This document provides important guidelines for caring for bonsai plants, including avoiding choosing plants with large leaves, flowers, or fruits; using styles unsuitable for the species; using blunt cutting tools; unnatural decorations; being impatient for flowers or fruits before shaping; mixing chemicals and fertilizers; keeping bonsai on the ground; tying wire too tightly; retaining wires too long; hard pruning of conifers; heavy fertilization; and unnatural appearances.
Choose plants suitable for the local climate and position them correctly in containers with adequate drainage. Care for bonsai by pruning regularly, providing balanced nutrition with fertilizer, plenty of sunshine, and thorough watering until it drains. Inspect frequently for pests and diseases, and develop a natural-looking design that is well-balanced through constant care and affection.
Planting times for certain crops are February through March and July through August. Seeds can be sown in early spring from February to March or during the summer months from July to August.
The document discusses a demonstration on Juniper bonsai trees that will take place in Columbia. Juniper bonsai are a popular type of bonsai tree that can be styled and shaped through careful pruning and training. The demonstration will cover basic bonsai techniques for caring for and maintaining Juniper bonsai trees.
This document lists the essential equipments and tools needed for bonsai, which includes a plant, pots of various shapes with drainage holes, a potting mixture of soil, sand and leaf mould, potting sticks, sieves, copper wire of varying thickness, wire cutters, pruning knives and secateurs, and watering equipment like a can and tub.
This document lists important plant species for growing bonsai in hilly areas, including Araucaria, Aucuba, Azalea, Camellia, Chinese hat, Coral tree, Cryptomeria, Cypress, Flame of the forest, Ginkgo, Juniper, Koelreuteria, Maple, Magnolia, Plane tree, Peach, Pines, Podocarpus, Sal, Silver fir, Spruce, Taxus, Thuja, Willows, and Zanthoxylum.
This document lists important plant species that are suitable for bonsai, including trees, shrubs, and bamboo. Some recommended species are amaltas, araucaria, babul, bamboo, banyan, ber, bottle brush, bougainvillea, casuarina, cherry, Chinese orange, coranda, cryptomeria, deodar, duranta, excoecaria, gulmohar, hibiscus, ixora, jacaranda, Java fig-tree, murraya, malpighia, oleander, peach, pines, pilkhan, pipal, plum, prosopis, silver oak, tamarind.
Propagation of plants can be done through seeds, cuttings, layering, grafting, or buying seedlings from a nursery. Some plants can also be propagated through collection from seeds or cuttings found in forests or fields.
Selection of plants for bonsai requires choosing species that can thrive in confined spaces with minimal resources. Good options are plants with small flowers and fruits that allow foliage to reduce to a quarter of its normal size, or those bearing flowers on leafless branches. The selected plant must be able to withstand stress from a small pot and low nutrients.
Pruning and trimming helps develop trees into attractive shapes by restricting growth and maintaining a proper balance between roots and shoots. It involves regularly cutting no more than 1/3 of roots or shoots to reduce growth in a controlled manner. Proper pruning techniques help develop good structure and form for trees.
Ideal nutrition for bonsai includes sludge or well rotten cow dung slurry mixed with groundnut, cotton, or neem cake allowed to ferment for a month before diluting. This mixture is given twice a month along with bone meal and single super phosphate, which are also very beneficial.
Growing media for bonsai should be coarse and well-drained to provide water, oxygen, and nutrients. An ideal medium consists of equal parts soil, leaf mold, and crushed brick or sand. The top layer needs sufficient humus, while conifer plants do better in drier soil and fruit trees prefer more humus-rich soil.
This document discusses a landscaping style using cascading plants with variegated star jasmine. Cascade style landscaping features plants hanging over walls or spilling out of containers to create a sense of movement. Variegated star jasmine is recommended as it has green and white variegated leaves and fragrant white flowers that bloom throughout the summer. This combination provides visual interest and fragrance.
This document provides important guidelines for caring for bonsai plants, including avoiding choosing plants with large leaves, flowers, or fruits; using styles unsuitable for the species; using blunt cutting tools; unnatural decorations; being impatient for flowers or fruits before shaping; mixing chemicals and fertilizers; keeping bonsai on the ground; tying wire too tightly; retaining wires too long; hard pruning of conifers; heavy fertilization; and unnatural appearances.
Choose plants suitable for the local climate and position them correctly in containers with adequate drainage. Care for bonsai by pruning regularly, providing balanced nutrition with fertilizer, plenty of sunshine, and thorough watering until it drains. Inspect frequently for pests and diseases, and develop a natural-looking design that is well-balanced through constant care and affection.
Planting times for certain crops are February through March and July through August. Seeds can be sown in early spring from February to March or during the summer months from July to August.
The document discusses a demonstration on Juniper bonsai trees that will take place in Columbia. Juniper bonsai are a popular type of bonsai tree that can be styled and shaped through careful pruning and training. The demonstration will cover basic bonsai techniques for caring for and maintaining Juniper bonsai trees.
This document lists the essential equipments and tools needed for bonsai, which includes a plant, pots of various shapes with drainage holes, a potting mixture of soil, sand and leaf mould, potting sticks, sieves, copper wire of varying thickness, wire cutters, pruning knives and secateurs, and watering equipment like a can and tub.
This document lists important plant species for growing bonsai in hilly areas, including Araucaria, Aucuba, Azalea, Camellia, Chinese hat, Coral tree, Cryptomeria, Cypress, Flame of the forest, Ginkgo, Juniper, Koelreuteria, Maple, Magnolia, Plane tree, Peach, Pines, Podocarpus, Sal, Silver fir, Spruce, Taxus, Thuja, Willows, and Zanthoxylum.
