摘要:

Simultaneous photographs of the polar aurora were made at two stations in northern Ontario, Canada, and from them a number of values for the height and position were obtained. For the lower limits of arcs and bands these ranged between 70 and 130 km. with a maximum frequency between 90 and 95 km. The mean height for all such lower limits was 95 km. The distribution of the points with reference to the earth's surface is shown.

ISSN:1923-4287    

DOI:10.1139/cjr31-067

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

With the aid of recent theories (H. Stenzel, N. W. McLachlan, H. Backhaus) the velocity potential and pressure distribution at points in the field of vibrating solid disks of 1 to 20 cm. diameter are calculated for a number of frequencies of practical importance. The graphs drawn from these values apply also to very high frequencies, but smaller disks (1 to 20 mm.). They illustrate the gradual transition from spherical distribution to directed transmission.

ISSN:1923-4287    

DOI:10.1139/cjr31-068

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Glycol-lignin prepared from spruce wood has been found to form a sodium salt which reacts with chloro-derivatives, giving rise to the corresponding glycol-lignin ethers. These compounds are insoluble in aqueous sodium hydroxide but still contain free hydroxyl groups which can be methylated without the ethereal linkage being broken. Hence glycol-lignin contains several free hydroxyl groups, one or more of which possess acidic properties. Both the methoxymethyl ether and the 2:4-dinitrophenyl ether of glycol-lignin have been prepared. The evidence would seem to indicate the presence of both phenolic and aliphatic hydroxyl groups.

ISSN:1923-4287    

DOI:10.1139/cjr31-069

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

The method for preparing an alkyl acetylene by the action of an alkyl halide on sodium dissolved in liquid ammonia was modified in certain details. Ethyl and methyl acetylene were prepared and purified and their melting and boiling points determined. Vapor pressures, densities and surface tensions were measured over a considerable temperature range. These properties together with constants calculated from the data are compared with similar data for paraffins and olefines.

ISSN:1923-4287    

DOI:10.1139/cjr31-070

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Seven factors have been described which seem to influence the tendency of sweet clover plants to produce seed by spontaneous self-fertilization. These are: length of stamens; stage of flower development when pollen is liberated from the pollen sacs; distribution of free pollen within the flower; size of cavity in the upper part of the keel; amount of pollen; condition of the pollen; and receptivity of the stigma.Spontaneous self-fertilization is the normal condition in certain plants of white blossom sweet clover,i.e.,M.alba. This was not found to occur in any variety of yellow blossom sweet clover with the exception of "Redfield Yellow". True breeding lines ofM.albahave been isolated consisting of naturally self-fertilized plants and other lines also which will not produce seed unless the flowers are manipulated.M.albaconsists of a mixture of normally self-fertilized plants and plants that are random pollinated. This is especially true of certain varieties such as "Arctic". In some plants ofM.albaan abundance of germinating pollen grains were found adhering to the stigmas before the flowers opened, thus precluding the possibility of natural crossing. Practically 100% of the flowers on such a plant produced selfed seed. The character of spontaneous self-fertilization exhibited clear cut segregation in a selfed line ofM.alba. The importance of this character in relation to breeding improved varieties and pure seed production is emphasized.The efficiency of the "suction" method of emasculating sweet clover flowers depends on the peculiarities of the latter. This method is quite reliable with many plants but very unsatisfactory with others, depending upon the particular type of flower structure and behavior.

ISSN:1923-4287    

DOI:10.1139/cjr31-071

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Exposure of the press-juice of unhardened winter wheat plants to frost caused a decrease in coagulable protein content, an increase in amino nitrogen content and an increased sensitivity to hydrolysis by dilute sodium hydroxide. Added sugar reduced the amount of change. No change resulting from freezing could be demonstrated in the inorganic nitrogen fractions. It is suggested that protein splitting as found in hardened plants may be the result of frost rather than an adaptation against it, and that the value of sugar as a protection to winter plants may lie partly in its ability to delay this action.

ISSN:1923-4287    

DOI:10.1139/cjr31-072

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

The catalase activity of press-juice of winter wheat leaves collected from the field at any time during the late summer and fall was directly related to the winter hardiness of varieties.

ISSN:1923-4287    

DOI:10.1139/cjr31-073

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Respiration measurements at −7°, 0° and 7 °C. with four winter wheat varieties and two spring wheat varieties grown in the field, were carried on during the fall and early winter of four years. The rate of respiration in winter wheat decreased as the plants hardened. At the outset all varieties respired about alike. After hardening began, the rates at −7 °C. were in the inverse order of hardiness, with the spring wheats faster than the least hardy winter wheat. As hardening progressed, the differentiation of the winter varieties at −7 °C. became sharper, and could be observed also at 0 °C., but at 7 °C. very little if any relationship of this sort developed. The spring varieties, because of frost damage, could not be compared with winter varieties in the fully hardened condition, but their behavior early in the season confirms the general conclusion that at the freezing point or lower temperatures respiratory activity is inversely related to winter hardiness. This accounts for the observed fact that hardy varieties maintain their sugar reserves better than non-hardy varieties during the winter.

ISSN:1923-4287    

DOI:10.1139/cjr31-074

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

A new method has been developed for preparing glutenin, using concentrated urea solution as a dispersion medium. The starch is removed from the dispersion by passing it through a Sharpies supercentrifuge. The glutenin is then removed from the gliadin by precipitation: (a) by adding magnesium sulphate to about 0.17 of saturation; or (b) by adding water until the urea is diluted to about 10% concentration. Alcohol precipitation is unsatisfactory, since the glutenin loses much of its original solubility. Drying, even at room temperature, renders glutenin insoluble in 30% urea solution. Different samples of glutenin isolated by the urea method have similar amide and arginine nitrogen contents. The amount of these constituents is intermediate between the values reported for glutenin isolated from alkali, and that isolated from acid. While urea solutions denature some proteins, they affect glutenin less than dilute alkalies, as judged by the sulphydryl test, and no more than dilute acids. Neutral urea solutions permit a study of the physical properties of glutenin without previous exposure to extremes of hydrogen ion concentration. This method should be applicable to the isolation of glutenins from other seeds.

ISSN:1923-4287    

DOI:10.1139/cjr31-075

出版商:NRC Research Press    

年代:1931

数据来源: NRC

摘要:

Accompanying dissociation of certain cultures of tubercle bacilli, a correlated loss in the specific antigenic activity in the complement-fixation reaction has been noted. All extracts made from attenuated cultures in which the R colony has been shown to be predominant have been found to be inferior in antigenic activity to similar preparations made from cultures composed of S types. Antisera prepared against R organisms appear to lack antibodies against certain substances present in the S organisms, although they have been found to contain a higher proportion of antibodies reacting with related acid-fast organisms than do the corresponding S antisera. It has been necessary to employ a strictly quantitative technique to demonstrate these differences.

ISSN:1923-4287    

DOI:10.1139/cjr31-076

出版商:NRC Research Press    

年代:1931

数据来源: NRC