From a distance, it's a flat land.

Up close, there is still a stone chip cushion foundation left by the removed tube building on this flat land, forming a rectangular gray structure that has been cut very neatly.

One of the rectangles has a hole in a square. The staircase of the cave leads to a basement that was the only commissary in the old neighborhood when the above-ground part was still there. From the miscellaneous items piled up at the "hole", you can see the account book of the commissary, which says that the last time the goods were purchased, just four days ago.

There was still a man lying on the side of the brick road next to this pile of debris.

It might be a bit polite to say that she was a person, because judging by normal human common sense, she should be a dead person, if not judged to be a corpse: wearing a dark red plaid shirt and black sweatpants, a black rollerball hanging between her right fingers, and a purple headband tied around her left wrist, but she has a deep wound on the border between her neck and collarbone, her body lying flat on the pavement, and her head is relatively low, and blood runs down her hair onto the masonry pavement, forming a dark red puddle. However, the blood pressure has now been lowered to the same level as the atmospheric pressure, so it is no longer significantly flowing.

Next to this "dead man" lay a black hiking bag, next to which was a pack of absorbent paper and a blood-stained utility knife. On the top of the mountaineering bag is a men's mechanical watch, and an orange notebook is spread out next to it, and the current page is full of experiment logs:

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【August 12th 15:00】

Death by suffocation - self-hanging: Failure

Instruments and materials: two-ball plane wood, rope (obtained from the commissary), maza (obtained from the commissary), mechanical watch (possibly owned by the original commissary owner)

Experimental process: Start looking for ropes and trees, put your head in it, and pedal the horse to make your feet hang in the air; asphyxia after about 15 seconds; Disconnect the rope sleeve after losing consciousness at 1min~4min (speculation: it may be due to convulsions caused by hypoxia, pay attention next time); Full regain of consciousness after 5 minutes.

NDE Record: Tinnitus and fever after asphyxiation, followed by hallucinations, feeling calm, and flashes of light in the dark.

【August 12th 16:30】

Asphyxiation to death - self-hanging: 2nd Round

Instruments and materials: Ibid

Procedure: Begin to pre-tighten the rope sleeve and hang it around the neck to ensure that it will not detach, and then fix it on the branch; 13s, suffocation; 3min~3.5min, loss of consciousness; At 13 min, consciousness begins to be restored; 15min, voluntarily detached from the rope sleeve, dark purple strangulation marks on the neck, slight deformation; After 17min, the strangulation marks and deformation disappeared completely.

NDE Notes: Tinnitus and fever after asphyxia, followed by a feeling of calm and pleasantness, a dark vision with a bright central light, sound of running water, auditory hallucinations, and a seeming out-of-body experience (I can't remember exactly).

【August 13th 11:30】

Suffocation to death - self-hanging: 3rd Round

Instruments and materials: two-ball plane wood, rope, maza, bracelet with heart rate monitoring function (found in the commissary), mechanical watch

Procedure: Tighten the rope around the neck, fix it on a branch, and start recording the bracelet; 17s, suffocation; 3min~3.5min, loss of consciousness; After 12 minutes, after regaining consciousness, he voluntarily detached from the rope sleeve, and the neck was deeply purple and slightly deformed; After 13 minutes, the strangulation marks and deformation disappeared completely.

NDE Records: Tinnitus and fever after asphyxiation, flowing light spots in the center of the dark field of vision after near-death, and out-of-body experience of seeing the subject hanging from a tree, with blurred details.

[Attached: Hand-drawn heart rate horizontal line chart]

【August 13th 15:00】

Death from blood loss - wrist cutting: failed

Instruments and materials: bracelets, utility knives, mechanical watches

Experimental procedure: find the location of the radial artery for incisation; 10min, give up; After 15 minutes, the wound healed completely.

NDE Record: I had to give up the experiment because it was too painful, and there was no NDE.

[Attached: Hand-drawn heart rate horizontal line chart]

【August 13th 19:00】

Death from blood loss - Cut wrists: 2nd Round, failed

Instruments and materials: bracelets, knives (found in the commissary), mechanical watches

Experimental procedure: find the location of the radial artery, insert the knife tip forcefully and pull it out; 5min, the wound stopped bleeding; 12min, completely healed, feeling thirsty; About 30min, ingesting 1.25L of cola, the thirst was completely relieved.

NDE Record: No NDE, just cold. (Note: The recovery function is strong, so this method is abandoned)

[Attached: Hand-drawn heart rate horizontal line chart]

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【August 13th 22:00】

Resilience test

Instruments and materials: knives, mechanical watches

Procedure: [Table: Number of behavioral experiments, listed as Recovery Time (S)]

Data processing: Fitting formula: t=-ax+b

[Calculation Process]

Conclusion: The recovery time decreases with the number of training sessions, which is in line with a linear trend. (crossed out) has not been statistically tested, and this conclusion is incorrect.

【August 14th, 9:30】

Resilience Test: Supplemental Experiment

Instruments and materials: utility knives, mechanical watches

Procedure: [Table: Number of behavioral experiments, listed as recovery time]

【August 14th 19:00】

Statistical test: coefficient of decision (R^2) test

Instruments and materials: Solar CASIO Scientific Calculator (found in the commissary)

Hypothesis: One curve fit, t=-ax+b

[Calculation Process]

Hypothesis: quadratic curve fit, t=-ax^2+b

[Calculation Process]

Hypothesis: quadratic curve fitting, t=-a(x-c)^2+b

[Calculation Process]

Conclusion: t(s)=-106.8(x-7)^2 + b, R^2 = 0.982. The b-value has no practical significance, just need to know the relative time reduction.

[Calculation Process]

The carotid artery flow rate can meet the experimental requirements.

The plan: try the carotid artery tomorrow.

【August 15th 10:00】

Death from blood loss - carotid artery:

Instruments and materials: utility knives, mechanical watches

Experimental procedure: find the carotid artery, quickly insert it and pull it out;

NDE Experience:

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After a while, the "corpse" on the ground trembled slightly, its pale fingers.

Then she came to life, sat up like nothing, put down the pen, tied her blood-soaked hair, wrung out a piece of absorbent paper, and wiped her hands with the paper. She took out a watering can for watering flowers from her backpack, washed her hands with the sprayed water, and then picked up the pen and continued to write in the "Experimental Process" on the notebook: "30s, the blood flow is fast; 1 min, confusion, to loss of consciousness; 6min, regain consciousness, at this time the bleeding has been completely stopped. ”

As she wrote, she also muttered to herself: "When is the confusion of consciousness...... Just write for a minute. When I woke up—more than five minutes and forty seconds, it was six minutes. ”

Then she wrote in the "NDE Experience": "I feel cold, and the irregular light spot in the center of the vision is dark......"

"It's the same, alas." She muttered again, and continued to write "the hallucinations that appeared on the frozen lake afterwards", hesitated for a moment, as if to add a little "unwarranted speculation", and then honestly put an end to it.

After she finished writing, she closed the notebook, and from the "name" column on the cover of the notebook, it was clear that her name was "Zheng Rui", and the "department" column below was impressively written "biology".