APC Science Union · Online Library

Culture and Consumer Society, Part 1: I’ll Take the Milk Tea and the Sneakers Author: 涛声 Reviewer: 观复·钧天   A few days ago, Taotao's WeChat Moments and Qzone feeds were flooded with posts about “the first cup of milk tea in autumn”:   Fine. Taotao wasn't jealous at all. Not one bit. QAQ. One post did catch his attention, though:   Interesting.jpg. After mulling it over, Taotao realized that “Is the ‘first cup of milk tea in autumn’ a capitalist scam?” was not such an easy question to answer. But the question does point to something important: our purchases are shaped not only by our empty wallets and less-than-careful budgeting, but also by culture and ideas.   Examples are everywhere in a consumer society. Whether we buy sneakers, anime merchan ...

Author: Abaiter Reviewer: Shiguang   Few countries have a spaceflight history as dramatic as Russia's. Tracing that history over time, this article offers a brief account and assessment of the Soviet and post-Soviet Russian space programs through two main threads: theory and engineering. For each theory, we will introduce the underlying mechanics and its engineering applications from a quantitative perspective. For each mission, we will gather as much information as possible about its scientific objectives, payload specifications, and instruments. For each space transportation system, we will present figures such as payload capacity to different orbits and specific impulse. Together, these details will let us see how Soviet and Russian spaceflight rose and declined before we tu ...

Protein Translation Author: Shenzhou Reviewed by: Shenzhou and Myelin   Proteins are the main functional molecules that sustain the activities of life, and the process by which cells synthesize them is called translation. During translation, mRNA serves as the template. With the help of the ribosome, tRNA interprets the nucleotide sequence in the mRNA as an amino acid sequence, producing a polypeptide chain. The principal participants are tRNA, rRNA, and mRNA. tRNA carries amino acids to the ribosome. rRNA joins with several ribosomal proteins to form the ribosome, the site of polypeptide synthesis. mRNA carries the codons that provide the template for translation. mRNA   Jacob and Monod proposed the concept of messenger RNA in 1961. Because proteins are synthesized ...

Spatiotemporal Trajectories in Memory Author: Myelin Reviewed by: 食野   Episodic memory is a form of long-term memory: memory for events that occurred at a particular time and place. It is inseparable from personal experience, and its defining quality is its narrative, event-based character—for example, remembering an activity you attended or a place you once visited. [1]   In daily life, we usually imagine space and time as separate dimensions of experience, yet we often bring them together when describing episodic memories. If I ask what you did this morning, you may mentally retrace the entire morning as its events unfolded across different times and places. This reflects a widely held view: episodic memory embeds our records of events in a unified representation o ...

Author: Taosheng   A friendly warning: you may need to read this article carefully, one section at a time, and go through it more than once. Brace yourself. Section 1: Introduction; Section 2: Propositions; Section 3: The Four Types of Categorical Propositions; Section 4: Syllogisms; Section 5: Conclusion.   Feel free to jump to whichever section best matches your level. Section 1: Introduction   As we happily surf the internet, we run into all kinds of views: some incisive, some warm and resolute, and some elaborate comic bits. We tend to accept certain views and reject others. Doing so can deepen our understanding of an issue and help us form views of our own, while also giving us emotional support.   From this perspective, a view has value simply by existing, no matter ho ...

Author: Shiguang Glass artwork The Development of Glass 1.1 The Origins of Glass around the World   Historical records indicate that by roughly 3000–2000 BCE, the Egyptians or Mesopotamians already possessed relatively mature glassmaking techniques. One legend relates that more than three thousand years ago, Phoenician merchants discovered crystals formed when fire caused a mineral called natron, or “natural soda” (or, in another account, saltpeter), to react chemically with the quartz sand on a beach. These crystals were the earliest glass. The Phoenicians recognized the commercial opportunity. They exploited the reaction to produce large quantities of crude glass beads by firing and fusing sand, stone, and soda, then sold them far and wide. They made substantial profits and set off ...

Author: Congyu Reviewer: Yuandao   Sirius is the brightest star in Earth’s night sky, and we can see it every winter. In 1844, German astronomer and mathematician Friedrich Bessel calculated that Sirius must be a binary system with a companion about as massive as the Sun. The companion was so faint that it remained unseen for years. It was finally photographed in 1862, shining with only one-thousandth the brightness of Sirius. Astronomers later obtained its spectrum and began to recognize a new class of object: the white dwarf. Sirius and its companion at X-ray wavelengths The Late Evolution of Sun-like Stars   To understand how white dwarfs form, we must begin with the post-main-sequence evolution of low- and intermediate-mass stars. Stars below 2.3 solar masses are generally classifi ...

Author: delta Reviewed by: Guanfu · Juntian   No. End of explainer.   But if you learned about Cavendish’s torsion-balance experiment in middle school, you probably will not be satisfied with stopping there. Physics has a technique known as two-stage amplification. Could the same idea, or something similar, be used to measure dimensions in the microscopic world?   It certainly can. This article uses accessible language to explain one way of measuring the cross-sectional area of a molecule: the surface-tension method. What is surface tension?   Really? Do we have to start this far back?   You have seen surface tension countless times: raindrops on a window, early-morning dew on leaves, and large soap bubbles in the laundry. You may also have encountered, or may soon encounter, the subjec ...

Author: Shenhong Preface   Hello, everyone. I’m Shenhong; nice to meet you. This is the second entry in my personal Unity journal (the first contains some private material, so I will not be publishing it). It is also the first submission from any member of our current team since we joined the Union. We look forward to getting to know you.   This series is not a development log. It records my experience of learning Unity and the moments that matter to me during game development. Since it is closer to a diary, I will not go too deeply into technical material, and entries will not appear on a fixed schedule. I hope to share the joys and frustrations of one person—and of a whole group—who chose to make games because they love them. I may also introduce parts of the development process along ...

Author: Shenzhou Reviewer: Weiming   Transposons, also known as jumping genes, were first described in 1947 by the renowned American geneticist Barbara McClintock. While studying the unstable inheritance of variegation in the maize aleurone layer, she uncovered a new mechanism by which an intact genetic unit can move from one location in a genome to another. Fu H. and Dooner H. K. examined the phenomenon further in a 2002 paper. Their work showed that, at the molecular level, every organism is a product of continuing genetic recombination: mutations create new sequences, while exchange, insertion, and rearrangement reshape existing ones.   A genetic unit capable of such movement is called a “transposable element,” or transposon. Transposition differs in both concept and mechanism from ho ...