1. Is it useful to fish sunscreen?

fishing out of summer, the most worrying about fishing people is the problem of Sun protection.Of course, it is ideal to find a cool place to fish.There are many good ways about fishing and sunscreen in summer. Plasizables and sunscreen are an effective sunscreen method that we often adopt.So is it useful for Fishing sunscreen?

The effect of sunscreen is mainly to directly block the exposure of UV on the Skin.Reduce ultraviolet damage and radiation to the Skin.It can be said that as long as the Fishing sunscreen is covered with your Skin, it still has a certain effect, but it is still small and small depending on the material.

2. What material is good for fishing sunscreen clothes?

As mentioned earlier, fishing sunscreens will be large and small according to the different materials. So what material does the Fishing sunscreen suit be good?

1. Ranking of sunscreen effect: polyester cloth & gt; composite cloth & gt; ice silk fabric

From the perspective of sunscreen effect, polyester cloth is undoubtedly the best, so it is the main material of sunscreen fishing clothes on the market.Don't look at polyester fabrics are common and cheap, but its sunscreen effect is specified!But unfortunately, polyester fabrics are poorly wet and not breathable.Polyester cloth used to make fishing clothes is generally deliberately woven into mesh to breathe.

2. Ranking of breathable effects: composite cloth & gt; ice silk cloth & gt; polyester fabric

From the perspective of the breathable effect, the composite fabric is the best, followed by ice silk fabric, and the polyester fabric is the worst.The so -called composite cloth is actually a compound fabric for two layers.Generally, the outer layer is a polyester large pore mesh for sunscreen. The inner layer is easy to discharge. Generally, this type of fishing clothing will indicate the material of the fabric and the linked.

It is worth noting that although the breathability of the polyester fabric itself is poor, its blended fabric breathability is different.For example, the commonly common bamboo charcoal fabric on the market is based on polyester, which is woven after weaving bamboo charcoal fibers.This blended fabric uses the advantages of bamboo charcoal breathable, dehumidification, anti -bacterial, deodorization, and the disadvantage of polyester fabrics not only has good sunscreen effect, but also feels soft.It's just a little expensive.

3. Wear comfort ranking: ice silk & gt; composite cloth & gt; polyester

To be honest, comfortable clothes are always one of the most important wearing standards.Ice wire is an ecological fiber, with the advantages of cotton cloth and silk. It is thin, breathable, elastic, soft, and the Sun protection effect is also acceptable, and it will feel a hint of coolness, which is very comfortable.

Therefore, these three material fishing sunscreens actually have their own strengths. When choosing, you can start according to your needs.

[Telescope parameters] Astronomical Telescope optical parameters explain in detail how to see the astronomical Telescope parameter

The caliber of the objective mirror (D)

The diameter of the objective mirror is the most important parameter of the Telescope. Generally, it refers to the effective diameter, that is, the diameter of the light, that is, the diameter of the incident pupil of the Telescope. It is the main symbol of the Telescope conservation, not the diameter of the glass of the lens.Generally, it is represented by an inch (in) or millimeter (mm). The larger the diameter, the more light it collects, and the better the brightness and sharpness of the imaging.

(Note: 1 in = 25.4 mm)

Cumping (Ji Guangli)

This is the ability to collect light compared with the eyes to collect light compared to the eyes.It is directly proportional to the area of the caliber.First, the caliber (unit: mm) of the Telescope is divided by 7mm (the size of the eyes of the young people's eyes), and then the obtained commercial Square is the result of the light.For example, the light power of the 8 -inch Telescope is 843 ((203.2/7) = 843).

Focus (F)

The distance from the lens (or main reflector) to the focus, usually the unit is millimeter (mm).Generally speaking, the longer the focal length of the Telescope, the larger the magnitude, the larger the size of the imaging, but the smaller the field of view.For example, compared with a Telescope with a focal length of 1000mm, the magnitude and field range of the 2000mm focal length Telescope are 2 times and 1/2 of the former, respectively.If you do nt know the focal length, you only know the Focal Ratio, you can get the focal length by calculating: the caliber (the unit is MM) by the coke ratio is the focal length.For example, a lens with a diameter of 8 inches (203.2mm) and a coking ratio is F/10, and its focal length is 203.2 x 10 = 2032mm.

