Dorm Room 404.
When Li Dong pushed open the door to his dorm room, no one was inside.
Lately, he was basically the only one left in the room.
Chen Nan and Liu Qiang were now constantly trailing after Professor Zhang Zhiqiang. One was doing preparatory reading on Algebraic Geometry, while the other was tackling Ravi Vakil’s intimidatingly thick *Foundations of Algebraic Geometry*.
They could even occasionally sneak into the group seminars Zhang Zhiqiang held for his graduate students.
As for Wang Hao...
That guy was practically tied to Gu Ming at the hip these days.
The National Mathematical Contest in Modeling was just around the corner, and the two of them spent every day grinding through problems in a small conference room at the School of Mathematics.
They ground away day and night. When they couldn’t grind anymore, they’d return to the dorm, collapse onto their beds, and curse the advisor’s problems for being inhuman.
Li Dong tossed his things onto his desk, pulled out his chair, and sat down.
He plugged the USB drive Zhang Yan had given him into his laptop.
The contents of the USB drive were meticulously organized.
There were folders for the project background, video tutorials, literature reviews, and so on...
Li Dong clicked on the project background first.
His reason for joining Wu Kai’s project team was actually very simple.
He was there to fleece Mendeleev and Madam Curie in the group chat.
As for the true purpose of Professor Wu Kai’s project team, Li Dong didn’t really have a clue.
The first page of the document was the project background.
Project Core: To integrate the energy-resolving capability of a synchrotron radiation X-ray source with the atomic-level spatial resolution of a scanning tunneling microscope onto a single tip-sample structure.
Objective: To achieve elemental identification and chemical state characterization of a single atom.
Li Dong stared at the line of text.
"Just as I thought. This project is tailor-made for me to fleece them."
"Elemental identification and chemical state characterization of a single atom."
Translated into plain language, it meant:
You aim the tip of a scanning tunneling microscope at a lone atom on a gold surface, shine a synchrotron X-ray on it, and ask that atom:
"What’s your name? What state are you in right now?"
The document stated clearly that this was a problem that had been hanging over the entire field for more than a hundred years.
Ever since Röntgen produced the first X-ray photograph in 1895, all applications of X-rays—bone scans, crystal diffraction, materials analysis—had to be done on a whole clump of atoms.
But to question a single atom?
That was something no one had ever truly accomplished.
Li Dong slowly scrolled down.
He reached the second page.
This page explained "why this project, why now".
Li Dong had expected an introduction along the lines of "for the purity of science".
Instead, the first sentence he saw was...
Application: Development of single-atom catalytic drugs for cardiovascular diseases.
Li Dong froze for a moment.
He continued reading.
The document wasn’t written in overly technical terms, but Li Dong understood the gist of it.
For the past year or two, researchers both in China and abroad had been working on something called a "single-atom nanozyme".
Simply put, you take a transition metal—like iron, manganese, or cobalt—reduce it to the scale of a single atom, and embed that atom in an organic ligand or an inorganic framework.
At this point, the single atom can mimic the activity of certain natural enzymes, such as superoxide dismutase (SOD) or catalase (CAT).
So what do these two enzymes do?
Basically, they clean up reactive oxygen species and free radicals.
And what do reactive oxygen species and free radicals do?
In the moment of a myocardial infarction, the deadliest part isn’t the ischemia itself.
It’s the instant after the ischemia when the blood vessel is reopened.
Blood flow returns, and oxygen returns with it.
But by then, the myocardial cells are half-dead from the lack of blood. When the mitochondria are reactivated by oxygen, they instantly spew out massive amounts of reactive oxygen.
This "oxidative burst" can tear the myocardial cells to shreds.
This phase is called "ischemia-reperfusion injury".
Whether a myocardial infarction patient ultimately survives and retains heart function largely depends on this phase.
Natural SOD and CAT have large molecular weights. They can’t cross the blood-brain barrier, struggle to pass through vessel walls, and can’t get inside myocardial cells.
But single-atom nanozymes, in theory, can.
