苏丹GNPOC原油管道减阻剂工业试验及应用

介绍了在苏丹GNPOC原油长输管道超长管段上采用EP W2 0 3减阻剂进行工业试验及其应用情况。先后在 1号站和 3号站间进行 1号站单点注入减阻试验与增输试验 ,在 1号站和 2号站进行两点注入增输试验。其后开始例行两点注入工业应用。分析了减阻剂工业应用中存在的问题 ,由于原油来源发生变化 ,原油粘度升高 ,同时受到雨季环境条件的影响 ,导致该管道 2号、3号站间原油雷诺数大大降低 ,因此降低了减阻剂的作用效果     

Improving agricultural water use efficiency by nutrient management in crop plants

Abstract

Improvement of agricultural water use efficiency is of major concern with drought problems being one of the most important factors limiting grain production worldwide. Effective management of water for crop production in water-scarce areas requires efficient approaches. Increasing crop water use efficiency and drought tolerance by genetic improvement and physiological regulation may be a means to achieve efficient and effective use of water. A limited water supply inhibits the photosynthesis of plants, causes changes of chlorophyll contents and components and damage to photosynthetic apparatus. It also inhibits photochemical activities and decreases the activities of enzymes in plants. Water stress is one of the important factors inhibiting the growth and photosynthetic abilities of plants through disturbing the balance between the production of reactive oxygen species and the antioxidant defence, causing accumulation of reactive oxygen species which induce oxidative stress to proteins, membrane lipids and other cellular components. A number of approaches are being used to enhance water use efficiency and to minimize the detrimental effect of water stress in crop plants. Proper plant nutrition is a good strategy to enhance water use efficiency and productivity in crop plants. Plant nutrients play a very important role in enhancing water use efficiency under limited water supply. In this paper we discuss the possible effective techniques to improve water use efficiency and some macronutrients (nitrogen, phosphorus, potassium, calcium and magnesium), micronutrients (zinc, boron, iron, manganese, molybdenum and chloride), and silicon (a beneficial nutrient) in detail to show how these nutrients play their role in enhancing water use efficiency in crop plant.     

Weed management in onion using chemical,non-chemical,and manual methods

Summary

Weed management studies in onions grown from seedlings were conducted during 2006 and 2007 at the National Agricultural Research Centre, Islamabad, Pakistan. Applications of pendimethalin at 0.825 l a.i. ha^–1, or oxadiazon at 0.240 l a.i. ha^–1, 2 d after transplanting (DAT) seedlings were evaluated alone, and in combination with one manual weeding, for their effects on weed competition and bulb yields. Other weed control treatments included the application of rice straw mulch 2 weeks after transplanting (WAT) combined with one manual weeding at 9 WAT, or a newspaper and rice straw mulch applied 2 WAT. Compared to the weed-free situation, competition with weeds caused reductions in bulb yields of 62% and 68% during the first and second year, respectively. Polygonum plebejum, Amaranthus viridis, Cyperus rotundus, and Coronopus didymus were the dominant weeds recorded in the field. Mulching reduced weeds by 56 – 60% compared to the chemical weed treatments. Compared to the weed-free treatment (four manual weedings at monthly intervals), which is a traditional method to control weeds in onion, bulb yields increased significantly under the rice straw mulch or when treated with pendimethalin in combination with one manual weeding at 9 WAT. The latter two treatments, on average, resulted in the highest increases of 26 t ha^–1 and 24 t ha^–1 in bulb yields with net returns of US$ 1,522 ha^–1 and US$ 1,486 ha^–1, respectively over the non-treated control.     

夏玉米叶片全氮含量高光谱遥感估算模型研究

在5种不同施氮量和2种夏玉米品种处理下,分别在玉米拔节期、大喇叭口期、抽雄期、吐丝期、乳熟期测定了玉米冠层高光谱反射率及其对应叶片的全氮含量。选取了470、550、620和720 nm 4个代表性光谱波段,分品种对叶片全氮含量与原始光谱反射率、光谱反射率一阶微分以及部分高光谱特征参数（基于光谱位置、面积、植被指数的特征参量）分别进行线性回归和非线性回归拟合。在每个生育时期,选择决定系数和F值最高的模型3个,并分别用第二年测定的光谱和全氮含量数据分别对两个品种进行均方根差和相对误差的验证,选择均方根差和相对误差较小的拟合模型。结果表明:在拔节期、大喇叭口期、抽雄期、吐丝期和乳熟期,玉米叶片全氮含量最佳拟合光谱参量分别为R720、DR720、SDb、DR550和DR550,玉米叶片全氮含量最佳高光谱遥感估算模型依次为:Y=5.129e-2.317x、Y=3.421－10.010x－477802.331x3、Y=4.070－2.304x－52.177x2、Y=－0.468－0.528lnx和Y=－2.390－0.793lnx。     

