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1.
Zusammenfassung Die Zentren des Schadauftretens verschiedener untersuchter forstschädlicher Insekten dürften nach zahlreichen Testungen Reizzonen umfassen, welche wieder als eine Kombination von elektrischen und magnetischen Feldern und durch diese freigelegte Metalleffekte erscheinen. Untersuchungen zur möglichen Wirksamkeit dieser Komponenten auf Vitalität und Fertilität vonLymantria monacha führten zu folgenden Ergebnissen. Es erscheint möglich, daß innerhalb von Reizzonen Sterblichkeit und Fruchtbarkeit vonLymantria monacha auch von niederfrequenten elektromagnetischen oder auch konstanten magnetischen oder elektrostatischen Feldern beeinflußt werden, die direkt oder auch über die Pflanze auf die Lebenskraft der Nonne von Wirksamkeit sind. Reizzonenbereich und Normalbereich zeigten hinsichtlich der Mortalität der Versuchstiere gegensätzliche Verhältnisse. Die Anfangsmortalität innerhalb von Reizzonen war gegenüber jener der Zuchten im Normalbereich erniedrigt, die Endmortalität vielfach erhöht. Futter aus Normalbereichen setzte in den Reizzonen, Reizzonenfutter im Normalbereich die Sterblichkeit herab und erhöhte im Normalbereich die Fruchtbarkeit. Im Normalbereich mit Normalfutter gezogene Nonnen wiesen die geringsten Zahlen an abgelegten Eiern auf, was sich besonders bei an Pflanzen eingebeutelten Tieren deutlich zeigte. Die wesentlich höhere Fruchtbarkeit von Nonnen an Pflanzen im Reizzonenbereich mag zusammen mit der hier erniedrigten Anfangsmortalität eine Erklärung zum gehäuften Auftreten vonLymantria monacha innerhalb von Reizzonen geben. Freigesetzte Metalleffekte könnten innerhalb von Reizzonen die Sterblichkeit aber auch die Fruchtbarkeit erhöhen.
Summary The centres of damages by different forest insects, examined in this research, seem to be in zones of Earth radiations (Reizzonen), which again seem to be combinations of magnetic or electric fields and metal effects, set free by them. Examinations for possible influences of these components on vitality and fecundity ofLymantria monacha showed the following results: It seems possible, that inside of zones of earth radiations mortality and fecundity of this butterfly could be directed from magnetic or electric fields also of low frequency or electrostatic, which either directly or indirectly by the nutrients (plants) influence the vital power ofLymantria monacha. Zones of Earth radiations and normal zones showed different conditions in respect of the mortality. Mortality of larvae of first developmental stages inside of zones of Earth radiations was decreased, such of late stages increased contrary to larvae in normal zones. Plant-food of normal zones decreased the mortality of larvae in zones of Earth radiations and food of zones of Earth radiations decreased the mortality of those of normal zones and increased fecundity in the latter cases. Female butterflies reared in normal zones showed the lowest number of developed eggs, especially when reared encaged on living plants (spruce). The essentially higher fecundity ofLymantria monacha reared on plants inside of zones of Earth radiations together with the decreased mortality of first instar larvae there, may give an explantation for the increased population ofLymantria monacha inside of zones of Earth radiations. Metal effects set free inside of zones of Earth radiations could increase there the mortality but also the fecundity.

Herrn Prof. Dipl.-Ing. Dr. ERWIN SCHIMITSCHEK zum 75. Geburtstag.

