Scanning electron microscope photography malfunctionScanning electron microscope photography may have a variety of faults. The following are some common faults and related analysis:
- ** Poor tube vacuum **: When the tube vacuum is poor, the 30kV-high voltage will be added to the grid cap for a few minutes, and the tube will be seriously polluted. The tube vacuum will directly affect the normal operation of the scanning electron microscope. Because the tube has a high vacuum, the 5 - 30 volts high voltage can work under good conditions, so the high-brightness electron gun can obtain a thinner electron probe. According to the working principle of the vacuum system, the flow chart of high and low vacuum fault analysis could be sorted out and drawn, and the part discrimination method could be used to check step by step, narrow the scope, and find the fault.
- ** Weak image signal, small contrast **: When this kind of fault occurs, it may be caused by many factors. If the acceleration voltage is not selected properly, it is necessary to select a suitable acceleration voltage for samples with different conductivity, stability, and vulnerability. Otherwise, the observed image is not the true appearance of the sample. For samples with good electrical and thermal conductivity, such as metals, a higher voltage can be used for observation, such as 10 volts and above; for some samples with poor electrical conductivity but relatively stable, a medium acceleration voltage can be used, such as about 5 volts; for some samples that are easy to damage, such as high molecular materials, biological materials, etc., a lower voltage may be needed, such as 2 volts or below.
- ** Interferential signal appears when observing the image **: Internal interference may be due to circuit self-oscillation, high-voltage ignition, large power ripple, etc. You can start from the three sets of low voltage of the vertical amplifier. If it is determined that the power supply itself has self-excited oscillation, it can be solved by adding a vibration elimination circuit between the two stages of the difference amplifier to reduce the output ripple to less than 15 millivolts. The sawtooth output wave is normal, thus eliminating the net interference on the screen.
- ** Aspect problem **: Image dispersion affects image clarity, especially when taking high-resolution pictures (such as taking high-resolution pictures with high acceleration voltage and low beam current). The image would be stretched and deformed during the focusing process, losing its original shape. When the image of the scanning electron microscope showed some aberrations, the image would be stretched when it was focused. Antagonism required the experimenter to have a wealth of operational experience in order to accurately identify and eliminate the image.
- ** Phenomenon of carbon deposit **: After observing an area for a period of time, there may be obvious carbon deposits on the surface of the sample. The surface of the particles seems to have a "thin film", which will affect the photo effect of the sample and reduce the clarity of the image. It will also affect the accuracy of the energy spectrum analysis of light elements. The main source of carbon deposits was the sample.(contact with grease and other impurities during preparation or storage), electron microscope components (for example, the vacuum system of the scanning electron microscope has an oil pump, and a trace of oil vapor enters the electron microscope chamber; improper operation may cause the sample to pollute the accessories, etc.), operators (contact with samples and accessories may cause pollution), electron microscope room environment (electron microscope and samples are exposed to a dusty environment for a long time, or powder sample preparation in the electron microscope room may cause powder floating pollution), etc. In response to these situations, corresponding measures could be taken, such as cleaning and drying the contaminated samples with alcohol and other organic liquids; for the vacuum system of the Feiner electron microscope, which was an oil-free mechanical pump, the user should properly keep the sample cup, store it in a sealed bag or a clean box when not in use, and wear gloves to avoid grease contamination during operation; the operator should wear gloves or use clean sample preparation tools to operate; do not perform powder sample preparation in the electron microscope room, etc.
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What is the depth of field of a scanning electron microscope?The depth of field resolution of the scanning electron microscope was not infinite, but there was no fixed value to accurately represent the depth of field. The imaging medium (electron beam) of the scanning electron microscope had good convergence, and the convergence angle of the electron beam was usually very small, so its depth of field resolution was often stronger than that of the optical microscope. However, when it came to special samples such as multi-layered materials that were placed almost vertically, even the scanning electron microscope could not capture all the details. The super-depth-of-field imaging mode developed by the Phenomena electron microscope could perform full-field scanning and other operations according to the depth of field of the sample, and obtain a scanning electron microscope image with unlimited theoretical depth of field. However, this was a special case, so it could not be used to define the conventional depth of field value of the scanning electron microscope.
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Destiny 2 configurationAccording to the search results provided, the following information could be obtained: The minimum configuration requirements were an i5 processor, a GTX960 graphics card, and 8GB of memory. The recommended configuration requirements were an i7 processor, a GTX1060 graphics card, and 16GB of memory. According to the official release of the final PC configuration requirements, the recommended GTX970 or 1060 graphics card was required, and the hard disk needed to reserve 68GB of space. Based on the players 'experience and comments, some thought that Fate 2's configuration requirements were not high, while others thought that it was not worth worrying about. Overall, Destiny 2's requirements were relatively high, but not too low.
Marriage configurationMarriage configuration involved many considerations:
** 1. Personal Attributes **
1. ** Altruistic and Selfish Attributes **
- In marriage matching, the altruistic attribute was considered to have an important value. For example, having economic strength (money, car, house), external advantages (beautiful, young), ability to bear family responsibilities (stable job, enough time to take care of family), good health, etc. These altruistic attributes could benefit the other party. Self-interest attributes such as love of photography and love of life were relatively low in value in marriage. Smart men would focus on pursuing their careers and money, while women would focus on dressing up and exercising on the basis of their careers. These were all ways to build their altruistic attributes.
2. ** Zodiac Matchmaking **
- For some people, zodiac pairing was a factor in marriage configuration. For example, there was a special marriage table for the twelve zodiac men and women for reference. Different zodiac combinations were believed to have differences in marriage and luck.
** 2. The compatibility between the two parties **
1. ** Value fit **
- ** Concept of Money **: The concept of money between husband and wife is an important support for marriage. For example, in terms of consumption, it was necessary to reach a consensus on whether it was a self-satisfied or thrifty consumption concept. For example, some couples had conflicts because one party paid attention to the quality of life and was willing to spend, while the other party wanted to save money, which eventually led to divorce.
- Future Planning: The right person will respect the other party's wishes and include the other party in their future plans. For example, in terms of career development, one party could not decide to work in another place or apply for permanent residence without considering the other party's work and family situation.
- ** Concept of division of labor in the family **: Family trivialities may lead to many marriage problems, so it is necessary to discuss the division of labor in the family before marriage. For example, who would take care of the elderly and children, who would bear more responsibility for supporting the family, how to distribute housework, and so on. If one party thought that household chores were exclusive to one person, it was easy to quarrel after marriage.
- ** Parenting Concept **: The concept of children's education needs to be unified. For example, in terms of education methods, whether it was a strict education or a free-range education, and whether it was a dink or a late birth. If they did not reach a tacit understanding before marriage, they might face a crisis after marriage.
2. ** In terms of emotions and understanding **
- The right person was not attracted by passion or appearance alone. Instead, both parties had similar values, could respect each other, find common ground, trust and rely on each other, had a calm and deep understanding, and could grow together and support each other.
** 3. Opportunity and environment **
1. ** Time **
- The timing was also crucial in the marriage configuration. Sometimes, when you met someone who might be suitable, you would miss it because of work, not being ready, and other reasons. A suitable marriage might be when both parties are ready to meet and spark naturally.
2. ** Place **
- The location was also a factor in fate. Many beautiful marriages happened in casual places such as gatherings of friends, work collaborations, and accidental activities. Going out of a fixed circle and trying new things in new places might lead to meeting the right person.
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