R-407C is a mixture of hydrofluorocarbons used as a refrigerant. It is a zeotropic blend of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a). Difluoromethane serves to provide the heat capacity, pentafluoroethane decreases flammability, tetrafluoroethane reduces pressure.[1] R-407C cylinders are colored burnt orange.
We aims to provide a complete knowledgeable report so that the readers will benefit from it. The report is properly examined and compiled by industry experts and will shed light on the key information that requires from the clients.
Case numbers are resurging in parts of the world where the COVID-19 pandemic was waning, falling in places that saw huge surges recently, and just beginning to rise in previously little-impacted parts of the globe.
Studying and analyzing the impact of Coronavirus COVID-19 on the R407c Refrigerant industry, the report provide in-depth analysis and professtional advices on how to face the post COIVD-19 period.
Market Segment by Product Type
10 Kg
11.3 Kg
850 Kg
Others
Market Segment by Product Application
Industrial Refrigeration
Residential & Light Air Conditioning
Industrial & Commercial Air Conditioning
Finally, the report provides detailed profile and data information analysis of leading company.
Chemours
Honeywell
Mexichem
Daikin
Weitron
Linde
Actrol
Weitron
ZHEJIANG V&T GROUP LIMITED
Sinochem Qingdao
Liangyou Environmental Protection Chemicals
Shanghai KuAo Refrigeration Equipment
Insights and Tools:
Projected and forecast revenue values are in constant U.S. dollars, unadjusted for inflation.
Product values and regional markets are estimated by market analyst, data analyst and people from related industry, based on companys' revenue and applications market respectively.
The data sources include but not limited to reports of companys,international organizations and governments, MMI market surveys,and related industry news.
Analyses of global market trends, with historical data, estimates for 2022 and projections of compound annual growth rates (CAGRs) through 2027
The market research includes historical and forecast data from like demand, application details, price trends, and company shares by geography, especially focuses on the key regions like United States, European Union, China, and other regions.
In addition, the report provides insight into main drivers,challenges,opportunities and risk of the market and strategies of suppliers. Key players are profiled as well with their market shares in the global market discussed.
Research Objectives
1.To study and analyze the global R407c Refrigerant consumption (value) by key regions/countries, product type and application, history data from 2017 to 2021, and forecast to 2027.
2.To understand the structure of R407c Refrigerant market by identifying its various subsegments.
3.Focuses on the key global R407c Refrigerant manufacturers, to define, describe and analyze the value, market share, market competition landscape, Porter's five forces analysis, SWOT analysis and development plans in next few years.
4.To analyze the R407c Refrigerant with respect to individual growth trends, future prospects, and their contribution to the total market.
5.To share detailed information about the key factors influencing the growth of the market (growth potential, opportunities, drivers, industry-specific challenges and risks).
6.To project the consumption of R407c Refrigerant submarkets, with respect to key regions (along with their respective key countries).
7.To analyze competitive developments such as expansions, agreements, new product launches, and acquisitions in the market.
8.To strategically profile the key players and comprehensively analyze their growth strategies.
Table of Contents
Global R407c Refrigerant Market Research Report 2022, Forecast to 2027
1 Market Study Overview
1.1 Study Objectives
1.2 R407c Refrigerant Introduce
1.3 Combined with the Analysis of Macroeconomic Indicators
1.4 Brief Description of Research methods
1.5 Market Breakdown and Data Triangulation
2 Global Trend Summary
2.1 R407c Refrigerant Segment by Type
2.1.1 10 Kg
2.1.2 11.3 Kg
2.1.3 850 Kg
2.1.4 Others
2.2 Market Analysis by Application
2.2.1 Industrial Refrigeration
2.2.2 Residential & Light Air Conditioning
