I started with a ship full of max-level veterans, and I'm just a complete noob.

As the armored vehicle came to a stop on the side slope, the artillery battalion commander's voice came through the walkie-talkie again.

"Seven minutes left. Without concrete evidence, I'll proceed with the plan to bomb the main entrance."

The forward artillery positions have been loaded, and the muzzles are still pointing towards the main entrance of the mine; none of the cannons have been turned towards the north ventilation shaft.

Fang Xudong looked at the military map and then gazed at the artillery positions in the distance.

"The artillery battalion commander's concerns are valid. Attacking the main entrance can suppress fire, but attacking the ventilation shaft might not damage the generator, and there are several bends in the shaft."

"The shells don't need to directly hit the generator."

Jiang Ming drew the three enemy devices on a piece of paper, marking the shortwave jammer, centimeter-wave radiator, and detonation control panel respectively, and then connected them to the same power distribution node with a thick line.

"The mine originally had three generators that took turns supplying power. Two of them stopped after the main system was attacked. The last one needs to power the ventilation, lighting and radiators at the same time. The load changes will leak from the entire line."

Upon hearing the term "power supply busbar," Lao Sun tightened the anti-vibration box latch and turned around.

"You have to speak to the artillery like a human; they only care about the impact point, the explosive charge, and the kill radius."

"Then let them check the ventilation shaft first."

Jiang Ming took the walkie-talkie and called the artillery observation post directly.

"Can your advanced telescopes see the ventilation shaft on the north slope?"

The observer quickly reported a positive answer: there were no personnel or heavy or light fire activity around the wellhead.

"Look at the heat. The temperature outside the main tunnel is close to zero, but the airflow from the exhaust shaft is able to continuously frost off the protective netting. This is not natural ventilation."

The artillery battalion commander still did not accept this assessment.

"There are people underground, and it's normal for the ventilation shaft to be hot. Do you expect me to change the blasting muzzle based on that alone?"

"The mine lighting has been reduced, and the main communication equipment has stopped transmitting. Ordinary personnel cannot generate enough heat to raise the temperature difference. Only the full-load generator and high-power magnetron are working at the same time."

Jiang Ming handed the microphone to Fang Xudong.

"Extend the probe of the thermistor temperature measuring instrument and place it downwind of the wellhead, away from the metal mesh."

Fang Xudong took out the thermometer from the equipment box and led Comrade Song along the stone ditch to the north. After the probe was connected to a wire of more than ten meters, it was fixed to the front end of an insulated wooden pole.

Using the rocky slope for cover, the two approached the downwind side. Comrade Song lifted the wooden pole over the gravel embankment and probed into the exhaust airflow. The thermometer needle immediately crossed the original scale.

Fang Xudong first zeroed the air in a leeward location, then sent the probe into the airflow, repeating this process three times, with the pointer always stopping at the same position.

"The ambient temperature is -12.5 degrees Celsius, the exhaust airflow is -4.4 degrees Celsius, and the temperature difference is more than eight degrees Celsius."

After reporting the readings to the channel, he did not immediately retract the probe, but measured left and right along the wellhead. The boundary of the hot zone was concentrated on the east side of the protective net, directly opposite the main air duct of the vertical shaft.

The artillery battalion commander couldn't see the instruments, but he could see the white frost continuously melting on the protective netting through his observation scope.

"An octave only indicates that there is machinery below, but it does not prove that the power line would pass through the shaft."

Give me two more minutes.

Jiang Ming connected the audio output of the mobile receiver to a low-frequency oscilloscope, allowing Lu Qinghe to simultaneously monitor shortwave remnants, centimeter-wave pulses, and stray signals generated by the mine's lighting equipment.

The waveforms of different frequency bands are divided into three layers on the screen, each with different strengths and periods, and they are not directly related to each other to the naked eye.

Lu Qinghe lowered the scanning speed and added a narrowband filter at the audio output to extract the low-frequency components below tens of hertz.

A tiny ripple emerged from the background noise, its seventeen cycles filling a one-second mark. No matter which device she switched the receiving frequency to, the ripple did not disappear.

"Shortwave remnants have 17-hertz ripples, centimeter-wave radiators also have them, and even stray signals leaked from lighting ballasts carry the same thing."

