not the upper. Learn more about not the upper.
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More than 50 kinds of books and 40000 selected books are delivered free of charge.
In order to help you rekindle your enthusiasm for reading paper books, we have carried out a long-term public welfare book delivery activity. As long as you pass on the reading with us, you can get physical books for free and choose what you like in the list below.
2018-09-06 -
Why is the bottom filter better than the top filter?
Insiders all know that the water quality filtered by the bottom filter fish tank is better than that filtered by the upper filter fish tank, but many novice friends may not know, how? My 1.8 meter long upper filter tank is not as good as this 1 meter long bottom filter tank,...
2018-06-02 -
Techniques for making stone bonsai in Sheung Shui
What is Sheung Shui Stone? Shangshui stone is also called absorbent stone (natural air purifier). It is so called because after the water is stored in the basin, it can be sucked to the top in an instant. Stone can plant weeds, moss moss, green and moist, is a good stone for bonsai production. It is probably only the expert who plays with flowers that he knows what the Sheung Shui Stone is.
2019-06-03 -
Strange phenomenon of cotton: young peaches in the middle and upper parts crack ahead of time
Recently, some farmers called to reflect a strange phenomenon in cotton production: the lower big bolls and early cotton bolls grew normally and did not open bolls, while the tender bolls in the middle and upper parts cracked ahead of time, and some of them rotted bolls after cracking. Wuqiao County Agricultural Bureau immediately organized technicians to go deep into the field to find the reason. First, the field showed that the sowing was too early. In the early cotton fields where there were no buds or few buds in the upper 1 and 3 fruit branches due to Rain Water or diseases and insect pests, the number of cracking of cotton peaches in the middle and upper part was relatively large, that is, the outer bolls of 7 fruit branches and 10 fruit branches were counted from below.
2019-01-16 -
Prevention and control methods of silkworm without cocooning
First, the reasons why silkworms do not cocoon: 1. Pathological factors. For example, purulent disease and malacia are easy to be infected before the upper cluster, which destroys the secretory function of silk glands of silkworm, or pathogens produce a large number of toxic metabolites in silkworm body, so that the nerves of silkworms are paralyzed and cannot be cocooned. 2, physiological factors. The first is the abnormality of the central silk gland, mainly because the feeding temperature is too high or too low, the leaf quality is too tender, and the secretory gland is maladjusted, which causes abnormal silk gland, and the second is the abnormal silk gland in the anterior part, mainly because of feeding.
2019-01-16 -
How to catch sparrows? Can sparrows be caught?
In the countryside, catching sparrows is the childhood memory of many people, but how to catch sparrows now? Can sparrows still be caught? 1. Can sparrows still be caught? The sparrow has been included in the IUCN Red list of Endangered species ver 3.1 in 2013.
2020-11-11 Sparrow how can you catch in the countryside catch sparrow yes -
Cocoon collection and sale of silkworm
1. The suitable time for cocoon collection: after the cocooning of mature silkworm, molting and pupation, with the development of pupa, the skin becomes hard and the skin color becomes darker, when the skin color changes to yellow, it is the suitable time for cocoon collection. The spring silkworm period is 6-7 days after the upper cluster. The summer and autumn silkworm period is 5-6 days after the upper cluster, and the late autumn silkworm period is 7-8 days after the upper cluster. The cocoon is picked too early, the silkworm has not yet pupated, the hairy foot cocoon is not easy to be evenly baked during cocoon drying, the cocoon quality is reduced, and the hairy foot cocoon is easy to seep the dirt out of the cocoon layer during cocoon cooking, which makes the color of raw silk worse.
2019-01-16 -
Small seal and great learning
Seal, as an art category with national historical and cultural characteristics, is like a wonderful flower, which continuously exudes a unique fragrance in the broad and profound Chinese art garden, attracting people to enter this inch world. The art of seals.
