HY-SRF05超声波模块资料以及示例程序下载;模块简介:HY-SRF05超声波测距模块可提供2cm-450cm的非接触式距离感测功能,测距精度达到3mm;模块包括超声波发射器接收器和控制电路
2025/12/7 6:43:54
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编译原理龙书答案完整性高第二章2.2ExercisesforSection2.22.2.1Considerthecontext-freegrammar:S-＞SS+|SS*|aShowhowthestringaa+a*canbegeneratedbythisgrammar.Constructaparsetreeforthisstring.Whatlanguagedoesthisgrammargenerate?Justifyyouranswer.answerS-＞SS*-＞SS+S*-＞aS+S*-＞aa+S*-＞aa+a*L={Postfixexpressionconsistingofdigits,plusandmultiplesigns}2.2.2Whatlanguageisgeneratedbythefollowinggrammars?Ineachcasejustifyyouranswer.S-＞0S1|01S-＞+SS|-SS|aS-＞S(S)S|εS-＞aSbS|bSaS|ε⧗S-＞a|S+S|SS|S*|(S)answerL={0n1n|n＞=1}L={Prefixexpressionconsistingofplusandminussigns}L={Matchedbracketsofarbitraryarrangementandnesting,includesε}L={Stringhasthesameamountofaandb,includesε}？2.2.3WhichofthegrammarsinExercise2.2.2areambiguousanswerNoNoYesYesYes2.2.4Constructunambiguouscontext-freegrammarsforeachofthefollowinglanguages.Ineachcaseshowthatyourgrammariscorrect.Arithmeticexpressionsinpostfixnotation.Left-associativelistsofidentifiersseparatedbycommas.Right-associativelistsofidentifiersseparatedbycommas.Arithmeticexpressionsofintegersandidentifierswiththefourbinaryoperators+,-,*,/.answer1.E-＞EEop|num2.list-＞list,id|id3.list-＞id,list|id4.expr-＞expr+term|expr-term|termterm-＞term*factor|term/factor|factorfactor-＞id|num|(expr)5.expr-＞expr+term|expr-term|termterm-＞term*unary|term/unary|unaryunary-＞+factor|-factorfactor-＞id|num|(expr)2.2.5Showthatallbinarystringsgeneratedbythefollowinggrammarhavevaluesdivisibleby3.Hint.Useinductiononthenumberofnodesinaparsetree.num-＞11|1001|num0|numnumDoesthegrammargenerateallbinarystringswithvaluesdivisibleby3?answerproveanystringderivedfromthegrammarcanbeconsideredtobeasequenceconsistingof11,1001and0,andnotprefixedwith0.thesumofthisstringis:sum=Σn(21+20)*2n+Σm(23+20)*2m=Σn3*2n+Σm9*2mItisobviouslycandivisibleby3.No.Considerstring"10101",itisdivisibleby3,butcannotderivedfromthegrammar.Question:anygeneralprove?2.2.6Constructacontext-freegrammarforromannumerals.Note:wejustconsiderasubsetofromannumeralswhichislessthan4k.answerwikipedia:Roman_numeralsviawikipedia,wecancategorizethesinglenomannumeralsinto4groups:I,II,III|IV|V,VI,VII,VIII|IXthengettheproduction:digit-＞smallDigit|IV|VsmallDigit|IXsmallDigit-＞I|II|III|εandwecanfindasimplewaytomapromantoarabicnumerals.Forexample:XII=＞X,II=＞10+2=＞12CXCIX=＞C,XC,IX=＞100+90+9=＞199MDCCCLXXX=＞M,DCCC,LXXX=＞1000+800+80=＞1880viatheuppertworules,wecanderivetheproduction:romanNum-＞thousandhundredtendigitthousand-＞M|MM|MMM|εhundred-＞smallHundred|CD|DsmallHundred|CMsmallHundred-＞C|CC|CCC|εten-＞smallTen|XL|LsmallTen|XCsmallTen-＞X|XX|XXX|εdigit-＞smallDigit|IV|VsmallDigit|IXsmallDigit-＞I|II|III|ε2.3ExercisesforSection2.32.3.1Constructasyntax-directedtranslationschemethattranslatesarithmeticexpressionsfrominfixnotationintoprefixnotationinwhichanoperatorappearsbeforeitsoperands;e.g.,-xyistheprefixnotationforx-y.Giveannotatedparsetreesfortheinputs9-5+2and9-5*2.。
