Zihan Zhang

Hi, I’m Zihan Zhang.

 

I’m from Shanghai, China.

I am interest in Economics, Environmental Science, Applied Mathematics and Statistics.

I am looking forward to meeting you.

 

Zihan Zhang
Plant Diary
Plant Diary
School's SAGE Business Club
SAGE Club
Fieldwork at Ningshan County
Fieldwork
Eco Ranger's Green Mission
Eco Ranger
Volunteer Work
Volunteer
Research
Research

Fieldwork

Fieldwork at Ningshan County

A four-day rural investigation in southern Shaanxi — meeting villagers, recording wildlife, and presenting findings on sustainable tourism.

Diaries & Presentation

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Exploring Nature

Plant Diary

Plant Diary page 1
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One day while walking down the school’s hallway, I spotted cracked soil on the ground. A bamboo shoot was coming out of the soil, just like Excalibur being pulled out from the stone in the legend of King Arthur. The bamboo’s dark brown sheaths were like layers of fish scales that wrapped tightly around the inside shoot, forming a sharp contrast with the tall, green bamboos nearby. Over the next few days, I slowed down each time passing by and squatted for a closer look. The sheaths gradually split open layer by layer from the bottom up along the stem, with dry edges curling outward. Rainwater accumulated in the folds between layers and didn’t evaporate until the temperature rose in the afternoon. In just one week, the shoot grew up to 1.8 meters with an incredible speed.

This unexpected finding sparked my curiosity. I joined the school’s Flower & Plant Service Team, carrying a notebook and camera to explore the campus whenever I had free time between classes, at lunch, or after school. The willow trees by the pond had dark brown barks covered with longitudinal cracks, rough and wrinkled like an elder’s hand. The photinia bushes beside the playground were covered with white flowers, emitting a distinctive pungent smell during the flowering season. The Buddhist pine beneath the classroom building had leathery leaves that spread outward like the sharp spines of a hedgehog.

I also saw gardeners working hard multiple times. Lawns overgrown with weeds were trimmed neatly every month; flower pots at the school gate were replaced with fresh flowers as seasons changed; pothos in offices were regularly moved outside to receive sunlight. I realized that the beautiful and lively campus scenery does not happen by chance — someone has always been caring for it behind the scenes.

Beyond observing plant morphology, I noticed subtle changes that can be easily missed. Hydrangeas growing in different parts of campus bloomed in different colours. I compared and recorded soil conditions at each site and discovered a pattern: blooms turned blue and purple in acidic soil and pink in alkaline soil, and a single flower could even show mixed colors. A cactus on the art classroom’s windowsill caught my eye: its petals opened and closed many times within one day. I visited it continuously over several days, recording the exact times its petals unfurled and folded back. It turned out that the flower opened fully on bright, sunny days and curled inward in the evening as the temperature dropped. Shifts in light also influenced its cycle of opening and closing.

I recorded my observations in a plant diary alongside the photos I took, hoping to bring more attention to the plant life surrounding us every day. Starting from the volunteer team, I encouraged peers to step outside and observe campus greenery. I combined our separate notes to expand and improve the note. To attract more students, I added the cultural value of plants into my diary. For example, the Chinese word for kumquat sounds similar to the word for good fortune. Pomegranate’s abundant seeds symbolize reunion and prosperity.

More students began to join. Members of school’s TV station took photos around campus and turned plant scenery into postcards. Students from the biology club collected fallen flowers and leaves to make specimens, which they later displayed and sold at campus fairs. My plant diary has been passed down to new students, who continue to add their own observations. The campus truly grew into a harmonious home shared by humans and plants.

Research

Research

My current research interests focus on the financial implications of sustainability and on mathematical modeling of environmental questions.

01

ESG performance and cost of debt

Empirical study · U.S. public firms, 2002–2018

Environmental, Social, Governance Performance and the Cost of Debt

This study examines the relation between ESG performance and the cost of debt. The sample consists of 9,763 firm-year observations for U.S. public firms over the period 2002–2018. The research applies baseline regressions with firm-level controls, year and two-digit SIC industry fixed effects, alongside cross-sectional analysis, ESG pillar analysis, endogeneity tests and robustness tests.