Relators (A) and Jiao Bi (1/A)

The ratio of valid diameter D to the focal length F is called relative diameter or relative aperture A, that is, A = d/f.This is a sign of the light mirror light power, so sometimes A is light power.Comet, nebula or galaxy, etc. The imaging illuminance of the surface celestial body is proportional to the Square (A2) of the relative caliber; the so -called linear celestial imaging illumination and relative caliber D (D2/f) of the so -called linear celestial body imaging such as meteor or artificial satellite (D2/F)Propopy.Therefore, when making celestial photography, pay attention to choosing a suitable A or Coking 1/A (that is, F/D. The camera is called the number or coefficient of the aperture).

Distinguish

For the Telescope, it refers to Dawes Limit.That is, the ability to separate two stars with a very close distance, the unit is angle seconds 1 (sex of Arc).The resolution ability is directly related to the caliber, that is, the greater the diameter, the better the resolution ability.The theoretical resolution ability of the Telescope is 4.56 Apart from the diameter (unit: inches) of the Telescope.For example, the resolution ability of a Telescope with a diameter of 8 -inch is 0.6 (4.56/8 = 0.6).However, the discerning ability is also related to the atmosphere and the visual acuity of the observer.

Contrast

Observe low -contrast objects, such as the moon and the planet, we expect the highest imaging contrast.The Newton Telescope and reflection refraction Telescope have a secondary reflex mirror (or auxiliary mirror), which blocked the launch light of some main reflective mirrors.Unless more than 25% of the main reflectors are blocked, the contrast of imaging will not be greatly affected.In order to calculate the secondary blocking rate, the formula (Pi) R can be used to calculate the area of the primary and secondary reflex lenses.Then it can be eliminated.For example, if the diameter of the 8 -inch Telescope is 2 inches, the blocking rate is 11.8%:

8 -inch main area = (pi) r = (pi) 4 = 50.27

2 -inch secondary area = (pi) r = (pi) 1.375 = 5.94

The blocking rate = 5.94 is 11.8% of 50.27

Observation conditions (atmospheric disturbances) are the most important factor affecting the contrast and planet details.

Airy Disk Brilliance Factor

When you look at the stars with a good Telescope, you don't see a bigger image.This is because the distance from the stars to our distance is too far (so that the light emitted is parallel light, and it is directly gathered in the focus of the plane), so even if it is enlarged many times, the stars should look like light spots, not, not, notLight spots or light balls.However, if the Telescope mirror is enlarged to the multiple of the 60 -diameter size (unit: inch), if you look closely at this time, you will find that there is a halo around the stars.The physical characteristics of the lapse and light.For further observation, when the stars are located in the middle of the Telescope vision, two phenomena will appear in the magnifying star map: a bright area in the middle, called Eli spot, and a weak ring surrounded by or or a series of surrounds.Diffraction ring.

When you increase the size of the caliber, the Eli spot will become smaller.The brightness of Eli (the image brightness of the light source star) is proportional to the four squares of the diameter size.Theoretically, when you double the diameter of the Telescope, its resolution ability will double, and its collection of light will increase by 4 times.But more importantly, you can also turn the area of the Eliga into 1/4 times, thereby turning the brightness of the astrology into 16 times.

Out of light

The output of the Telescope refers to the diameter of the round beam of the eyepiece, and the unit is MM.In order to calculate the pupils, the caliber (unit MM) can be divided by the magnification of the eyepiece.For example, a magnification of a Telescope with a diameter of 8 inches (203.2mm) with a 20mm eyepiece mirror is 102, then its pupil is 2mm (203.2/102 = 2mm).Alternatively, you can also get the focal length of the eyepiece to get the pupil size with the coking of the Telescope.