A 1130 Wien XIII, Fasangasse 5-7, 1/8  相似文献   

2.
Zusammenfassung Die SalatwurzellausPemphigus bursarius (L.)(Aphidoidea, Pemphigidae) gehört wegen ihrer unterirdischen Lebensweise zu den schwer bekämpfbaren Schädlingen, die in Salatkulturen regional starke Schäden verursachen können und von zunehmendem Interesse sind. In einem Befallsgebiet in Wolfenbüttel bei Braunschweig werden daher mehrjährige Untersuchungen zur Ermittlung der Bedeutung und geeigneter Bekä mpfungsmöglichkeiten der Salatwurzellaus durchgeführt. Bisher können über das Auftreten und die Bedeutung dieses Schädlings folgende Aussagen gemacht werden: Es besteht kein ursächlicher Zusammenhang zwischen dem Auftreten der Salatwurzellaus und zweier Salatvirosen (Salatmosaikvirus und Gurkenmosaikvirus). Sie alle traten unabhängig voneinander auf. Im Untersuchungsgebiet überwintertP. bursarius ausschließ lich an Pappeln, nicht dagegen im Ackerboden oder an Wurzelresten. Die Anfälligkeit verschiedener Salatsorten gegenüberP. bursarius ist nach den bisherigen Ergebnissen an 30 Sorten recht unterschiedlich, wobei die Sorten Hilmar, Kordaat, Unico, Kloek, Viktoria und Winter Butterkopf einen geringen oder gar keinen Befall zeigten, während die Sorten Wunder von Voorburg, Kagraner Sommer und Winter Mombacher stark befallen wurden. Diese Versuche müssen weitergeführt werden, bevor eine abschließende Beurteilung möglich ist. Die Schäden durch die Virosen, speziell das Salatmosaikvirus, sind in den Salatkulturen wesentlich schwerwiegender als die durchP. bursarius verursachten Verluste. Über Bekämpfungsversuche wird später berichtet.
Summary The lettuce root AphidPemphigus bursarius (L.)(Aphidoidea, Pemphigidae) belongs to the difficult controlable pests because of their subterranean mode of life. In lettuce cultures of certain regions this aphid can cause serious damages and therefore it is of increasing interest. In an area severely attacked byP. bursarius at Wolfenbü ttel near Braunschweig investigations are going on for several years to get to know the importance of this insect and to find out appropriate possibilities for its control. Up to now the following statements can be made concerning the appearance and the importance of this pest: There is no causal association between the lettuce root Aphid and two viroses of lettuce (lactuca virus 1 and cucumis virus 2). These pests appear independent from each other. In the investigated areaP. bursarius does hibernate only on poplars but not in the soil or on remaining roots. According to the hitherto existing results of 30 lettuce sorts the susceptibility of the various sorts againstP. bursarius is very different. The sorts Hilmar, Kordaat, Unico, Kloek, Viktoria and Winter Butterkopf did show a low or no attack, during the sorts Wunder von Voorburg, Kagraner Sommer and Winter Mombacher were severely attacked. These experiments must be continued before a definitive decision is possible. The damages in the lettuce cultures caused by the viroses, especially by lactuca virus 1, are more serious than those caused byP. bursarius. The control experiments are reported later.
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3.
Summary That the behavior of wood in service results from its structure is generally accepted by wood scientists. No doubt this acceptance is due to the broad interpretation of such a term. Structure can refer to the organization of elements on a macro scale, such as in a laminated beam, as well as to the arrangement of cellulose molecules in the crystalline region of an elementary fibril.This presentation focuses on a structural domain that appears increasingly to be a critical one in wood behavior-ultrastructure. The spectrum of terminology that has been used in profusion during the electron microscopic era must first be defined so that confusion is minimized. Then a historical evolution of the field of wood ultrastructure can be presented to provide perspective. Structures that have been shown to affect or indeed to control certain processes can be identified. The role of a non-structure, the elusive transient capillary, can be illustrated. Microfibrillar organization and cell wall archictecture fall into the realm of ultrastructure as well.The past decade of research in wood science has been productive to a significant extent because of scanning electron microscopy and its accessory tools and techniques. The exploration of wood penetration by wood preservatives, pulping liquors and coatings using this approach has yielded much new evidence. One can speculate about the anticipated contributions of computer-driven SEM, stereology, STEM, and even higher resolution microscopy in the near future.  相似文献   

