沙蒿植被粗糙度动力学特性的检验与研究

主要利用Dong等提出的曲线拟合的方法,结合野外实测数据计算沙蒿植被的空气动力学粗糙度,对计算出的粗糙度和风速进行回归分析和相关分析,由此对沙蒿植被地表粗糙度的动力学特性进行检验与研究,结果表明:在下垫面不发生改变的情况下,沙蒿的空气动力学粗糙度与风速的增长呈负相关关系,即粗糙度具有动力学特性。但是由于两者相关程度并不显著,因此在实际工作中可以忽略风速对粗糙度的影响,仍然应用Bagnold的传统方法对粗糙壁面的粗糙度进行测量。     

Assessment of the stability of pesticides during cryogenic sample processing. 1. Apples.

An assessment of the stability of a large number (106) of pesticides and related compounds during the cryogenic sample processing of apples has been undertaken. For the first time the procedure included an assessment of the losses during the freezing of the fruits, prior to processing. The stability of each pesticide during processing was assessed by comparing the mean recovery for the laboratory-spiked samples with the mean "survival" of the pesticides in cryogenically processed samples. The results clearly demonstrate that the vast majority, 94 of 106, of pesticides were stable during cryogenic processing. Of particular importance was that losses of several pesticides [bitertanol (95%), heptenophos (50%), isofephos (40%), and tolylfluanid (48%)] reported to occur during ambient processing of apples did not occur during cryogenic processing. Losses of dichlofluanid (54%), chlozolinate (22%), and etridiazole (40%), previously reported to occur during ambient processing of apples, were reduced to barely significant levels (10, 17, and 14%, respectively) by cryogenic processing. Small apparent losses for a few of the compounds were attributable to analytical and sample handling difficulties, rather than to losses during processing, and need further investigation.     

湖南省水田机械化路子的研究

湖南省经过三十多年探索和实践,已初步找到了一条初级可行的水田机械化路子,这条路子以水田耕整机和手扶拖拉机两个小动力为主要动力,配套相应的育秧、耕整、栽插、排灌、植保、收割、脱粒和运输等八种主要作业机械。两个小动力各有特点,水田耕整机能完成耕整、栽插和收割分堆作业,其动力还可带动水泵,植保和脱粒机作业;手扶拖拉机主要是解决田间和短途运输,两小动力互相配合,互相补充。一套能担负120亩水田机械化作业的机械,总投资1.5—2万元,据调查和有关材料反映,使用这套水田机械进行水田作业,每年可增收稻谷1万斤以上,增加收入5000元以上。这套水田机械有两个特征:一是初级的,是机械化和半机械化并存和结合;二是可行的,受到农户的欢迎,但不完全配套;如育秧工厂和收割分堆机械等都正在下力气研究和试验,当前已经有了很好的进展。     

南方红豆杉扦插繁殖技术研究——Ⅳ.促根剂对扦插穗条生根的影响

试验研究促根剂对南方红豆杉扦插穗条生根的影响结果表明,促根剂A3生根效果最佳,其始根天数、生根率、根数、根长和根系效果指数分别为52.7~64.0d、90.0%~93.7%、8.00~8.67条、8.67~8.93cm和0.61~0.69,显著优于其他3种促根剂;其次为促根剂A2>促根剂A1>萘乙酸(对照)。除20ng/kg浓度促根剂A1所得根系效果指数显著高于10ng/kg和15ng/kg浓度外,促根剂A2和A3各浓度间差异不明显,但20ng/kg浓度促根剂A2根系效果指数也高于其他2个浓度,提高促根剂A1和A2的应用浓度有望提高扦插穗条生根效果。     

Metal concentrations in the ground water of the Ouachita Mountains,Arkansas, U.S.A.