The main finding shows that higher ESG scores are associated with lower loan spreads. This negative relation is more pronounced among small-sized firms and loss-making firms and is primarily driven by the governance pillar of ESG.

Keywords: ESG performance; loan spread; cost of debt; corporate governance.

02

HiMCM 2025

Mathematical Contest in Modeling · Team #16547

This problem is from the contest of 2025 HiMCM (High School Mathematical Contest in Modeling) – Problem B: Environmental Impact of Sport Mega-Events

Question

As we grow more concerned about sustainability, large-scale sporting events or sport mega events like the Super Bowl are being made more environmentally responsible. External organizations have developed models and scoring systems to rate the sustainability of these large-scale events based on many factors from energy use and waste management to transportation and carbon offsets.

The Consulting Organization Making Athletics Planet positive (COMAP) has hired your team as sustainability consultants to assess and reduce the environmental footprint of sport mega-events. The goal is to understand the ecological impact of these events and explore how changes in event planning could make a difference.

  1. Understand the Problem. Investigate the environmental impact of hosting a sport mega event using 2025 Super Bowl LIX in New Orleans, USA as a baseline.
  2. Create Your Model. Create a model to determine where to hold the next Super Bowl based completely on environmental concerns. When building the model, teams should consider what drives environmental impact and how location specific characteristics can make a difference. Keep in mind that your model may be qualitative or quantitative.
  3. Apply Your Model. Determine which city should host the Super Bowl in 2029, the next year currently without a confirmed location.
  4. Expand Your Model and Reflect on Your Analysis.
  5. Share Your Model and its Results. Write a one-to-two-page letter to the NFL recommending your chosen host city for the Super Bowl in 2029. In your letter, persuade the organization to accept your choice by highlighting the environmental advantages associated with your proposal. Be specific about why your top choice stands out and how it aligns with sustainability goals.

Question in detail

2025_HiMCM_Problem_B.pdf

Our paper

HiMCM_16547.pdf

Team

I led a team of four members, including myself.

  • ZZ

    Zihan Zhang Team lead

    Data collecting, mathematical modeling, programming, paper writing and verification.

  • MC

    Meizhen Chen

    Mathematical modeling, drafting “NFL Host City Letter”.

  • RH

    Ruoyang Huang

    Illustration making, drafting Introduction & Model Assumption.

  • JX

    Jessica Xu

    Data collecting, drafting Strength & Limitation, Conclusion.

SAGE Club

School’s SAGE Business Club

A

Group photo of club members

SAGE stands for Students for the Advancement of Global Entrepreneurship. As the school’s only business club, we chose this name because we hope every member can build an entrepreneurial mindset, a strong sense of social responsibility, awareness of sustainable development, and a global vision.

Our club is split into three main teams:

  1. Academics Team: Host economics & business-related sharing sessions and take part in business competitions
  2. Events Team: Plan and run campus activities including garden party, club festivals and other school events
  3. Design Team: Create our club’s unique merchandise, such as plush bears, T-shirts, fridge magnets and so on.

We have around 35–40 members each year, made up of Grade 10 and Grade 11 students. The photos above show our club group pictures from my Grade 11 and Grade 10 years, respectively. Every year, we hold two to three club-bonding events. We spend roughly 30% of our annual club revenue on these gatherings, to celebrate all the hard works our club members have done over the past year. Another 40% of our income goes toward developing new merchandise and covering production and startup costs. The remaining 30% is used to support brand-new student clubs on campus, helping them start and develop. We also donate part of these funds to off-campus charity organizations.

B

Stall on Club Festival

Designed merchandises

Canvas tote bag design
Envelope design
Campus scene poster
Plush mascot

Stall

When I was in Grade 10, I joined the Design Team. I turn my creative ideas into finished designs that we sold around school at annual celebrations and holiday events. Some of my most successful projects include:

  • Campus-scenery-themed memo pads, with 12 unique designs in total. Priced at ¥4 per notebook, we sold over 100 copies in just two days.
  • Gold-stamped envelopes in red, green and blue. They feature school buildings, our club’s plush bear and the SAGE logo. At ¥16 for a set of three, more than 100 sets were sold within one school year.
  • Little goose plush toys, with changeable clothes like glasses and scarves that buyers could mix and match. The clothing came free with purchase. We sold over 200 plushies at ¥58 a piece.

