Reaction Diagram Analysis of Flux and Gold Plating
When analyzing the reaction mechanism between the flux and the gold plating layer, it was necessary to consider the situation of different bottom gold plating. For the mainstream method of nickel-based gold plating, during the welding process, the actual welding layer was related to the bottom layer of nickel-based alloy, that is, the tin alloy and nickel-based alloy formed a metal compound (Sn-Ni <2> compound). However, the purity of the gold-plated layer, the rate of voids, and the cleanliness of the surface directly affected the solderability of the contact body. When there was a nickel-plated bottom layer, the inertia of the nickel-plated part was higher than that of the gold-plated part, which could ensure a higher resistance to atmospheric corrosion. During welding, the flux and the bottom layer of nickel-plated part would have a smelting reaction, and the gold-plated layer might affect the welding process due to its own characteristics, but it was not the main reaction layer. As for the gold plating on the copper base, the copper base had a certain role in the welding. The copper ions easily penetrated into the gold coating and caused the gold coating to change color. Moreover, the copper coating was easy to be deactivated in the air and affected the cohesion of the gold coating. When the flux was in contact with the gold-plated layer of this structure, on the one hand, it had to deal with possible problems such as the possible oxidization of the copper surface to achieve good welding. On the other hand, the gold-plated layer was affected by the change of the copper layer and showed different solderability during welding. However, this method was rarely used at present. As for the silver plating, due to the lack of sufficient information, it was difficult to accurately analyze the reaction principle between the flux and it. It was only known that when the silver plating layer was contaminated, the black color would appear through the pores of the coating. This process was rarely used (except for special requirements). Generally speaking, when the flux was used in the welding process related to the gold-plated layer, it would be affected by the properties of the underlying metal under the gold-plated layer and the characteristics of the gold-plated layer (such as purity, voids, cleanliness, etc.). The reaction principle of the gold-plated layer and the flux with different underlying structures would have different performances in the welding process. The smelting change of the underlying metal during the welding was a more critical part, but the characteristics of the gold-plated layer could not be ignored. Under the joint action of many factors, the welding effect would be affected. Read more exciting novels for free
Diagram Analysis of Vulcanization Reaction
The principle of rubber curing was to heat a mixture of rubber and sulfur or other curing agents, so that the sulfur reacted with the double bonds in the rubber to form a cross-linked structure. During the operation of the flat-plate curing machine, the hot plate raises the temperature of the rubber compound and causes the rubber molecules to cross-link. Its structure changes from a linear structure to a net-shaped structure. This process can obtain products with certain physical and mechanical properties, but the rubber compound will begin to soften after being heated. At the same time, the moisture and volatile substances in the rubber compound will be vaporized. From a microscopic point of view, the rubber curing system had its own cross-linking mechanism. Peroxides were compounds containing O-O bonds. This peroxidic bond broke down when heated to produce free radical (the breaking of this bond was called homolytic cleavage because the two electrons in the bond were separated). This free radical had a high reaction activity and was the driving force behind the cross-linking of the compound. Peroxides undergo homolytic cleavage, forming two alkoxy free radical, which takes hydrogen atoms from the chain of the compound. The free radical of the two adjacent chains combine to form a carbon-carbon bond, which is an important feature of the cross-linking of peroxides. In these three steps, the one that determined the speed was the homolitic cleavage of the peroxide-based molecules, which usually took a few seconds to a few minutes (thermal dispersion was usually an important factor). After the formation of the highly active free radical, the next step of the reaction could be completed in a few seconds or even less. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Gold Plating Technique