answerproductions:expr-＞expr+term|expr-term|termterm-＞term*factor|term/factor|factorfactor-＞digit|(expr)translationschemes:expr-＞{print("+")}expr+term|{print("-")}expr-term|termterm-＞{print("*")}term*factor|{print("/")}term/factor|factorfactor-＞digit{print(digit)}|(expr)2.3.2Constructasyntax-directedtranslationschemethattranslatesarithmeticexpressionsfrompostfixnotationintoinfixnotation.Giveannotatedparsetreesfortheinputs95-2*and952*-.answerproductions:expr-＞exprexpr+|exprexpr-|exprexpr*|exprexpr/|digittranslationschemes:expr-＞expr{print("+")}expr+|expr{print("-")}expr-|{print("(")}expr{print(")*(")}expr{print(")")}*|{print("(")}expr{print(")/(")}expr{print(")")}/|digit{print(digit)}AnotherreferenceanswerE-＞{print("(")}E{print(op)}E{print(")"}}op|digit{print(digit)}2.3.3Constructasyntax-directedtranslationschemethattranslatesintegersintoromannumeralsanswerassistantfunction:repeat(sign,times)//repeat('a',2)='aa'translationschemes:num-＞thousandhundredtendigit{num.roman=thousand.roman||hundred.roman||ten.roman||digit.roman;print(num.roman)}thousand-＞low{thousand.roman=repeat('M',low.v)}hundred-＞low{hundred.roman=repeat('C',low.v)}|4{hundred.roman='CD'}|high{hundred.roman='D'||repeat('X',high.v-5)}|9{hundred.roman='CM'}ten-＞low{ten.roman=repeat('X',low.v)}|4{ten.roman='XL'}|high{ten.roman='L'||repeat('X',high.v-5)}|9{ten.roman='XC'}digit-＞low{digit.roman=repeat('I',low.v)}|4{digit.roman='IV'}|high{digit.roman='V'||repeat('I',high.v-5)}|9{digit.roman='IX'}low-＞0{low.v=0}|1{low.v=1}|2{low.v=2}|3{low.v=3}high-＞5{high.v=5}|6{high.v=6}|7{high.v=7}|8{high.v=8}2.3.4Constructasyntax-directedtranslationschemethattranslatesromannumeralsintointegers.answerproductions:romanNum-＞thousandhundredtendigitthousand-＞M|MM|MMM|εhundred-＞smallHundred|CD|DsmallHundred|CMsmallHundred-＞C|CC|CCC|εten-＞smallTen|XL|LsmallTen|XCsmallTen-＞X|XX|XXX|εdigit-＞smallDigit|IV|VsmallDigit|IXsmallDigit-＞I|II|III|εtranslationschemes:romanNum-＞thousandhundredtendigit{romanNum.v=thousand.v||hundred.v||ten.v||digit.v;print(romanNun.v)}thousand-＞M{thousand.v=1}|MM{thousand.v=2}|MMM{thousand.v=3}|ε{thousand.v=0}hundred-＞smallHundred{hundred.v=smallHundred.v}|CD{hundred.v=smallHundred.v}|DsmallHundred{hundred.v=5+smallHundred.v}|CM{hundred.v=9}smallHundred-＞C{smallHundred.v=1}|CC{smallHundred.v=2}|CCC{smallHundred.v=3}|ε{hundred.v=0}ten-＞smallTen{ten.v=smallTen.v}|XL{ten.v=4}|LsmallTen{ten.v=5+smallTen.v}|XC{ten.v=9}smallTen-＞X{smallTen.v=1}|XX{smallTen.v=2}|XXX{smallTen.v=3}|ε{smallTen.v=0}digit-＞smallDigit{digit.v=smallDigit.v}|IV{digit.v=4}|VsmallDigit{digit.v=5+smallDigit.v}|IX{digit.v=9}smallDigit-＞I{smallDigit.v=1}|II{smallDigit.v=2}|III{smallDigit.v=3}|ε{smallDigit.v=0}2.3.5Constructasyntax-directedtranslationschemethattranslatespostfixarithmeticexpressionsintoequivalentprefixarithmeticexpressions.answerproduction:expr-＞exprexprop|digittranslationscheme:expr-＞{print(op)}exprexprop|digit{print(digit)}ExercisesforSection2.42.4.1Constructrecursive-descentparsers,startingwiththefollowinggrammars:S-＞+SS|-SS|aS-＞S(S)S|εS-＞0S1|01Answer1）S-＞+SS|-SS|avoidS(){switch(lookahead){case"+":match("+");S();S();break;case"-":match("-");S();S();break;case"a":match("a");break;default:thrownewSyntaxException();}}voidmatch(Terminalt){if(lookahead=t){lookahead=nextTerminal();}else{thrownewSyntaxException()}}2）S-＞S(S)S|εvoidS(){if(lookahead=="("){S();match("(");S();match(")");S();}}3）S-＞0S1|01voidS(){switch(lookahead){case"0":match("0");S();match("1");break;case"1"://match(epsilon);break;default:thrownewSyntaxException();}}ExercisesforSection2.62.6.1ExtendthelexicalanalyzerinSection2.6.5toremovecomments,definedasfollows:Acommentbeginswith//andincludesallcharactersuntiltheendofthatline.Acommentbeginswith/*andincludesallcharactersthroughthenextoccurrenceofthecharactersequence*/.2.6.2ExtendthelexicalanalyzerinSection2.6.5torecognizetherelationaloperators.2.6.3ExtendthelexicalanalyzerinSection2.6.5torecognizefloatingpointnumberssuchas2.,3.14,and.5.AnswerSourcecode:commit8dd1a9aCodesnippet(src/lexer/Lexer.java)：publicTokenscan()throwsIOException,SyntaxException{for(;;peek=(char)stream.read()){if(peek==''||peek=='\t'){continue;}elseif(peek=='\n'){line=line+1;}else{break;}}//handlecommentif(peek=='/'){peek=(char)stream.read();if(peek=='/'){//singlelinecommentfor(;;peek=(char)stream.read()){if(peek=='\n'){break;}}}elseif(peek=='*'){//blockcommentcharprevPeek='';for(;;prevPeek=peek,peek=(char)stream.read()){if(prevPeek=='*'&&peek=='/'){break;}}}else{thrownewSyntaxException();}}//handlerelationsignif("".indexOf(peek)＞-1){StringBufferb=newStringBuffer();b.append(peek);peek=(char)stream.read();if(peek=='='){b.append(peek);}returnnewRel(b.toString());}//handlenumber,notypesensitiveif(Character.isDigit(peek)||peek=='.'){BooleanisDotExist=false;StringBufferb=newStringBuffer();do{if(peek=='.'){isDotExist=true;}b.append(peek);peek=(char)stream.read();}while(isDotExist==true?Character.isDigit(peek):Character.isDigit(peek)||peek=='.');returnnewNum(newFloat(b.toString()));}//handlewordif(Character.isLetter(peek)){StringBufferb=newStringBuffer();do{b.append(peek);peek=(char)stream.read();}while(Character.isLetterOrDigit(peek));Strings=b.toString();Wordw=words.get(s);if(w==null){w=newWord(Tag.ID,s);words.put(s,w);}returnw;}Tokent=newToken(peek);peek='';returnt;}ExercisesforSection2.82.8.1For-statementsinCandJavahavetheform:for(exprl;expr2;expr3)stmtThefirstexpressionisexecutedbeforetheloop;itistypicallyusedforinitializingtheloopindex.Thesecondexpressionisatestmadebeforeeachiterationoftheloop;theloopisexitediftheexpressionbecomesO.Theloopitselfcanbethoughtofasthestatement{stmtexpr3;}.Thethirdexpressionisexecutedattheendofeachiteration;itistypicallyusedtoincrementtheloopindex