Tensile Characteristics of Polygonaceae Weed Roots in Slope Collapse Watershed

2013 ◽  
Vol 690-693 ◽  
pp. 1792-1795
Author(s):  
Xiao Ming Zhang ◽  
Shu Wen Ding ◽  
Shuang Xi Li
Keyword(s):  
Aboveground Biomass ◽  
Tensile Force ◽  
Belowground Biomass ◽  
Scientific Basis ◽  
Root Diameter ◽  
Electrical Machine ◽  
Fresh Weight ◽  
Single Root ◽  
Slope Collapse ◽  
The Relationship

Root systems, as the reinforced materials, are essential to increase slope stability and mitigate soil erosion. Polygonaceae family weeds are widespread in slope collapse watershed for its rapid growth and hardiness. Some growing around farmlands and ditches affect the farm crop yield. While others growing in slope collapse have medicinal value, revegetation, and root reinforcement effect. The plant height, fresh weight and expansion range of aboveground biomass and roots were measured to research the relationship between the aboveground biomass and the belowground biomass. The relationship between the aboveground biomass fresh weight and root system fresh weight was consistent with linear function. Single root was tested by digital display push-tension meter (SH-100) fixed in vertical electrical machine (SJY-500) to obtain the relationship between tensile force and root diameter. The relationship between tensile force and root diameter conformed to exponential decay function. At last, the relationship between root diameter classes and average tensile force of Polygonaceae family weeds was analyzed. The result showed that the diameters mainly ranged from 0 mm to 2 mm, 87.75% of the total, and the average tensile force increased with the diameter class. At the beginning, the shape of tensile force was a line, then a curved line during pulling, which deformation was nonlinear. It could provide a scientific basis for design of weeder in farmland, and greening, erosion control in slope collapse.

Mechanical Characteristics of Peanut Root System and its Tribological Properties against Soil

2012 ◽  
Vol 209-211 ◽  
pp. 1177-1182
Author(s):  
Xiao Ming Zhang ◽  
Qian Jin Liu ◽  
Xing Xiu Yu
Keyword(s):  
Applied Stress ◽  
Mechanical Characteristics ◽  
Root Diameter ◽  
Soil Resistance ◽  
Reinforcement Effect ◽  
Root Reinforcement ◽  
Single Root ◽  
Pull Out ◽  
The Relationship ◽  
Diameter Classes

Peanut root of crop lands in Menglianggu watershed in the upper reaches of Yi River were classified into different diameter classes by root diameter. The results show that (1) the relationship between force of pullout or breaking and root diameter is approximately linearity, and more significant linear for the latter; (2) Laboratory tests confirm the presence of a threshold or range of root diameter. When the diameter within the range (1.80-3.01mm), both root breaking and pullout occurred; when the diameter above 3.01mm, all roots broke under applied stress. While below 1.80mm, only roots were pulled out under applied stress. Root-soil resistance characteristic and root reinforcement effect were analyzed for different root classes: (3) pull out force of root-soil resistance is stronger than that of single root of the same root classes with the range from 6.03% to 39.39%.

Estimating coarse root biomass of balsam fir

2007 ◽  
Vol 37 (6) ◽  
pp. 991-998 ◽  
Author(s):  
M.B. Lavigne ◽  
M.J. Krasowski
Keyword(s):  
New Brunswick ◽  
Root Biomass ◽  
Abies Balsamea ◽  
Belowground Biomass ◽  
Root Diameter ◽  
Balsam Fir ◽  
Stand Age ◽  
Coarse Root ◽  
The Relationship ◽  
Diameter Classes

Root systems of 31 balsam fir ( Abies balsamea (L.) Mill.) trees were excavated at five sites in central New Brunswick. Sites ranged from 10 to >80 years in stand age; most had been thinned at least once, and densities ranged from 750 to 44 000 trees·ha–1. The relationship between diameter at breast height and coarse root biomass in the present investigation was similar to one reported for balsam fir in northern New Brunswick but differed from two other published biomass equations. Coarse root biomass per hectare ranged from 3 to 30 Mg·ha–1 among studied sites. Coarse root biomass in the smaller root diameter classes was similar at all sites, but biomass in diameter classes >50 mm increased with stand age. Precommercial thinning added 3 Mg coarse root biomass·ha–1 to the detrital pool. The ratio of coarse root biomass to stem biomass averaged 0.36 (±0.02 SE). These results show that there is more belowground biomass in balsam fir ecosystems than would be expected from the generic ratio of belowground to aboveground biomass often applied to coniferous ecosystems, pointing to a need for using ratios that are more specific.

