http://www.runyvmat.com/As the industry leader in phosphine ligands and catalysts for homogeneous catalysis, Solvay offers a range of phosphorus compounds used in a breadth of applications and markets. Our scalable phosphorus chemistry meets the unique requirements of reactions that are crucial to several manufacturing processes across markets and applications, including petrochemicals, life sciences, flavors and fragrances, agrochemicals, fine chemicals, and plastics and other polymers. And do you what is Phosphine Ligands? Phosphines are a three-valent phosphorus compound and act as a "soft" σ-donating ligand with an unshared electron pair. This gives solubilization and stabilization to organometallic complexes by forming complexes with various transition metal species including latter-period transition metals and others, and is also used for controlling the reactivity and selectivity of the transition metal promoted reactions. Electron density and bulkiness of phosphine ligands are greatly related to the reactivity of their forming metal complexes. Generally, the phosphine ligands with high electron density increase the reactivity of oxidative addition from a metal center, and their bulkiness improves the reductive elimination. For example, trialkylphosphines especially tert-butyl or cyclohexyl group substituted phosphines show the highest electron density while the electron density of triarylphosphines and phosphite are sequentially decreasing. On the other hand, as an index of the bulkiness of phosphine ligands, that of monodentate phosphine ligands shows the cone angle (θ) while bidentate phosphine ligands show the bite angle (ω). As the angle of the phosphine ligands is wider, their steric effect is greater and they are regarded as more bulky phosphine ligands. A monodentate phosphine ligand of tri(o-tolyl)phosphine, and bidentate phosphine ligands of 1,1'-bis(diphenylphosphino)ferrocene and Xantphos are known as representative bulky phosphine ligands. There are many different kinds of Phosphine Ligands, such as Chiral Phosphine Ligands, Chelated Phosphine Ligands, Biaryl Phosphine Ligand, Trisubstituted Phosphine Ligands and Other Phosphine Ligands. Homogeneous catalysis is an efficient alternative to its heterogeneous counterpart, and enables access to certain molecules that are not accessible through heterogeneous catalysis. Our high-performance phosphine ligands provide endless customization opportunities for catalytic processes. Phosphorus chemistry offers substantial diversity of structure, tunability and thermal stability, which leads to its use in many essential industries and an abundance of applications. A majority of Solvay's phosphorus technologies are available in liquid or solution form, which facilitates ease of handling and safe product stewardship. Solids are available if preferred. Produced via industry-recognized manufacturing processes, our phosphine ligands and catalysts can be manufactured at any scale. Solvay offers expertise and manufacturing wherewithal at any phase of the value chain, but specializes in developing ligand solutions from the initial R&D stage all the way to industrial-scale production and distribution. Except for Phosphine Ligands, there are also many other material Intermediate and Function Materials like Catalyst including Homogeneous Catalyst and Olefin Copolymerization Catalyst. posted an update 1년, 7개월전
http://www.hongkingled.com/What is LED?
LED is short for Light Emitting Diode. An LED emits light as a result of electric luminescence. It is also known as “cold light” as, unlike with old-fashioned incandescent bulbs, the light is not produced by heating a metal filament. The diode, on the other hand, emits light when flowing through two specially coated silicon semiconductors. It is one of the most energy-efficient and power-saving ways to produce light.
An LED consists of solid materials without movable parts and is often moulded into transparent plastic. This ensures high durability. When an LED is on, it emits almost zero heat. This reduces the problem of cooling the electronic parts.
The first LED was created by Russian inventor Oleg Losev in 1927. For many years, it was only possible to produce infrared, red and yellow LEDs. These diodes were found in everything from remote controls to clock radios. It was not until 1994 that Japanese scientist Shuji Nakamura was able to demonstrate an efficient blue LED. White and green LEDs soon followed, laying the foundation for the LED revolution we have seen in lighting and display technology.
What is an LED Display?
An LED display is a video display made up of light-emitting diodes, or LEDs. LEDs are small electronic devices which produce a very efficient light source. They are widely used in everyday devices from traffic lights to remote controls. Many LED displays are used outdoors in billboards and store signs.
A typical LED display is composed of many LED panels, which are sometimes used as a form of lighting or illumination rather than for display. Two classes of LED panels exist: conventional LED panels, which use discrete LEDs, and surface-mounted device (SMD) panels. Conventional panels are the more common of the two, especially for large outdoor display screens. In this type of LED panel, clusters of red, green, and blue LEDs are grouped together to form numerous square-shaped pixels.
How does an LED Display work?
An LED display consists of many closely-spaced LEDs. By varying the brightness of each LED, the diodes jointly form an image on the display.
To create a bright colour image, the principles of additive colour mixing are used, whereby new colours are created by mixing light in different colours. An LED display consists of red, green and blue LEDs mounted in a fixed pattern. These three colours combine to form a pixel. By adjusting the intensity of the diodes, billions of colours can be formed. When you look at the LED screen from a certain distance, the array of coloured pixels are seen as an image.
There are many types of LED players in the market nowadays, such as MINI LED Display, COB LED Display, GOB LED Disolay, Ultra HD LED Display, Rental LED Display, Indoor Rental LED Display, and Outdoor Rental LED Display. And they may be used together with LED Modules including Indoor LED Module, Outdoor LED Module, Spherical LED Display, etc.