We also have our signature club product: campus plush bear. It is by far our most popular item and always sells out most quickly. Last year, we even expanded sales to another branch campus and built a cross-campus distribution partnership with their business club. The bears come with red, blue or green outfits — either casual T-shirts or formal suits — matching the school uniforms of each grade level. Priced at ¥65 each, 400 bears were completely sold out over one weekend during our school’s open-day.

C

Campus Monopoly Game

I created this board game ahead of our annual club festival. I aim to draw more students to our SAGE stall and keep them engaged. I redesigned a map of our school as the game map, turning real campus buildings into purchasable properties. I added fun, school-themed surprise events on special squares. For example, landing on our campus snack shop “Sweet Hut” lets players enjoy a snack bonus; getting caught during a dorm check-in means you have to stay still until the punish time period ends.

I worked with local suppliers to produce the physical board, print event cards and rulebooks. Different-colored Lego blocks represented each player. Within just one hour, more than 100 students stopped by to play, and the game got positive feedback. The full set of game rules is in the attached document above.

D

Course slides

After I entered Grade 11, I took on the role of Academics Team Lead. I wanted to pass on what I had learned from my AP Microeconomics and Macroeconomics classes, as well as my hands-on experience from outside competitions including IEO, NEC and BPC, to younger students in our club. I created a ten-session lesson series covering game theory, risk-taking decisions, behavioral economics and other economic topics in real life.

During these classes, we also played my Campus Monopoly Game. This helped our members fully understand how the game worked, so they could confidently explain the rules and answer visitors’ questions at the club festival. It was incredibly joyful to watch my teammates grow — many started out only curious about economics with very little background knowledge, and slowly learned how to connect economic concepts to everyday life. That experience showed me how meaningful it can be to share knowledge with others.

Volunteer

Volunteer Work

A

Bring children experience woodblock rubbing

I have volunteered at Shanghai Library East Branch and Shanghai Library Huaihai Branch since 2025. During this past winter vacation, I was assigned to the children’s section by library staff. As the Lunar New Year was approaching, the library held a woodblock rubbing activity. I happened to have experienced this traditional Chinese craft earlier, during a school farm-study trip to Chongming Island, so I was already familiar with the whole process. My job was to guide young kids print festive patterns to welcome the new year.

The process of woodblock rubbing is as follows.

  1. Spread paint evenly over a carved wooden board.
  2. Lay a sheet of paper on top, tuck its edges under the board, and roll a brayer back and forth so the paint transfers fully onto the paper.
  3. Lift the paper off slowly to avoid smudging, revealing a beautiful finished pattern.

We offered black and gold ink. The gold ink faded quickly and often produced blurry, incomplete prints. Most visitors in the children’s section were under 10 years old, and nearly all of them preferred the bright, eye-catching gold color. Hoping to give them a wonderful experience, I tested several different types of paper. Eventually I found that paper napkins worked best — this highly absorbent material held the gold pigment far better. After switching materials, the prints turned out much clearer, and I could see how happy the kids were. Kids had small hands and lacked the strength to hold the board steady while rolling the brayer. So I held the board for them and repair prints that came out faint. In total, I helped over 100 children discover the charm of this traditional craft.

B

Help readers borrow books

Books at Shanghai Library are shelved by categories — for example, D stands for politics-related books and J stands for art books. Readers often struggle to locate books when they are unsure which category the book falls into. When visitors felt confused, I showed them how to use the library’s book-search website: type in the book title, check whether it was available or lent out, then head to the right shelf after obtaining each book’s unique serial number. Even with clear directions, readers still met problems. Sometimes shelf numbers skipped between levels. Other times readers reshelved books in the wrong spot. In those cases, I helped search for missing books, sometimes books were in the book-return cart, other times I checked records and found books were at different floors.