2.2.3 Industrial & Commercial Air Conditioning
2.3 Global R407c Refrigerant Market Comparison by Regions (2017-2027)
2.3.1 Global R407c Refrigerant Market Size (2017-2027)
2.3.2 North America R407c Refrigerant Status and Prospect (2017-2027)
2.3.3 Europe R407c Refrigerant Status and Prospect (2017-2027)
2.3.4 China R407c Refrigerant Status and Prospect (2017-2027)
2.3.5 Japan R407c Refrigerant Status and Prospect (2017-2027)
2.3.6 Southeast Asia R407c Refrigerant Status and Prospect (2017-2027)
2.4 Basic Product Information
2.4.1 Basic Product Information & Technology Development History
2.4.2 Product Manufacturing Process
2.4.3 Interview with Major Market Participants
2.4.4 High-end Market Analysis and Forecast
2.5 Coronavirus Disease 2019 (Covid-19): R407c Refrigerant Industry Impact
2.5.1 R407c Refrigerant Business Impact Assessment - Covid-19
2.5.2 Market Trends and R407c Refrigerant Potential Opportunities in the COVID-19 Landscape
2.5.3 Measures / Proposal against Covid-19
3 Competition by Manufacturer
3.1 Global R407c Refrigerant Sales and Market Share by Manufacturer (2017-2022)
3.2 Global R407c Refrigerant Revenue and Market Share by Manufacturer (2017-2022)
3.3 Global R407c Refrigerant Industry Concentration Ratio (CR5 and HHI)
3.4 Top 5 R407c Refrigerant Manufacturer Market Share
3.5 Top 10 R407c Refrigerant Manufacturer Market Share
3.6 Date of Key Manufacturers Enter into R407c Refrigerant Market
3.7 Key Manufacturers R407c Refrigerant Key Manufacturers
3.8 Mergers & Acquisitions Planning
4 Analysis of R407c Refrigerant Industry Key Manufacturers
4.1 Chemours
4.1.1 Compan Detail
4.1.2 Chemours R407c Refrigerant Product Introduction, Application and Specification
4.1.3 Chemours 167 Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.1.4 Main Business Overview
4.1.5 Chemours News
4.2 Honeywell
4.2.1 Compan Detail
4.2.2 Honeywell R407c Refrigerant Product Introduction, Application and Specification
4.2.3 Honeywell R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.2.4 Main Business Overview
4.2.5 Chemours News
4.3 Mexichem
4.3.1 Compan Detail
4.3.2 Mexichem R407c Refrigerant Product Introduction, Application and Specification
4.3.3 Mexichem R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.3.4 Main Business Overview
4.3.5 Mexichem News
4.4 Daikin
4.4.1 Compan Detail
4.4.2 Daikin R407c Refrigerant Product Introduction, Application and Specification
4.4.3 Daikin R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.4.4 Main Business Overview
4.4.5 Daikin News
4.5 Weitron
4.5.1 Compan Detail
4.5.2 Daikin R407c Refrigerant Product Introduction, Application and Specification
4.5.3 Weitron R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.5.4 Main Business Overview
4.5.5 Weitron News
4.6 Linde
4.6.1 Compan Detail
4.6.2 Linde R407c Refrigerant Product Introduction, Application and Specification
4.6.3 Linde R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.6.4 Main Business Overview
4.6.5 Linde News
4.7 Actrol
4.7.1 Compan Detail
4.7.2 Actrol R407c Refrigerant Product Introduction, Application and Specification
4.7.3 Actrol R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.7.4 Main Business Overview
4.7.4 Main Business Overview
4.8 Weitron
4.8.1 Compan Detail
4.8.2 Weitron R407c Refrigerant Product Introduction, Application and Specification
4.8.3 Weitron R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.8.4 Main Business Overview
4.8.5 Weitron News
4.9 ZHEJIANG V&T GROUP LIMITED
4.9.1 Compan Detail
4.9.2 ZHEJIANG V&T GROUP LIMITED R407c Refrigerant Product Introduction, Application and Specification
4.9.3 ZHEJIANG V&T GROUP LIMITED R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.9.4 Main Business Overview
4.9.5 ZHEJIANG V&T GROUP LIMITED News
4.10 Sinochem Qingdao
4.10.1 Compan Detail
4.10.2 Sinochem Qingdao R407c Refrigerant Product Introduction, Application and Specification
4.10.3 Sinochem Qingdao R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.10.4 Main Business Overview
4.10.5 Sinochem Qingdao News
4.11 Liangyou Environmental Protection Chemicals
4.11.1 Compan Detail
4.11.2 Liangyou Environmental Protection Chemicals R407c Refrigerant Product Introduction, Application and Specification