4.
Zusammenfassung 1. Es wurden Hydroponikkulturen der Ziernessel mit 11 verschiedenen Insektiziden (Chlorierten Kohlenwasserstoffen, Phosphorsäureestern und Carbamaten) behandelt.2. Die Insektizide wurden bei bewurzelten und unbewurzelten Sprossen über die Nährlösung appliziert und nach verschieden langer Dauerkultur Extrakte von Blättern, Sprossen und Wurzeln auf ihre insektizide Wirkung im Biotest(Drosophila melanogaster) überprüft.3. Allgemein war die Kontaktwirksamkeit der Wurzelextrakte hoch, während Sproß- und Blattextrakte nur bei systemischen oder ähnlich wirkenden Mittein Wirkungen beobachten ließen. Hierbei erwies sich das Carbamat Isolan als besonders blattwirksam.4. Durch Vergleich mit Kontrollextrakten unbehandelter Pflanzen konnte eine unterschiedliche Maskierung der WS durch die Lipoide gezeigt werden. Blattlipoide waren erheblich wirksamer bezüglich der Abfangpotenz als Wurzelextrakte.5. Da jedoch diese Kontrollextrakte eine Eigentoxizität fürDrosophila beobachten ließen, wird die Beachtung solcher Störwirkungen gefordert und auch bei Modellversuchen, wie den hier angestellten, eine Reinigung der Extrakte vor den Biotesten vorgeschlagen.
Summary Bioassay with crude plant extracts(Coleus blumei) after basal treatment with insecticides in hydroponic culture resulted differenciated contact activity. 11 insecticides (and acaricides) have been investigated in commercial formulation (emulsion and wettable powder, application of different concentrations via mineral salt solution). Apical treatment with insecticides (spray- application) will be reported in later papers.Leaf, stem and root of isolatedcoleus developed contact reactions in extracts forDrosophila melanogaster M. (Rutshurel, sensitive and Göttingen, sensitive). Leaf-extracts after basic treatment with Isolan, Parathion, Diazinon, Demeton-o-methyl and Malathion caused high contact effects. Lower intensities are recovered in leaves after application (via roots) of Lindane and Trichlorphon (Dipterex®). Additions of DDT-formulations and Phenkapton are causing poisoning action of root extracts only and Chlorobenzilate was not effective onDrosophila. All other insecticides showing high poisoning in root extracts, resulted insecticidal actions in stem extracts regarding the degree of systemic properties. Thiodan is less active in that response than Lindane and the typical systemic substances as Isolan, Demeton-o-methyl etc.Some of the reactions could be regarded as well as action of the insecticidal substance as possible effect of formula. The bioassay of pesticides residues in crude extracts is serviceable under certain circumstances. It is proposed that better and more instructive information should be obtained by tracer-substances or by cleaning and separating procedures of the extracts (chemical methods) and subsequent bioassay.
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5.
Zusammenfassung In den Erdbeeranlagen der Sorte Tioga wurden mittels Blattpfropfung aufFragaria vesca alpina zwei Virosen ermittelt, die auf Grund der Symptome dem strawberry mottle = Erdbeervirus 1 zuzuordnen sind.Der Virusbefall des Ausgangspflanzgutes lag zwischen 4,1 bis 8,2 %, Er stieg im Anbaugebiet unter dem Einfluß einer intensiven Besiedlung durchPentatrichopus fragaefolii innerhalb eines Jahres von 65,2 % bis 69,6 %.Über den Test von Mutterpflanzen konnten inzwischen mehr als tausend virusfreie Stammpflanzen selektiert bzw. vermehrt werden. Die blattlausfreie Vermehrungslage in der Sierra Nevada ermöglicht die Fortfuhrüng einer virusfreien Erhaltungszucht.Die Ansteckungsrate kann in den Ertragsanlagen auf der Grundlage gezielter Blattlausbekämpfungen im Oktober/November sowie im Januar bis März erheblich gesenkt und damit praktisch bedeutungslos werden.
Summary Studies on viroses of strawberries in southern Spain After grafting strawberries of the sort Tioga uponFragaria vesca alpina two kinds of viroses belonging to the strawberry mottle group were observed. The primary attack amounted to 4.1–8,2%. Under the influence of the aphidPentatrichopus fragaefolii the attack rises to 65.2–69.6 %.More than thousand healthy plants were selected and multiplied. By this a plantation of healthy strawberries was settled in Sierra Nevada. Controlling measures against aphids in October/November as well as in January/March prevent the virus from enlarging on the plantation anew.
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6.
We prepared carpet cleaners containing three wood oils extracted from Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino, Chamaecyparis obtusa Endl., and Chamaecyparis taiwanensis Masamune et Suzuki and studied their effects on mites and perfumerists' impressions. The oil concentrations were set at 0.1%, 0.2%, 0.4%, 0.8%, and 1.6%. The effects on Dermatophagoides pteronyssinus Trouessart were investigated. The sensory evaluations were conducted by seven male perfumerists using the SD method and they were asked to describe freely their impressions of the scents. These results showed that: (1) all three types of wood oil had a significant effect on making D. pteronyssinus inactive at 0.1% concentration; and (2) the wood oil of T. dolabrata evoked refreshing, natural, rich, and intellectual feelings; C. obtusa oil evoked vivacious, rich, and intellectual feelings; and C. taiwanensis evoked refreshing, natural, rich, rough, masculine feelings. According to the test subjects, T. dolabrata evoked woody and earthy impressions; C. obtusa evoked woody, citrus, and pine-resin impressions; and C. taiwanensis evoked woody, citrus, and medical impressions. Many issues remain to be investigated, but the inclusion of wood oil in carpet cleaners offered both good mite control and a pleasant aroma to humans. This study suggests a new potential for using these wood oils.  相似文献   

