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Category: Science and Technology

Technology, abbreviated by science and technology, generally refers to human use of machines, hardware, or man-made utensils, but it can also contain a wider range of architectures, such as systems, organizational methodologies, and techniques.Science (English: Scientific, Greek: επιστήμη) is a subject that, through empirical evidence, is attributed to phenomena (originally referred to as natural phenomena, which now refer to phenomena such as social phenomena).The knowledge derived from scientific activities is clearly conditional, can withstand testing and cannot contradict any known facts within the scope of application. Science and technology is the main body of knowledge evolution, shaped by society or shaping society.The proliferation of new technologies, such as computers, has led people to believe that technology is the decisive force for social evolution, in other words, it is the spontaneous driving force that drives change.

  • What does the ‘Score validation’ feature of Google reCAPTCHA’s human verification mean?

    What does the ‘Score validation’ feature of Google reCAPTCHA’s human verification mean?

    reCAPTCHA is a verification system developed by Google to determine whether website visitors are humans or automated programs.

    reCAPTCHA Score Validation is a feature of reCAPTCHA v3 that evaluates user behavior on a website and assigns a score based on that behavior to determine whether the user is human. This score is referred to as the reCAPTCHA score.

    reCAPTCHA Score Validation is the process of evaluating a user’s authenticity based on their interactions with a website. These interactions include the way a user clicks and scrolls, the speed at which they fill out forms, and other behaviors that are difficult to mimic. As a result, reCAPTCHA Score Validation is highly accurate at determining whether a user is human or not.

    reCAPTCHA Score Validation assigns a score between 0 and 1 to each user, with higher scores indicating a greater likelihood that the user is human. Website administrators can use the reCAPTCHA score to identify and filter out spam emails and malicious behavior, thereby protecting the security of the website.

  • What are DKIM and SPF used for?

    What are DKIM and SPF used for?

    DKIM (DomainKeys Identified Mail) and SPF (Sender Policy Framework) are two technologies used for email authentication.

    SPF is a standard that allows domain owners to specify which mail servers are authorized to send emails on behalf of their domain. When an email recipient receives an email, it can check if the mail server claimed to have been used by the sender is listed in the SPF record of the domain. If the mail server is not listed, then the email is likely to be spam or fraudulent, which increases the chances of it being marked as spam. Therefore, SPF can help detect and reduce the amount of spam and fraudulent emails.

    DKIM is an encryption technology that allows the sender to sign the email and encrypt the signature using a private key. The recipient can verify if the email was sent by the sender by checking the signature and ensuring that the content of the email was not altered during transmission. DKIM can help identify and reduce fraudulent emails because it can verify the sender’s identity and detect if the email was tampered with.

    In summary, SPF and DKIM aim to increase the security and trustworthiness of emails and reduce the amount of spam and fraudulent emails. They are usually used together with DMARC (Domain-based Message Authentication, Reporting, and Conformance), which can integrate the results of SPF and DKIM into the email header and control and report on unverified emails based on the domain owner’s requirements.

  • How to train knife sharpening technique?

    How to train knife sharpening technique?

    Knife sharpening is a handicraft skill that requires much practice and honing to master. If you want to learn sharpening techniques, there are some steps you can follow systematically, including:

    1. Buy and learn about sharpening tools and materials, including whetstones, grinding wheels, saws, and more.
    2. Learn the basic principles and methods of knife sharpening, including blade angle, cutting direction, etc.Learn the basic principles and methods of knife sharpening, including blade angle, cutting direction, etc.
    3. Get hands-on with guidance from professional craftsmen, including master knife makers on YouTube. Beginners can start with simple knives, such as spatulas and table knives, and gradually increase the difficulty.
    4. Through continuous practice, honing technique, improving accuracy and speed. Experiment with different whetstones and sharpening methods to find the technique that works best for you.
    5. Check your knives regularly to maintain the sharpness of your blades. The knives will wear out during use and need regular grinding and maintenance. In addition, the surface flatness of the whetstone also needs regular attention.

    The knife-sharpening technique requires patience and perseverance, and it takes a lot of practice to become proficient. Through continuous operation and training, you can improve your sharpening skills and bring more convenience to your daily life and work.

  • Should the micro switch of the mouse button be made in Japan or the People’s Republic of China?

    Should the micro switch of the mouse button be made in Japan or the People’s Republic of China?

    A frequently asked question about mouse repairs is “Should the microswitches of the mouse buttons be made in Japan or the People’s Republic of China?”

    A mouse is cheap from more than 100 yuan to several thousand yuan. The biggest difference is in key design such as feel, ergonomics, appearance structure and motion detection resolution, but no matter how much the mouse is, the only difference is The constant is that the button brake sensing element (micro switch) hidden in the body is actually very easy to fail and damage.