4.11.3 Liangyou Environmental Protection Chemicals R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.11.4 Main Business Overview
4.11.5 Liangyou Environmental Protection Chemicals News
4.12 Shanghai KuAo Refrigeration Equipment
4.12.1 Compan Detail
4.12.2 Shanghai KuAo Refrigeration Equipment R407c Refrigerant Product Introduction, Application and Specification
4.12.3 Shanghai KuAo Refrigeration Equipment R407c Refrigerant Sales, Price, Cost, Gross Margin, and Revenue (2017-2022)
4.12.4 Main Business Overview
4.12.5 Shanghai KuAo Refrigeration Equipment News
5 Global R407c Refrigerant Market Segment by Big Type
5.1 Global R407c Refrigerant Revenue, Sales and Market Share by Big Type (2017-2022)
5.1.1 Global R407c Refrigerant Sales and Market Share by Big Type (2017-2022)
5.1.2 Global R407c Refrigerant Revenue and Market Share by Big Type (2017-2022)
5.2 10 Kg Sales Growth Rate and Price
5.2.1 Global 10 Kg Sales Growth Rate (2017-2022)
5.2.2 Global 10 Kg Price (2017-2022)
5.3 11.3 Kg Sales Growth Rate and Price
5.3.1 Global 11.3 Kg Sales Growth Rate (2017-2022)
5.3.2 Global 11.3 Kg Price (2017-2022)
5.4 850 Kg Sales Growth Rate and Price
5.4.1 Global 850 Kg Sales Growth Rate (2017-2022)
5.4.2 Global 850 Kg Price (2017-2022)
5.5 Others Sales Growth Rate and Price
5.5.1 Global Others Sales Growth Rate (2017-2022)
5.5.2 Global Others Price (2017-2022)
6 Global R407c Refrigerant Market Segment by Big Application
6.1 Global R407c Refrigerant Sales Market Share by Big Application (2017-2022)
6.2 Industrial Refrigeration Sales Growth Rate (2017-2022)
6.3 Residential & Light Air Conditioning Sales Growth Rate (2017-2022)
6.4 Industrial & Commercial Air Conditioning Sales Growth Rate (2017-2022)
7 Global R407c Refrigerant Forecast
7.1 Global R407c Refrigerant Revenue, Sales and Growth Rate (2022-2027)
7.2 R407c Refrigerant Market Forecast by Regions (2022-2027)
7.2.1 North America R407c Refrigerant Market Forecast (2022-2027)
7.2.2 Europe R407c Refrigerant Market Forecast (2022-2027)
7.2.3 China R407c Refrigerant Market Forecast (2022-2027)
7.2.4 Japan R407c Refrigerant Market Forecast (2022-2027)
7.2.5 Southeast Asia R407c Refrigerant Market Forecast (2022-2027)
7.2.6 Other Regions R407c Refrigerant Market Forecast (2022-2027)
7.3 R407c Refrigerant Market Forecast by Type (2022-2027)
7.3.1 Global R407c Refrigerant Sales Forecast by Type (2022-2027)
7.3.2 Global R407c Refrigerant Market Share Forecast by Type (2022-2027)
7.4 R407c Refrigerant Market Forecast by Application (2022-2027)
7.4.1 Global R407c Refrigerant Sales Forecast by Application (2022-2027)
7.4.2 Global R407c Refrigerant Market Share Forecast by Application (2022-2027)
8 Market Analysis
8.1.1 Market Overview
8.1.2 Market Opportunities
8.1.3 Market Risk
8.1.4 Market Driving Force
8.1.5 Porter's Five Forces Analysis
8.1.6 SWOT Analysis
9 R407c Refrigerant Related Market Analysis
9.1 Upstream Analysis
9.1.1 Macro Analysis of Upstream Markets
9.1.2 Key Players in Upstream Markets
9.1.3 Upstream Market Trend Analysis
9.1.4 R407c Refrigerant Manufacturing Cost Analysis
9.2 Downstream Market Analysis
9.2.1 Macro Analysis of Down Markets
9.2.2 Key Players in Down Markets
9.2.3 Downstream Market Trend Analysis
9.2.4 Sales Channel, Distributors, Traders and Dealers
10 Research Findings and Conclusion
List of Tables and Figures
Figure Product Picture R407c Refrigerant
Figure Market Concentration Ratio and Market Maturity Analysis of R407c Refrigerant
Figure Bottom-up and Top-down Approaches for This Report
Figure Part of Our External Database
Figure Part of Our External Database
Figure Key Executives Interviewed
Table Global R407c Refrigerant Market Size by Big Type
Figure Global Market Share of R407c Refrigerant by Big Type in 2021
Figure 10 Kg Picture (2017-2022)
Figure 11.3 Kg Picture (2017-2022)
Figure 850 Kg Picture (2017-2022)
Global R407c Refrigerant Market Size by Big Application
Table Global R407c Refrigerant Market Size by Application
Figure Global R407c Refrigerant Market Share by Big Application in 2021
Figure Industrial Refrigeration Picture
Figure Residential & Light Air Conditioning Picture
Figure Industrial & Commercial Air Conditioning Picture
Table Global R407c Refrigerant Comparison by Regions (M USD) (2017-2027)
