Effects of nutrient cycling on grain yields and potassium balance

Soybean-maize rotation is a profitable cropping system and is used under rain fed conditions in north China. Since crop yields have been reported to decrease when K fertilizers are not used, we analyzed the productivity trends, soil-exchangeable and non-exchangeable K contents, and K balance in a continuous cropping experiment conducted in an area with an alfisol soil in the Liaohe River plain, China. The trial, established in early 1990 and continued till 2007, included 8 combinations of recycled manure and N, P, and K fertilizers. In the unfertilized plot, the yields of soybean and maize were 1,486 and 4,124 kg ha⁻¹ respectively (mean yield over 18 years). The yields of both soybean and maize increased to 2,195 and 7,476 kg ha⁻¹, respectively, in response to the application of inorganic N, P, and K fertilizers. The maximum yields of soybean (2,424 kg ha⁻¹) and maize (7,790 kg ha⁻¹) were obtained in the plots under treatment with N, P, and K fertilizers and recycled manure. K was one of the yield-limiting macronutrients: regular K application was required to make investments in the application of other mineral nutrients profitable. The decrease in the yields of soybean and maize owing to the absence of K application averaged 400 and 780 kg ha⁻¹, respectively. Soybean seed and maize grain yields significantly increased with the application of recycled manure. For both these crops, the variation coefficients of grain were lower with treatments that included recycled manure than without treatment. After 18 years, the soil-exchangeable and non-exchangeable K concentrations decreased; the concentrations in the case of treatments that did not include K fertilizers were not significantly different. Treatment with N, P, and K fertilizers appreciably improved the fertility level of the soil, increased the concentration of soil-exchangeable K, and decreased the non-exchangeable K concentration. In soils under treatment with N, P, and K fertilizers and recycled manure, the soil-exchangeable and non-exchangeable K levels in the 0–20 cm-deep soil layer increased by 34% and 2%, respectively, over the initial levels. Both soil-exchangeable and non-exchangeable K concentrations were the highest with on treatment with N, P, and K fertilizers and recycled manure, followed by treatment with N, P, and K fertilizers. These concentrations were lowest in unfertilized soils; the other treatments yielded intermediate results. The results showed a total removal of K by the crops, and the amount removed exceeded the amount of K added to the soil; in treatments that did not include K fertilizers, a net negative K balance was observed, from 184 to 575 kg ha⁻². The combined use of N, P, and K fertilizers and recycled manure increased the K content of the 0–20 cm-deep soil layer by 125% compared to the increase obtained with the application of N, P, and K fertilizers alone. The results clearly reveal that current mineral fertilizer applications are inadequate; instead, the annual application of recycled manure along with N, P, and K fertilizers could sustain future yields and soil productivity.     

纳米增效肥料在冬小麦上的应用研究

2007年,纳米碳第一次应用到肥料中,显示出明显的增产效果。其中,谷类作物增产幅度为10％～20％;蔬菜作物增产幅度为20％～40％,并且能节肥30％。纳米增效肥料使小麦籽实脂肪含量增加,蛋白质含量减少,该结果如果在油料作物上能普遍显现出来,将对我国非转基因大豆提高油质含量有着重要的意义。     

海洋胶红酵母、光合细菌、生化黄腐酸在海参育苗和养成中的应用效果

用二氧化氯（含量≥8％）日投量1g／m^3水体两天处理一次水质,海洋胶红酵母（浓度为1X10^10cfu／mL）日投量1～10mL／m。水体、光合细菌（浓度为2×10^10cfu／mL）日投量1～10mL／m^3水体、生化黄腐酸（含量≥60％）日投量5～10g／m^3水体在海参育苗中应用。试验结果表明：与用恩诺沙星日投量1g／m^3水体、EDTA螯合剂日投量2g／m^3水体,及常规投饵方式进行比较,海参幼体烂边病发病率从20．0％降低到10．0％,烂胃病发病率从23．0％降低到10．0％。在海参养殖中应用海洋胶红酵母、光合细菌（球形红假单胞菌）,可提菏成参产量14．3％～16．4％。海洋胶红酵母、光合细菌和生化黄腐酸在海参育苗和养成中应用具有广阔前景。     

Analytical and comparative testing of EnergyPlus using IEA HVAC BESTEST E100–E200 test suite

The EnergyPlus building energy simulation software has been tested using the IEA HVAC BESTEST E100–E200 series of tests. The volume 1 final report for the International Energy Agency (IEA) solar heating and cooling programme task 22 building energy simulation test and diagnostic method for heating, ventilating, and air conditioning equipment models (HVAC BESTEST) was recently published in January 2002. HVAC BESTEST is a series of steady-state tests for a single-zone DX cooling system. Cases range from dry to wet coil, low to high part load, and low to high temperatures. This published test suite includes three sets of analytical solutions and results from several other simulation programs for comparison.This test suite was initially used to test EnergyPlus beginning with beta versions prior to its official public release, and it is also applied as an ongoing quality assurance test. The application of these tests proved to be very useful in several ways:

• •revealed input model shortcomings, which resulted in new user inputs being added;
• •revealed reporting errors which were fixed;
• •revealed algorithmic errors which were fixed;
• •revealed algorithmic shortcomings which were improved or eliminated through the use of more rigorous calculations for certain components;
• •in later versions, caught newly introduced bugs before public release of updates.

Overall, the application of this test suite has been extremely useful in debugging and verifying the DX cooling algorithms in EnergyPlus. This paper summarizes the difficulties encountered and the benefits gained in applying the tests.     