This document lists important plant species that are suitable for bonsai, including trees, shrubs, and bamboo. Some recommended species are amaltas, araucaria, babul, bamboo, banyan, ber, bottle brush, bougainvillea, casuarina, cherry, Chinese orange, coranda, cryptomeria, deodar, duranta, excoecaria, gulmohar, hibiscus, ixora, jacaranda, Java fig-tree, murraya, malpighia, oleander, peach, pines, pilkhan, pipal, plum, prosopis, silver oak, tamarind.
Propagation of plants can be done through seeds, cuttings, layering, grafting, or buying seedlings from a nursery. Some plants can also be propagated through collection from seeds or cuttings found in forests or fields.
Selection of plants for bonsai requires choosing species that can thrive in confined spaces with minimal resources. Good options are plants with small flowers and fruits that allow foliage to reduce to a quarter of its normal size, or those bearing flowers on leafless branches. The selected plant must be able to withstand stress from a small pot and low nutrients.
Pruning and trimming helps develop trees into attractive shapes by restricting growth and maintaining a proper balance between roots and shoots. It involves regularly cutting no more than 1/3 of roots or shoots to reduce growth in a controlled manner. Proper pruning techniques help develop good structure and form for trees.
Ideal nutrition for bonsai includes sludge or well rotten cow dung slurry mixed with groundnut, cotton, or neem cake allowed to ferment for a month before diluting. This mixture is given twice a month along with bone meal and single super phosphate, which are also very beneficial.
Growing media for bonsai should be coarse and well-drained to provide water, oxygen, and nutrients. An ideal medium consists of equal parts soil, leaf mold, and crushed brick or sand. The top layer needs sufficient humus, while conifer plants do better in drier soil and fruit trees prefer more humus-rich soil.
This document discusses a landscaping style using cascading plants with variegated star jasmine. Cascade style landscaping features plants hanging over walls or spilling out of containers to create a sense of movement. Variegated star jasmine is recommended as it has green and white variegated leaves and fragrant white flowers that bloom throughout the summer. This combination provides visual interest and fragrance.
1. CHAPITRE 1. OPTIQUE CLASSIQUE 1.3. LA RÉFLEXION
Fig. 1.4 Le miroir sphérique
On remarque que les rayons rééchis, en traits pleins,
ne se croisent pas en un même point sur l'axe optique :
il n'y a pas de foyer.
b
b
a
a
axe optique
Fig. 1.5 Le miroir parabolique
On remarque que les rayons rééchis se croisent en un
même point sur l'axe optique : il y a un foyer.
Foyer
Sphérique
Parabolique
axe optique
gence des rayons sur un miroir sphérique n'est que
partielle : les rayons parallèles à l'axe optique par-venant
aux bords du miroir sont rééchis sur l'axe
optique plus près du miroir que ceux parvenant plus
au centre du miroir (voir gure 1.4).
1.3.4 Le miroir parabolique
Par contre, avec un miroir parabolique, les bords
du miroir étant plus aplatis (voir gure 1.5) que pour
un miroir sphérique, ils permettent aux rayons pa-rall
èles à l'axe optique qui les frappent de converger
vers un même point que ceux du centre. Ce point est
désigné par le terme de foyer du miroir. Ainsi, un mi-roir
parabolique possède un foyer, au contraire d'un
miroir sphérique.
Il existe évidemment beaucoup d'applications aux
miroirs paraboliques. Elles sont présentées aux pa-ragraphes
suivants. Remarquons que les miroirs pa-raboliques
ne sont pas facile à construire. Mais, en
bonne approximation, le centre d'un miroir sphérique
est parabolique. Il s'agit donc de construire des mi-roirs
très plats.
1.3.5 Le télescope
C'est un excellent exemple de miroir parabolique.
Pour des raisons que nous verrons plus tard, l'ob-servation
des étoiles est facilitée par l'utilisation de
télescope (comportant des miroirs), par opposition à
celle de lunettes (comportant des lentilles). Dans les
télescopes se trouvent en eet deux miroirs. L'un est
dit secondaire et est plat et l'autre dit primaire est
parabolique. La gure 1.6 présente la situation. Les
rayons provenant du ciel sont tout d'abord rééchis
sur le miroir (qui joue le rôle d'un objectif) parabo-lique
en direction du miroir secondaire. Ce dernier
transforme l'image du miroir (notée image virtuelle
de l'objectif sur la gure 1.6) en une image de même
taille dans la direction de l'÷il (notée image réelle
de l'objectif sur la gure 1.6). Cette image est nale-ment
agrandie par un oculaire qui jour le rôle de loupe
pour donner l'image nale (notée image virtuelle de
l'oculaire sur la gure 1.6).
Le phare de voiture
De nos jours les phares des voitures sont munis
de réecteurs qui ne sont pas paraboliques. Ils sont
construits sur la base de la loi de la réexion pour
éclairer sélectivement certaines parties de la route.
Pourtant les anciens phares étaient de forme parabo-lique
et l'ampoule se trouvait au foyer de la parabole
de manière à ce que les rayons rééchis soient envoyés
vers l'avant parallèlement à l'axe optique.
La lampe de poche
De la même manière une lampe de poche est munie
d'un réecteur plus ou moins parabolique qui dirige
les rayons parallèlement à l'axe de la lampe.
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