Figure Global R407c Refrigerant Market Size (Million US$) (2017-2027)
Figure North America R407c Refrigerant Revenue (Million US$) Growth Rate (2017-2027)
Figure Europe R407c Refrigerant Revenue (Million US$) Growth Rate (2017-2027)
Figure China R407c Refrigerant Revenue (Million US$) Growth Rate (2017-2027)
Figure Japan R407c Refrigerant Revenue (Million US$) Growth Rate (2017-2027)
Figure Southeast Asia R407c Refrigerant Revenue (Million US$) Growth Rate (2017-2027)
Table Business Impact Assessment - Covid-19
Table Market Trends and R407c Refrigerant Potential Opportunities in the COVID-19 Landscape
Table Measures / Proposal against Covid-19
Table Global R407c Refrigerant Sales by Manufacturer (2017-2022)
Figure Global R407c Refrigerant Sales Market Share by Manufacturer in 2021
Table Global R407c Refrigerant Revenue by Manufacturer (2017-2022)
Figure Global R407c Refrigerant Revenue Market Share by Manufacturer in 2021
Table Global R407c Refrigerant Manufacturers Market Concentration Ratio (CR5 and HHI)
Figure Top 5 R407c Refrigerant Manufacturer (Revenue) Market Share in 2021
Figure Top 10 R407c Refrigerant Manufacturer (Revenue) Market Share in 2021
Table Date of Key Manufacturers Enter into R407c Refrigerant Market
Table Key Manufacturers R407c Refrigerant Product Type
Table Mergers & Acquisitions Planning
Table Chemours Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Chemours
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company One 2017-2022
Table Company One Main Business
Table Company One Recent Development
Table Honeywell Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Honeywell
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Honeywell Recent Development
Table Mexichem Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Mexichem
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Mexichem Main Business
Table Mexichem Recent Development
Table Daikin Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Daikin
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Daikin Main Business
Table Daikin Recent Development
Table Daikin Main Business
Table Daikin Recent Development
Table Weitron Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Weitron
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Weitron Main Business
Table Weitron Recent Development
Table Linde Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Linde
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Linde Main Business
Table Linde Recent Development
Table Actrol Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Actrol
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Actrol Main Business
Table Actrol Recent Development
Table Weitron Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Weitron
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Weitron Main Business
Table Weitron Recent Development
Table ZHEJIANG V&T GROUP LIMITED Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of ZHEJIANG V&T GROUP LIMITED
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table ZHEJIANG V&T GROUP LIMITED Main Business
Table ZHEJIANG V&T GROUP LIMITED Recent Development
Table Sinochem Qingdao Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Sinochem Qingdao
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Sinochem Qingdao Main Business
Table Sinochem Qingdao Recent Development
Table Liangyou Environmental Protection Chemicals Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Liangyou Environmental Protection Chemicals
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Liangyou Environmental Protection Chemicals Main Business
Table Liangyou Environmental Protection Chemicals Recent Development
Table Shanghai KuAo Refrigeration Equipment Company Profile
Table R407c Refrigerant Product Introduction, Application and Specification of Shanghai KuAo Refrigeration Equipment
Table R407c Refrigerant Sales (K Unit), Price (USD/Unit), Revenue (M USD) and Gross Margin of Company Two 2017-2022
Table Shanghai KuAo Refrigeration Equipment Main Business
Table Shanghai KuAo Refrigeration Equipment Recent Development
Figure Global R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure Global R407c Refrigerant Revenue and Growth Rate (2017-2022)
Table Global R407c Refrigerant Sales by Regions (2017-2022)
