【正文】 s new deal, imposed a five percent excise tax on dividend receipts, imposed a capital stock tax and an excess profits tax, and suspended all deductions for losses (June 16, 1933, ch. 90, 48 Stat. 195). The repeal in 1933 of the eighteenth amendment, which had prohibited the manufacture and sale of alcohol, brought in an estimated $90 million in new liquor taxes in 1934. The social security act of 1935 provided for a wage tax, half to be paid by the employee and half by the employer, to establish a federal retirement fund (Old Age Pension Act, Aug. 14, 1935, ch. 531, 49 Stat. 620). The Wealth Tax Act, also known as the Revenue Act of 1935, increased the maximum tax rate to 79 percent, the Revenue Acts of 1940 and 1941 increased it to 81 percent, the Revenue Act of 1942 raised it to 88 percent, and the Individual Ine Tax Act of 1944 raised the individual maximum rate to 94 percent. The postWorld War II Revenue Act of 1945 reduced the individual maximum tax from 94 percent to 91 percent. The Revenue Act of 1950, during the korean war, reduced it to percent, but it was raised the next year to 92 percent (Revenue Act of 1950, Sept. 23, 1950, ch. 994, Stat. 906). It remained at this level until 1964, when it was reduced to 70 percent. The Revenue Act of 1954 revised the Internal Revenue Code of 1939, making major changes that were beneficial to the taxpayer, including providing for child care 基于 PLC 的井下排水控制系統(tǒng)設(shè)計(jì) 33 deductions (later changed to credi。 trust, 158 . 601, 15 S. Ct. 912, 39 L. Ed. 1108 [1895]). After many years of debate and promise, the sixteenth amendment to the Constitution was ratified in 1913, providing Congress with the power to lay and collect taxes on ine without apportionment among the states. The objectives of the ine tax were the equitable distribution of the tax burden and the raising of revenue. Since 1913 the . ine tax system has bee very plex. In 1913 the ine tax laws were contained in eighteen pages of legislation。 disdain for this taxation without representation (socalled because the colonies had no voice in the establishment of the taxes) gave rise to revolts such as the Boston Tea Party. However, even after the Revolutionary War and the adoption of the . Constitution, the main source of revenue for the newly created states was money received from customs and excise taxes on items such as carriages, sugar, whiskey, and snuff. Ine tax first appeared in the United States in 1862, during the Civil War. At that time only about one percent of the population was required to pay the tax. A flatrate ine tax was imposed in 1867. The ine tax was repealed in its entirety in 1872. Ine tax was a rallying point for the Populist party in 1892, and had enough support two years later that Congress passed the Ine Tax Act of 1894. The tax at that time was two percent on individual ines in excess of $4,000, which meant that it reached only the wealthiest members of the population. The Supreme Court struck down the tax, holding that it violated the constitutional requirement that direct taxes be apportioned among the states by population (pollock v. farmers39。 最后，再次向我的導(dǎo)師 張 星榮 老師和所有曾給予我?guī)椭娜吮硎菊嬲\的感謝！