scholarly journals Rapid growth of a large-scale (600 mm aperture) KDP crystal and its optical quality

2014 ◽  
Vol 2 ◽  
Author(s):  
Guohui Li ◽  
Guozong Zheng ◽  
Yingkun Qi ◽  
Peixiu Yin ◽  
En Tang ◽  
...  
Keyword(s):  
Rapid Growth ◽  
Inertial Confinement Fusion ◽  
Large Scale ◽  
Pure Water ◽  
Raw Material ◽  
Dihydrogen Phosphate ◽  
Optical Parameters ◽  
Spontaneous Nucleation ◽  
Large Bulk ◽  
Kdp Crystals

AbstractPotassium dihydrogen phosphate (KDP) single crystals are the only nonlinear crystals currently used for electro-optic switches and frequency converters in inertial confinement fusion research, due to their large dimension and exclusive physical properties. Based on the traditional solution-growth process, large bulk KDP crystals, usually with sizes up to 600 $\times $ 600 mm$^{{2}}$ so as to make a frequency doubler for the facility requirement loading highly flux of power laser, can be grown in standard Holden-type crystallizers, without spontaneous nucleation and visible defects, one to two orders of magnitude faster than by conventional methods. Pure water and KDP raw material with a few ion impurities such as Fe, Cr, and Al (less than 0.1 ppm) were used. The rapid-growth method includes extreme conditions such as temperature range from 60 to 35$^{\circ }$C, overcooling up to 5$^{\circ }$C, growth rates exceeding 10 mm/day, and crystal size up to 600 mm. The optical parameters of KDP crystals were determined. The optical properties of crystals determined indicate that they are of favorable quality for application in the facility.

scholarly journals Facile bottom-up synthesis of partially oxidized black phosphorus nanosheets as metal-free photocatalyst for hydrogen evolution

2018 ◽  
Vol 115 (17) ◽  
pp. 4345-4350 ◽  
Author(s):  
Bin Tian ◽  
Bining Tian ◽  
Bethany Smith ◽  
M. C. Scott ◽  
Qin Lei ◽  
...  
Keyword(s):  
Large Scale ◽  
Field Effect Transistors ◽  
Low Cost ◽  
Pure Water ◽  
Black Phosphorus ◽  
Raw Material ◽  
Bottom Up ◽  
Metal Free ◽  
Wet Chemical Synthesis ◽  
Intense Activity

Few-layer black phosphorus (BP) nanosheets were first reported as a 2D material for the application of field-effect transistors in 2014 and have stimulated intense activity among physicists, chemists, and material and biomedical scientists, driving research into novel synthetic techniques to produce BP nanosheets. At present, exfoliation is the main route toward few-layer BP nanosheets via employing bulk BP as raw material. However, this is a complicated and time-consuming process, which is difficult for the large-scale synthesis of BP nanosheets. Moreover, BP degrades rapidly when exfoliated to nanoscale dimensions, resulting in the rapid loss of semiconducting properties. Here, we report the direct wet-chemical synthesis of few-layer BP nanosheets in gram-scale quantities in a bottom-up approach based on common laboratory reagents at low temperature, showing excellent stability due to partial oxidation of surface. Solvent and temperature are two critical factors, controlling not only the formation of BP nanosheets but also the thickness. The as-prepared BP nanosheets can extract hydrogen from pure water (pH = 6.8), exhibiting more than 24-fold higher activity than the well-known C3N4 nanosheets. Our results reporting the ability to prepare few-layer BP nanosheets with a facile, scalable, low-cost approach take us a step closer to real-world applications of phosphorene including next-generation metal-free photocatalysts for photosynthesis.

A Vacuum Sucking Approach to Preventing Chips from Attaching to Machined Surface in Cutting of KDP Crystals

2010 ◽  
Vol 443 ◽  
pp. 573-581
Author(s):  
Zi Wen Zheng ◽  
Hao Feng Chen ◽  
Yi Fan Dai ◽  
Hang Gao ◽  
Gui Lin Wang ◽  
...  
Keyword(s):  
High Power ◽  
Inertial Confinement Fusion ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Dihydrogen Phosphate ◽  
Inertial Confinement ◽  
Machined Surface ◽  
Kdp Crystals

Potassium Dihydrogen Phosphate (KDP) crystals are used for the key components in high power density solid-state laser for Inertial Confinement Fusion. KDP crystals are mainly machined in the dry cutting condition to avoid ‘Fogging’ of the crystals. The main difficulty identified in dry machining of KDP is chip removal from the machined surface. A vacuum sucking device based on venturi vacuum pump is used to suck the chips during cutting, and the relationship between level of vacuum in cutting zone and the comply air pressure was established. An empirical model for chip emission during turning processes is used to analyze the influence of cutting parameters on the chip emission. The influence of cutting parameters on the removal of chips is investigated. Finally, a face turning of KDP crystals is carried out with the turning parameters of feed rate 1um/rev, depth of cut of 0.8 um/rev and the cutting speed from 1.82m/s to 3.9m/s. A super-smooth surface with chips free in the whole sample is achieved, having the surface roughness of 2.994nm (Ra) measured by AFM. The surface quality achieved satisfies the requirements of KDP crystals implemented in high power lasers.

scholarly journals Rapid growth of large-scale (40-55 cm) KDP crystals

1997 ◽  
Author(s):  
Natalia P. Zaitseva ◽  
James J. De Yoreo ◽  
Martin R. DeHaven ◽  
Russell L. Vital ◽  
L. M. Carman ◽  
...  
Keyword(s):  
Rapid Growth ◽  
Large Scale ◽  
Kdp Crystals

scholarly journals Rapid Growth of KDP Crystals in the [101] Direction

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 108
Author(s):  
Mengfei Qin ◽  
Xinguang Xu ◽  
Guangwei Yu ◽  
Bo Wang ◽  
Wenyong Cheng
Keyword(s):  
Liquid Flow ◽  
Rapid Growth ◽  
Inertial Confinement Fusion ◽  
Damage Threshold ◽  
Optical Transmittance ◽  
Laser Damage Threshold ◽  
Hydrodynamic Condition ◽  
Inertial Confinement ◽  
Two Dimensional ◽  
Kdp Crystals

KDP crystals have important applications in inertial confinement fusion. However, during the rapid growth of large-sized KDP crystals, inclusion is prone to occur. The existence of inclusion will lead to the reduction of crystal quality and utilization and even the end of the growth process. The generation of inclusion is related to the interaction between the crystal and the liquid flow. In this paper, we changed the hydrodynamic condition around the crystal by changing the crystal growth direction and achieve the rapid growth of [101] direction KDP crystals without inclusion at a low rotation rate. The utilization of the crystal was improved and the crystal has good optical transmittance, crystalline perfection and laser damage threshold. Meanwhile, atomic force microscopy was used to study the characteristics and changes of the micromorphology on (100) and (101) faces under different levels of supersaturation. The analysis results show that under high supersaturation, the uneven distribution of solutes and insufficient flow rate cause local macrosteps, two-dimensional step platforms and two-dimensional cores to form irregular structures with large slopes, thereby reducing the stability of the interface. This study will help to better understand the effect of the interaction between liquid flow and crystals on the formation of inclusion and guide the growth of KDP crystals.

scholarly journals Effect of cyclohexane diamine tetraacetic acid on micro morphology of rapidly grown potassium dihydrogen phosphate crystals

RSC Advances ◽  
2017 ◽  
Vol 7 (37) ◽  
pp. 23102-23108
Author(s):  
Weidong Li ◽  
Shenglai Wang ◽  
Guangwei Yu ◽  
Duanliang Wang ◽  
Pingping Huang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Rapid Growth ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Tetraacetic Acid ◽  
Growth Technique ◽  
Potassium Dihydrogen ◽  
Micro Morphology ◽  
Kdp Crystals ◽  
Point Seed

Potassium dihydrogen phosphate (KDP) crystals were grown from aqueous solutions with different concentrations of cyclohexane diamine tetraacetic acid (CDTA) by the “point seed” rapid growth technique.

scholarly journals Alien Wood Species as a Resource for Wood-Plastic Composites

2020 ◽  
Vol 11 (1) ◽  
pp. 44
Author(s):  
Sergej Medved ◽  
Daša Krapež Tomec ◽  
Angela Balzano ◽  
Maks Merela
Keyword(s):  
Wood Species ◽  
Dimensional Stability ◽  
Laser Scanning ◽  
Large Scale ◽  
Laser Scanning Microscopy ◽  
Raw Material ◽  
Confocal Laser ◽  
Alien Plant ◽  
Wood Plastic Composites ◽  
Plastic Composites

