UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)		Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash		$ 78,891,580	$ 41,301,817
Restricted cash		427,321,731	325,690,023
Accounts receivable, net of allowance for doubtful accounts		154,051,127	294,688,288
Inventories		793,243,874	620,033,195
Prepaid expenses and other current assets		96,270,070	132,218,528
Total current assets		1,549,778,382	1,413,931,851
Property, plant and equipment, net		770,413,511	775,941,280
Land use rights, net		30,213,879	29,796,795
Long-term prepayments to equipment and construction suppliers		524,297,914	530,636,319
Operating lease right-of-use assets, net		15,918,647
Other non-current assets		3,171,583	3,212,986
Total assets		2,893,793,916	2,753,519,231
Current liabilities:
Short-term bank loans, including current portion of long-term bank loans		723,302,348	729,666,920
Bills payable		730,318,556	618,166,453
Accounts payable		40,865,322	84,958,469
Amounts due to related parties	[1]	18,995,751	18,365,738
Income taxes payable		16,337,961	15,975,367
Operating lease liabilities, current		2,304,598
Accrued expenses and other current liabilities		82,423,884	126,926,898
Total current liabilities		1,614,548,420	1,594,059,845
Long-term bank loans, excluding current portion		188,183,909	111,808,244
Deferred income		100,255,791	99,583,477
Operating lease liabilities, non-current		14,666,805
Other non-current liabilities		103,993,582	101,573,772
Total liabilities		2,021,648,507	1,907,025,338
Redeemable Series D convertible preferred stock (redemption amount of US$290,491,100 and US$280,650,800 as of March 31, 2019 and December 31, 2018, respectively)		97,576,465	97,576,465
Stockholders' equity:
Series B preferred stock		100	100
Common stock, US$0.0001 par value, 500,000,000 shares authorized, 50,969,841 shares issued, 50,948,841 shares outstanding as of March 31, 2019 and December 31, 2018, respectively		5,097	5,097
Treasury stock, 21,000 shares at cost		(92,694)	(92,694)
Additional paid-in capital		86,633,582	86,633,582
Retained earnings		728,084,605	717,103,890
Accumulated other comprehensive loss		(40,061,746)	(54,732,547)
Total stockholders' equity		774,568,944	748,917,428
Commitments and contingencies
Total liabilities, redeemable convertible preferred stock and stockholders' equity		$ 2,893,793,916	$ 2,753,519,231

[1] During the year ended December 31, 2018, the Company received RMB68.0 million (equivalent to US$10.1 million) from Mr. Jie Han, the Chairman of the Company, RMB21.8 million (equivalent to US$3.2 million) from Ms. Limei Sun, the wife of Mr. Jie Han, RMB5.0 million (equivalent to US$0.7 million) from Mr. Tiexin Han, the son of Mr. Jie Han.