畢業(yè)論文山西下合煤業(yè)有限公司礦井采區(qū)設(shè)計(jì)

m3的移動儲水箱中，注水泵從水箱中吸水加壓向煤層注水。二、預(yù)防井下火災(zāi)的措施①加強(qiáng)電氣設(shè)備管理，嚴(yán)禁明火作業(yè)，防止外源火災(zāi)發(fā)生。②井下設(shè)消防灑水系統(tǒng)。③及時(shí)清除易燃物品，嚴(yán)禁坑木等易燃物品雜亂無章堆放。④清掃浮煤，及時(shí)封閉采空區(qū)，廢棄巷道避免風(fēng)流通過。⑤井下人員按規(guī)定配備自救器。⑥井下設(shè)有消防材料庫，并有足夠的消防材料，消防材料庫設(shè)備明細(xì)見表。⑦井下使用阻燃膠帶、風(fēng)筒和不延燃電纜。⑧膠帶輸送機(jī)巷安設(shè)自動報(bào)警滅火裝置。井下消防材料庫備用品表第六章工作面采煤、裝煤、運(yùn)煤方式及設(shè)備選型第一節(jié)采煤機(jī)的選型與計(jì)算1、按采煤機(jī)工作面生產(chǎn)能力計(jì)算公式如下：Q采=60MBV采γ式中：Q采——采煤機(jī)工作面實(shí)際生產(chǎn)能力，t/h；M——采高，15號煤平均厚度3.37m；B——截深，0.6m；V采——給定條件下采煤機(jī)牽引速度，1.89m/min；投產(chǎn)時(shí)工作面的循環(huán)進(jìn)度0.6m，日循環(huán)次數(shù)6次，日循環(huán)進(jìn)度為3.60m。每天三班生產(chǎn)一班檢修，每班2個(gè)循環(huán)。則最大班6小時(shí)循環(huán)2次，割2刀（工作面長170m）。取50%的開機(jī)率，則工作面割煤速度為170m÷180min÷50%=1.89m/min。γ——煤的實(shí)體視密度，為1.41t/m3；Q=60×3.37×0.6×1.89×1.41=323.31t/h2、按單位能耗計(jì)算采煤機(jī)裝機(jī)功率為：N=60Kb·B·H·Vave·Hw式中：N——采煤機(jī)裝機(jī)功率，kW；Kb——備用系數(shù)，取1.2；B——采煤機(jī)截深，0.6m；H——采煤機(jī)割煤高度，取15號平均厚度3.37m；Hw——采煤機(jī)割煤單位比能耗，按實(shí)測統(tǒng)計(jì)資料Hw=0.65-0.85kWh/m3，根據(jù)該礦煤層煤質(zhì)、裂隙發(fā)育等的特點(diǎn)，取Hw=0.85kWh/m3；Vave——采煤機(jī)平均割煤速度，15號煤1.89m/min；N=60Kb·B·H·Vave·Hw=60×1.2×0.6×3.37×1.89×0.85=249.8kW15號煤層平均厚度為3.37m，最大厚度為3.80m，煤層結(jié)構(gòu)較簡單，故15號煤滾筒直徑取2000mm。根據(jù)以上計(jì)算結(jié)果并結(jié)合煤層厚度、結(jié)構(gòu)以及結(jié)合采煤機(jī)生產(chǎn)廠家的產(chǎn)品系列型號的特點(diǎn)，15號煤回采工作面選用MG200/490—W型采煤機(jī)。采煤機(jī)技術(shù)參數(shù)見表6—1—1。表6—1—1采煤機(jī)技術(shù)特征表型號采高(m)電機(jī)功率(kW)滾筒直徑(mm/個(gè))截深(mm)牽引速度(m/min)牽引方式重量(t)備注MG200/490—W2.0—3.84902000/26300～5.4電牽引24第二節(jié)工作面刮板輸送機(jī)的選型與計(jì)算工作面刮板輸送機(jī)選型需滿足三個(gè)方面要求：一是運(yùn)輸能力與采煤機(jī)生產(chǎn)能力相適應(yīng)；二是外型尺寸和牽引方式與采煤機(jī)相匹配；三是運(yùn)輸機(jī)長度與工作面長度相一致。根據(jù)環(huán)節(jié)能力配套并考慮1.20富裕系數(shù)，刮板輸送機(jī)的運(yùn)量應(yīng)達(dá)到323.31×1.2=387.97t/h；考慮上述因素，綜采工作面刮板輸送機(jī)選用SGB764/264型可彎曲刮板輸送機(jī)，刮板輸送機(jī)主要技術(shù)參數(shù)見表4—1—2。表6—2—1刮板輸送機(jī)技術(shù)特征表型號機(jī)長(m)輸送能力(t/h)刮板鏈速(m/s)中部槽(mm)電機(jī)功率(kW)電壓等級(V)備注SGB764/2641706001.001500×764×2222×1321140第三節(jié)轉(zhuǎn)載機(jī)、順槽帶式輸送機(jī)順槽轉(zhuǎn)載機(jī)轉(zhuǎn)載能力要求與工作面的生產(chǎn)能力相適應(yīng)，并要求與工作面刮板輸送機(jī)和順槽可伸縮膠帶輸送機(jī)相配套，綜采工作面選用SZZ764/160型轉(zhuǎn)載機(jī)、DSJ100/45/2×132型膠帶輸送機(jī)。其主要技術(shù)參數(shù)見表6—3—1、6—3—2、6—3—3.