黄土高原苹果园深层土壤干燥化特征

为了评价黄土高原苹果产区深层土壤干燥化特征及其区域分布规律,测定了其半湿润黄土台塬区(Ⅰ)、半湿润易旱黄土旱塬区(Ⅱ)、半湿润偏旱和半干旱黄土丘陵区(Ⅲ)等不同气候和地貌类型区32块苹果园地0～1500cm土层土壤湿度,定量比较和分析了各类型区苹果园地深层土壤含水率、土壤湿度剖面分布及其土壤干燥化特征。结果表明:1)Ⅰ、Ⅱ、Ⅲ区苹果园地0～1500cm土层土壤含水率依次为17.53%、13.44%和10.29%,土壤有效贮水量依次为1273.70、973.98和864.05mm,土壤水分过耗量依次为199.93、465.10和362.70mm,年均土壤干燥化速率依次为8.47、26.29和23.44mm/a。人工补灌、树龄、种植密度和地貌类型等因素影响果园土壤湿度和土壤干燥化程度。2)各区有补充灌溉的果园土壤剖面湿度显著高于旱作果园,不存在或部分土层存在干燥化现象;旱作果园土壤剖面均存在深厚的干燥化土层。3)Ⅰ、Ⅱ和Ⅲ区有补充灌溉的苹果园地土壤干燥化指数(SDI)分别为-8%、-11%和-34%;旱作果园土壤干燥化指数(SDI)分别为32%、50%和46%,各类型干层厚度分别达到或超过790、1297和910cm。研究结果为黄土高原苹果园地深层土壤水分可持续利用和苹果生产基地可持续发展提供参考。     

Pea symptomless virus,a newly recognized strain of red clover mottle virus

A virus contaminating a culture of pea enation mosaic virus was isolated and studied. The virus, tentatively named pea symptomless virus (PSV), was not aphid-borne but was readily transmitted by sap inoculation of Amaranthaceae, Chenopodiaceae and Leguminosae. Purified preparations of PSV contained isometric particles 26 nm in diameter, which sedimented as three components with sedimentation coefficients of 55, 94 and 118S, respectively, and contained ribonucleic acid with a molar base content of G 22%, A 26%, C 17%, U 34%.PSV is a member of the cowpea mosaic group of plant viruses, is closely related to red clover mottle broad bean stain, and pea green mottle viruses, and protects plants against infection with red clover mottle virus. PSV, the viruses of broad bean stain, red clover mottle and pea green mottle, and possibly MF-virus, probably constitute a subgroup of the cowpea mosaic virus group and may even considered to be members of a single virus species.Samenvatting Een virus dat als verontreiniging voorkwam in een cultuur van het erwte-enatiemozaïekvirus werd geïsoleerd en bestudeerd. Het virus dat voorlopig met de naam pea symptomless virus (PSV) wordt aangeduid, gaat met sap over en wordt niet door de bladluizenMyzus persicae enAcyrthosiphon pisum overgedragen.Plantesoorten uit de families der Amaranthaceae, Chenopodiaceae en Leguminosae (Tabel 1) zijn vatbaar voor dit virus. Gezuiverde preparaten van PSV bevatten isometrische deeltjes met een diameter van 26 nm (Fig. 1) en bestonden uit drie fracties (met sedimentatieconstanten van 118,94 en 55S (Fig. 2). Voor de basenverhouding in het RNZ werd 22% guanine, 26% adenine, 17% cytosine en 34% uracil (Tabel 2) gevonden.Het beschreven virus is serologisch zeer nauw verwant met het rode-klavervlekkenvirus (RCMV) en wat minder verwant met andere leden van de cowpea mosaic virus (CPMV) groep, zoals het broad bean stain virus (BBSV), en pea green mottle virus (PGMV). De symptomen die PSV en RCMV veroorzaakten werden vergeleken (Tabel 1); RCMV veroorzaakte in alle gevallen heviger symptomen.PSV is in staat om erwteplanten volledig tegen RCMV te beschermen indien de planten 9 dagen van te voren met eerstgenoemd virus geïnoculeerd waren. De auteurs concluderen uit hun werk dat PSV met BBSV, PGMV en RCMV een sub-groep binnen de CPMV-groep vormen, waartoe ook het MF-virus dat in Frankrijk is gevonden, zou kunnen worden gerekend.     

