trials with maize and sunflower, OPW was applied as an air‐dried solid form at 3 and 4.5 kg m^?2. It provided an effectiveness level on Portulaca oleracea of 63–98%. In trials with wheat, OPW was applied as solid and liquid forms, each at two different doses, namely 4.5 and 6 kg m^?2 (solid), and 5 and 10 L m^?2 (liquid). Solid OPW provided a reduction in total weed coverage of 75% and 81% at doses of 4.5 and 6 kg m^?2, respectively. The weed coverage reduction by liquid OPW was 39% and 62% with 5 and 10 L m^?2, respectively. Apart from 12–26% reduction of the number of germinating seeds, OPW showed no toxic effects on maize and sunflower. Wheat was affected in the initial stages but no adverse effect was detected at harvest. It can be concluded that the herbicidal effect of OPW may be considered as an alternative to chemical weed control in some important summer crops (maize and sunflower) and for most of the weeds in winter wheat.     

Potentially toxic elements in the riparian soils of the Sava River

Purpose

Riparian zone contamination is a growing problem for several European catchments due to high anthropogenic pressures. This study investigates As, Cd, Cr, Cu, Ni, Pb, and Zn concentrations in the Sava River riparian zone, characterized by wide agricultural areas, various geological substrates, and different types of industrial pollution. The accumulation and mobility of these elements were studied because they are listed as priority substances in the Water Framework Directive and environmental objectives for surface waters.

Materials and methods

Sampling was performed during the sampling campaign of the EU 7th FW-funded GLOBAQUA project in September 2015 during a low-water event. Soil samples were collected along the Sava River at 12 selected sampling sites, from a depth of 0–30 cm, at a distance of 10–15 m from the river bank. The extent of pollution was estimated by determining total and readily soluble element concentrations in the soils. Potential ecological risk and the source of the selected elements in the soils was determined using the enrichment factor (EF), potential ecological risk index (RI), and statistical methods such as the principal component analysis (PCA) and multiple linear regression analysis (MLRA).

Results and discussion

This study showed that concentrations of the selected elements increase along the Sava. In terms of origin, PCA and MLRA indicated that Cr and Ni in soils are predominantly lithogenic, while As, Cd, Pb, and Zn are both lithogenic and anthropogenic (ore deposits, industry, and agriculture). PCA singled out Cu since its origin in soil is most probably from specific point-source pollution. EF was generally minor to moderate for most of the examined elements, apart from Cu, for which the EF was significant at one sampling site. Overall ecological risk (RI) fell within the low-risk category for most sites, apart from Belgrade sampling site (BEO), where high total Cd content affected individual and overall ecological risk indicators, indicating Cd could represent a considerable ecological risk for the downstream riparian zone.

Conclusions

At downstream sites, there was a noticeable increase in PTE content, with Cd, Cr, Ni, and Zn exceeding the proposed threshold values for European soils, indicating rising contamination in riparian soils. In terms of the ecological risk, only Cd could pose a potential ecological threat for the downstream riparian zone.

     

华南地区新城疫病毒WS_(99)株HN基因片断的克隆和序列分析

用RT -PCR一步法扩增了华南地区野毒NDVWS99株的HN基因 890bp片断 ,并对其进行克隆、核苷酸测序及同源性分析 结果表明 :WS99株的HN基因与其他 2 9株NDV的核苷酸同源性在 88.0 %～ 99.8%之间 ,氨基酸同源性在 90 %～ 97%之间 鸡源NDVWS99株与鹅源副粘病毒GPMV株有极高的同源性 ,高达 99.8% 该毒株与TEX/ 48和B1/ 47一样 ,在HN基因 130 1bp处由G突变为A ,对应氨基酸由V突变为I,但其半胱氨酸位点和个数没有改变 ,且所克隆的目的片段中含有HN基因上 5个凝血抗原位点其中的 4个     