Fang Xudong had already returned to the armored vehicle with the thermometer. He took the spectrum film and superimposed the low-frequency ripples of the three signals, with all the peak and valley positions overlapping.

"If each device uses an independent power supply, the speed deviation, rectifier circuit, and load cycle will not be exactly the same."

"The fact that all three devices are now oscillating at the same 17 Hz indicates that they share a generator and also share the rectified power supply bus."

Jiang Ming placed the film next to the walkie-talkie. Although the artillery battalion commander could not see the actual object, the observation post could verify the same ripple through a regular receiver.

"Artillery observation post, switch the receiver to the mine's residual carrier wave, connect the audio end to the oscilloscope, and adjust the scan speed to one-twentieth of a second per division."

The observers adjusted the parameters and reported the same 17 Hz low-frequency fluctuations a moment later.

The artillery battalion commander did not immediately refute, but the assault company in front of the main tunnel entrance had already sent a message urging them to hurry up. Footprints of enemy personnel moving had appeared near the southeast branch tunnel. If they delayed any longer, the technical supervisor might take the data into the deeper tunnel.

"Even with shared power, how could opening the exhaust vent cut off the busbar?"

Jiang Ming used a pencil to draw a bend downwards along the cross-section of the ventilation shaft. A blower and an exhaust fan must be installed at the bottom of the shaft, and the motor cable will be led out from the main distribution panel in the generator room.

The old mine shaft was built many years ago, and the underground cables could not pass through the whole granite block. They could only be laid along the maintenance tunnel and ventilation duct. The ventilation shaft is the only vertical passage in the equipment area on the north side that can accommodate thick cables and maintenance personnel.

"The magnetron consumes too much power after starting up, which slows down the generator speed, causing the 17 Hz ripple to appear on all devices at the same time."

"The temperature in the exhaust shaft is eight degrees higher than normal, which means that the generator and radiator are located below the shaft. The main busbar must pass through the power distribution room at the bottom of the shaft before distributing power to the various tunnels."

"The shells are fired along the wellhead. They don't need to penetrate 200 meters of rock. They only need to impact the cable tray at the bottom of the well, causing the main line to short-circuit or collapse, and the detonator will lose its power source."

The artillery battalion commander asked from the other end of the channel, "Where are the spare batteries?"

"Ordinary detonators can be ignited by batteries. Since they have installed centimeter-wave radiators, it is to trigger them simultaneously across multiple branches. Batteries cannot power this magnetron system."

Jiang Ming glanced at his watch; less than half of the ten minutes remained, and the frontline troops were only a few dozen meters away from the nearest point of the resonance red line.

Inside the underground central chamber, the technical supervisor had already turned the detonation key to the ready position, the green light on the instrument panel lit up, and the centimeter-wave radiator began sending detection pulses into the pipeline according to the set cycle.

The mechanical timer on the wall ticked down to the last three ticks, and three minutes later, all the detonator branches outside the main entrance would be connected.

An operator, carrying a data bag, stood at the entrance of the southeast branch tunnel and waited.

"They haven't come in yet."

"They'll come in. The cannons are always pointed at the main tunnel. They think blowing up the entrance will end it all."

The technical supervisor placed his palm on the detonator button, and the sound of artillery firing above the shaft was muffled by the thick rock layer.

Inside the armored vehicle, Lu Qinghe superimposed the three sets of ripples again, connecting all the peaks into a row of teeth on the transparent film.

"The evidence is sufficient, as long as they are willing to switch sides."

Jiang Ming pressed the microphone.

"Artillery Battalion Commander, the 17 Hz common mode ripple has been verified by your observation post. The temperature difference in the ventilation shaft is eight degrees Celsius, and its location coincides with the power distribution tunnel on the old mine map."

"The main entrance is the target they left for you; the heart of the entire mine is below the ventilation shaft."

The sound of firing tables being turned could be heard over the channel; the artillery battalion commander was still calculating turning times and remaining ammunition.

Deep within Jiang Ming's consciousness, bronze-colored pages surfaced, and three famous calligraphic works simultaneously emitted a golden light. For the first time, complete text appeared in the previously dull academic fusion section.

The interdisciplinary chain of evidence has been completed.

[Prerequisites for academic integration met]

[Should a report on the combined underground power supply and feeder structure be generated?]

With only three minutes remaining on the mechanical timer, Jiang Ming's hand had already landed on the confirmation position.