Also known as electronic chemical materials. Generally refers to the electronics industry uses specialized chemicals and chemical materials, that is, electronic components, printed circuit boards, industrial and consumer production and packaging of various chemicals and materials. It can be divided into substrates, photoresists, electroplating chemicals, packaging materials, high purity reagents, specialty gases, solvents, pre-cleaning dopants, flux masks, acids and etchants, electronic adhesives and auxiliary materials Other categories. Electronic chemicals with many varieties, high quality requirements, small dosage, demanding on the cleanliness of the environment, product replacement fast, large capital investment, higher value-added products, etc., these characteristics with the development of micro-processing technology more and more obvious.
Electronic chemicals, also referred to as electronic chemical materials, refer to the fine chemical materials that are used in the electronics industry. The electronic chemicals are a kind of special chemicals. As far as the properties of the production process are concerned, they belong to the fine chemical industry. In terms of product use, Belongs to the electronic material industry. According to the classification standard of China's national economy, the electronic chemicals industry belongs to "Specialized Chemical Products Manufacturing Industry" (2662); according to the "Guidelines for Industry Classification of Listed Companies" promulgated by China Securities Regulatory Commission in April 2001, it belongs to "Specialized Chemical Products Manufacturing Industry" C4360 ). They include integrated circuits and discrete device chemistries, such as chip production photoresist, ultra-clean high-purity reagents, ultra-clean high purity gas, plastic packaging materials; color TV with chemical materials, such as color phosphor, CPT Supporting the water-soluble resist, high-purity inorganic salts, organic films, etc .; chemical materials used in printed circuit boards, such as dry film resist, ink, chemical and electroplating copper plating solution and its additives, surface mount process conductive paste , Cleaning agents, liquid solder resist photoresist, adhesive patch, conductive adhesive, solder paste, pre-coated flux, clean and water-based process flux; liquid crystal display devices with chemical materials, such as liquid crystal, photoresist , Oriented films, adhesives, slurries, electrolytes, films and encapsulants, polarizers, etc .; polishing materials, ect.
Surface Active Agent Tc-1000,Surface Active Agent Tc-2000,Surface Active Agent,Electronic Chemicals Shandong Tiancheng Chemical Co., Ltd. , https://www.akdchemical.nl
Several small secrets affecting pigs' birth and birth weight
The factors affecting litter size and birth weight can be considered from three aspects: genetic perspective, management perspective, and nutritional perspective. Among these three factors, genetics have limited effects on litter size and birth weight. Nutrition can generally be met according to the needs of pigs at different stages. Management is a place where many farms need to be improved and strengthened. Grasping the feeding and management of lactating sows is an important factor in raising the number of litters and birth weight. 1. Influence of genetics Birth weight is an important trait that affects piglet quality and survival. The average birth weight and total birth weight have very high heritability, 0.25 and 0.15, respectively. Most producers know that the low birth weight of piglets and the heterogeneity of litter-born piglets are the major factors affecting pre-weaning losses. The heritability of these factors is also quite high, 0.10 and 0.07, respectively, suggesting that these traits have the potential for genetic improvement. The simple pursuit of litter size may obviously lead to a decrease in birth weight and a decrease in evenness, because litter size is negatively correlated with piglet quality traits. 2. Influence of environmental and nutritional factors The most important factor affecting litter size in environmental factors is temperature. High temperature and high humidity can reduce the litter size, the number of litter-born piglets, and the nutritional status of the first litter sows. Affecting the physiological state of sows, fertilization, embryo implantation, embryonic development and other physiological processes are inseparable from good nutritional status. These physiological processes are also the main factors affecting litter size. Young sows should begin at least 10 days before mating. Feeding high-quality diets and eating freely can maximize ovulation rates and litter size. However, if the young sows are fed too much (over 2.5 kg, days) within 2 to 3 days after the breeding, the embryo survival rate will be reduced. Previous studies have found that pig embryos are rich in arginine. It is particularly evident at 40 days of pregnancy. At this stage, arginine plays a crucial role in embryonic development and survival. Scientists at the University of Texas in the United States have found that adjusting arginine levels during the critical period of pregnancy can increase the number of live births by two. Live births can increase litter weight by 24%. In the case of herding, when the number of herds is too large (more than 20), litter size will be reduced, especially for young sows. 3. Effect of breeding management The weight of young sows at the time of initial deployment can significantly affect the number of litters in the first litter, the birth weight of the piglets, the survival rate and the weaning weight, which in turn determines the number of litters born in the future. Mating options are best when the sow is 0 to 24 hours prior to ovulation (12 hours optimal f) to get the most litter size. In order to determine the timing of breeding based on ovulation, it is important to ascertain the duration of estrus in sows and young sows for young sows. Sexual maturation time (number of estrus cycles experienced) is more important than litter size and weight compared to first-time estrus breeding. Breeding of young sows in the second estrus can increase 0.7 litter size . If the gilt-boring boar first mates the young sow on the first estrus, the second estrus is then mated with the normal boar. The resulting litter size is 0.7 higher than the first estrus unmatched condition. For young sows, the combination of natural mating and artificial insemination is higher than that of litters obtained only by artificial insemination. For adult sows, there is no difference in litter size between artificial insemination and natural mating. 4. Effect of embryo survival rate The early stage of pregnancy is the process of implantation of a fertilized egg into the uterine wall. During this period, the embryo is very sensitive and any stress may cause the loss of the embryo. Therefore, do not transfer sows 28 days before pregnancy. Keep the environment quiet and keep the sows free from disturbances.
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