Magnification

The amplification multiple is one of the most important parameters of the Telescope.The magnification of the Telescope is actually the ratio of the focal length of two independent optical systems -telescopic mirrors and the used eyepiece.

The focal length (unit: MM) of the Telescope mirror can be obtained by the zoom distance (unit: MM) of the eye mirror to get the magnitude of the Telescope.For example, the focal length of the Telescope with a model C8 is 2032mm. If you equipped with a 30mm eyepiece, the magnifying rate is 68X (2032/30 = 68)..Because the eyepiece is replaced, the Telescope can have different magnification as needed.

In actual use, the Telescope has an upper and lower limit amplification rate.This is determined by the characteristics of optical and eyes.In ideal, the maximum magnification available for the Telescope is about 60 times its diameter size (unit: inch).If the increase rate exceeds this upper limit, the image often becomes dim, and the contrast is reduced.For example, the maximum magnifying rate of a Telescope with a diameter of 60mm (that is, 2.4 -inch) is 142X.When the magnification continues to increase, the sharpness and details of the image will decrease.The higher magnification is usually used for the observation of the moon, planets and Gemini stars.Those manufacturers who call the 60mm caliber Telescope can reach 375 or even 750, which is actually misleading consumers.In the evening, the lower limit of the long mirror amplification rate is 3 to 4 times the caliber.The lower limit during the day is 8 to 10 times the caliber.If the amplifier rate is lower than this lower limit, due to the projection of the secondary reflex mirror or oblique mirror, a black spot will appear in the center of the reflection refraction Telescope or Newton Telescope.

Extreme stars, etc.

On the sunny night, use Telescope to observe the darkest star near the ceiling, etc., called the extreme star (MB). Extreme stars and other effective caliber, relative caliber, the absorption coefficient of the objective mirror, and the atmospheric absorption of the atmospheric mirrorThe system is related to various objective factors such as the brightness of the sky background, and it is also related to the visual sensitivity of the observer.The experience expression given by different authors is slightly different.The simpler estimate is MB = 6.9 5LGD. D is used in CM as a unit. For photographic observations, extreme stars, etc. are also related to dew time and negative characteristics.There is a commonly used experience formula: MB = 4 5LGD 2.15LGT type T is the limit exposure time, regardless of the negligent law of mutual failure, and does not consider the impact of urban lighting.The convenient method of testing the limited star of the Telescope is to use the standard star of the target star in the central government of the Star Group, or use the standard star of the Arctic Star (NPS) to estimate or calculate.

Diffraction limit (Ruili judgment)

Near the focus, the residual wave of the split Telescope is far less than 1/4 of the incident light wavelength.Such a Telescope is suitable for an astronomical Telescope.Near the focus of the combination optical system, the wave image difference of separate optical components must be less than 1/4.When the wave ahead of the wave is reduced (1/8 or 1/10 wavelength), the optical quality will be greatly improved.

Close focus

This refers to the nearest distance you can see clearly in the near -land observation task.

Field angle ()

The sky areas that can be used by the telescopic mirror directly in the eyes of the observer are called the field of view or field angle ().The viewing field of the Telescope is often determined during design.The refraction Telescope is restricted by the limitation of the image and is restricted to the viewing angle. The reflection Telescope or refractive Telescope is often influenced by the sub -mirror size and restricted the viewing angle.However, for celestial photography, the field may also be restrained by the size of the receiver.The viewing rate of the Telescope is inversely proportional. The larger the magnitude, the smaller the view.