Ninety-one ground water samples (predominantly from springs) in two mineralized areas of the Ouachita Mountains in west-central Arkansas, were analyzed for Fe, Mn, Zn, Cu, Co, Ni, Pb, Hg, Sb, Sr, Ba, Ca, and Li. These areas contain Mn, barite, strontianite, cinnabar, stibnite and scattered Pb-Zn mineralization, Cumulative frequency curves were used to determine the threshold and anomalous concentrations for each element in the two areas. These values were, in general, higher in the ground water from the more mineralized area for several of the base metals, but most notably for Mn and Fe, the principal metals in the Mn oxide minerals. The United States Environmental Protection Agency (EPA, 1976) criteria for Fe (300 μg L ^?1) and Mn (50 μg L^?1) in drinking water were exceeded, respectively, in 34% and 30% of the springs in Area I, and 13% and 23% in Area II. One spring exceeded the EPA Hg criterion (2 μg L^?1) and 3 springs exceeded the 50 μg L^?1 criterion for Pb. In spite of the large number of anomalous Ba concentrations, the highest concentration of Ba was 930 μg L^?1 (EPA criterion 1000 μg L ^?1).     

解开神秘的杂交优势黑盒子之谜--纪念英国爱丁堡大学动物遗传研究所F.A.E.Crew教授

文章揭示了20世纪杂种优势的发展历程。早在史前时期就已发现往往杂种的生活力优于其亲本，而生殖力却受到伤害(如驴和马杂交所产生的骡子不能生育)，但如双亲关系在同一物种内，这个问题是可以避免的。杂种优势的优点至今仍被利用，但其大小难以预测，直至本世纪之交，作者于15年前提出的解决此问题的理论，才逐渐被认识和接受。在这一历程中，有很多环节与李森科事件有关，期望由科教兴国的政策予以解决，并在近期将会胜利地得以实现。     

On the 70th anniversary of Yu.N. Vodyanitskii

Jubilees

On the 70th anniversary of Yu.N. Vodyanitskii     

Dedicated to the 100th birthday of Professor Dr. Dr. h. c. mult. Eduard von Boguslawski

Identifying the optimum resolution where differences in corn (Zea mays L.) grain yields are detectable could theoretically improve nitrogen (N) management, thereby resulting in economic and environmental benefits for producers and the public at large. The objective of this study was to determine the optimum resolution for prediction of corn grain yield using indirect sensor measurements. Corn rows, 15–30 m long, were randomly selected at three locations where the exact location of each plant was determined. In 2005 and 2006, four of eight rows at each location were fertilized with 150 kg N ha^?1 as urea ammonium nitrate (28% N). A GreenSeeker? optical sensor was used to determine average Normalized Difference Vegetation Index (NDVI) across a range of plants and over fixed distances (20, 40, 45.7, 60, 80, 91.4, 100, 120, 140, 160, 180, 200, 220, and 240 cm). Individual corn plants were harvested and grain yield was determined. Correlation of corn grain yield versus NDVI was evaluated over both increasing distances and increasing number of corn plants. Then, the squared correlation coefficients (r_cc ²) from each plot (used as data) were fitted to a linear plateau model for each resolution treatment (fixed distance and number of corn plants). The linear-plateau model coefficient of determination (r_lp ²) was maximized when averaged over every four plants in 2004 and 2006, and over 11 plants in 2005. Likewise, r_lp ² was maximized at a fixed distance of 95, 141, and 87 cm in 2004, 2005, and 2006, respectively. Averaged over sites and years, results from this study suggest that in order to treat spatial variability at the correct scale, the linear fixed distances should likely be <87 cm or <4 plants as an optimum resolution for detecting early-season differences in yield potential and making management decisions based on this resolution.     

On the 80th birthday of A.G. Bondarev

Jubilee

On the 80th birthday of A.G. Bondarev     

U.S. market basket study to determine residues of the insecticide chlorpyrifos.

A market basket study was conducted to measure residues of the insecticide chlorpyrifos in samples of apples, applesauce, apple juice, fresh orange juice, tomatoes, peanut butter, whole milk, ground beef, and pork sausage collected during a 12-month period from 200 grocery stores across the United States. Approximately 90% of the samples contained no detectable levels of chlorpyrifos, and all residues detected were below tolerances, the legal limits for the United States. No values greater than the limit of quantitation (LOQ) were found in applesauce (LOQ = 0.008 ppm), apple juice (LOQ = 0.003 ppm), whole milk (LOQ = 0.006 ppm), ground beef (LOQ = 0.005 ppm), or pork sausage (LOQ = 0.007 ppm) samples. Only one fresh orange juice sample contained residues greater than the LOQ at 0.015 ppm. Only about 20% of the apples (maximum = 0.052 ppm), 20% of the tomato samples (maximum = 0.058 ppm), and 50% of the peanut butter samples (maximum = 0.021 ppm) contained quantifiable residues.     