感謝你們?cè)趯W(xué)業(yè)和生活中給予我的指導(dǎo)、理解和支持！ 由于本人水平有限， 本文 難免有缺點(diǎn)或未涉及到的地方，懇請(qǐng)各位老師加以批評(píng)指正。在寫作的過程中，是你們幫我解決一些難題與困惑，也幫助我學(xué)會(huì)更多的知識(shí)。我也會(huì)將這些態(tài)度帶到我以后的生活和工作中去，認(rèn)真面對(duì)自己的生活，對(duì)待生活和工作中遇到的困難也要做到抓住每一個(gè)問題并尋找解決方案，對(duì)待問題不能含糊。 沈陽工程學(xué)院畢業(yè)設(shè)計(jì)（論文） 30 致 謝 本篇論文是在我的導(dǎo)師張 星榮 老師的指導(dǎo)下完成的，首先要向我的老師表達(dá)最誠摯的謝意！ 在本學(xué)期的畢業(yè)設(shè)計(jì)過程中，從選題到細(xì)化方向，從查閱資料到完成論文，都凝聚著老師的心血。 綜合本次設(shè)計(jì)內(nèi)容，可以看出井下排水系統(tǒng)是綜合了各方面因素進(jìn)行選擇和控制，工作狀態(tài)具有較高的可靠性與穩(wěn)定性，但是仍有很多不足之處，有很多因素例如傳感器輸入信號(hào)的靈敏度、監(jiān)測(cè)模擬的準(zhǔn)確程度等等還需要更進(jìn)一步的研究，未來礦山自動(dòng)化發(fā)展的要求，還需要加入更多例如神經(jīng)網(wǎng)絡(luò)技術(shù)等較先進(jìn)的技術(shù)，使其不斷發(fā)展、完善。針對(duì)系統(tǒng)所處的實(shí)際環(huán)境，選取合適的傳感器，采取一些抗干擾措施，以保證系統(tǒng)可靠、穩(wěn)定的運(yùn)行。采用自動(dòng)、半自動(dòng)和手動(dòng)三種操作模式相結(jié)合，用西門子 S7300 系列 PLC 進(jìn)行自動(dòng)控制，主要排水設(shè)備水泵及管路采用自動(dòng)輪換工作制，以確保水泵及管路的正常使用并延長其使用壽命。監(jiān)控畫面形象易懂 ， 工作人員 可以 方便的進(jìn)行監(jiān)控操作。當(dāng)有故障發(fā)生，故障畫面就會(huì)立即彈出，用以提示監(jiān)控人員并方便其查看操作。因此，一旦發(fā)現(xiàn)預(yù)加入的異常邏輯關(guān)系程序被執(zhí)行，就可立即得知對(duì)應(yīng)的設(shè)備故障 ， 操作員可以據(jù)此方便的采取報(bào)警、停機(jī)等保護(hù)措施。在設(shè)備正常運(yùn)轉(zhuǎn)時(shí)，控制系統(tǒng)的各個(gè)輸入、輸出信號(hào)、中間記憶裝置等 互相 存在確定的邏輯關(guān)系。如果結(jié)果符合正常值的要求，說明一切正常，系統(tǒng)可以正常運(yùn)轉(zhuǎn)，反之，則需要啟動(dòng)報(bào)警程序，并且根據(jù)故障的不同和故障嚴(yán)重程度不同分別采取不同的保護(hù)方案。 圖 監(jiān)控主畫面 沈陽工程學(xué)院畢業(yè)設(shè)計(jì)（論文） 28 此控制系統(tǒng)監(jiān)控保護(hù)功能 主要包括過壓、過流、漏電保護(hù)以及水泵漏水 、 水泵軸承超溫 、 電機(jī)超溫保護(hù)。 表 I/O地址分配表 輸入 功能 輸出 功能 水倉水位高 一號(hào)水泵啟動(dòng) /停止 水倉水位低 二 號(hào)水泵啟動(dòng) /停止 一號(hào)泵出水口壓力 三 號(hào)水泵啟動(dòng) /停止 二號(hào)泵出水口壓力 四 號(hào)水泵啟動(dòng) /停止 三號(hào)泵出水口壓力 五 號(hào)水泵啟動(dòng) /停止 四號(hào)泵出水口壓力 一號(hào)泵出水口壓力高報(bào)警 五號(hào)泵出水口壓力 二號(hào)泵出水口壓力高報(bào)警 一號(hào)泵水泵軸承溫度 三號(hào)泵出水口壓力高報(bào)警 二號(hào)泵水泵軸承溫度 四號(hào)泵出水口壓力高報(bào)警 三號(hào)泵水泵軸承溫度 四號(hào)泵水泵軸承溫度 五號(hào)泵水泵軸承溫度 一號(hào)泵電機(jī)溫度 二號(hào)泵電機(jī)溫度 三號(hào)泵電機(jī)溫度 四號(hào)泵電機(jī)溫度 五號(hào)泵電機(jī)溫度 一號(hào)電機(jī)電流 二號(hào)電機(jī)電流 三號(hào)電機(jī)電流 四號(hào)電機(jī)電流 五號(hào)電機(jī)電流 一號(hào)電機(jī)電壓 二號(hào)電機(jī)電壓 三號(hào)電機(jī)電壓 四號(hào)電機(jī)電壓 五號(hào)電機(jī)電壓 啟動(dòng) T1 標(biāo)志 水泵接通脈沖標(biāo)志 啟動(dòng) T2 標(biāo)志 水泵切除脈沖標(biāo)志 水泵接通寄存器 1 水泵接通寄存器 2 水泵接通寄存器 3 五號(hào)泵出水口壓力高報(bào)警 一號(hào)泵軸承溫度高報(bào)警 二號(hào)泵軸承溫度高報(bào)警 三號(hào)泵軸承溫度高報(bào)警 四號(hào)泵軸承溫度高報(bào)警 五號(hào)泵軸承溫度高報(bào)警 一號(hào)泵電機(jī)溫度高報(bào)警 二號(hào)泵電機(jī)溫度高報(bào)警 三號(hào)泵電機(jī)溫度高報(bào)警 四號(hào)泵電機(jī)溫度高報(bào)警 五號(hào)泵電機(jī)溫度高報(bào)警 一號(hào)電機(jī)電流大 二號(hào)電機(jī)電流大 三號(hào)電機(jī)電流大 四號(hào)電機(jī)電流大 五號(hào)電機(jī)電流大 一號(hào)電機(jī)電壓高 二號(hào)電機(jī)電壓高 三號(hào)電機(jī)電壓高 四號(hào)電機(jī)電壓高 五號(hào)電機(jī)電壓高 基于 PLC 的井下排水控制系統(tǒng)設(shè)計(jì) 19 續(xù)表 水泵接通寄存器 4 水泵接通寄存器 5 水泵接通寄存器 6 水泵切除寄存器 1 水泵切除寄存器 2 水泵切除寄存器 3 水泵切除寄存器 4 主控制程序梯形圖： 水泵開啟與停止的程序如下： Network 1:檢測(cè)水位的變化 Network 2:水位高判定 Network 3:水位低判定 沈陽工程學(xué)院畢業(yè)設(shè)計(jì)（論文） 20 Network 4:水位低啟動(dòng)水泵接通標(biāo)志 Network 5:水泵接通標(biāo)志 Network 6:啟動(dòng) T1 接通延時(shí) Network 7:水位高卸載 Network 8:水泵切除標(biāo)志 基于 PLC 的井下排水控制系統(tǒng)設(shè)計(jì) 21 Network 9:啟動(dòng) T2 切除延時(shí) Network 10:水泵接通寄存器 1 Network 11:水泵接通寄存器 2 沈陽工程學(xué)院畢業(yè)設(shè)計(jì)（論文） 22 Network 12:水泵接通寄存器 3 Network 13:水泵接通寄存器 4 Network 14:水泵接通寄存器 5 Network