Since invasive alien species are one of the main causes of biodiversity loss in the region and thus of changes in ecosystem services, it is important to find the best possible solution for their removal from nature and the best practice for their usability. The aim of the study was to investigate their properties as components of wood-plastic composites and to investigate the properties of the wood-plastic composites produced. The overall objective was to test the potential of available alien plant species as raw material for the manufacture of products. This would contribute to sustainability and give them a better chance of ending their life cycle. One of the possible solutions on a large scale is to use alien wood species for the production of wood plastic composites (WPC). Five invasive alien hardwood species have been used in combination with polyethylene powder (PE) and maleic anhydride grafted polyethylene (MAPE) to produce various flat pressed WPC boards. Microstructural analyses (confocal laser scanning microscopy and scanning electron microscopy) and mechanical tests (flexural strength, tensile strength) were performed. Furthermore, measurements of density, thickness swelling, water absorption and dimensional stability during heating and cooling were carried out. Comparisons were made between the properties of six WPC boards (five alien wood species and mixed boards). The results showed that the differences between different invasive alien wood species were less obvious in mechanical properties, while the differences in sorption properties and dimensional stability were more significant. The analyses of the WPC structure showed a good penetration of the polymer into the lumens of the wood cells and a fine internal structure without voids. These are crucial conditions to obtain a good, mechanically strong and water-resistant material.

scholarly journals Scaling Up Delivery of Biofortified Staple Food Crops Globally: Paths to Nourishing Millions

2021 ◽  
pp. 037957212098250
Author(s):  
Jennifer K. Foley ◽  
Kristina D. Michaux ◽  
Bho Mudyahoto ◽  
Laira Kyazike ◽  
Binu Cherian ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Large Scale ◽  
Scale Up ◽  
Lessons Learned ◽  
Raw Material ◽  
Micronutrient Deficiencies ◽  
Seed Systems ◽  
Public And Private ◽  
Context Specific ◽  
Public And Private Sector

Background: Micronutrient deficiencies affect over one quarter of the world’s population. Biofortification is an evidence-based nutrition strategy that addresses some of the most common and preventable global micronutrient gaps and can help improve the health of millions of people. Since 2013, HarvestPlus and a consortium of collaborators have made impressive progress in the enrichment of staple crops with essential micronutrients through conventional plant breeding. Objective: To review and highlight lessons learned from multiple large-scale delivery strategies used by HarvestPlus to scale up biofortification across different country and crop contexts. Results: India has strong public and private sector pearl millet breeding programs and a robust commercial seed sector. To scale-up pearl millet, HarvestPlus established partnerships with public and private seed companies, which facilitated the rapid commercialization of products and engagement of farmers in delivery activities. In Nigeria, HarvestPlus stimulated the initial acceptance and popularization of vitamin A cassava using a host of creative approaches, including “crowding in” delivery partners, innovative promotional programs, and development of intermediate raw material for industry and novel food products. In Uganda, orange sweet potato (OSP) is a traditional subsistence crop. Due to this, and the lack of formal seed systems and markets, HarvestPlus established a network of partnerships with community-based nongovernmental organizations and vine multipliers to popularize and scale-up delivery of OSP. Conclusions: Impact of biofortification ultimately depends on the development of sustainable markets for biofortified seeds and products. Results illustrate the need for context-specific, innovative solutions to promote widespread adoption.

scholarly journals Forecast of International Trade of Lithium Carbonate Products in Importing Countries and Small-Scale Exporting Countries

2021 ◽  
Vol 13 (3) ◽  
pp. 1251
Author(s):  
Yichi Zhang ◽  
Zhiliang Dong ◽  
Sen Liu ◽  
Peixiang Jiang ◽  
Cuizhi Zhang ◽  
...  
Keyword(s):  
International Trade ◽  
Large Scale ◽  
Prediction Method ◽  
Lithium Ion ◽  
Lithium Carbonate ◽  
Raw Material ◽  
Small Scale ◽  
Trade Restrictions ◽  
Energy Field ◽  
Structure Of Trade

As the raw material of lithium-ion batteries, lithium carbonate plays an important role in the development of new energy field. Due to the extremely uneven distribution of lithium resources in the world, the security of supply in countries with less say would be greatly threatened if trade restrictions or other accidents occurred in large-scale exporting countries. It is of great significance to help these countries find new partners based on the existing trade topology. This study uses the link prediction method, based on the perspective of the topological structure of trade networks in various countries and trade rules, and eliminates the influence of large-scale lithium carbonate exporting countries on the lithium carbonate trade of other countries, to find potential lithium carbonate trade links among importing and small-scale exporting countries, and summarizes three trade rules: (1) in potential relationships involving two net importers, a relationship involving either China or the Netherlands is more likely to occur; (2) for all potential relationships, a relationship that actually occurred for more than two years in the period in 2009–2018 is more likely to occur in the future; and (3) potential relationships pairing a net exporter with a net importer are more likely to occur than other country combinations. The results show that over the next five to six years, Denmark and Italy, Netherlands and South Africa, Turkey and USA are most likely to have a lithium carbonate trading relationship, while Slovenia and USA, and Belgium and Thailand are the least likely to trade lithium carbonate. Through this study, we can strengthen the supply security of lithium carbonate resources in international trade, and provide international trade policy recommendations for the governments of importing countries and small-scale exporting countries.

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