Beyond book searching, I assisted readers to use the borrowing machines. One common confusion was that the children’s section only had a borrowing machine, with no returning machine. Many people showed up trying to return their books, so I directed them to the correct return location. I also explained library borrowing rules: the standard loan period is 28 days, renewable for up to 56 days total, late returns incur fines, and each person may borrow a maximum of 15 books before having to return older ones...

Whenever new users came to borrow books, I taught them patiently through every step. I also handled unexpected issues from time to time — expired QR codes for borrowing, blocked accounts from overdue books, or repaying fees for lost books. In these situations, I transmitted their concerns to more experienced library staff so that problems could be solved properly. Altogether, I assisted roughly 800 library visitors. Spending time with children and supporting readers helped me understand what being a volunteer truly means: showing genuine kindness to everyone around me.

C

Sort and deliver books

Apart from these front-end tasks, I also took part in the works behind scene to support the library’s internal operations. At the Huaihai Branch, I worked in the storage room. My role was similar to a delivery worker. I received book request scrips sent by fax, located these books by the call numbers, and placed each book with its scrip into a small transport cart. The cart then travelled through the library’s internal conveyor system to deliver books to the correct floor, so readers could pick them up without walking across the whole building. I transported more than 100 books in total. This job gave me insight into the daily routine of library employees. While the repetitive work could feel tedious sometimes, I found it worthy in serving others and improving the local community.

Edutainment Game

Eco Ranger’s Green Mission

Click this link to experience the game!

Detailed game introduction

The progress of building this game

After taking the environmental science course at school, I came to see how closely humans are connected to the Earth. I began to notice many unsustainable habits in daily life, such as excessive food waste in school cafeterias and peers leaving lights and air-conditioners on in empty classrooms. Although terms like carbon emissions and carbon neutrality are well known, most people still don’t have the awareness to turn these environmental ideas into real-life action. To make a change, I decided to take a novel approach: creating an edutainment game to transform environmental science into a world that players can explore and reshape.

The idea for designing a game originated from my volunteer work at Shanghai Library. My responsibility was guiding young children through woodblock rubbing activities, a traditional Chinese craft, to welcome the New Year. As I interacted with kids, I witnessed their intense curiosity about the mechanics behind printmaking. They were surprised when they obtained delicate horse patterns from wooden planks, asking endless questions about how rollers and ink boards created such vivid pictures. This process made me realize that simply lecturing children about cultural or scientific knowledge can hardly catch their attention. Without playful participation, they would quickly become bored and distracted. Game serves as a powerful tool to attract audiences and make knowledge accessible.

I began incorporating renewable energy and ecological concepts I learned in environmental science class into my game. For example, after discovering that biofuel generates far fewer CO2 emissions than coal, I created a farm-themed scene where players collect cow dung to produce biofuel. Based on the knowledge that mangrove forests provide vital ecosystem-regulating services, I designed a plot where players protect mangrove habitats by clearing litter and caring for resident wildlife. I developed a 6-stage gameplay where players can protect forests, accumulate carbon assets, and trade them strategically to experience a simplified version of the real-world carbon market.

I searched real-world data and built up some formulas to support the scoring mechanism of this game:

  • 2kg cow manure + charging time ≤ 1.2s + heat power ≥ 80W = 3kg reduction in CO2 emissions.
  • Removing 1 unit of coastal litter = 2kg increase in blue carbon
  • Final game score = Σcarbon credit trading volume × carbon price × pledge rate (which fluctuates between 20% & 30%)

To make the game appealing to children, I used pixel art as the game’s art style. Factories and banks appear as friendly patterns rather than the serious buildings in realistic scenes. Since most people live in cities nowadays, the scene of farms and factories may seem unusual. I wish that the contrast between cities and countrysides can attract them to explore further and learn the lifestyle of countryside, which is to live in harmony with nature.

I established a publicity team of 15 people to bring this game to schools, corporations and communities, spreading carbon finance knowledge to more people. During promotion, we received plenty of feedback and suggestions from players of different backgrounds and made corresponding improvements.