Figure Global R407c Refrigerant Sales Market Share by Regions in 2021
Table Global R407c Refrigerant Revenue by Regions (2017-2022)
Figure Global R407c Refrigerant Revenue Market Share by Regions in 2021
Figure North America R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure Europe R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure China R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure Japan R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure Southeast Asia R407c Refrigerant Sales and Growth Rate (2017-2022)
Figure Other Regions R407c Refrigerant Sales and Growth Rate (2017-2022)
Table Global R407c Refrigerant Sales by Big Type (2017-2022)
Table Global R407c Refrigerant Sales Market Share by Big Type (2017-2022)
Figure Global R407c Refrigerant Sales Market Share by Big Type in 2019
Table Global R407c Refrigerant Revenue by Big Type (2017-2022)
Table Global R407c Refrigerant Revenue Market Share by Big Type (2017-2022)
Table Global R407c Refrigerant Revenue Market Share by Big Type in 2019
Figure Global 10 Kg Sales Growth Rate (2017-2022)
Figure Global 10 Kg Price (2017-2022)
Figure Global 11.3 Kg Sales Growth Rate (2017-2022)
Figure Global 11.3 Kg Price (2017-2022)
Figure Global 850 Kg Sales Growth Rate (2017-2022)
Figure Global 850 Kg Price (2017-2022)
Figure Global Others Sales Growth Rate (2017-2022)
Table Global R407c Refrigerant Sales by Big Application (2017-2022)
Table Global R407c Refrigerant Sales Market Share by Big Application (2017-2022)
Figure Global R407c Refrigerant Sales Market Share by Big Application in 2019
Figure Global Industrial Refrigeration Sales Growth Rate (2017-2022)
Figure Global Residential & Light Air Conditioning Sales Growth Rate (2017-2022)
Figure Global Industrial & Commercial Air Conditioning Sales Growth Rate (2017-2022)
Figure Global R407c Refrigerant Sales and Growth Rate (2022-2027)
Figure Global R407c Refrigerant Revenue and Growth Rate (2022-2027)
Table Global R407c Refrigerant Sales Forecast by Regions (2022-2027)
Table Global R407c Refrigerant Market Share Forecast by Regions (2022-2027)
Figure North America Sales R407c Refrigerant Market Forecast (2022-2027)
Figure Europe Sales R407c Refrigerant Market Forecast (2022-2027)
Figure China Sales R407c Refrigerant Market Forecast (2022-2027)
Figure Japan Sales R407c Refrigerant Market Forecast (2022-2027)
Figure Southeast Asia Sales R407c Refrigerant Market Forecast (2022-2027)
Figure Other Regions Sales R407c Refrigerant Market Forecast (2022-2027)
Table Global R407c Refrigerant Sales Forecast by Type (2022-2027)
Table Global R407c Refrigerant Market Share Forecast by Type (2022-2027)
Table Global R407c Refrigerant Sales Forecast by Application (2022-2027)
Table Global R407c Refrigerant Market Share Forecast by Application (2022-2027)
Table Market Opportunities in Next Few Years
Table Market Risks Analysis
Table Market Drivers
Figure Porter's Five Forces Analysis
Table Macro Analysis of Upstream Markets
Table Key Players in Upstream Markets
Table Key Players of Upstream Markets
Table Key Raw Materials
Figure Price Trend of Key Raw Materials
Table Key Suppliers of Raw Materials
Figure Manufacturing Cost Structure of R407c Refrigerant
Table Macro Analysis of Down Markets
Table Key Players in Down Markets
Table Key Players of Downstream Markets
Figure Sales Channel
Figure North America R407c Refrigerant Sales (K Units) Growth Rate Forecast (2021-2025)
Figure North America R407c Refrigerant Revenue (Million US$) Growth Rate Forecast (2021-2025)
Figure Europe R407c Refrigerant Sales (K Units) Growth Rate Forecast (2021-2025)
Figure Europe R407c Refrigerant Revenue (Million US$) Growth Rate Forecast (2021-2025)
Figure Japan R407c Refrigerant Production (K Units) Growth Rate Forecast (2021-2025)
Figure Japan R407c Refrigerant Revenue (Million US$) Growth Rate Forecast (2021-2025)
Figure China R407c Refrigerant Production (K Units) Growth Rate Forecast (2021-2025)
Figure China R407c Refrigerant Revenue (Million US$) Growth Rate Forecast (2021-2025)
Figure Methodology/Research Approach
Figure Market Size Estimation
Figure Author List
Chemours
Honeywell
Mexichem
Daikin
Weitron
Linde
Actrol
Weitron
ZHEJIANG V&T GROUP LIMITED
Sinochem Qingdao