7.
Bayley  A.D.  Kietzka  J.W. 《New Forests》1997,13(1-3):341-356
Two types of containerized P. patula seedlings, referred to as hard and soft seedlings, were raised by droughting and different fertilizer applications. Hard seedlings were raised by applying half the water and a quarter of the fertilizer (0.01 g per seedling 21%N:7.1%P:14.2%K) applied to the soft seedlings. At the end of the nursery cultural treatments the two types of seedlings were morphologically distinct. Hard seedlings had lower heights, height to root collar diameter ratios and seedling dry masses than soft seedlings, but mortality was similar for both seedling types when planted during seven different production periods within the planting season on three sites which differed climatically and geologically. Correlations between mortality and height to root collar diameter ratio (r = 0.76), root to shoot ratio (r = 0.83) and root growth potential (r = --0.69) were obtained indicating that grading of seedlings on these parameters may improve survival. However, it was evident that survival could be significantly improved by identifying the best time of year and conditions for planting, as well as improving stock quality.  相似文献   

8.
Summary Twentieth anniversary of the European Plant Protection Organization. Importance, functions and merits of the EPPO It is intended to report on the working of EPPO from time to time running parallel with informations on the European Economic Community on the field of plant protection. This is the first contribution of the new EPPO-series. It informs on history and functions of the organization, — on the suppositions and principles of the plant protection laws produced by the EPPO and effective in the member states of EEC —, and on the principles of cooperations between these states.  相似文献   

9.
Little information is available on the effect of root cutting by the collar pre-insertion technique on soil respiration. In this study, we found that soil respiration rates decreased with increasing depth of collar insertion in both the with live roots intact and with live roots severed treatments, but the rate of decrease was substantially higher in the former. The cutting of roots, especially fine roots, may be responsible for this result.  相似文献   

10.
Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12.  相似文献   

11.
Summary The problem of vessel length determination in hardwood trees has been approached in many ways by various workers. The paint infusion technique was utilized in a research programme investigating the subject of vessels of New Zealand beech (Nothofagus) stem sapwood. Two different models of stainless steel paint applicator were used: (a) the horizontal T shaped applicator and (b) the new vertical Y joint applicator. Applicator construction is discussed. The techniques are modifications of the Zimmermann and Jeje (1981) latex paint infuction method.The author gratefully acknowledges Dr. B. G. Butterfield, Dr. B. A. Meylan and L. A. Donaldson for advice and Dr. L. M. H. Middleton for field assistance  相似文献   

12.
A contribution to the definition of the fiber saturation point   总被引：3，自引：0，他引：3  
Summary There is hardly any term in wood science literature that has been defined so many times as the term fiber saturation point (FSP). In spite of this fact the discussion is still going on how to define and how to measure it. The aim of the paper is to evaluate some of the known definitions and propose a method of experimental measurement of FSP. The term cell wall saturation, in contrast with FSP, is clearly defined quantity that can be easily measured.The authors are grateful to the Slovak Grant Agency for Science for partial support of this work  相似文献   