The common gold plating process was as follows: ** 1. Electroplating process ** 1. ** Deconstruction and cleaning ** - Alkaline washing: Use an alkaline solution such as a solution of soda to remove organic matter such as grease. - Acid washing: use sulfuric acid, sulfuric acid and other acid cleaners to remove the metal surface of the rust layer and rust. - Washing with water: removing the residue after the alkali-washing and acid washing. 2. ** Undercoat ** - selecting Ni, copper, and the like as the plating base material, using the object to be plated as the negative pole, Ni or copper as the positive pole, and dissolving the positive pole through the current in the bath to form a plating base layer on the surface of the object to be plated. The methods of plating the base layer include plating, chemical plating, and the like. 3. ** Gold Plating ** - Metal gold was used as the material, and the metal gold of the positive pole was dissolved and plated on the negative pole (the object that had been plated) through the current in the bath. The thickness of the gold plated layer could be adjusted from a few millimeters to dozens of millimeters according to the needs. 4. ** Electrolyte adjustment ** - The composition and process conditions of the Electrolyte were adjusted. The commonly used Electrolyte components were acidic cyanide-based Electrolyte and alkali-based Electrolyte to ensure that the coating was uniform, smooth, and stable. 5. ** Post-processing ** - Washing: Remove any remaining liquids. - Neutralization: Neutralize acidic and acidic residue. - Dry: Remove moisture. - [Polishing: Makes the gold-plated layer brighter and smoother.] ** 2. Electroless Gold Plating Technique ** - The product that needed to be gold-plated was placed into the gold-plating solution. The melted gold atoms reacted with the chemical to form a gold-plated layer on the product. The chemical gold-plating did not require a direct power supply. ** 3. Other gold-plating process examples ** 1. ** Copper and Brass Gilding ** - Using organic liquids to remove oil: Use gasoline or carbon dioxide to remove the oily stains on the electronic components. - Supersonic chemical oil removal: This step is carried out after the oil removal with organic solution is completed. - Washing: Hot water, cold water, acid washing (a mixture of sulfuric acid, nitric acid, and water), and soaking in a solution of soda. - Gold plating: Use a gold plating solution that contains gold potassium cyanide and potash to carry out gold plating. - Washing and drying: Wash with ultrasonic agitation in purified water at 70 - 80 ° C (the electrical conductivity of purified water should be less than 10us/cm) for no less than 10 minutes, and finally dry. 2. ** Phosphor Bronze Gilding ** - Gasoline to remove oil stains: First, use gasoline to remove the oil stains on the electronic components. - [Supersonic chemical oil removal: This step will be carried out later.] - Washing and acid washing: hot water, cold water, and acid washing. - Gold Plating: Use a gold-plating solution containing gold potassium cyanide and potash to plate gold. 3. ** Gold-plated process of special golden finger lead wire (a special case)** - The processing of the printed circuit board (PC) was to form a connection module with broken gold-plated leads on the outer circuit. - "Ink resistance printing: Print a carbon ink resistance between the connecting modules at both ends, and use the carbon ink resistance to conduct the connecting modules at both ends. - Gold-plated: Use the connection module and carbon ink resistance to gold-plate the predetermined gold-plated pad position of the printed circuit board to complete the production of the golden finger. There were the following steps to recover and refine the gold-plated waste: - To prepare the gold removal powder, add the gold removal powder into hot water, stir it to accelerate the dissolution, and let it settle. - Gold removal: The electronic waste was added to the gold removal water, and the agitation accelerated the gold removal. - Acid adjustment: After removing the gold, add lemon acid to adjust the acid. Stir to accelerate the dissolution and test the acid. - "Substitute oxidization: Add in the zinc-wire, and after two hours of substitution, it will be oxided. Then, add in the solute to start the oxidization. - Impurity removal: such as adding impurity removal agent, heating to remove impurities, cleaning sponge gold, etc. In addition, there was another gold-plating process, which was three spraying and two baking, that is, spraying the primer → drying → spraying the reaction layer → spraying the topcoat → drying. The novel "Gilded Palm" is equally exciting. Everyone is welcome to click and read it!
The usage of gilding and gold-plating
Gold gilding and gold-plating were essentially the same process. The first step was to prepare the gold amalgam. First, the gold had to be thinned and cut into pieces, then placed into a pre-heated crucible, and then injected with mercury. The ratio of gold to mercury was 1:5 - 1:7, so that it was mixed into a paste. During this process, the surface of the object needed to be cleaned with an acid and base solution. Then, it was time to apply the gold. The gold amalgam was evenly applied to the surface of the object (such as bronze). Next was to crack the gold. By baking the plated object, the mercury would evaporate and the gold would remain on the surface of the object. Finally, it was calendering to make the coating more dense and bright. When the operation was done, the color of the coating could remain unchanged for a long time. This kind of craft could be used to decorate building components such as copper and iron and various utensils. In ancient times, apart from being used on the surface of utensils, it was also used to gild weapons. The entire process usually needed to be repeated about three times, but to achieve a better gilding effect, it was common to repeat it five to seven times. The novel "Gilded Palm" is equally exciting. Everyone is welcome to click and read it!