When the value of the unknown field, you can measure it by itself.Met the stars near the Equatorial Eachi with a Telescope, adjust the instrument, and make the star statue pass in the center of the field.The instrument does not move (without turning instrument clock), record the time interval of the star through the field of view, set to T seconds, the redttire of the star body is , the viewing angle is = 15tcos

Optics

Ivability is all factors that cause imperfections.There are several aberrations in the Telescope design, without the so -called perfect optical system.Optical design engineers must be able to balance all kinds of aberrations to get the desired design results.Here are some different looking portraits in different Telescopes:

Polysis: It often appears on the objective mirror that reflects the Telescope because the lens cannot focus on the light of different wavelengths (color) to focus.As a result, there was a circle of halo around the bright objects.This phenomenon often worsen when the sensitivity and diameter increase.

Ball difference: Make light through different caliber angles through the lens (or transmitted from the mirror) cannot focus on the same point on the axis.It makes the image of the stars not look sharp, but a vague light spot.

Comet: It is mainly related to the parabolic reflection Telescope, which affects the imaging of the external axis, and it is often more obvious at the edge of the field of view.The image of the stars looks like a V -shaped pattern.For high -quality instruments, the smaller the Jiao Bi, the more obvious the comets on the edge will be, but there will be no comets in the center of the field of view.

Portrait: The aberration is stretched from the horizontal position to the vertical position on both sides to the vertical position at the best focus point.This is often caused by poor production or assembly errors.

Field song: It refers to the plane formed by the precise focus of light, but a curved surface.The center of the noodles may be sharp and accurate, but the edges are not focused or opposite.

1. What is good to wear in outdoor down jackets

The Outdoor down jacket itself has excellent warmth, but it can be paired with a variety of clothes to enhance comfort.The specific type of clothing that can be selected is as follows:

1. sweater:The sweater is a classic match for down jackets, and the material is mostly soft and comfortable wool or chemical fiber.It has good heating, can effectively block the invasion of cold air, and it is easy to combine with outdoor down jackets to form a multi -layer warm effect.

2. keep warm underwear:The warm underwear sticker is worn by the Skin, which is generally made of high -heat reaction material, which can absorb and store the calories emitted by the human body.This kind of clothing is not only lightweight, but also can effectively enhance the warmth of outdoor down jackets.

3. Long -sleeved shirt or sweater:These clothes can also be used as the inner matching of outdoor down jackets.Long -sleeved shirts are good for breathability and are suitable for wearing in warm rooms or actives. knitwear has good elasticity and breathability, which can provide good warmth effects while maintaining comfort.

4. Grab the velvet:Capture is a common intermediate clothing in outdoor activities.It is usually made of polyester and has the characteristics of lightness, softness, and warmth.The warmth of the velvet jacket mainly depends on its thickness and weaving.The thicker fleece jacket has better warming performance, but it will also increase the overall weight and volume.

In short, the inside Outdoor down jacket should be selected according to the principle of warmth, comfort, and breathability, and choose according to the specific temperature and personal needs.In the cold winter, reasonable combinations can keep people warm and comfortable while maintaining warmth.

2. How to match outdoor down jackets

1. pants matching

(1) With a pair of tight pants

tight pants can not only play a warmth, but also strengthen the proportion of the figure, so that the wearer looks more slender and tall.This kind of Outdoor activity suitable for long -distance hikes and skiing requires a lot of exercise.

(2) With a pair of jeans

jeans are versatile, with down jackets to add highlights.Pay attention to the selection of hard jeans, which can play a certain windproof role.This combination is suitable for outdoor activities such as Camping and cycling.

(3) With a pair of waterproof trousers

waterproof trousers not only prevent cold and windproof, but also prevent rainwater from wetting the pants legs.In addition, most of the waterproof trousers adopt a more loose design, which can make the wearer more comfortable.This combination is suitable for outdoor activities such as Hiking and Rock climbing.

2. accessories

(1) hat

In outdoor sports, the head should be the best heating part.A hat can not only play a role in warmth, but also increase the highlights of wearing.

(2) scarf

The scarf can not only keep warm, but also make the wearer more fashionable.It is recommended to choose the plush material, which feels comfortable.

(3) gloves

Choosing a pair of windproof gloves can protect the Skin's Skin and increase the sense of layering.