13.
Zusammenfassung Die Befallsstärke von Erdbeerpflanzen durch Blattälchen wird allgemein in Älchen je 20 g Herzen ausgedrückt. Man versteht unter dem Herz einer Erdbeerpflanze die Knospe, die jungen Blütenanlagen und die unentfalteten Blätter. Es besteht aber ein gewisser Ermessensspielraum in der Zuordnung zu gefaltet bis zu voll entfaltet. Meist ist die Knospe am dichtesten befallen. Der Durchschnittsbefall sinkt deshalb um so tiefer, je mehr nicht zur Knospe gehörende Pflanzenteile mituntersucht werden. Es handelt sich um die Frischgewichte der Herzen. Diese unterliegen Schwankungen je nach Jahreszeit, Erdbeersorte und Witterung. Ferner sind die Herzen stark befallener Pflanzen leichter als die gesunder Pflanzen. Im Durchschnitt wiegen im Frühjahr 30 Herzen 20 g. Es wird vorgeschlagen, die veränderliche Bezugsgröße 20 g Herzen durch das konstante Maß 30 Pflanzen oder 30 Rosetten zu ersetzen.
Summary On the isolation of bud and leaf nematodes (Aphelenchoides fragariae andA. ritzemabosi) from strawberry and chrysanthemum. Part II.The degree of infestation to strawberry plants by the leaf and bud nematodes is usualy expressed in nematodes per 20 g hearts. The heart of a strawberry plant includes the bud, the young inflorescences and the young closed leaves. A certain degree of judgement is requirred to distinguish between a closed leaf and an opened one. As the nematodes are usualy most concentrated in the bud, the degree of infestation is brought down by the inclusion of parts of the plant that do not directly belong to the bud.The weight of the hearts is also natably affected by weather conditions, season and plant variety. Furthermore heavily infested hearts are lighter than healthy ones. In spring, 30 hearts weigh approximately 20 g. It is suggested that the unstable measure of 20g hearts be substituted by the more reliable amount 30 plants or 30 rosettes.
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14.
Summary A simple model for density distribution within an annual ring is proposed. The model originates from the concept that a tree has two growing modes early and late wood mode respectively and that during a growing season there is transition from the first to second. An annual ring is described by six parameters. The use of the model is discussed and a number of possible measures are suggested. The advantages and limitations of the model is also discussed.  相似文献   

15.
Zusammenfassung 19 verschiedene Nährböden wurden in ihrer Brauchbarkeit für Massenanzuchten vonDrosophila melanogaster Meig. getestet. Die Entwicklungsdauer der Larven unterschied sich auf den verschiedenen Substraten nur geringfügig, die Fliegenausbeuten waren aber sehr verschieden. Viele Tiere mit mittleren bis hohen Frischgewichten wurden besonders auf den Nährböden Göttingen, Bridges, Carnegie, Rußland und Freiburg erhalten.Die Schwankungen in der Empfindlichkeit gegenüber Parathion, DDT und Aldrin waren zwar nicht in jedem Fall richtungsgleich, doch zeigte sich, daß Taufliegen von den Substraten Japan, Synth. II, Synth. IV und etwas weniger auch von Kartoffel und Göttingen besonders empfindlich waren.Die Versuche zeigen, daß einheitliche Ernährungsbedingungen die Voraussetzung für den Vergleich verschiedener Testreihen sind.
Summary 19 different substrates have been tested for their utility for breeding flies in mass cultures. In each case the velocity of larval development was rather similar: the numbers of flies produced differed considerably.Flies bred on several half-synthetic media, as well as to a lesser degree on cooked potatoes, were especially sensitive to toxicants. The order of sensitivity to parathion, DDT, and aldrin was not always altered to the same degree. There was no clear correlation between the weight of the flies from different food and their sensitivities.The experiments demonstrate that standardized nutrition must be precluded to compare different test series.
Résumé 19 substrats nourriciers différents ont été l'objet de tests portant sur les aptitudes qu'ils offraient à la culture de colonies deDrosophila melanogaster. La durée de développement des larves ne présentait pas de différence sensible selon les différents substrats mais le nombre de mouches nées de ces cultures était très variable.Les mouches provenant de quelques substrats misynthétiques et de deux substrats de pommes de terre se montrèrent particulièrement sensibles aux insecticides. Cependant là encore les variations dans la sensibilité au parathion, DDT et aldrin n'allaient pas toujours dans le même sens.Les essais montrent que des conditions de nutrition homogènes supposent la comparaison de différentes séries de tests.
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16.
Inter- and intra-storm oxygen-18 variations in rain, throughfall, and stemflow were measured to estimate accurate new water inputs to the watershed within a 0.84-ha watershed planted with 80-year-old Cryptomeria japonica and Chamaecyparis obutusa artificial forest at the Hitachi Ohta experimental watershed in Japan. In addition two-component hydrograph separation using oxygen-18 concentrations was conducted with four types of new water concentration: (1) incremental volume-weighted mean concentrations of rainfall; (2) constant concentrations of rainfall; (3) incremental volume-weighted mean concentrations of throughfall; and (4) constant concentrations of throughfall. Six storms from June to October 2000 were investigated. In the 26 July, 24 September, and 29 October storms, old-water percentages at the hydrograph peak were more than 56.4%, 66.6%, and 80.4%, respectively. In the 24 September and 29 October storms, the old-water contribution estimated by incremental volume-weighted mean concentrations of throughfall was the greatest. On the other hand, this was the smallest after the 26 July storm. Thus, by estimating the new water inputs more accurately, the old water contribution could be either large or small. In addition, there was a relative difference of about 5–10% between old water percentages calculated from the four types of new water. The uncertainty associated with the analysis of oxygen-18 concentrations was up to 4.8%. Thus the difference in estimates of new water affected the old water percentage more than the uncertainty of the two-component model itself.  相似文献   