表6—3—1橋式轉(zhuǎn)載機(jī)技術(shù)特征表型號機(jī)長(m)輸送能力(t/h)刮板鏈速(m/s)電機(jī)功率(kW)電壓等級(V)備注SZZ764/160508001.28160660/1140表6—3—2破碎機(jī)技術(shù)特征表型號破碎能力（t/h）最大給料尺寸（mm）最大排料尺寸（mm）電機(jī)功率（kW）電壓等級（V）備注PCM110800700×700300551140表6—3—3順槽帶式輸送機(jī)技術(shù)特征表型號運(yùn)輸能力(t/h)運(yùn)距(m)速度(m/s)電機(jī)功率(kW)電壓等級(V)備注DSJ100/45/2×1324507642.52×132660/1140第四節(jié)乳化液泵站、噴霧泵站工作面液壓支架對乳化液泵站要求MRBZ200/31.5型乳化液泵站其主要技術(shù)參數(shù)見表6—4—1：表6—4—1乳化液泵站的技術(shù)特征表型號額定壓力（MPa）公稱流量（L/min）配套電機(jī)外型尺寸長×寬×高（mm）重量（kg）液箱容積（L）功率（kW）曲軸轉(zhuǎn)速(r/min）MRBZ200/31.531.52001255632360×960×10303000150根據(jù)所選采煤機(jī)配套噴霧泵站要求選ZPB200／5.5型噴霧泵站，其主要技術(shù)參數(shù)見表6—4—2。表6—4—2噴霧泵站技術(shù)特征表型號工作壓力（MPa）公稱流量（L/min）電動機(jī)備注功率（kw）電壓（v）轉(zhuǎn)速（r/mim）ZPB200／5.55.5200226601485第五節(jié)支護(hù)設(shè)備選型和計(jì)算工作面頂板管理方式為全部垮落法。（1）確定支架的工作阻力或支護(hù)強(qiáng)度時(shí)，一般考慮垮落帶巖層變形破壞時(shí)對支架的影響。（2）按實(shí)測的支架外載荷有關(guān)數(shù)據(jù)，利用回歸分析計(jì)算支架的支護(hù)強(qiáng)度時(shí)，先求出支護(hù)強(qiáng)度的折算系數(shù)n。來壓前：n1=7.46M—0.829（R=0.94，S=0.13）來壓時(shí)：n2=9.768M—0.769（R=0.98，S=0.06）（3）按上述頂板來壓時(shí)載荷折算系數(shù)回歸公式，得出計(jì)算，支架額定支護(hù)強(qiáng)度qH（kN/m2）的公式qH=9.768K.M0.21.γ=9.768×1.3×3.800.21×26=437.00（kN/m2）437.00÷0.75=582.67（kN/m2）P=LBqH=5.3×1.4×582.67=4323.41（kN）式中：K——備用系數(shù)，K=1.3。支架阻力的實(shí)際利用系數(shù)為75%；M——煤層厚度，m；15號煤最大厚度為3.80m。γ——頂板巖石容重，kN/m3。根據(jù)液壓支架工作阻力計(jì)算數(shù)據(jù)，結(jié)合煤層賦存情況及煤層厚度，及選用的采煤方法，工作面支護(hù)選用ZZ5200/19/42型液壓支架，支架支護(hù)高度1.9—4.2m，工作阻力為5200kN。工作面過渡支架選用ZZG5200/19/42型液壓支架，支架支護(hù)高度1.9—4.2m，工作阻力為5200kN?；夭晒ぷ髅娑祟^采用單體液壓支柱四對八梁支護(hù)，采用DZ31.5配HDL-3500型π型鋼梁支護(hù)。運(yùn)輸順槽超前支護(hù)采用DZ31.5配HDL—4500型π型鋼梁進(jìn)行支護(hù)；回風(fēng)順槽超前支護(hù)采用DZ31.5配HDL—3500型π型鋼梁進(jìn)行支護(hù)，超前支護(hù)距離暫按20m考慮。表6-5-1ZZ5200/19/42型液壓支架技術(shù)特征表型號支架寬度（mm）支架高度（mm）工作阻力(kN)支架中心距(mm)架型操作方式重量（t）ZZ5200/19/4213501900-420052001350掩護(hù)式鄰架18.6表6-5-2回采工作面采、裝、運(yùn)設(shè)備配備表設(shè)備名稱設(shè)備型號功率(kW)單位總數(shù)量其中備用雙滾筒采煤機(jī)MG200/490—W490臺1可彎曲刮板輸送機(jī)SGB764/2642×132臺1液壓支架ZZ5200/19/42架14725過渡液壓支架ZZG5200/19/42架51單體液壓支柱DZ31.5根16433π型鋼梁HDL-3500根427π型鋼梁HDL-4500根427刮板轉(zhuǎn)載機(jī)SZZ764/160160臺1破碎機(jī)PCM110110臺1可伸縮膠帶輸送機(jī)DSJ100/45/2×1322×132臺1乳化液泵站MRBZ200/31.5125臺1兩泵一箱噴霧泵站ZPB200／5.522臺1回柱絞車JH-811臺2探水鉆MAZ-20011臺1煤層注水泵7BZ-45/13022臺1雖然支架工作阻力核算，滿足設(shè)計(jì)要求。但實(shí)際生產(chǎn)中仍不可掉以輕心，礦方應(yīng)按照規(guī)程要求配備相應(yīng)的礦山壓力觀測設(shè)備，隨時(shí)監(jiān)控礦山壓力的變化情況，壓力大時(shí)配備足夠單體柱加強(qiáng)支護(hù)，確保安全的情況下，方可進(jìn)行生產(chǎn)。第六節(jié)采區(qū)電氣設(shè)備的選型一、采區(qū)高、低壓配電系統(tǒng)井下中央變電所分別向回采工作面移動變電站、回采工作面運(yùn)輸順槽移動變電站、回采工作面回風(fēng)順槽移動變電站、順槽掘進(jìn)面移動變電站、二采區(qū)軌道巷掘進(jìn)面移動變電站提供1回10kV電源。回采工作面移動變電站選用一臺KBSGZY-800/10，10/1.2kV，800kVA型礦用隔爆型移動變電站為回采工作面采煤機(jī)及刮板輸送機(jī)供電，負(fù)荷率為79％。