Spectral assessments of wheat plants grown in pots and containers under saline conditions

2013 ◽  
Vol 40 (4) ◽  
pp. 409 ◽  
Author(s):  
Harald Hackl ◽  
Bodo Mistele ◽  
Yuncai Hu ◽  
Urs Schmidhalter
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Aboveground Biomass ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Spectral Indices ◽  
Fresh Weight ◽  
Normalised Difference Vegetation Index ◽  
Spectral Sensing ◽  
Reflectance Ratio

Spectral measurements allow fast nondestructive assessment of plant traits under controlled greenhouse and close-to-field conditions. Field crop stands differ from pot-grown plants, which may affect the ability to assess stress-related traits by nondestructive high-throughput measurements. This study analysed the potential to detect salt stress-related traits of spring wheat (Triticum aestivum L.) cultivars grown in pots or in a close-to-field container platform. In two experiments, selected spectral indices assessed by active and passive spectral sensing were related to the fresh weight of the aboveground biomass, the water content of the aboveground biomass, the leaf water potential and the relative leaf water content of two cultivars with different salt tolerance. The traits were better ascertained by spectral sensing of container-grown plants compared with pot-grown plants. This may be due to a decreased match between the sensors’ footprint and the plant area of the pot-grown plants, which was further characterised by enhanced senescence of lower leaves. The reflectance ratio R760 : R670, the normalised difference vegetation index and the reflectance ratio R780 : R550 spectral indices were the best indices and were significantly related to the fresh weight, the water content of the aboveground biomass and the water potential of the youngest fully developed leaf. Passive sensors delivered similar relationships to active sensors. Across all treatments, both cultivars were successfully differentiated using either destructively or nondestructively assessed parameters. Although spectral sensors provide fast and qualitatively good assessments of the traits of salt-stressed plants, further research is required to describe the potential and limitations of spectral sensing.

Effects of grazing intensity on organic carbon stock characteristics in Stipa breviflora desert steppe vegetation soil systems

2017 ◽  
Vol 39 (2) ◽  
pp. 169 ◽  
Author(s):  
Heyun Wang ◽  
Zhi Dong ◽  
Jianying Guo ◽  
Hongli Li ◽  
Jinrong Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Aboveground Biomass ◽  
Carbon Stock ◽  
Belowground Biomass ◽  
Total Carbon ◽  
Desert Steppe ◽  
Light Fraction Organic Carbon ◽  
Grazing Intensities ◽  
Organic Carbon Stock

Grassland ecosystems, an important component of the terrestrial environment, play an essential role in the global carbon cycle and balance. We considered four different grazing intensities on a Stipa breviflora desert steppe: heavy grazing (HG), moderate grazing (MG), light grazing (LG), and an area fenced to exclude livestock grazing as the Control (CK). The analyses of the aboveground biomass, litter, belowground biomass, soil organic carbon and soil light fraction organic carbon were utilised to study the organic carbon stock characteristics in the S. breviflora desert steppe under different grazing intensities. This is important to reveal the mechanisms of grazing impact on carbon processes in the desert steppe, and can provide a theoretical basis for conservation and utilisation of grassland resources. Results showed that the carbon stock was 11.98–44.51 g m–2 in aboveground biomass, 10.43–36.12 g m–2 in plant litters, and 502.30–804.31 g m–2 in belowground biomass (0–40 cm). It was significantly higher in CK than in MG and HG. The carbon stock at 0–40-cm soil depth was 7817.43–9694.16 g m–2, and it was significantly higher in LG than in CK and HG. The total carbon stock in the vegetation-soil system was 8342.14–10494.80 g m–2 under different grazing intensities, with the largest value in LG, followed by MG, CK, and HG. About 90.54–93.71% of the total carbon in grassland ecosystem was reserved in soil. The LG and MG intensities were beneficial to the accumulation of soil organic carbon stock. The soil light fraction organic carbon stock was 484.20–654.62 g m–2 and was the highest under LG intensity. The LG and MG intensities were beneficial for soil nutrient accumulation in the desert steppe.