西南山地丘陵区永久性基本农田的多目标决策划定方法

为科学地引导西南山地丘陵区永久性基本农田的划定,该文以重庆市垫江县为例,通过层次分析法、熵权系数法、TOPSIS法（technique for order preference by similarity to an ideal solution）和约束因子建立决策模型体系,结果表明：耕地指标中灌溉保证率、平均降雨量、交通和农村居民点辐射的自身优势突出。土壤质量各指标平均值（介于0.2～0.75之间）、标准差（介于0.09～0.3之间）、变异系数（介于13～75之间）为中等以下水平。自然条件中,灌溉保证率和耕地连片性的综合权重最大,大于10℃积温和平均降雨量的综合权重最小、且指标值的区间变化最大;土壤质量中,有机碳在层次分析法下权重最大;距离条件中,入选耕地受城镇的辐射作用明显、区位优势突出。耕地在入选重要程度上,依次排序前4位的是灌溉保证率、耕地连片性、城镇的辐射和土壤有机碳,测度和贴近度显示,地块间优劣接近,距离条件整体较优。耕地的入选从贴近度等级划分为：重点型、适宜型、调控型、后备型,约束条件下调出的地块为优势耕地（即重点型和适宜型）。最终划定成果显示适宜型和调控型比例增大,重点型和后备型比例减小。并利用数据验证了该决策模型体系的合理性、规范化和可行性。     

Heavy Metals Removal in a Horizontal Rotating Tubular Bioreactor

Mixed microbial culture was isolated from heavy metal-contaminated ground soils located inside iron, vinyl and cement factory area. Isolated mixed microbial culture was used for the heavy metal ions (Fe²⁺, Cu²⁺, Ni²⁺ and Zn²⁺) removal process in horizontal rotating tubular bioreactor (HRTB). In this research, the effect of bioreactor process parameters on the bioprocess dynamics in the HRTB was studied. Results of this research have shown that profiles of heavy metals concentration were gradually reduced along HRTB at all combinations of bioreactor process parameters [inflow rates (0.5?C2.0 L?h^-1) and rotation speed (5?C30 min^-1)]. Hydrodynamic conditions and biomass sorption capacity have main impact on the metal ions removal efficiency that was varied in the range of 38.1% to 95.5%. Notable pH gradient (cca 0.7 pH unit) along the HRTB was only observed at the inflow rate of 2.0 L?h^-1. On the basis of obtained results, it is clear that medium inflow rate (F) has higher impact on the heavy metal removal process than bioreactor rotation speed (n) due to the fact that increase of inflow rate was related to the reduction of equilibrium time for all examined metal ions. Furthermore, equilibrium times for all metal ions are significantly shorter than medium residence times at all examined combinations of bioreactor process parameters. The main impact on the biofilm sorption capacity has covalent index of metal ions and biofilm volumetric density. The sorption capacity of suspended microbial biomass is closely related to its concentration. Results of this research have also shown that the removal of heavy metals ion can be successfully conducted in an HRTB as a one-step process.     

Effects of Different Irrigation Levels and Arbuscular Mycorrhizal Fungi (AMF), Photosynthesis Activator,Traditional Fertilizer on Yield and Growth Parameters of Dry Bean (Phaseolus Vulgaris L.) in Arid Climatic Conditions

