Question 2: What is water-soluble colored lead? Water-soluble pencil is the feeling of pencil when drawing, but it will melt when it meets water, resulting in watercolor effect. Just use that to draw a few times when you need any color in a place, and then dip that small brush in some water to dissolve the color. Both a pencil and Gou Xianbi can draw an outline. Ordinary pencils can't get watercolor effect when they meet water, and they are hard. Water-soluble pencils are very soft.
Question 3: What does water solubility 13 g/l mean? Soluble per liter of water 13g.
Question 4: How to write the key words and abstract of the paper? The abstract of a thesis is generally about 100 to 200 words, and a large thesis (such as a graduation thesis of 40,000 words) can also be about one page (7800 words). It is necessary to explain what problems (significance) and methods the paper aims to solve. If there is an experiment, explain the basic methods of the experiment and draw one or several conclusions under the research conditions. The last sentence summarizes the conclusion and popularization significance under the given application scope. For example, something is very important under a certain condition, but the measurement accuracy of a parameter under a certain condition is not high. This paper measures how accurate it is to get a certain result in a certain way under certain conditions, and what effect this method can have in a certain range. Keywords must be content words, which are generally used to summarize one or more fields involved in your thesis and the research methods you think are important. For example, the key words of a paper on water treatment can be: drinking water, ultraviolet disinfection, organic matter, enough. Of course, the specific words involve the content of your paper. Keyword writing |MBA, MPA, PMP | Writing of academic papers | Writing of abstracts | Labeling of classification numbers | Problems that should be paid attention to in paper writing | How to write graduation thesis | Writing of keywords | Graduation defense | Keyword is the document retrieval logo of scientific papers, and it is a natural language vocabulary to express the concept of document theme. The key words of scientific papers are selected from their titles, hierarchical titles and text, which can smoothly reflect the theme concept of the papers. Keywords are put forward to meet the needs of computer retrieval, and the position is after the abstract. As early as 1963, American Chemical Abstracts rolled up from page 58, and began to use computers to compile keyword indexes, which provided a quick way to retrieve literature topics. Today, with the rapid development of scientific and technological information, hundreds of thousands of scientific and technological papers are published every day all over the world, and academic circles have long agreed to use subject concept words to retrieve the latest published papers. If the author's published papers are not marked with keywords or descriptors, such articles will not be included in the literature database, and readers will not be able to retrieve them. Whether the keywords are properly selected is related to the retrieval of this article and the utilization rate of this achievement. 1 keyword classification keywords include narrative words and free words. ? 1) Description-refers to the standardized words or phrases that can be used to index the document theme concepts in Chinese thesaurus, MeSH and other vocabularies. 2) Free words-new nouns and terms that reflect the new technologies and disciplines in the theme of this paper, but are not included in the thesaurus or can't be found in the thesaurus. 2 Keyword Indexing In order to meet the needs of computer automatic retrieval, GB/T 3 179-92 stipulates that all modern sci-tech journals should give 3-8 keywords (or descriptions) at the back of academic papers. Keyword indexing should be selected according to the principles and methods of GB/T 3860- 1995 "Indexing Rules for Document Description" and referring to various thesaurus and reference books. Important terms in new disciplines and technologies that are not included in the glossary, as well as the names and places of articles can also be marked as keywords (free words). The so-called indexing refers to the process of subject analysis of documents and some features of retrieval significance, such as research objects, processing methods, experimental equipment, etc., and the identification of subject retrieval is given by using thesaurus. Document theme analysis is to find out the basic elements that constitute the document theme from the complex documents, so as to accurately index the required descriptors. Index is the premise of retrieval. Without the correct index, there is no correct retrieval. Scientific papers should index keywords according to the indexing method of descriptors, and standardize free words as descriptors as much as possible. 3 Basic principles of keyword indexing 3. 1 specificity principle A word can only express one theme concept as specificity. As long as the corresponding specific thesaurus is found in the thesaurus, it is not allowed to use the superordinate word (item S) or the subordinate word (item F) in the thesaurus; If you can't find a narrative directly corresponding to the theme concept, and the superordinate word is really consistent with the theme concept, you can choose. For example, "aircraft fire prevention" can be found in the thesaurus, so you must choose it first. The superordinate word "fire prevention" shall not be used for indexing, nor shall the two subject words "airplane" and "fire prevention" be used for indexing. ? 3.2 collocation principle: the collocation of narrative phrases should be conceptual collocation. Conceptual collocation includes two types:? Cross combination. Refers to two or two ... >>
Question 5: What is water-soluble colored lead? I bought this pencil online. General stationery stores in China sell oily colored lead.
A painting tool that can draw lines at the same time as a pencil and watercolor is a water-soluble colored pencil, which is relatively soft. The method of use is quite simple, just like ordinary pencils. After painting, paint it with a pen dipped in water, and the color will melt. If the penholder of a colored pencil is directly dipped in water, you can draw neat lines on the screen and freely mix colors, which is the greatest charm of a water-soluble colored pencil. When you paint colors on the screen with a pen containing water, the colors will be mixed with each other, which can show the colors you want to express and create a unique painting style.
Parents can buy online, Amazon, Taobao and so on.
Question 6: What do you mean by water solubility in small water-soluble molecules? Generally refers to the solubility in water.
1, in a narrow sense, refers to the solubility of substances in water.
2. In a broad sense, it refers to the solubility of substances in polar solvents.
3. The molecules of water-soluble substances usually contain polar groups, such as -OH, -SO3H, -NH2, -COOH, etc. And the carbon chain is not too long.