工作面運(yùn)輸順槽移動變電站選用一臺KBSGZY-315/10，10/0.69kV，315kVA型礦用隔爆型移動變電站為運(yùn)輸順槽的設(shè)備供電，負(fù)荷率為60％。工作面回風(fēng)順槽移動變電站選用一臺KBSGZY-200/10，10/0.69kV，200kVA型礦用隔爆型移動變電站為回風(fēng)順槽的設(shè)備供電，負(fù)荷率為84％?；仫L(fēng)順槽掘進(jìn)工作面移動變電站選用一臺KBSGZY-400/10，10/0.69kV，400kVA型礦用隔爆型移動變電站為膠帶順槽掘進(jìn)的設(shè)備供電，負(fù)荷率為81％。二采區(qū)軌道巷掘進(jìn)工作面移動變電站選用一臺KBSGZY-400/10，10/0.69kV，400kVA型礦用隔爆型移動變電站為軌道順槽掘進(jìn)的設(shè)備供電，負(fù)荷率為81％。在井下中央變電所設(shè)置2臺KBSG-100/1010/0.69kV100kVA型干式變壓器為2個(gè)掘進(jìn)工作面局部通風(fēng)機(jī)供電，負(fù)荷率55％，保障率100%。井下40kW及以上用電設(shè)備的控制開關(guān)選用QBZ礦用隔爆型真空起動器；40kW以下設(shè)備選用QBD型礦用隔爆磁力起動器；煤電鉆選用ZBM-4.0型礦用隔爆電鉆變壓器綜合保護(hù)裝置以127V供電。井下中央變電所的高壓饋電線上，裝設(shè)選擇性的單相接地保護(hù)裝置，供移動變電站的高壓饋電線上，必須裝設(shè)有選擇性動作于跳閘的單相接地保護(hù)裝置。井下低壓饋電線上裝設(shè)帶有漏電閉鎖裝置。井下供配電電壓為10kV、1140V、660V。煤電鉆及照明燈具電壓127V，由電鉆或照明變壓器綜合裝置供給。二、井下電纜、照明選型井下10kV供電電纜選用MYPTJ—6/10型礦用金屬屏蔽橡套軟電纜；井下供電電纜選用MYP—0.66/1.14型礦用橡套軟電纜；采煤機(jī)采用專用電纜；煤電鉆選用MZ—0.3/0.5型礦用電鉆軟電纜；井下照明選用MYQ—0.3/0.5型礦用輕型橡套軟電纜。膠帶大巷、軌道大巷、工作面膠帶順槽及主要機(jī)電硐室設(shè)固定照明。固定照明電壓127V，選用DGS—13/127礦用隔爆型節(jié)能燈具。燈具電源由BZX—4.0660/127V照明變壓器綜合裝置供電。照明干線選用MYQ—0.3/0.53×4礦用輕型橡套軟電纜。三、井下接地井下主、副水倉中各埋設(shè)一塊2000mm×400mm×5mm鋼板作為井下主接地極，各配電點(diǎn)處設(shè)局部接地極，通過電纜的接地芯線及鎧裝電纜金屬外皮相互連接，構(gòu)成井下總接地網(wǎng)，網(wǎng)上任一保護(hù)接地點(diǎn)測得的接地電阻值不超過2Ω。每一個(gè)移動式和手持式電氣設(shè)備至局部接地極之間的保護(hù)接地連接導(dǎo)線的電阻值不超過1Ω。為防止雷電侵入井下，引入井下的金屬部件均在井口處設(shè)可靠接地，且接地點(diǎn)不得少于兩處。第七章主要技術(shù)經(jīng)濟(jì)指標(biāo)礦井設(shè)計(jì)主要技術(shù)經(jīng)濟(jì)指標(biāo)順序指標(biāo)名稱單位指標(biāo)備注（1）（2）（3）（4）（5）井田范圍（1）東西長（2）南北長（3）井田面積kmkmkm3.1652.623.452.4煤層可采煤層數(shù)可采煤層總厚度首采煤層厚度m煤層傾角層mm°1層；15號煤3.373.3763.4資源/儲量保有地質(zhì)資源/儲量工業(yè)資源/儲量設(shè)計(jì)資源儲量設(shè)計(jì)可采儲量ktktktkt112401117398966981.644.1煤類15號煤PM5.4煤質(zhì)灰份（原煤/浮煤）硫份（原煤/浮煤）揮發(fā)份（原煤/浮煤）原煤發(fā)熱量％％％MJ/kg24.29%2.39%17.64%25.43礦井設(shè)計(jì)主要技術(shù)經(jīng)濟(jì)指標(biāo)順序指標(biāo)名稱單位指標(biāo)備注（1）（2）（3）（4）（5）66.16.2礦井設(shè)計(jì)生產(chǎn)能力年生產(chǎn)能力日生產(chǎn)能力kt/at/a900272777.1礦井服務(wù)年限設(shè)計(jì)生產(chǎn)年限a5.588.18.2礦井設(shè)計(jì)工作制度年工作制度日工作班數(shù)天班330“四六”制作業(yè)9.49.5井田開拓開拓方式水平數(shù)目水平標(biāo)高大巷主運(yùn)輸方式大巷輔助運(yùn)輸方式個(gè)m斜—立井混合開拓1+789膠帶調(diào)度絞車1010.4.210.4.3采區(qū)回采工作面?zhèn)€數(shù)掘進(jìn)工作面?zhèn)€數(shù)采煤方法主要采煤設(shè)備采煤機(jī)支架輸送機(jī)個(gè)個(gè)12綜采一次采全高M(jìn)G200/490-WZZ5200/19/42SGB764/2641111.1礦井主要設(shè)備主井提升設(shè)備DTL100/20/2×132輸送機(jī)礦井設(shè)計(jì)主要技術(shù)經(jīng)濟(jì)指標(biāo)順序指標(biāo)名稱單位指標(biāo)備注（1）（2）（3）（4）（5）11.211.311.411.5輔助提升設(shè)備主通風(fēng)設(shè)備主排水設(shè)備壓風(fēng)設(shè)備JK-2/31.5型提升機(jī)FBCDZ-8-№22BMD155-30LG132-8