Soil Shear Strength Characteristic in Slope Disintegration Area

2013 ◽  
Vol 353-356 ◽  
pp. 735-739
Author(s):  
Xiao Ming Zhang ◽  
Shu Wen Ding ◽  
Shuang Xi Li
Keyword(s):  
Shear Strength ◽  
Direct Shear Test ◽  
Shear Test ◽  
Clay Content ◽  
Scientific Basis ◽  
Soil Mechanic ◽  
Direct Shear ◽  
Soil Cohesion ◽  
Soil Shear Strength ◽  
The Relationship

Development of slope disintegration is close to soil mechanic characteristics such as shear strength indices. Soil grain diameter and water content were tested. Soil direct shear test was conducted to analyze the relationship between shear strength indices and the influencing factors. The experimental data indicate that clay content and the range affect soil cohesion value and the scope. Soil cohesion increases with bulk density before 1.6g/cm3. But it decreases when the bulk after that. The results could provide a scientific basis for control of slope disintegration.

Change Analysis of Enzyme Activity under Different Conditions of Film Remnant in Soil

2012 ◽  
Vol 518-523 ◽  
pp. 39-43
Author(s):  
Xiao Guang Zhao ◽  
Yuan Yuan Guan ◽  
Wen Yu Huang
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Scientific Basis ◽  
Soil Enzyme ◽  
Soil Microorganism ◽  
Soil Enzyme Activities ◽  
Change Analysis ◽  
Soil Material ◽  
The Relationship

In this paper, simulated experiments were performed in pots by using soil materials in different conditions of film remnant. Based on the research on soil microorganism quantity trends of soil enzyme activities were analyzed systematically: soil without film remnant, soil with film remnant for 5, 10, 15 and 20 years. By analyzing crop progress, the relationship with soil material was studied, in order to provide scientific basis for the variation laws between different conditions of film remnant and the activity of soil enzyme.

Meat qualities in the sheep with special reference to Scottish breeds and crosses. I

1939 ◽  
Vol 29 (4) ◽  
pp. 544-626 ◽  
Author(s):  
H. Pálsson
Keyword(s):  
Scientific Basis ◽  
Accurate Estimate ◽  
Quantitative Composition ◽  
Carcass Quality ◽  
Strongly Correlated ◽  
Precise Measure ◽  
Total Fat ◽  
Highly Correlated ◽  
High Degree ◽  
The Relationship

1. By establishing the relationship between linear carcass measurements and the quantitative composition of the carcass in terms of bone, muscle and fat, we have provided a scientific basis for the use of many measurements hitherto only presumed to provide an index to carcass quality.2. External carcass measurements are correlated with weight of the skeleton. The most useful for this purpose are length of tibia + tarsus and length of the fore-cannon.3. As indices of muscle, external measures are only of indirect value. Thus, both F – T and G/F × 100 are strongly correlated with weight of muscle as a percentage of skeletal weight.4. Similarly, F provides an index of fat, being negatively correlated with fat as a percentage of bone.5. For muscle and fat internal measures permit a more precise estimate to be made. A + B is the best index of the former while C + J + Y provide the most accurate estimate of the weight of fat.6. Still better indices for muscle and fat are provided by suitable combinations of external and internal measurements. Thus L/10 + A + B is very highly correlated with the weight of muscle, and L/10 × (C + J + Y) is the best index of fat in the hoggets. For bone, a most efficient single index is shown to be the weight of the fore-cannon bone.7. The weight of the skeleton can be estimated with a high degree of accuracy from the weight of the bones in either one leg or loin. Both these joints combined, however, provide a still better estimate.8. The muscle in one leg or loin + leg provides an excellent index of the weight of muscle in the whole carcass.9. The fat in one leg, loin, or both these joints combined provides a good index of the weight of the total fat in the carcass. Both joints combined give the most precise measure.10. The value of certain measurements which are not necessarily associated with the quantity of the major tissues of the carcass, but which nevertheless have important qualitative significance, is emphasized.

scholarly journals The Proposal and Research on the Most Basic Problem of Fault Diagnosis

2020 ◽  
Author(s):  
Hu Jun
Keyword(s):  
Fault Diagnosis ◽  
Basic Problem ◽  
Scientific Basis ◽  
Parameter Analysis ◽  
Analytic Method ◽  
Systematic Development ◽  
The Relationship