Alterations in the intestinal brush border membrane structure and function in chronic DDT-exposed monkeys

Intestinal uptake of d-glucose, l-leucine, and glycine is considerably enhanced in monkeys exposed to subacute doses of DDT for 100 days. The brush border sucrase and lactase activities were also significantly elevated but there was no change in alkaline phosphatase, lactate dehydrogenase, and Mg²⁺-ATPase activities in the pesticide-administered animals compared to controls. Kinetic evidence revealed that augmentation of disaccharidases in the pesticide-treated animals is because of an increase in the enzyme content. Cholesterol and triglyceride fractions of the brush border membrane were also elevated but sialic acid content was reduced in the insecticide-treated animals compared to control group. These results suggest that observed changes in the functional activity of the enterocytes in DDT toxicity are possibly related to the alterations in the brush border membrane structural organization.     

Improvement of quality and storability of apple cv. Aroma by adjustment of some pre-harvest conditions

To improve the quality of the important Swedish apple cultivar Aroma and increase its resistance to bruising and storage decay, three studies were conducted at Kivik research station during the period 1998–2003. The effects of tree age, pruning time and nitrogen fertilization were investigated. Fruits from young trees (younger than 6 years) had a lower resistance to bruising and Pezicula malicorticis decay, while fruits from trees older than 20 years seemed to show a quality and storability decline. Choosing a suitable summer pruning time was an effective factor for fruit storage potential. Thinning cut during August (5–6 weeks before harvesting) improved fruit colour and decreased decay without negatively influencing tree yield. Applying fertigation according to fruit development phase and soil nitrogen content had a very important influence on fruit quality and storability. Appropriate nutrition supply produced more deeply coloured fruit that maintained their quality after storage for 4 months. The bruising sensitivity of cv. Aroma apples was correlated with their N and K/Ca content. More coloured fruits showed less sensitivity to bruising.     

Use of chemical treatments to reduce antinutritional effects of tannins in salseed meal: Effect on performance and digestive enzymes of broilers

This study investigated the effects of chemical treatments of salseed (Shorea robusta) meal (SSM), on intake, growth performance, feed efficiency, and activities of digestive enzymes in broilers. Five experimental iso-nitrogenous and iso-caloric diets, one without SSM (control) and four SSM based, were formulated. The four SSM diets differed in the treatment given to the SSM. The USSM diet contained untreated SSM and the three other diets were contained SSM incubated with (820 ml/ kg of SSM DM) distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), or 0.67 M sodium hydrogen carbonate (pH 8.2) for 12 h at 37 °C. Inclusion of untreated SSM in the diets markedly depressed the feed intake, growth rate and, feed efficiency in broilers. Treatment of SSM with chemicals partly alleviated these negative effects on the performance of broilers. Growth rate of broilers was significantly higher on alkali and water treated SSM diets than on USSM diet. The broilers on alkali treated SSM diet consumed more feed than those on water or acid-treated SSM diets. Alkali and water treatments of SSM significantly improved the feed efficiency in broilers fed SSM diets however; the effect due to acid treatment was negligible. Inclusion of untreated SSM in diets caused the pancreatic hypertrophy and subsequent depression in the activity of chymotrypsin and α-amylase in pancreatic tissue. Treatment of SSM with alkali and water substantially increased the activity of chymotrypsin in the pancreas. The activities of trypsin, chymotrypsin and α-amylase in the jejunum were depressed with USSM diet. This depression in broilers was partly alleviated with alkali and water treatments to SSM. The activities of dipeptidase, sucrase, and maltase in the jejunal and duodenal mucosa were also depressed with USSM diet. Activity of dipeptidase in the duodenal and jejunal mucosa of the broilers fed treated SSM was improved with alkali treatment. It can be concluded that inclusion of SSM in the diets of broilers markedly depressed the activities of pancreatic and intestinal enzymes, feed consumption, and growth rate. Treatment of SSM with water or alkali improved the digestive enzymatic activity, intake, growth, and subsequently feed efficiency in broilers.