Atmospheric lead and cadmium deposition within forests in the Kanto district, Japan

Atmospheric lead and cadmium deposition in bulk precipitation and throughfall was investigated at four forests in the Kanto district, Japan, to assess the impact of human activities on the environmental health of forests. Annual lead and cadmium depositions in bulk precipitation ranged from 8.9 to 25.7 g ha⁻¹ year⁻¹ and from 0.77 to 1.30 g ha⁻¹ year⁻¹, respectively. Lead and cadmium deposition increased in the summer at every forest due to large amounts of rainfall. At one of the forests, the depositions were also high in the winter due to heavy snowfall. These depositions were similar to recent depositions observed at other rural and urban sites in Japan and several forests in Europe and North America after 1990. These results indicate that although anthropogenic lead and cadmium are deposited at these rates over wide areas, depositions are still higher than in remote areas.     

海山仙馆的匾题诗联与园林艺术美的交融

"海山仙馆"是广州十三行时期由行商潘仕成兴建的一座吸收了较多西方技艺要素的岭南古典园林。海山仙馆之园林艺术引发出丰富的诗联匾额之作,诗联匾额之作也修饰了海山仙馆的自然山水之美、建筑文化之美、人文精神之美。认识并把握二者间的互动原理与表现手法,有利于加深对行商园林的研究、评赏和传承。     

Evaluation of two organosilicone adjuvants at reduced foliar spray volumes in South African citrus orchards of different canopy densities

van Zyl, J.G., Sieverding, E.G., Viljoen, D.J., Fourie, P.H., 2014. Evaluation of two organosilicone adjuvants at reduced foliar spray volumes in South African citrus orchards of different canopy densities Crop Protection 00:0000–0000.Citrus producers in South Africa generally use high spray volumes (6000 to 16,000 l ha⁻¹) to control pests and diseases adequately for the fresh fruit market. In order to study the benefit of organosilicone adjuvants at reduced spray volumes, trials were conducted with two organo tri-siloxane adjuvants. Two separate spray trials were conducted in the Western and Eastern Cape provinces of South Africa in uniform navel orange orchards. Break-Thru S240 (super-spreader) and Break-Thru Union (spreader-sticker), at recommended dosages per hectare (300 ml ha⁻¹, respectively), were sprayed separately in combination with a yellow fluorescent pigment (1 ml l⁻¹) at a high (20 l tree⁻¹ ≈ 9600 to 12,100 l ha⁻¹, depending on tree and inter-row spacing), medium (14 l tree⁻¹ ≈ 6500 to 8500 l ha⁻¹) and low (8 l tree⁻¹ ≈ 3700 to 4800 l ha⁻¹) spray application volumes. Sprays consisting of the fluorescent pigment in water alone were used as control treatments. Trees were sprayed from both sides with a commercial multi-fan tower sprayer (BSF-Multiwing) at a constant tractor speed (2.4 km h⁻¹) and spray pressure (1500 kPa). The different spray volumes were achieved by using different spray nozzles (TeeJet Disc-Core type; full and hollow cone nozzles D3-DC56/46, D4-DC56/46, D5-DC56/46). Leaves were sampled from six canopy positions (inner and outer canopy position at bottom, middle and top of the tree). Deposition quantity and quality of fluorescent pigment were determined on upper and lower leaf surfaces using fluorometry, digital photomacrography and image analyses. Spray uniformity and efficiency were also compared among treatments. Deposition quantity generally increased with increasing spray volume, but normalised values showed better spray efficiency at lower volumes. In pruned and less dense canopies, a beneficial effect of adjuvants was observed in terms of deposition quantity, efficiency and uniformity, especially at reduced volume applications (14 l tree⁻¹) on the inside and outside of the canopy. Little improvement in deposition quality was generally observed with the use of adjuvants. These benefits were not as evident in very dense canopies, illustrating the importance of canopy management when spraying at reduced volumes. Data obtained from the study is valuable for future improvement in spray application methodology in South Africa and other developing countries.     

超级稻摘穗收获机沉降箱性能分析与运行参数优化

为使4ZTL-2000型摘穗收获机收获超级稻时具有最佳清选性能,以谷物清洁率和沉降箱能耗为指标,沉降箱入口气流速度、谷物喂入量及其初速度为影响因素,采用二次正交旋转组合设计试验,利用Design-Expert 6.0.10进行数据处理,得出回归数学模型,通过响应曲面方法分析指标与因素间的相互作用,并对回归数学模型进行多目标优化。结果表明:沉降箱入口气流速度对沉降箱指标影响最大,谷物初速度相对小,谷物喂入量的影响最小。为使沉降箱处理超级稻(目前谷物喂入量最大为3.78 kg/s)时具有最佳性能,通过优化获得运行参数的最佳组合为:沉降箱入口气流速度为13.93 m/s,谷物初速度为18.84 m/s。通过试验验证谷物清洁率达到了90.1%,沉降箱能耗为348.3 Pa,籽粒沉降效率为100%。     

茶饮料沉淀的成因与澄清技术的应用

茶饮料沉淀现象是茶饮料发展关键性问题。随着科学技术的发展，大量的先进技术应用到茶饮料的发展中来，推动了茶饮料的发展。综合了近年来茶饮料浑浊的形成原因与澄清技术的应用方面研究进展。     

Erosion and deposition history derived by depth-stratigraphy of Cs and soil organic carbon