Analysis of the reaction process diagram of reducing hydrogen and methyruvic acid
In the process of oxygen free breathing, the reduction of hydrogen and the reaction of Ruvic acid could produce actic acid. In addition, the reaction of Ruvic acid with the reduction of hydrogen could produce alcohol, but not Ruvic acid. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Diagram of the Inhibition Reaction
The principle of the inhibition reaction can be divided into competitive inhibition and non-competitive inhibition: 1. ** competitive inhibition **: A competitive inhibition agent will compete with the base for the active site of the protein, thereby suppressing the activity of the protein. In this case, both the initiator and the reagent could bind to the active site of the reagent. Due to the existence of the initiator, the chances of binding the reagent to the reagent were reduced, resulting in a decrease in the rate of the reaction. 2. ** Non-competitive Inhibition **: A non-competitive inhibition agent will bind to a site other than the active site of the protein, thereby suppressing the activity of the protein. This binding method changed the structure of the protein, which reduced the affinity of the active center of the protein to the protein. Even if the concentration of the protein increased, the reaction rate of the protein would not increase. For example, in the pesticide residue detection method, the target pesticide's inhibition of a specific reagent was an inhibition reaction. The specific reagent could catalyze the conversion of the reagent into a reagent when there was no pesticide. If the test sample contained the target pesticide, the pesticide would interact with the reagent to inhibit the activity of the reagent, thereby indirectly determining the level of pesticide residue in the sample. Also, in terms of whiteness, 4 -Butylated Resorcinol (577) mainly achieved whiteness and freckles by suppressing the activity of "Tyrosinase" and "Trp - 1." The inhibition of "Tyrosinase" may involve the principle of competitive or non-competitive inhibition. When constructing a nanoase sensor array to detect substances, for example, using 2D-MOF nanoase to detect phosphorus, the inhibition of phosphorus on the activity of 2D-MOF peroxide-like was also an inhibition reaction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Reaction Diagram of Alkane and Halogen
There were several reactions between the two: 1. ** Substitute Halogenation **: - ** Substituted Halogenation on Aromatic Ring **: It is suitable for aromatic compounds. During the reaction, the hydrogen atom on the aromatic ring is replaced by a halo atom. - ** Aromatic ring side chain and fatty carbon substitution: For aromatic ring side chain and fatty carbon, the hydrogen atom in the structure can be replaced by a halo atom. Among these substitution and substitution, chloride-bromination was more common. 2. ** addition reaction **: An addition reaction between an unsatured carbon (such as a carbon-carbon double bond or a carbon-carbon triple bond) and a single substance such as a halo, hydrogen, etc., thereby introducing a halo atom into the unsatured carbon molecules to form a halo carbon. For example, when an alkene reacted with a single substance, the carbon-carbon double bond would be broken, and two halo atoms would be added to two carbon atoms. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Reaction Diagram of Oxidants and Reductants
When an oxidiser and a reducing agent react, the following relationship exists: the oxidiser obtains electrons, and the valency of the elements contained in it is reduced, resulting in a reduction reaction. The oxidiser itself is reduced to produce a reduction product; the reducing agent loses electrons, and the valency of the elements contained in it increases, resulting in an oxidiser reaction. The oxidiser itself is oxided to produce an oxidiser product. It could be simply represented by the following graph: |reactant| reaction type| Electronic gain and loss| change in valency| product| |----|----|----|----|----| |oxidizing agent| reduction reaction| de electronics| lower| reduzate| |reducing agent| oxidizing reaction| betatopic| rise| oxidative product| For example, in the reaction of burning carbon in oxygen (C + O ^== CO ^, ignition), carbon C is a reducing agent. It loses electrons, and its valency increases from 0 to +4, and is then oxided to carbon dioxide (as an oxided product). As an oxidiser, oxygen O ^is an oxidiser, and it gains electrons. Its valency decreases from 0 to-2, and it is reduced to oxygen in carbon dioxide (as a reduced product). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Analysis of Portrait Photographic Diagram