請刪除以下內(nèi)容，O(∩_∩)O謝謝?。。heoriginoftaxationintheUnitedStatescanbetracedtothetimewhenthecolonistswereheavilytaxedbyGreatBritainoneverythingfromteatolegalandbusinessdocumentsthatwererequiredbytheStampTax.Thecolonists'disdainforthistaxationwithoutrepresentation(so-calledbecausethecolonieshadnovoiceintheestablishmentofthetaxes)gaverisetorevoltssuchastheBostonTeaParty.However,evenaftertheRevolutionaryWarandtheadoptionoftheU.S.Constitution,themainsourceofrevenueforthenewlycreatedstateswasmoneyreceivedfromcustomsandexcisetaxesonitemssuchascarriages,sugar,whiskey,andsnuff.IncometaxfirstappearedintheUnitedStatesin1862,duringtheCivilWar.Atthattimeonlyaboutonepercentofthepopulationwasrequiredtopaythetax.Aflat-rateincometaxwasimposedin1867.Theincometaxwasrepealedinitsentiretyin1872.IncometaxwasarallyingpointforthePopulistpartyin1892,andhadenoughsupporttwoyearslaterthatCongresspassedtheIncomeTaxActof1894.Thetaxatthattimewastwopercentonindividualincomesinexcessof$4,000,whichmeantthatitreachedonlythewealthiestmembersofthepopulation.TheSupremeCourtstruckdownthetax,holdingthatitviolatedtheconstitutionalrequirementthatdirecttaxesbeapportionedamongthestatesbypopulation(pollockv.farmers'loan&trust,158U.S.601,15S.Ct.912,39L.Ed.1108[1895]).Aftermanyyearsofdebateandcompromise,thesixteenthamendmenttotheConstitutionwasratifiedin1913,providingCongresswiththepowertolayandcollecttaxesonincomewithoutapportionmentamongthestates.Theobjectivesoftheincometaxweretheequitabledistributionofthetaxburdenandtheraisingofrevenue.Since1913theU.S.incometaxsystemhasbecomeverycomplex.In1913theincometaxlawswerecontainedineighteenpagesoflegislation;theexplanationofthetaxreformactof1986wasmorethanthirteenhundredpageslong(Pub.L.99-514,Oct.22,1986,100Stat.2085).CommerceClearingHouse,apublisheroftaxinformation,releasedaversionoftheInternalRevenueCodeintheearly1990sthatwasfourtimesthickerthanitsversionin1953.Changestothetaxlawsoftenreflectthetimes.Theflattaxof1913waslaterreplacedwithagraduatedtax.AftertheUnitedStatesenteredworldwari,theWarRevenueActof1917imposedamaximumtaxrateforindividualsof67percent,comparedwitharateof13percentin1916.In1924SecretaryoftheTreasuryAndrewW.Mellon,speakingtoCongressaboutthehighleveloftaxation,stated,Thepresentsystemisafailure.Itwasanemergencymeasure,adoptedunderthepressureofwarnecessityandnottobecounteduponasapermanentpartofourrevenuestructure….Thehighratesputpressureontaxpayerstoreducetheirtaxableincome,tendtodestroyindividualinitiativeandenterprise,andseriouslyimpedethedevelopmentofproductivebusiness….Wayswillalwaysbefoundtoavoidtaxessodestructiveintheirnature,andtheonlywaytosavethesituationistoputthetaxesonareasonablebasisthatwillpermitbusinesstogoonandindustrytodevelop.Consequently,theRevenueActof1924reducedthemaximumindividualtaxrateto43percent(RevenueActs,June2,1924,ch.234,43Stat.253).In1926theratewasfurtherreducedto25percent.TheRevenueActof1932wasthefirsttaxlawpassedduringtheGreatDepression(RevenueActs,June6,1932,ch.209,47Stat.169).Itincreasedtheindividualmaximumratefrom25to63percent,andreducedpersonalexemptionsfrom$1,500to$1,000forsinglepersons,andfrom$3,500to$2,500formarriedcouples.Thenationalindustrialrecoveryactof1933(NIRA),partofPresidentfranklind.roosevelt'snewdeal,imposedafivepercentexcisetaxondividendreceipts,imposedacapitalstocktaxandanexcessprofitstax,andsuspendedalldeductionsforlosses(June16,1933,ch.90,48Stat.195).Therepealin1933oftheeighteenthamendment,whichhadprohibitedthemanufactureandsaleofalcohol,broughtinanestimated$90millioninnewliquortaxesin1934.Thesocialsecurityactof1935providedforawagetax,halftobepaidbytheemployeeandhalfbytheemployer,toestablishafederalretirementfund(OldAgePensionAct,Aug.14,1935,ch.531,49Stat.620).TheWealthTaxAct,alsoknownastheRevenueActof1935,increasedthemaximumtaxrateto79percent,theRevenueActsof1940and1941increaseditto81percent,theRevenueActof1942raiseditto88percent,andtheIndividualIncomeTaxActof1944raisedtheindividualmaximumrateto94percent.Thepost-WorldWarIIRevenueActof1945reducedtheindividualmaximumtaxfrom94percentto91percent.TheRevenueActof1950,duringthekoreanwar,reduceditto84.4percent,butitwasraisedthenextyearto92percent(RevenueActof1950,Sept.23,1950,ch.994,Stat.906).Itremainedatthisleveluntil1964,whenitwasreducedto70percent.TheRevenueActof1954revisedtheInternalRevenueCodeof1939,makingmajorchangesthatwerebeneficialtothetaxpayer,includingprovidingforchildcaredeductions(laterchangedtocredits),anincreaseinthecharitablecontributionlimit,ataxcreditagainsttaxableretirementincome,employeedeductionsforbusinessexpenses,andliberalizeddepreciationdeductions.From1954to1962,theInternalRevenueCodewasamendedby