    Many people may not use the mouse for a few years, and they begin to feel that the button’s response has become very insensitive. It does not respond after several consecutive clicks, or it is too sensitive. After pressing it once, it becomes a double-click, which is completely uncontrollable.

    Why does the mouse break?

    A big reason is that the micro switch under the button has become insensitive. There are many possible reasons for insensitivity. A large number of clicks will cause the loss of metal contacts inside the part, and even poor contact due to dust entry will gradually cause the mouse control to fail.

    Generally speaking, most of this kind of wear does not need to be sent back to the original factory for repair. After all, the internal parts and mechanical structure have begun to age. This time, after the switch is repaired, the plastic structure inside the mouse has also been worn, which affects the button control.

    A cheap mouse can be replaced by a new one. If the mouse is less than a year old, consider reporting it to the original factory for repair.

    Of course, there is another method, which is to buy the micro switch by yourself and come back to D.I.Y for maintenance. In fact, this is also a solution that many people will consider, so the micro switches of various manufacturers on the market can be easily purchased.

    If you want to repair the switch of the mouse, in addition to purchasing the components, you also need a soldering iron and solder to perform the repair. For friends who have never been in contact with them at all, it may still be a little difficult.

    Pick a Micro Switch

    The author once said that there are some tips for selecting micro switches. From practical experience, 🇯🇵MIJ’s micro switches made in Japan (eg: Omron Omron D2F-01) are more precise, and copper sheets can be designed to be thinner and lighter. Not durable.

    🇨🇳MIC Made in the People’s Republic of China, the precision is relatively poor, and the manufacturing technology is also poor. The copper sheet itself has a certain thickness, but it is relatively durable. It is also a good choice for those who need more durability than hand feel.

    🇩🇪MIG German-made micro switches (eg: Cherry GD2 GD4 black dots) are more expensive, have high precision, but are also solid and durable.

    Cost-effective and patriotic, you can also choose 🇹🇼TTC dust-proof gold products made by MIT Taiwan in the Republic of China.

    In fact, it only needs to be replaced once. After knowing the location and how to replace it, it is not difficult to replace it next time. Therefore, it is more important to choose high precision and good hand feeling.

  • What circuit design issues need to be paid attention to when using PWM to control a motor?

    What circuit design issues need to be paid attention to when using PWM to control a motor?

    A common question with circuit design is “What should I pay attention to when controlling a motor with Pulse-width modulation (PWM)?”

    If you want to use PWM to control the motor action, it is generally referred to as a DC motor.

    If you want to use a relay to control it, it will definitely not work, because the round trip time of the mechanical structure is too long, as long as the frequency is high, it will not act, and the mechanical structure will be broken if the life is not high.

    In the worst case, optocoupler isolation IC+BJT should be used to amplify the current to control.

    But in fact the best choice is to use a high-power transistor (Power MOSFET) for control.

    Of course, you can choose the built-in PWM module of the motor itself. If you use a single chip to implement PWM, you need to pay attention to whether the output current of the pin is enough to drive. Generally, the traditional 8051 IC can supply 15mA, while the new Arduino can reach 20-30mA.

    When designing a PWM-controlled motor circuit with a single chip, special attention should be paid to electrical protection and power pollution issues.

    The former is because the PWM operation itself will generate a back electromotive force, which can be protected by the design of the transistor circuit.

    Power pollution is due to the current feedback from the motor startup, which may crash the chip and cause a crash, which can be protected by the circuit design of voltage regulation and power isolation.

  • Why do airplane windows have rounded corners?

    Why do airplane windows have rounded corners?

    A common question related to aviation equipment is: “Why are the windows in the bulkheads of airplanes rounded?”

    When traveling by plane, I like to look out at the blue sky and sea through the lovely round windows in the cabin.

    But in addition to its own aesthetic effect, what is the special reason for the shape of the aircraft windows are rounded?

    In fact, this is because up to 70% of the cabin pressure inside an aircraft is concentrated in the four corners of these windows.

    The round window is designed so that the four corners can effectively decompose the pressure, and it is also stronger and more resistant to deformation. Avoid stress concentrations that can lead to cracks in the structure.

  • What are the 50 most popular hashtags on Instagram?

    A common question with online social media operations is about “What are the 50 most popular hashtags on Instagram?”

    Friends who are playing Instagram must be troubled every time they post a post. They need to use those hashtags to increase the exposure of their posts. Below is the statistics of Instagram that are popular with everyone. In the past year, the top 50 popular tags used by users all over the world are the most popular tags. You can refer to these tags when posting your own posts.