There are a number of uncertainties in the use of ¹³⁷Cs as a marker for deriving soil erosion rates. However, this should not limit other potential uses of this anthropogenic radionuclide in the study of soil landscape processes. This study outlines a sampling methodology which aids in the assessment of the history of erosion and depositional processes within a landscape unit. The depth distribution of ¹³⁷Cs and soil organic carbon (SOC) was utilized as a means of determining the erosion and depositional history of a conventionally tilled agricultural field in southern Ontario, Canada. Three transects oriented along the slope of a large field had five soil profiles excavated at the summit, sideslope, shoulder slope, footslope and toeslope landscape positions. The soils were sampled in 5 cm increments, and ¹³⁷Cs and SOC were determined on the samples. The results show that soil redistribution within landscape units of agricultural fields has been substantial both before and after fallout of ¹³⁷Cs to the soil surface. Soils in depositional areas contained significant ¹³⁷Cs and SOC at depths beyond which the plow can attain at present. This implies that a significant amount of carbon is being sequestered beneath the present plow layer, and the characterization of this pool must be considered in deriving the dynamics of SOC in agroecosystems.     

Multi-scale system approaches in agronomic research at the landscape level

Spatial multi-scale analyses of actual land use system performance as determined by spatial yield variability reveals the need for landscape research in agronomy. Main ‘drivers’ of spatial yield variability for five different crops in Honduras, Costa Rica and Ecuador were identified. It is demonstrated how they vary with spatial scales and that landscape-related factors often play a large and significant role in when the variability in yield is determined. These results indicate that landscape experiments in agronomy are relevant. Apart from empirical analysis, spatial–temporal explicit modeling of landscape process dynamics such as water and soil redistribution within a landscape can give insight in the performance of agronomic systems within a dynamic landscape context. For a case study in the South of Spain it is demonstrated how within a landscape this type of research can determine the on- and off-site effects of water and soil redistribution in agro-ecosystems. Only after a spatially explicit multi-scale system analysis and explorative landscape process modeling is completed, relevant agronomic landscape experiments can be designed.     

Orographic enhancement of wet deposition in the United Kingdom: case studies and modelling

Two field experiments to observe the detailed response of wet deposition to orography in a polluted environment are reported. Rain events were classed as frontal, convective or mixed on the basis of meteorological data. Analysis of the deposition enhancement and cap cloud composition confirmed that for the frontal events the seeder-feeder effect (scavenging of cap cloud by rain drops) dominates. The greater concentration of ions in the water scavenged from the cap cloud than in the rain means that deposition is enhanced for all ions. For marine ions the scavenged water was found to be between five and six times as concentrated as the rain and for anthropogenically produced ions it was about twice as concentrated.A computational model of rainfall incorporating the seeder-feeder effect has been broadly successful in predicting enhancement although some details of the observed pattern remain to be explained.     

Effects of adjuvants on deposition efficiency of fenhexamid sprays applied to Chardonnay grapevine foliage

Adequate spray deposition on susceptible grapevine tissue is an essential requirement for effective chemical control of economically important diseases, such as grey mould, powdery mildew and downy mildew. The objective of this study was to evaluate the potential of some agricultural adjuvants to improve foliar spray deposition. Deposition quantity and quality was assessed by means of a spray assessment protocol using fluorometry, photomicrography and digital image analyses. The visual droplet rating technique developed by G Furness, Australia, was also included in initial assessments. Both assessment protocols showed that spray deposition quantity increased with increasing spray volume applications of 27 l ha⁻¹ to 581 l ha⁻¹ with a motorised backpack mistblower, but decreased at 698 l ha⁻¹, possibly due to run-off. Addition of selected spray adjuvants at 526 l ha⁻¹ volume demonstrated improved deposition quantity and quality. Agral 90 (ethoxylated alkylphenol), BB5 (acidifier), Nu-film-P (terpene oil), and Solitaire (silicone/plant oil) significantly improved deposition on upper and lower leaf surfaces compared with the fenhexamid-only and water sprayed control. Break-thru S240 (organosilicone) and Villa 51 (alkylpolyethylene glycol ether) did not improve deposition quantity, although remarkably better deposition quality was obtained. An adjuvant concentration effect (within the registered concentration range) was evident at spray volumes of 502 l ha⁻¹, especially those retained on the upper leaf surfaces. Agral 90 and Nu-film-P effected significant improvement of spray deposition at the higher concentrations (18 ml and 50 ml hl⁻¹, respectively), but not at the lower concentrations (6 ml and 20 ml hl⁻¹, respectively). Solitaire improved deposition at the lower concentration tested (50 ml hl⁻¹), whereas reduced deposition at the higher concentration (100 ml per hl⁻¹) was attributed to excessive spray run-off. No significant improvement of spray deposition was observed for both concentrations tested with Villa 51 (50 and 100 ml hl⁻¹). Spray mixtures with adjuvants Agral 90 and Solitaire yielded similar deposition values at 500 l ha⁻¹ compared with the fenhexamid-only control at 720 l ha⁻¹, but reduced deposition at the higher spray volume, possibly due to spray run-off. This study clearly demonstrated the potential of adjuvants to improve deposition quantity and quality, but highlights the necessity to match adjuvant concentrations and application volumes on the spray target to achieve maximum spray deposition.     

长江镇扬河段世业洲汊道冲淤现状研究

通过对长江镇扬河段世业洲汊道固定断面连续3 a的水下地形测量,综合固定断面面积、0 m等深线、最大深度、平均深度和分流数据分析得出:世业洲右汊道仍处于主导地位,汊道上游各指标数据变化不明显,汊道下游则有变宽加深趋势,并略有淤积;世业洲左汊道仍处于次航道地位,各项指标表明左汊道宽度基本稳定,但汊道水深有加深趋势,尤其是汊道下游变化较为明显。