3. What color is good -looking for outdoor down jackets

The color choice of outdoor down jackets mainly depends on personal hobbies and use scenarios, but dark colors such as black, gray, brown, etc. are usually more dirty and more mature and stable.Eyeing can increase vitality.

1. Dark color system

The dark down jacket can better cover the stains. It is not only good -looking, but also easier to match. It also looks mature and stable.Generally suitable for business or formal occasions.Black is one of the most common colors. It is also very temperamental. Gray is also low -key elegance, and brown is more fashionable.

2. Bright color system

Bright -colored down jackets are usually more suitable for leisure, Outdoor, sports and other occasions, which can add a vitality and youth.Red, yellow, and blue are more bright and eye -catching colors.Unlike the choice of black and white and gray, if you prefer more vibrant colors and are not afraid of attractiveness, then these colors are a good choice.

3. Other color systems

In addition to dark and bright colors, there are some uncommon colors that can also be selected according to personal preferences.For example, military green, orange, purple, etc. can give people a fresh feeling, more in line with personalized taste.However, the matching of these colors also needs to be carefully considered.

1. Can men's Casual pants be equipped with sports shoes?

Men's Casual pants can be equipped with sports shoes.

The style of Casual pants is very close to the style of sneakers. The combination of the two can be said to be great.Of course, leisure pants are best with casual shoes.But now the casual shoes launched by various sports brands also have a certain sports function. Strictly speaking, casual shoes and sneakers are inseparable.

Second, men's Casual pants with shoes taboo

Although Casual pants with sports and casual shoes are a stylish way of wear, you need to pay attention to the following aspects when matching:

1. Unified style

In order to improve the overall sense of fashion, the style of Casual pants and sports casual shoes needs to be consistent.If you are tight pants, you can choose a high -gang or mid -gang sneakers. If you are loose Casual pants, you can choose a running shoes or casual shoes.

2. color coordination

The color of Casual pants and sports casual shoes also needs to be coordinated.You can choose a color for matching, or choose two products with similar colors for matching.

3. Scene control

The combination of Casual pants and sports casual shoes is suitable for informal occasions, such as dating, shopping and other activities.For formal occasions, appropriate formal shoes should be selected.

4. Personal temperament

Finally, you need to choose a Casual pants and sports casual shoes that are suitable for you according to your personal temperament.The overall match needs to be in line with personal style to truly show fashion and personal charm.

To sum up, the way to wear Casual pants with sports and casual shoes is very suitable, which can make people feel fashionable and young.However, you need to pay attention to style, color, occasion and personal temperament to achieve the best effect.

1. Can Sunscreen masks be washed water?

The Sunscreen mask is to block and reflect the ultraviolet rays through fabrics, fiber and black technology, so can Sunscreen masks be washed water?

The Sunscreen mask can be washed with water.

It should be noted that if the mask is only sunscreen function, it can be washed water, but if the mask still has a dust -proof effect, it cannot be washed.Because the dust -proof principle of the mask is static electrostatic adsorption or activated carbon adsorption, it will affect its filtering efficiency after cleaning, which cannot achieve the dustproof effect, so it cannot be washed.If you want to clean the mask, you must distinguish the material and filtering principle of the mask.

2. Will the sunscreen cover affect the Sun protection effect?

The previous article has simply learned that the Sunscreen mask can be washed water, but many people are worried whether the sun suns will affect the sunscreen effect after washing.

After washing the sunscreen, the sun can also be sunscreen. The normal cleaning of the Sunscreen mask will not only affect its sunscreen effect, but also ensure the cleaning of the Sunscreen mask, and it will be more comfortable to wear.

In addition, it is best to put the mask in cold water when cleaning the sun mask, wash it by hand, and try to avoid machine washing or brushing with a brush, so as to better maintain the sunscreen effect of Sunscreen masks.At the same time, do not use soft agents and bleaching agents when cleaning Sunscreen masks, otherwise it will affect the sunscreen effect and comfort of the Sunscreen mask.