There are many composition structures in portrait photography. The following is your analysis: 1. * * Simple portrait composition ** - [Close-up and Chest Portrait (1): Capture the upper or lower part of the chest. The focus is on showing the expression and demeanor of the character. Pay special attention to the angle of the face when shooting.] - * * Half-body Portrait (2)**: The image was captured above the hip bone. In addition to the expression and facial angle, the position of the arm also needed to be taken into consideration. - * * Seven clones (upper body, 3)**: Cut off the upper part of the knee, and design a beautiful posture for the thigh, upper body, and arms. - * * Nine Separations (4)**: Capture the upper part of the ankle. It is usually used when it is not suitable to take a full-body photo. It can be used to hide the actual height. - [Full-body Portrait (5): Arrange the position of each joint from the feet up. Every detail of the whole body must be considered.] - * * Landscape Portrait (6)**: It is a portrait with an environment or background. In addition to meeting the above requirements for a simple portrait composition, it also needs to consider the environmental background factors. Exterior, documentary photography, news photography, and other compositions mostly belong to this category. The composition methods are more complicated. - * * Basic rules **: Joints (such as knee joints, elbow joints, fingers, etc.) and overall organs (such as chest, buttocks, etc.) cannot be cut in the middle. In 90% of portrait compositions, the space above the head of the character should be larger than the space in front of the feet, and the space in front of the feet should be as small as possible. 2. * * Center composition ** - [Version 1.0: Equalized Symmetries][Commonly used for shooting ancient buildings and portraits.] Usually, the model's left and right hands and legs had to move in unison to achieve left and right symmetrical movements. It was also suitable for taking pictures of people's backs, but it required a simple background. When there is a horizontal line or horizon in the background of the photo, it is necessary to avoid "crossing" the important parts of the model's body. You can weaken the lines through illusory processing or avoid these lines when framing. The middle composition could also be shot in a symmetrical manner, using the reflection images of the street after the rain, the square that had been sprinkled with water, and the shiny floor. - * * Version 2.0: Large areas are symmetrical, small areas are not symmetrical **: On the basis of maintaining the large areas of symmetrical, the details can be symmetrical. For example, the model's face was facing left and the skirt was floating to the right, or the model and the props (such as fans) were used to balance each other to make the photo vivid and not stiff. The middle composition did not mean that the composition was absolutely symmetrical. When shooting a portrait in a natural environment, the model's movements did not have to be exactly the same. 3. Diagonal composition: The two opposite corners are connected into a line and extend, using this as the basis for composition. 4. * * Nine Palace Box: Divide the picture into nine parts, and the character is located at the intersection of the four parts as the better portrait position. 5. * * Triangle composition **: Usually used when shooting while sitting, the portrait poses in a triangular shape. 6. [Close-up composition (incomplete composition)]: It was more commonly used for close-up portraits. 7. * * frame composition **: Clever use of the frame structures such as the doors and windows around you to create the interaction between the character and the frame. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Sulfur and Metal Reaction Formula and Phenomenon Diagram
The following is a summary of the equations and phenomena of the reaction between sulfur and metals: 1. ** Sulfur and Iron Reaction ** - The equation is: FeS ${stack}{triangle}{=}=}$ FeS (Iron Sulphide, dark brown) - [Phenomenon: Iron powder and sulfur powder are mixed and heated to red heat. The reaction produces a black solid that releases a lot of heat.] 2. ** Sulfur and Copper Reaction ** - The equation: 2Cu + S $\stacking rel {\triangle}{=\!=}$ Copper Sulfur (black) - [Phenomenon: The reaction produces a black solid.] 3. ** Sulfur and mercury react ** - Formula: Mercury + S = HgS (Mercury Sulphide, black) - [Phenomenon: The reaction produces a black solid.] In general, when sulfur reacted with metals, sulfur showed its oxidisation, while metals showed its reduction. The reaction formed a black solid. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Gold Market Analysis
As of 10:32 on December 15,2024, the current international gold price was 2649.01 USD/ounce, which was stable compared to yesterday. On December 12th, the gold price of a certain brand store reached 823 yuan/gram, and the gold futures rose again for four consecutive days, setting a new high in the past two weeks. The global economic uncertainty intensified, the frequent occurrence of geographical risks, and the decline of investors 'confidence in risky assets made gold's risk-averse nature prominent. Its multiple attributes such as preservation and anti-inflationability could provide investors with stable returns in times of market turmoil. The increase in investor demand for risk-averse assets such as gold would push the price of gold up. The Federal Reserve's interest rate cut policy would reduce the attractiveness of the US dollar and thus push up the price of gold. However, factors such as the slowing US economy and the rise in inflated pressures would also increase the fluctuation of gold prices. In addition, central banks around the world increased their gold purchases, which was also the main driving force behind the global gold price surge of more than 30% since 2024. Although the price of gold may be affected by a variety of factors in the short term, the trend of strength in the medium and long term remains unchanged. The novel "Small Business" is equally exciting. Everyone is welcome to click and read it!