17.
Ohne ZusammenfassungDer Originalaufsaß erschien unter dem Titel The house Fly can be eradicated in The Southern Planter im Mai 1948 in Richmond (Virginia, USA.).  相似文献   

18.
Stress-strain state of wood at kiln drying   总被引：3，自引：1，他引：3  
Summary A model has been suggested which allows the calculation of stresses arising in kiln drying and humidification of wood, as well as the total residual strain, i.e. set strain s, consisting of purely residual strain r and the so-called frozen strain f. Frozen strains arise under the operating influence of loading when the stiffness is increased because of a decrease in moisture content (or temperature) of the wood. The process of formation of set strains s has been shown to depend on the history of loading, variations of the moisture content of the wood, as well as cooling of the section before the measurement of s. The possibility of using set strain as a parameter of the state of stress of wood in kiln drying has been noted.Presented at the VIII. International Symposium on Fundamental Research of Wood. Warsaw, Poland, October 1990  相似文献   

19.
The results of dynamic mechanical measurements in dual cantilever and uniaxial tension of untreated Scots pine veneer and unbleached sulphate paper under stepwise changes in the relative humidity of the surrounding atmosphere between 5% and 85% are compared to corresponding results for acetylated samples and samples treated by impregnation with poly(ethylene oxide) (PEO), glycerol or melamine formaldehyde resin. The treatments resulted in significant reductions in the transient mechanical losses associated with stepwise humidity changes. Although acetylation of wood and impregnation with PEO or glycerol both result in greatly improved dimensional stability with respect to humidity changes, the two types of treatment appear to be fundamentally different in terms of the models used here to interpret the results.We find that it is helpful to consider the dynamic process of moisture sorption/ desorption in these samples in terms of two coupled processes: the diffusion of moisture into or out of the sample, with a characteristic diffusion time given approximately by t* = /16)h2/D where h is the sample thickness and D a characteristic diffusion constant for the moisture in the material, and the attachment/detachment of (clusters of) water molecules to binding sites in the samples, apparently with characteristic chemical relaxation times of the order of seconds or minutes. Clearly, when the sample thickness is quite small, 0.8 mm in our case, and the diffusion coefficient of the order of 50 × 10–8 cm2/s, then the characteristic diffusion time is about 40 minutes, already for these small dimensions more than an order of magnitude larger than the characteristic chemical relaxation time. By varying the frequency of the dynamic mechanical measurements these characteristic processes for untreated and treated samples can be probed in some detail.  相似文献   

20.
We investigated the physiological and psychological responses of ten healthy male volunteers to a single heavy floor-impact sound generated by dropping an automobile tire from heights of 50, 100, and 150cm in a wooden house. Blood pressure and peripheral blood flow were measured simultaneously, and sensory evaluation was conducted using the semantic differential method. The results obtained were as follows: (1) the systolic blood pressure increased and the peripheral blood flow decreased when the subjects heard the heavy floor-impact sound; (2) the heavy floor-impact sound caused the subjects to feel uncomfortable, but there was no significant change in sharp and monotonous feelings; and (3) for the heavy floor-impact sound for 100cm and that for 150cm, the subjects showed no difference in comfortable feeling, but we detected differences in the variations of both the systolic blood pressure and the peripheral blood flow.Part of this research was presented at the 48th Annual Meeting of the Japan Wood Research Society, Shizuoka, April 1998.  相似文献   

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