    50 most popular Instagram Hashtags

    1. #love （1.835B）
    2. #instagood （1.150B）
    3. #fashion （812.7M）
    4. #photooftheday （797.3M）
    5. #beautiful （661.0M）
    6. #art （649.9M）
    7. #photography （583.1M）
    8. #happy （578.8M）
    9. #picoftheday （570.8M）
    10. #cute （569.1M）
    11. #follow （560.9M）
    12. #tbt （536.4M）
    13. #followme （528.5M）
    14. #nature 525.7 百萬
    15. #like4like 515.6 百萬
    16. #travel 497.3 百萬
    17. #instagram 482.6 百萬
    18. #style 472.3 百萬
    19. #repost 471.4 百萬
    20. #summer 454.2 百萬
    21. #instadaily 444.0 百萬
    22. #selfie 422.6 百萬
    23. #me 420.3 百萬
    24. #friends 396.7 百萬
    25. #fitness 395.8M
    26. #girl 393.8M
    27. #food 391.9 百萬
    28. #fun 385.6 百萬
    29. #beauty 382.8M
    30. #instalike 374.6 百萬
    31. #smile 364.5 百萬
    32. #family 357.7 百萬
    33. #photo 334.6 百萬
    34. #life 334.5 百萬
    35. #likeforlike 328.2 百萬
    36. #music 316.1百萬
    37. #ootd 308.2 百萬
    38. #follow4follow 290.6 百萬
    39. #makeup 285.3 百萬
    40. #amazing 277.5 百萬
    41. #igers 276.5 百萬
    42. #nofilter 268.9 百萬
    43. #dog 264.0 百萬
    44. #model 254.7 百萬
    45. #sunset 249.8M
    46. #beach 246.8M
    47. #instamood 238.1 百萬
    48. #foodporn 229.4 百萬
    49. #motivation 229.1 百萬
    50. #followforfollow 227.9 百萬
  • What are the professional cameras and cameras that support the ProResRAW recording format?

    What are the professional cameras and cameras that support the ProResRAW recording format?

    Apple first released ProRes HQ, the boss of the Apple ProRes series, in 2007. Up to the technological development of the latest generation of ProResRAW today, ProRes encoding has been accepted by mainstream film creation teams all over the world (including Hollywood, USA), and the encoder format and variety have also been expanded very richly.

    ProRes video coding is a kind of high-bit-depth coding with real-time playback, multi-track editing, and high picture quality. It is divided into 4:2:2 and 4:4:4 color samples according to different coding levels. The RAW version has the performance of ProRes and the flexibility of RAW.

    Since the release of ProResRAW codec in April 2018, from the very beginning, only Atomos, a professional external recording equipment manufacturer in Australia, and DJI, a professional imaging manufacturer from China, have been authorized to use it. So far, many camera manufacturers support the ProRes RAW codec. We The detailed camera models are listed below to provide photographers who need it.

    Support ProResRAW format professional cameras and cameras

    Canon EOS R5

    FujiFilm GFX100S

    FujiFilm GFX-100

    Nikon Z7 II

    Nikon Z6 II

    Nikon Z7

    Nikon Z6

    Olympus OM-D E-M1 Mark III

    Olympus OM-D E-M1X

    Panasonic GH5S

    Panasonic LUMIX DC-BGH1

    Panasonic Lumix S5

    Panasonic LUMIX DC-BS1H

    Panasonic LUMIX DC-S1

    Panasonic S1H

    Panasonic AU EVA1

    Sigma fp

    Sigma fp L

    Sony Alpha 1 (ILCE-1)

    Sony FX3 (ILME-FX3)

    Sony A7S III

    Sony PXW-FX9

    Sony FX6

    Z CAM E2C

    Z CAM E2

    Z CAM E2-S6

    Z CAM E2-M4

    Z CAM E2-F6

  • When does the router DMZ host service need to be used?

    When does the router DMZ host service need to be used?

    Question: “Generally, when a computer connects to the Router, it will be assigned an intranet ip location, so why do you need the DMZ function?”

    The computer (server) side of the home router’s internal network needs to enable the Port forward/virtual server function to open PORT to external systems or users for connection, so that outsiders can connect to our designated system (such as Apache web server) ).

    However, if the IP address of the intranet computer is directly set to the DMZ host, the above setting is not required, and the port (port) channel of the computer can be designated one-to-one for external connection.

    Generally, this is also a function required by home routers, because there are still a few people who need to disclose their own transmission ports in the home area network, so this function is mostly only used for emergency use.

    Of course, the disadvantage of this is that the firewall protection of the router is missing, and the firewall needs to be manually set on the DMZ host to prevent hackers from intruding and destroying.