2018-09-13 -
The reason why silkworms do not cocoon
1. Pathological factors. For example, purulent disease and malacia are easy to be infected before the upper cluster, which destroys the secretory function of silk glands of silkworm, or pathogens produce a large number of toxic metabolites in silkworm body, so that the nerves of silkworms are paralyzed and cannot be cocooned. 2, physiological factors. The first is the abnormality of the central silk gland, mainly because the feeding temperature is too high or too low, the leaf quality is too tender, the secretory gland is maladjusted, and the silk gland is abnormal, and the second is the abnormality of the anterior silk gland. it is mainly due to excessive exposure to bad gases such as gas, fishy gas, alcohol and so on.
2019-01-15 -
How to reproduce the dragon blood tree, the propagation method / pressing or cutting of the dragon blood tree
Dragon blood tree is a perennial plant, but after it has been planted for several years, its basal leaves may fall, resulting in a decline in ornamental value. Flower friends should reproduce it at this time, but some flower friends do not know its reproductive skills.
2018-12-11 -
Pots Selection and Upper Pots of Chinese Cupressus Bonsai
The ground is covered with green cypress branches and leaves, winding and creeping, and suitable for viewing in all seasons. The best viewing effect is when the new branches and leaves sprout in spring. It is not advisable to keep it indoors for a long time during the growth period. The cypress is easy to shape and can be made into a horizontal symmetrical bonsai, which can be placed in the courtyard or reception room for appreciation.
2019-05-23 -
Yuan Huiyi: rhinitis can be diagnosed by itself.
People almost have upper respiratory tract infections such as rhinitis and pharyngitis. For example, in a cold, they are often accompanied by upper respiratory tract infections such as rhinitis. It can also be said to be part of the symptoms of a cold. As the cold improves, most people call.
2018-04-28 -
Introduction to grafting methods of Fruit trees
Introduction to grafting methods of Fruit trees
2019-03-06 -
Basic knowledge of bonsai modeling: bonsai root modeling has knowledge and skill
First, when introducing roots and young trees, cut off the main roots to promote the occurrence of lateral roots, and extend horizontally to adapt to cultivation in a shallow basin. If the larger tree, the root system is thicker, the root system can be fixed with wire, the shape according to the shape of the basin.
2018-05-16 -
Plant material and upper basin for raising orchid on balcony
Plant material and upper basin for raising orchid on balcony
2018-05-04 -
Liwei "irrigation"-- 4 (upper basin)
Liwei "irrigation"-- 4 (upper basin)
2018-04-14 -
Analysis and Countermeasures of hypoxia in cultured Fish
Hypoxia refers to the state in which the internal tissues and cells of fish do not get enough oxygen to maintain their normal function. In order to distinguish from hypoxia in water, it can be called "biological hypoxia" or "tissue hypoxia". Asphyxia (dyspnea) is a phenomenon that occurs during biological hypoxia, and floating head is a common manifestation of dyspnea or asphyxia in aquaculture production. There are two cases of anoxic asphyxia in fish: one is that when the dissolved oxygen in the water is insufficient and the air pressure is too low, even if the respiratory function of the fish is normal, the tissues and cells in the body can not get enough oxygen, resulting in "anaerobic hypoxia";
2019-01-16 -
The technique of high grafting and changing head of planting pear trees in autumn
In the production of grafting time, the high grafting and replacement of pear trees in a large area is generally carried out from early August to late September in autumn, that is, from summer shoot growth to autumn shoot growth. This stage of grafting has the advantages of high survival rate, low cost and good effect, which usually takes only one year.
2020-11-08 Species pear trees autumn high grafting head technology grafting time -
How to trim the bonsai of fruit trees
The excellent works of fruit tree bonsai not only have the harvest beauty of fruit tree cultivation, but also have the artistic beauty of Chinese traditional bonsai, which has its own distinct style and characteristics. When there are too many bonsai branches of fruit trees, it is easy to cause scattered nutrients, lack of internal light, poor fruit quality and so on. Therefore, before the fruit trees sprout in spring,
2019-06-10 -
Architectural layout of Rabbit Farm
Architectural layout of Rabbit Farm
2018-07-04