Scientific principles for water utilization in the U.S.S.R.

Water resources are essential for economic and cultural development of a territory. Both economic development and the health of the people depend on the provision of pure water. Scientifically founded plans of water resources use and conservation should be based on a balance approach to the assessment of available water supply sources and, on the forecast of their interconnected change in the future in a close association with the forecast of the whole economy and culture of the studied region. In the future the main threat to the normal development of the economy and life will not be water deficiency but the conversion of rivers, lakes and other water supply sources into sewers. Therefore it is proposed that there be a complete cessation of sewage discharge (even of the so-called purified) into water supply sources while drawing up long-term water management balances.     

Estimation of the bioavailability of iron.

Eight laboratories conducted a test for the estimation of the bioavailability of iron from 4 sources, using depleted male albino rats. Ferrous sulfate was used as the reference standard. Ferric orthophosphate was found to have a relative biological value of 11 (range 6-22), an old sample of hydrogen-reduced iron 27 (range 15-41), and ferric citrate 96 (range 75-125). Good results were obtained with a simplified basal diet prepared without ingredients that had previously contributed variable quantities of iron. There was no apparent advantage in using the change in hemoglobin during the repletion period instead of the final homoglobin value as the criterion of response to iron supplements. Several statistical treatments of the data yielded similar conclusions regarding relative biological values of the iron sources.     

Specific and intraspecific classification ofSorghum species of the ser.Bicoloria (Snowd.) Ivanjuk. et Doron. and of the ser.Caffra (Snowd.) Ivanjuk. et Doron

Summary The intraspecific classification of cultivatedSorghum species of the ser.Bicoloria and ser.Caffra is discussed. The classification is based on studies or large living and herbarium collections as well as on the typical and authentic material; published monographs on the genus being made use of. In 8 cultivated species 70 varieties are considered, 8 of them were discovered for the first time. The data received contributed to enlarging the intraspecific systematics of a number of species presented inSnowden's monograph (1936).Parallelism in the evolution for a number of characters, i.e. homologous series, was discovered when intraspecific variability ofSorghum was investigated.The detailed study of the species and of the intraspecific taxons reveals new features of their affinity and differences and contributes to developing the phylogenetic system of the genus.As a result of the studies varieties were found out which would be of practical value for breeding work.

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Spezies- und intraspezifische Klassifikation von Arten aus der ser.Bicoloria (Snowd.)Ivanjuk. etDoron. und der ser.Caffra (Snowd.)Ivanjuk. etDoron. der GattungSorghum Moench

Zusammenfassung Die intraspezifische Klassifikation kultivierterSorghum-Arten aus der ser.Bicoloria und der ser.Caffra wird diskutiert. Die Klassifikation basiert sowohl auf dem Studium umfangreicher lebender und Herbarium-Kollektionen als auch auf Typus- und Originalmaterial; publizierte Gattungsmonographien wurden genutzt. Bei 8 Kulturarten werden 70 Varietäten akzeptiert, von denen 8 zum ersten Mal gefunden wurden. Die erzielten Ergebnisse führten zu einer Erweiterung der intraspezifischen Systematik einer Anzahl der Arten, die inSnowden's Monographie (1936) aufgeführt sind.Parallelevolution für eine Anzahl von Merkmalen, d. h. homologe Reihen, wurde bei der Untersuchung der intraspezifischen Variabilität vonSorghum nachgewiesen.Die ausführliche Untersuchung der Arten und der intraspezifischen Taxa läßt neue Grundzüge ihrer Ähnlichkeiten bzw. Unterschiede erkennen und trägt zur Entwicklung des phylogenetischen Systems der Gattung bei.Im Ergebnis der Untersuchungen wurden Varietäten gefunden, die von praktischem Wert für die Züchtung sein können.

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ser. Bicoloria (Snowd.) ivanjuk. et Doron. ser. Caffra (Snowd.) Ivanjuk. et Doron. SorghumMoench

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