A field experiment has been conducted to determine the effects of different irrigation water and AMF (Arbuscular Mycorrhizal Fungi) biofertilizer, photosynthesis activator and traditional fertilizer dry bean (Phaseolus vulgaris L.) on yield and growth parameters in Nevsehir Province of Turkey in 2015. The experiment has been carried out using three replications in a split plot design with three different irrigation types as main plots and AMF biofertilizer (ERS), photosynthesis activator (Multigreen-Mg), traditional fertilization (TF-Control), ERS + Mg, ERS + TF and TF + Mg applied as subplots. The number of pods per plant, the length of pods, the number of grains per pod, the weight of grains per plant, the yield of grains, 1000 seed weight, the number of grains per plant, protein yield, arbuscular mycorrhizal fungi rate have been evaluated as yield and growth criteria in the study. In the experiment, as well as the treatment x irrigation interaction, the plant height, pod number per plant, pod lenght, grain number per pod, grain weight per plant, grain yield, 1000 seed weight, grain number per plant, protein rate/grain, protein yield, root weight and AMF colonization parameters, were the other studied properties that were found to be significant. The results obtained were 877.6 mm for I₁₀₀ irrigation treatment, 512.2 mm for I₅₀ irrigation treatment and 40.19 mm water for I₃₀ irrigation treatment. Regarding the growth parameters of dry bean, the highest PH was in ERS + Mg (67.66 cm), the lowest PH was in ERS (54.33 cm); In I₅₀, the highest Plant Height (PH) was in ERS + Mg (65.66 cm), the lowest PH was in TF-Control (53.00 cm); and in I₃₀, the highest PH was in TF-Control (50.66 cm), and the lowest PH was again in ERS + Mg (44.33 cm). For protein yield (PY) value, ERS + Mg, ERS + TF, TF + Mg have been placed in the same group, in I₁₀₀ and I₅₀ irrigation treatment. The highest value was ERS + TF (34.90 kg da^?1) in I₁₀₀, The lowest value was TF-control (19.90 kg da^?1) in I₃₀ irrigation treatment. In terms of mycorrhiza colonization ratio, ERS has been ranked first in all irrigation treatments, while the highest mycorrhiza colonization has been observed in I₃₀ irrigation treatment (26.30%). ERS was followed by ERS + Mg (23.33%). As expected, the lowest mycorrhiza colonization ratio in all irrigation treatments have been observed in TF-control treatment, while the highest mycorrhiza colonization ratio has been respectively observed in I₃₀ and I₅₀ irrigation topics. The highest root weight (RW) in I₁₀₀ irrigation treatment was observed in ERS (15.06 g plant^?1) and it was observed in ERS (19.05 g plant^?1; 26.30 g plant^?1) in I₅₀ and I₃₀ irrigation treatments. The lowest RW in all irrigation treatments has been observed in TF + Mg (4.43 g plant^?1, 6.40 g plant^?1, 10.26 g plant^?1), respectively.     

Sedimentological and geochemical characterization of river suspended particulate matter (SPM) sampled by time-integrated mass flux sampler (TIMS) in the Sava River (Croatia)

Purpose

Suspended particulate matter (SPM) plays a crucial role in the transport of natural and anthropogenic substances. However, obtaining a representative sample and a substantial amount of SPM in rivers, where the flux and quantity of SPM are highly episodic, can be a challenging task. To collect a sufficient quantity of SPM for detailed sedimentological and geochemical analysis, a time-integrated mass flux sampler (TIMS) was used for the sampling in a medium size river (the Sava River, Croatia).

Materials and methods

Sampling was conducted in August and October 2014, and February and May 2015 under different discharge conditions. The SPM collected by TIMS was characterized with respect to its particle size distribution (PSD), mineral content, and geochemical composition.

Results and discussion

PSD analysis identified silt as a dominant size fraction in all samples except in May 2015 when sand prevailed; subsequent chemical dispersion of samples revealed flocculation as the main factor responsible for the resulting PSD. The mineralogical composition of the SPM was quite constant (quartz, calcite, dolomite, feldspar, illite/muscovite, kaolinite), but the contribution of particular mineral varied depending on the sampling period. In May 2015, unusually high calcite content was determined. Though the dominant source is still uncertain, a portion of calcite is likely detrital in origin. Geochemical analyses of collected material revealed significant anthropogenic input of ecotoxic elements (Ni, As, Cr, Pb, Bi, Cd, Zn, Sb) primarily associated with the fine fraction of the Sava River SPM.

Conclusions

A considerable amount of the SPM was collected by TIMS, both during high and low river discharge. Sedimentological analyses of the Sava River SPM suggested the input of material from various sources during different river regimes. Geochemical composition of the SPM followed its sedimentological characteristics—preferential adsorption of trace elements to fine-grained clay mineral particles was documented. Some processes inside TIMS were observed during this investigation—the suspended material captured inside the sampler underwent additional changes. The flocculation of the colloidal material instigated by algal bloom was observed.