scholarly journals Temperature variations in simulated warming alter photosynthesis of two emergent plants in plateau wetlands, China

Ecosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Derong Xiao ◽  
Pengfei Yan ◽  
Pengfei Zhan ◽  
Yun Zhang ◽  
Zhenya Liu ◽  
...  
Keyword(s):  
Temperature Variations ◽  
Emergent Plants ◽  
Plateau Wetlands

Observations of the spatial structure of interstellar hydrogen

1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles
Keyword(s):  
High Resolution ◽  
Spatial Structure ◽  
Velocity Dispersion ◽  
Temperature Variations

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.

Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

1967 ◽  
Vol 25 ◽  
pp. 366-367
Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
High Altitude ◽  
Amyl Acetate ◽  
Temperature Variations ◽  
Film Forming ◽  
Film Specimen ◽  
Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

Holocene sea surface temperature variations recorded in corals from Kikai Island, Japan

2017 ◽  
Vol 51 (4) ◽  
pp. e9-e14 ◽  
Author(s):  
Hiroto Kajita ◽  
Atsuko Yamazaki ◽  
Takaaki Watanabe ◽  
Chung-Che Wu ◽  
Chuan-Chou Shen ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Temperature Variations

The vegetation of the small rivers of Novosibirsk Region (a syntaxonomic essay)

2019 ◽  
pp. 3-27 ◽  
Author(s):  
L. M. Kipriyanova ◽  
M. A. Kleshchev
Keyword(s):  
Anthropogenic Impact ◽  
West Siberia ◽  
Steppe Zone ◽  
Small Rivers ◽  
Forest Steppe ◽  
Aquatic Communities ◽  
Emergent Plants ◽  
Novosibirsk Region ◽  
General Chemical ◽  
Wide Range

Information on the aquatic and semiaquatic vegetation of the major watercourses of West Siberia is relatively scarce, while this of small rivers is practically absent. There are 430 rivers whose length exceeds 10 km within the Novosibirsk Region. The aim of our work was to study the phytocenotic diversity of their aquatic and semiaquatic vegetation. 130 geobotanical relevés were performed by the authors in July–August 2003–2005. The object was aquatic communities formed by true aquatic (submergent and floating-leaved) plants and semiaquatic ones with emergent plants and these of water′s edge. In total 10 watercourses were studied (Table 1): 2–3 in each of five geomorphologic regions within the forest-steppe zone (Table 2). The upper, middle and lower courses (Fig. 1, Table 1) with the length of 2–2.5 km were studied in each case to ensure the 4–5 repetition of main elements (stream pools and ridges) that would give a reliable information on their flora and vegetation. The sample plots were selected above the settlements, whenever possible in sites with no to intensive anthropogenic impact. The data were collected according to J. Braun-Blanquet (1964) approach. The relevés were done on the sample plot of 100 m2 placed in the most homogeneous part of the community or, in case of its smaller area, within the natural boundaries. The following scale was used for abundance estimation: r — the species is extremely rare; + — rare, small cover; 1 — the number of individuals is large, the cover is small or individuals are sparse, but the cover is large; 2 —cover of 5–25 %; 3 — 26–50 %; 4 — 51–75 %; 5 — more than 75 %. The date on water depth, transparency (on a white Secchi disk with a diameter of 30 cm), temperature and the flow rate were obtained. The soil mechanical composition and color, the degree and nature of anthropogenic impact on vegetation and river banks were quantified. Water samples for general chemical analysis were taken in the middle course of each river. Computer programs TURBOVEG and MEGATAB (Hennekens, 1996) were used for database. The syntaxonomic affiliation of phytocenoses was determined using modern literature (Bobrov, Chemeris, 2006; Vegetace..., 2011; Chepinoga, 2015; Landucci et al. 2015; Mucina et al., 2016, etc.). 36 associations and 3 communities belonging to 12 alliances, 9 orders, and 5 classes have been identified (Tables 3–14, Fig. 2–9). Such great syntaxonomic diversity is determined by the significant ecotopic variety, the variability of substrates, the wide range of water flow rates and the different water trophicity. For comparison, 26 associations, 13 variants, 2 communities were identified in the study of 50 rivers of Lithuania (Sinkyavichene, 1992); altogether 84 associations are known for the Upper Volga region as a whole (Bob­rov, Chemeris, 2006), while 45 ones were recorded previously in 130 watercourses of this region (Bobrov, 1999). Information on small river macroalgae cenoses in the study area is partially reflected in the paper published earlier (Bobrov et al., 2005).

INVAR

Alloy Digest ◽  
1964 ◽  
Vol 13 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Iron Alloy ◽  
Heat Treating ◽  
Temperature Variations ◽  
Nickel Iron ◽  
Dimensional Changes ◽  
Temperature Performance ◽  
Nickel Iron Alloy

Abstract INVAR is a 36% nickel-iron alloy having the lowest coefficient of expansion, recommended for applications requiring no dimensional changes with temperature variations. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-24. Producer or source: Carpenter.

Experimental Investigations into the Use of Emergent Plants to Treat Sewage in South Africa

1987 ◽  
Vol 19 (10) ◽  
pp. 51-59 ◽  
Author(s):  
W. V. Alexander ◽  
A. Wood
Keyword(s):  
South Africa ◽  
Rural Communities ◽  
Experimental Investigations ◽  
Artificial Wetlands ◽  
E Coli ◽  
Effluent Quality ◽  
Emergent Plants ◽  
Treatment Facilities ◽  
High Standards ◽  
Oxidation Ponds

South Africa is a relatively water-short country which has many rural communities with water-borne sewage infrastructures requiring low technology treatment facilities. In order to protect the water resources of the country the authorities have set high standards for effluent quality (COD < 75 mg/l, NH3 < 10 mg/l, E. coli < 1000 and in some areas P < 1 mg/l). Traditionally, oxidation ponds have been used in these applications but have not been able to consistently meet the required standards and recently interest has been shown in artificial wetlands as a low technology means of solving the problem. As a result several experimental projects are at present being initiated in South Africa, both as primary and secondary treatment for domestic sewage and also as a tertiary treatment to remove nitrogen, phosphorus and E. coli from conventional sewage plant effluents. The designs of these experimental projects are described in the paper and it is hoped that data will be available for presentation at the seminar.

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