Prevalence and numbers of Escherichia coli O157:H7 in minced beef and beef burgers from butcher shops and supermarkets in the Republic of Ireland

This study investigated the prevalence and numbers of Escherichia coli O157:H7 in minced beef and beef burgers in supermarkets and butcher shops in the Republic of Ireland. Fifteen samples were collected quarterly from each of 26 counties over a 13-month period. All samples (n=1533) were (1) directly plated on SMAC, and (2) enriched in mTSB with novobiocin, extracted by immunomagnetic separation (IMS), plating onto SMAC-CT agar and finally confirmed by PCR. Overall, E. coli O157:H7 was recovered from 43 samples (2.80%) with counts ranging from <0.52–4.03 log₁₀ cfu g⁻¹. Of the positive samples, 2.70% (32/1183) were purchased from supermarkets and 3.14% (11/350) from butcher shops. Only one product type (fresh unpacked burgers from supermarkets) was negative for E. coli O157:H7. Of the products containing the pathogen, fresh packaged burgers from supermarkets had the highest prevalence of 4.46% (7/157) while fresh unpackaged mince purchased from supermarkets had the lowest prevalence of 2.01% (6/299). Of the 43 isolates recovered, 41 possessed verotoxin-producing genes (vt1 and vt2), E. coli attaching and effacing gene (eaeA), haemolysin gene (hlyA), 60-MDa plasmid or rfb gene cluster that encodes for the biosynthesis of the O-antigen (pO157) and flagellar H7 antigen encoding gene (fliC_h7). The remaining 2/43 isolates contained only one of the verotoxin-producing genes (vt1 or vt2) and all the other genes named.     

Mechatronic solutions for high-speed railway vehicles

This paper presents recent developments in the study of active steering for railway wheels. It demonstrates the potential benefits from this form of active control and studies what could be achieved when modern control techniques are used on the vehicles via mechatronic components. The study is based on a mechanically simplified vehicle and active control strategies for three wheelset/wheel-pair configurations are studied, which are solid axle wheelset, independently rotating wheelset and directly steered wheel pairs. Various mechatronic vehicle configurations are discussed and different control schemes are presented. Two key performance requirements, i.e. the curving performance of the wheelset and ride quality of the vehicle, are assessed for all proposed schemes. Finally, actuation requirement is also investigated.     

多环芳烃生物降解及转化途径的研究进展

多环芳烃(PAHs)作为一种持久性有机污染物,因其危害性突出备受关注,微生物降解作为一种高效的修复手段,逐渐成为环境修复领域的研究热点,综述PAHs生物降解及转化途径的国内外研究进展,以期为今后深入分析PAHs降解机理奠定理论基础。以萘(Nap)、菲(Phe)、苯并［a］芘(BaP)等典型PAHs作为研究对象,并结合微生物的生长环境,阐述好氧微生物与厌氧微生物对PAHs的生物降解和转化途径。研究表明,细菌、真菌及古菌对PAHs均有一定的降解效能,其中,细菌对PAHs降解能力优于真菌和古菌,而且可通过双加氧酶氧化过程及羧化、甲基化或羟化等还原途径实现PAHs降解。     

US registration brings global status for Avecia's new plastic antimicrobial

Avecia Biocides has obtained US EPA registration for its new Vanquish◐ 100 plastics antimicrobial. The company says that it is the first new biocidal active ingredient to be registered as a preservative for plastics in the US in the past five years. Already a successful product in Europe, Asia, and Latin America, the company says that US registration for this member of the Vanquish^™ product range means that it now has global regulatory status.This is a short news story only. Visit www.addcomp.com for the latest additives and compounding industry news     

Combustion performance and emissions of ethyl ester of a waste vegetable oil in a water-cooled furnace

Food consumption around the world produces large amounts of waste vegetable oils and fats that, in many world regions, are disposed of in harmful ways. Consequently, this study intended to investigate the feasibility of utilizing this renewable and low cost fuel raw material as a diesel fuel replacement in small-scale applications such as in residential heating boilers. Specifically, the study examined the aspects of combustion performance and emissions of the ethyl ester of used palm oil (biodiesel) relative to the baseline diesel fuel in a water-cooled furnace. The combustion efficiency, η_c, and exhaust temperature, T_exh, as well as the common pollutants and emissions were tested over a wide range of air/fuel ratio ranging from very lean to very rich (10:1–20:1). All tests were conducted at two different energy inputs for both fuels. The findings showed that, at the lower energy rate used, biodiesel burned more efficiently with higher combustion efficiency and exhaust temperature of, respectively, 66% and 600 °C compared to 56% and 560 °C for the diesel fuel. At the higher energy input, biodiesel combustion performance deteriorated and was inferior to diesel fuel due to its high viscosity, density and low volatility. As for emissions, biodiesel emitted less pollutants at both energy levels over the whole range of A/F ratio considered.     

Fluorescence enhancement from Eu3+ ions in CdSe nanocrystal containing silica matrix hosts

Semiconductor cadmium selenide particles together with europium ions were incorporated into the silica matrix using sol–gel method. Here, the effect of nanocrystals on the absorption and fluorescence features of europium ions is discussed. The fluorescence spectra reveal that the intensity of characteristic emission of europium increases considerably in the presence of CdSe particles. This phenomenon can be explained as due to the energy transfer resulting from electron–hole recombination in the CdSe to the rare earth ion. These zero-dimensional materials, along with the effect of matrix incorporating europium ions, are found to have increased the optical gain.