Abstract By keep asking “what happened to the part that was connected between normal and fault?” The basic problem of fault diagnosis is put forward. Based on the parameter analysis, the most basic problem of fault diagnosis is pointed to the generalized stiffness looseness through the congenital underlying logic presupposition of the fault. The relationship between generalized looseness, part fault and system fault is analyzed by analytic method, which further proves that looseness fault is the most basic problem in fault diagnosis.Finally, the essential priority of looseness fault in fault diagnosis is expounded.The essential priority of loosening fault in fault diagnosis explains the basic problem of fault diagnosis and provides a scientific basis for the systematic development of fault diagnosis.

scholarly journals Effects of Stand Age on Biomass Allocation and Allometry of Quercus Acutissima in the Central Loess Plateau of China

Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 41 ◽  
Author(s):  
Bin Yang ◽  
Wenyan Xue ◽  
Shichuan Yu ◽  
Jianyun Zhou ◽  
Wenhui Zhang
Keyword(s):  
Biomass Allocation ◽  
Aboveground Biomass ◽  
Belowground Biomass ◽  
Stem Bark ◽  
Stand Age ◽  
Tree Biomass ◽  
Quercus Acutissima ◽  
Stem Wood ◽  
Biomass Equations ◽  
Total Tree

We studied the effects of stand age on allocation and equation fitting of aboveground and below-ground biomass in four Quercus acutissima stands (14, 31, 46, and 63 years old) in the Central Loess Plateau of China. The stem wood, stem bark, branch, foliage, and belowground biomass of each of the 20 destructive harvesting trees were quantified. The mean total biomass of each tree was 28.8, 106.8, 380.6, and 603.4 kg/tree in the 14-, 31-, 46-, and 63-year-old stands, respectively. Aboveground biomass accounted for 72.25%, 73.05%, 76.14%, and 80.37% of the total tree biomass in the 14-, 31-, 46-, and 63-year-old stands, respectively, and stem wood was the major component of tree biomass. The proportion of stem (with bark) biomass to total tree biomass increased with stand age while the proportions of branch, foliage, and belowground biomass to total tree biomass decreased with stand age. The ratio of belowground biomass to aboveground biomass decreased from 0.39 in the 14-year-old stand to 0.37, 0.31, and 0.24 in the 31-, 46-, and 63-year-old stands, respectively. Age-specific biomass equations in each stand were developed for stem wood, stem bark, aboveground, and total tree. The inclusion of tree height as a second variable improved the total tree biomass equation fitting for middle-aged (31-year-old and 46-year-old) stands but not young (14 years old) and mature (63 years old) stands. Moreover, biomass conversion and expansion factors (BCEFs) varied with stand age, showing a decreasing trend with increasing stand age. These results indicate that stand age alters the biomass allocation of Q. acutissima and results in age-specific allometric biomass equations and BCEFs. Therefore, to obtain accurate estimates of Q. acutissima forest biomass and carbon stocks, age-specific changes need to be considered.

Experimental Study about Testing Masonry Shear Strength with Drilled Core Method

2012 ◽  
Vol 166-169 ◽  
pp. 1241-1244
Author(s):  
Shi Qi Cui ◽  
Xu Wen Kong ◽  
Xin Wang ◽  
Ming Liang Yang
Keyword(s):  
Shear Strength ◽  
Scientific Basis ◽  
Core Sample ◽  
Masonry Structure ◽  
Data Regression ◽  
Drilling Method ◽  
Testing Data ◽  
Wall Materials ◽  
Result Analysis ◽  
The Relationship

Key technology of testing masonry shear strength with core drilling method is that standard shear strength of masonry is determined from the shear strength of masonry core sample, while current code or specification has not provided the corresponding calculating formula. To investigate their relationship, a series of tests have been carried out. Existing test result analysis shows that standard shear strength of masonry and shear strength of masonry core sample are closely related. By means of testing data regression analysis, this work can establish the relationship formula between shear strength of single core sample and standard shear strength of masonry. This Technology can be suitable both to traditional masonry structure and to new wall materials masonry structure, especially to seismic appraiser and reinforcement calculation of masonry structure. This technology can support scientific basis to quality examination and assessment of new wall materials and analysis of engineering quality accident.

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