183separateacts.In1974theemployeeretirementincomesecurityact(ERISA)createdprotectionsforemployeeswhoseemployerspromisedspecifiedpensionsorotherretirementcontributions(Pub.L.No.93-406,Sept.2,1974,88Stat.829).ERISArequiredthattobetaxdeductible,theemployer'splancontributionmustmeetcertainminimumstandardsastoemployeeparticipationandvestingandemployerfunding.ERISAalsoapprovedtheuseofindividualretirementaccounts(IRAs)toencouragetax-deferredretirementsavingsbyindividuals.TheEconomicRecoveryTaxActof1981(ERTA)providedthelargesttaxcutuptothattime,reducingthemaximumindividualratefrom70percentto50percent(Pub.L.No.97-34,Aug.13,1981,95Stat.172).ThemostsweepingtaxchangessinceworldwariiwereenactedintheTaxReformActof1986.ThisbillwassignedintolawbyPresidentronaldreaganandwasdesignedtoequalizethetaxtreatmentofvariousassets,eliminatetaxshelters,andlowermarginalrates.Conservativeswantedtheacttoprovideasingle,lowtaxratethatcouldbeappliedtoeveryone.Althoughthissingle,flatratewasnotincludedinthefinalbill,taxrateswerereducedto15percentonthefirst$17,850ofincomeforsinglesand$29,750formarriedcouples,andsetat28to33percentonremainingincome.Manydeductionswererepealed,suchasadeductionavailabletotwo-incomemarriedcouplesthathadbeenusedtoavoidthe"marriagepenalty"(agreatertaxliabilityincurredwhentwopersonsfiledtheirincometaxreturnasamarriedcoupleratherthanasindividuals).Althoughthepersonalexemptionexclusionwasincreased,anexemptionforelderlyandblindpersonswhoitemizedeductionswasrepealed.Inaddition,aspecialcapitalgainsratewasrepealed,aswasaninvestmenttaxcreditthathadbeenintroducedin1962byPresidentjohnf.kennedy.TheOmnibusBudgetReconciliationActof1993,thefirstbudgetandtaxactenactedduringtheClintonadministration,wasvigorouslydebated,andpassedwithonlytheminimumnumberofnecessaryvotes.Thislawprovidedforincometaxratesof15,28,31,36,and39.6percentonvaryinglevelsofincomeandforthetaxationofsocialsecurityincomeifthetaxpayerreceivesotherincomeoveracertainlevel.In2001CongressenactedamajorincometaxcutattheurgingofPresidentgeorgew.bush.Overthecourseof11yearsthelawreducesmarginalincometaxratesacrossalllevelsofincome.The36percentratewillbeloweredto33percent,the31percentrateto28percent,the28percentrateto25percent.Inaddition,anewbottom10percentratewascreated.Sincetheearly1980s,aflat-ratetaxsystemratherthanthegraduatedbracketedmethodhasbeenproposed.