Furthermore, at the single-atom scale, their catalytic efficiency is even higher than traditional enzymes.
This was a research direction that could save lives.
And this was precisely the area Professor Wu Kai’s group was working on.
Reading this, Li Dong found himself unconsciously growing serious.
The things he had discussed with Mendeleev and Madam Curie in the group chat, no matter how profound, were ultimately just scientific games.
This work, however, could genuinely save lives.
He continued to scroll.
Current Bottlenecks.
This section was the toughest part of everything Li Dong had read today.
The document was very direct.
Synthesizing this class of single-atom nanozymes wasn’t difficult.
The truly difficult part was...
After you make it, you need to know exactly where that iron atom (or other atom) is embedded, which surrounding atoms it’s coordinated with, what the bond lengths are, and what its electronic structure looks like.
Without knowing this, you can’t optimize it.
And without optimization, it will never pass clinical trials.
And to know all that...
You need a "mouth" that can ask that single iron atom what its name is and what it’s up to.
That "mouth" is the SX-STM.
The document listed a series of current international bottlenecks.
Li Dong stared at the two most critical ones for a long time.
First: The ill-posed nature of the measurement operator.
This refers to the step of taking the sparse set of collected tunneling spectra and inverting it to derive the coordination field tensor around the atom.
It follows the methodology of inverse problems.
But this inverse problem is ill-posed; a tiny perturbation in the input can be amplified to an astronomical degree in the output.
When Gikhmanov regularization is forced, the peak positions in the third coordination shell are always blurred into a mess, impossible to resolve.
Second: Conflicting basis functions.
When expanded using three different sets of basis functions, each set yields contradictory phases, differing by a full π.
This means the so-called "X-ERT criterion"—ev≤n—simply doesn’t hold up.
You say you’ve measured an iron atom?
How do you prove you didn’t measure the one next to it?
These were the two walls that the entire project had been stuck behind for several years.
When Li Dong read this section, he subconsciously rubbed the bridge of his nose.
He navigated to the "Previous Experimental Records" folder on the USB drive.
The first file inside was an internal memo from Wu Kai’s research group from three years ago.
In the beginning, they were still trying to change the tip material, switching from ordinary tungsten to a PtIr alloy, then coating it with SiO2 for insulation, then sputtering a layer of gold for grounding, and finally, milling the apex of the tip with a focused ion beam.
It was all hardcore chemistry and engineering work.
But the resulting signal was still a blur.
The second memo, the third, all the way to the tenth and beyond.
Li Dong went through them one by one, and the more he read, the blurrier the results got.
The number of tricks they tried grew and grew, from improving the sample stage, to adjusting the frequency of the X-ray chopping system, to calibrating the reference phase of the lock-in amplifier.
Every trick seemed like it might solve a small part of the problem.
But in the end, every single one ran into the same two walls.
Eventually,
a sentence appeared in one of the memos.
It was written about half a year ago.
Since we’ve more or less exhausted the paths in chemistry and engineering, perhaps we could ask some mathematicians to try and work backward from the other end.
Li Dong stared at this sentence for a long time.
He scrolled down, then further down.
From that point on, words like "inverse problem," "variational methods," "spectral methods," and "regularization" started appearing in the memos.
It was clear.
In the last year or two, Wu Kai’s team had started investing heavily in this mathematical path.
The document ended with a summary.
About a dozen research groups working in this field, both in China and abroad, had all been heading down this same path for the last two years.
"Mathematical inversion" had become the acknowledged most-promising breakthrough for the field.
Li Dong stared at the summary for a long time.
He had an indescribable feeling in his heart.
He could understand why everyone was going down this path.
They had tried every conceivable breakthrough in chemistry and engineering.
The only thing left untouched was mathematics.
It was like a person trapped in a room. He’s felt his way around, knocking on every wall, but found no door.
Finally, he looks up at the ceiling.
’Maybe I can chisel a hole through the ceiling?’
This had nothing to do with whether it was mathematics or not.
This was simply a last resort.

Comments

Loading...