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Every ton of cement requires six to seven tons of sand and gravel to make concrete. Concrete is the predominant use for sand. But sand also makes up 90 percent of asphalt on roads. ... Lake Poyang on …
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This paper focuses on the streamwise migration of the erosion center along the ∼400-km-long Yichang to Chenglingji reach (YCR) downstream of the Three Gorges Dam (TGD), China. We analyzed channel morphological adjustment based on water, sediment and channel geometry data collected during 2002–2020.
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Gravel mulch has been used as an agricultural water conservation measure for over three hundred years in China's semiarid regions. In this study, a 3-year gravel mulch experiment on slopes in the northwestern Loess Plateau was conducted to evaluate the impact that different sized gravel mulch and natural rainfall has on surface runoff, soil …
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1 day agoMine sand and gravel for a new generation of cement. ... since countries like China and India are adding plants about as fast as the U.S. and European countries are decommissioning theirs. The U.S ...
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In the semiarid loess region of northwest China, the use of gravel and sand as mulch has been an indigenous farming technique for crop production for over 300 …
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Gravel–sand mulch is a unique mode of conservation tillage (no–tillage) applied widely in northwest China. For a long time, research on gravel–sand mulching focused on soil temperature, soil moisture, crop yield, and microbiology, leaving a dearth of research on CO 2 emissions. One study showed gravel–sand mulch can enhance soil ...
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May 22, 2017. A report said that sand and gravel mining "greatly exceeds natural renewal rates.". Illustration by Javier Jaén. The final event of last year's beach-volleyball world tour was ...
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China's Artificial Islands In South China Sea Are Harming Environment, Hague Tribunal Says : ... to make more gravel and sand to be sucked up and used for island-building."
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Gravel and sand mulching is an indigenous technology used for the crop yield for at least 300 years in the loess area of northwest China; however, little is known about the changes of soil bacterial community and metabolic capability under the mulching. In this study, we investigated the soil microb …
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Seismic sedimentology, in this case, provides an effective means of identifying and characterizing the complex, coarse-grained sediments. We use a large number of cores, logs, and seismic data and establish the third- and fourth-order sequence frameworks in the Shahejie Formation on the steep slope of the northern Dongying Sag …
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In order to cope with drought and water shortages, the working people in the arid areas of Northwest China have developed a drought-resistant planting method, …
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China Grove, NC 28023-9495 (704) 857-0166 (704) 857-7351 (fax) Hours: ... brick nuggets, brixment mix, building stones, creek sand, crushed stone, fill dirt, gravel, masonry products, mortar sand, pine bark mulch, sawdust, thin veneer stones, top soil and white decorative gravel. What's Nearby? Distance: mi.
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In 2018, China as the world's largest producer and consumer of sand and gravel, consumed more than 20 billion tons (accounting for nearly half of the global …
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Item added to your cart. Download unprotected-PDF in 1 second -- Top-secure payment Credit Cards / PayPal, translated by Singapore supplier. Try $1 DEMO. Skip to product information. JGJ 52-2006: Standard for technical requirements and test method of sand and crushed stone (or gravel) for ordinary concrete (JGJ52-2006)
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Sand, gravel and rock crushed together are melted down to make the glass used in every window, computer screen and smart phone. ... driven primarily by China, which constitutes 58% of today's sand ...
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Gravel mulch is an agricultural water conservation practice that has been widely used in the semi-arid region of northwest China, but its effectiveness is now lessening due to soil degradation caused by long-term gravel mulching. In this study, we report on a 6-year-long gravel mulch experiment conducted in the northwestern Loess …
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The use of gravel and sand as mulch has been an indigenous farming technique for crop production for over 300 years in the semiarid loess region of northwest China. The objective of this study was to determine the influence of texture and thickness of gravel and sand mulch layers on soil water storage by field experiments. The texture ...
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Based on previous field investigations (Zhang et al. 2016a), we found that gravel desert surfaces in north-western China include gravel with loose sand and without a crust (a gravel surface with deposited loose sand material and without crust, which is distributed mainly along the shores of seasonal rivers or some relative flat regions), …
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Gravel and sand mulching is an indigenous technology used for the crop yield for at least 300 years in the loess area of northwest China; however, Effects of gravel …
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Fig. 1 shows the various cultivation patterns for ridge and furrow rainwater harvest system, conventional ridge planting and flat gravel–sand mulched watermelon field. All treatments were arranged in a randomized complete block design with 3 replications. The gravel–sand mulch was a mixture of gravel (size range 1–4 cm) and coarse sand (3 mm).
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The use of gravel–sand mulch is a traditional water-conservation technique in the semi-arid Loess Plateau of North-western China. In this study, we investigated the 16-year effects of this mulch on … Expand
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Soils containing gravel (particle size ≥2 mm) are widely distributed over the Qinghai–Tibet Plateau (QTP). Soil mixed with gravel has different thermal and hydrological properties compared with fine soil (particle size <2 mm) and thus has marked impacts on soil water and heat transfer. However, the most commonly used land models do not consider …
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In China's Gansu province, gravel mulched farmland totaled 72,327 ha at the end of 2016, about 2.4 times its area in 1949 according to the "Gansu Rural Yearbook" …
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There is a rapidly unfolding sand supply crisis in meeting growing material needs for infrastructure. We find a ~45% increase in global building sand use from 2020 to 2060 under a middle-of-the ...
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China's construction boom means it needs a huge amount of sand – it currently accounts for a fifth of the world's imports (Credit: Getty Images) Even the United Arab Emirates imported $456m ...
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Sand and gravel mining has grown to be an integral component and a major source of the Kenyan economy with about 90% of annual sand generation coming from river sources alone. Like many other developing countries, indiscriminate river sand and gravel mining is a major environmental concern in Kenya as the activity causes irreparable …
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Gravel-sand mulch has been used for centuries to conserve water in the Loess Plateau of northwestern China. In this study, we assessed the influence of long-term (1996–2012) gravel-sand mulching of cultivated soils on total organic carbon (TOC), light fraction organic carbon (LFOC), microbial biomass carbon (MBC), total organic nitrogen …
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Sand and gravel are used in a wide range of applications, but of reported uses, the vast majority is consumed in construction materials such as cement. Global demand has increased rapidly over the past two decades and has largely been driven by growth in the Asia Pacific region, particularly in China. China is the largest cement
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Gravel and sand mulching has been used for at least 300 years in the arid area of northwestern China 1,2.A layer of gravel and sand approximately 10 cm thick lies on the soil surface.
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A field and modeling study was carried out to quantify the effect of a gravel-sand mulch material on soil water and soil temperature in the semiarid loess region of …
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