(Thegraduatedbracketedmethodistheonethathasbeenusedsincegraduatedtaxeswereintroduced:thepercentageoftaxdiffersbasedontheamountoftaxableincome.)Theflat-ratesystemwouldimposeonerate,suchas20percent,onallincomeandwouldeliminatespecialdeductions,credits,andexclusions.Despitefirmsupportbysome,theflat-ratetaxhasnotbeenadoptedintheUnitedStates.Regardlessofthechangesmadebylegislatorssince1913,thebasicformulaforcomputingtheamountoftaxowedhasremainedbasicallythesame.Todeterminetheamountofincometaxowed,certaindeductionsaretakenfromanindividual'sgrossincometoarriveatanadjustedgrossincome,fromwhichadditionaldeductionsaretakentoarriveatthetaxableincome.Oncetheamountoftaxableincomehasbeendetermined,taxratechartsdeterminetheexactamountoftaxowed.Iftheamountoftaxowedislessthantheamountalreadypaidthroughtaxprepaymentorthewithholdingoftaxesfrompaychecks,thetaxpayerisentitledtoarefundfromtheIRS.Iftheamountoftaxowedismorethanwhathasalreadybeenpaid,thetaxpayermustpaythedifferencetotheIRS.CalculatingthegrossincomeofrestaurantemployeeswhoseincomeispartiallyderivedfromgratuitiesleftbycustomershasledtodisputeswiththeIRSandemployersoverhowmuchtheyshouldcontributeinfederalinsurancecontributionact(fica)taxes.Althoughcustomerspaythesetipsdirectlytoemployees,federallawdeemsthetipstohavebeenwagespaidbytheemployerforFICAtaxpurposes.Employersareimputedtohavepaidlargesumsofmoneytheyneverhandledandforwhichtheynowayofascertainingtheexactamount.TheSupremeCourt,in

UnitedStatesv.FiorD'Italia,536U.S.238,122S.Ct.2117,153L.Ed.2d280(2002),upheldtheIRS"aggregatemethod"ofreportingtipincome.InsteadofrequiringtheIRStomakeindividualdeterminationsofunreportedtipsforeachemployeewhencalculatingFICAtax,theCourtheldthattheIRScouldmakeemployersreporttheirgrosssalesonamonthlystatementtohelpdeterminetipincome.Employeesalsomustreporttheirtipincomemonthlyonaform.TheIRSthenusesthesetwopiecesofinformationtocalculatewhattheemployerneedstocontributeinFICAtax.基于C8051F單片機(jī)直流電動機(jī)反饋控制系統(tǒng)的設(shè)計(jì)與研究基于單片機(jī)的嵌入式Web服務(wù)器的研究MOTOROLA單片機(jī)MC68HC（8）05PV8/A內(nèi)嵌EEPROM的工藝和制程方法及對良率的影響研究基于模糊控制的電阻釬焊單片機(jī)溫度控制系統(tǒng)的研制基于MCS-51系列單片機(jī)的通用控制模塊的研究基于單片機(jī)實(shí)現(xiàn)的供暖系統(tǒng)最佳啟停自校正（STR）調(diào)節(jié)器單片機(jī)控制的二級倒立擺系統(tǒng)的研究基于增強(qiáng)型51系列單片機(jī)的TCP/IP協(xié)議棧的實(shí)現(xiàn)基于單片機(jī)的蓄電池自動監(jiān)測系統(tǒng)基于32位嵌入式單片機(jī)系統(tǒng)的圖像采集與處理技術(shù)的研究基于單片機(jī)的作物營養(yǎng)診斷專家系統(tǒng)的研究基于單片機(jī)的交流伺服電機(jī)運(yùn)動控制系統(tǒng)研究與開發(fā)基于單片機(jī)的泵管內(nèi)壁硬度測試儀的研制基于單片機(jī)的自動找平控制系統(tǒng)研究基于C8051F040單片機(jī)的嵌入式系統(tǒng)開發(fā)基于單片機(jī)的液壓動力系統(tǒng)狀態(tài)監(jiān)測儀開發(fā)模糊Smith智能控制方法的研究及其單片機(jī)實(shí)現(xiàn)一種基于單片機(jī)的軸快流CO〈,2〉激光器的手持控制面板的研制基于雙單片機(jī)沖床數(shù)控系統(tǒng)的研究基于CYGNAL單片機(jī)的在線間歇式濁度儀的研制基于單片機(jī)的噴油泵試驗(yàn)臺控制器的研制基于單片機(jī)的軟起動器的研究和設(shè)計(jì)基于單片機(jī)控制的高速快走絲電火花線切割機(jī)床短循環(huán)走絲方式研究基于單片機(jī)的機(jī)電產(chǎn)品控制系統(tǒng)開發(fā)基于PIC單片機(jī)的智能手機(jī)充電器基于單片機(jī)的實(shí)時(shí)內(nèi)核設(shè)計(jì)及其應(yīng)用研究基于單片機(jī)的遠(yuǎn)程抄表系統(tǒng)的設(shè)計(jì)與研究基于單片機(jī)的煙氣二氧化硫濃度檢測儀的研制基于微型光譜儀的單片機(jī)系統(tǒng)單片機(jī)系統(tǒng)軟件構(gòu)件開發(fā)的技術(shù)研究基于單片機(jī)的液體點(diǎn)滴速度自動檢測儀的研制基于單片機(jī)系統(tǒng)的多功能溫度測量儀的研制基于PIC單片機(jī)的電能采集終端的設(shè)計(jì)和應(yīng)用基于單片機(jī)的光纖光柵解調(diào)儀的研制氣壓式線性摩擦焊機(jī)單片機(jī)控制系統(tǒng)的研制基于單片機(jī)的數(shù)字磁通門傳感器基于單片機(jī)的旋轉(zhuǎn)變壓器-數(shù)字轉(zhuǎn)換器的研究基于單片機(jī)的光纖Bragg光柵解調(diào)系統(tǒng)的研究單片機(jī)控制的便攜式多功能乳腺治療儀的研制基于C8051F020單片機(jī)的多生理信號檢測儀基于單片機(jī)的電機(jī)運(yùn)動控制系統(tǒng)設(shè)計(jì)Pico專用單片機(jī)核的可測性設(shè)計(jì)研究基于MCS-51單片機(jī)的熱量計(jì)基于雙單片機(jī)的智能遙測微型氣象站MCS-51單片機(jī)構(gòu)建機(jī)器人的實(shí)踐研究基于單片機(jī)的輪軌力檢測基于單片機(jī)的GPS定位儀的研究與實(shí)現(xiàn)基于單片機(jī)的電液伺服控制系統(tǒng)用于單片機(jī)系統(tǒng)的MMC卡文件系統(tǒng)研制基于單片機(jī)的時(shí)控和計(jì)數(shù)系統(tǒng)性能優(yōu)化的研究基于單片機(jī)和CPLD的粗光柵位移測量系統(tǒng)研究單片機(jī)控制的后備式方波UPS提升高職學(xué)生單片機(jī)應(yīng)用能力的探究基于單片機(jī)控制的自動低頻減載裝置研究基于單片機(jī)控制的水下焊接電源的研究基于單片機(jī)的多通道數(shù)據(jù)采集系統(tǒng)基于uPSD3234單片機(jī)的氚表面污染測量儀的研制基于單片機(jī)的紅外測油儀的研究96系列單片機(jī)仿真器研究與設(shè)計(jì)基于單片機(jī)的單晶金剛石刀具刃磨設(shè)備的數(shù)控改造基于單片機(jī)的溫度智能控制系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)基于MSP430單片機(jī)的電梯門機(jī)控制器的研制基于單片機(jī)的氣體測漏儀的研究基于三菱M16C/6N系列單片機(jī)的CAN/USB協(xié)議轉(zhuǎn)換器基于單片機(jī)和DSP的變壓器油色譜在線監(jiān)測技術(shù)研究基于單片機(jī)的膛壁溫度報(bào)警系統(tǒng)設(shè)計(jì)基于AVR單片機(jī)的低壓無功補(bǔ)償控制器的設(shè)計(jì)基于單片機(jī)船舶電力推進(jìn)電機(jī)監(jiān)測系統(tǒng)基于單片機(jī)網(wǎng)絡(luò)的振動信號的采集系統(tǒng)基于單片機(jī)的大容量數(shù)據(jù)存儲技術(shù)的應(yīng)用研究基于單片機(jī)的疊圖機(jī)研究與教學(xué)方法實(shí)踐基于單片機(jī)嵌入式Web服務(wù)器技術(shù)的研究及實(shí)現(xiàn)基于AT89S52單片機(jī)的通用數(shù)據(jù)采集系統(tǒng)基于單片機(jī)的多道脈沖幅度分析儀研究機(jī)器人旋轉(zhuǎn)電弧傳感角焊縫跟蹤單片機(jī)控制系統(tǒng)基于單片機(jī)的控制系統(tǒng)在PLC虛擬教學(xué)實(shí)驗(yàn)中的應(yīng)用研究基于單片機(jī)系統(tǒng)的網(wǎng)絡(luò)通信研究與應(yīng)用基于PIC16F877單片機(jī)的莫爾斯碼自動譯碼系統(tǒng)設(shè)計(jì)與研究基于單片機(jī)的模糊控制器在工業(yè)電阻爐上的應(yīng)用研究基于雙單片機(jī)沖床數(shù)控系統(tǒng)的研究與開發(fā)基于Cygnal單片機(jī)的μC/OS-Ⅱ的研究