.Themeaningofthefor-statementissimilartoexpr1;while(expr2){stmtexpr3;}DefineaclassForforfor-statements,similartoclassIfinFig.2.43.AnswerclassForextendsStmt{ExprE1;ExprE2;ExprE3;StmtS;publicFor(Exprexpr1,Exprexpr2,Exprexpr3,Stmtstmt){E1=expr1;E2=expr2;E3=expr3;S=stmt;}publicvoidgen(){E1.gen();Labelstart=newLable();Lalelend=newLable();emit("ifFalse"+E2.rvalue().toString()+"goto"+end);S.gen();E3.gen();emit("goto"+start);emit(end+":")}}2.8.2TheprogramminglanguageCdoesnothaveabooleantype.ShowhowaCcompilermighttranslateanif-statementintothree-addresscode.AnswerReplaceemit("isFalse"+E.rvalue().toString()+"goto"+after);withemit("ifNotEqual"+E.rvalue().toString()+"0goto"+after);oremit("isNotEqualZero"+E.rvalue().toString()+"goto"+after);
answerproductions:expr-＞expr+term|expr-term|termterm-＞term*factor|term/factor|factorfactor-＞digit|(expr)translationschemes:expr-＞{print("+")}expr+term|{print("-")}expr-term|termterm-＞{print("*")}term*factor|{print("/")}term/factor|factorfactor-＞digit{print(digit)}|(expr)2.3.2Constructasyntax-directedtranslationschemethattranslatesarithmeticexpressionsfrompostfixnotationintoinfixnotation.Giveannotatedparsetreesfortheinputs95-2*and952*-.answerproductions:expr-＞exprexpr+|exprexpr-|exprexpr*|exprexpr/|digittranslationschemes:expr-＞expr{print("+")}expr+|expr{print("-")}expr-|{print("(")}expr{print(")*(")}expr{print(")")}*|{print("(")}expr{print(")/(")}expr{print(")")}/|digit{print(digit)}AnotherreferenceanswerE-＞{print("(")}E{print(op)}E{print(")"}}op|digit{print(digit)}2.3.3Constructasyntax-directedtranslationschemethattranslatesintegersintoromannumeralsanswerassistantfunction:repeat(sign,times)//repeat('a',2)='aa'translationschemes:num-＞thousandhundredtendigit{num.roman=thousand.roman||hundred.roman||ten.roman||digit.roman;print(num.roman)}thousand-＞low{thousand.roman=repeat('M',low.v)}hundred-＞low{hundred.roman=repeat('C',low.v)}|4{hundred.roman='CD'}|high{hundred.roman='D'||repeat('X',high.v-5)}|9{hundred.roman='CM'}ten-＞low{ten.roman=repeat('X',low.v)}|4{ten.roman='XL'}|high{ten.roman='L'||repeat('X',high.v-5)}|9{ten.roman='XC'}digit-＞low{digit.roman=repeat('I',low.v)}|4{digit.roman='IV'}|high{digit.roman='V'||repeat('I',high.v-5)}|9{digit.roman='IX'}low-＞0{low.v=0}|1{low.v=1}|2{low.v=2}|3{low.v=3}high-＞5{high.v=5}|6{high.v=6}|7{high.v=7}|8{high.v=8}2.3.4Constructasyntax-directedtranslationschemethattranslatesromannumeralsintointegers.answerproductions:romanNum-＞thousandhundredtendigitthousand-＞M|MM|MMM|εhundred-＞smallHundred|CD|DsmallHundred|CMsmallHundred-＞C|CC|CCC|εten-＞smallTen|XL|LsmallTen|XCsmallTen-＞X|XX|XXX|εdigit-＞smallDigit|IV|VsmallDigit|IXsmallDigit-＞I|II|III|εtranslationschemes:romanNum-＞thousandhundredtendigit{romanNum.v=thousand.v||hundred.v||ten.v||digit.v;print(romanNun.v)}thousand-＞M{thousand.v=1}|MM{thousand.v=2}|MMM{thousand.v=3}|ε{thousand.v=0}hundred-＞smallHundred{hundred.v=smallHundred.v}|CD{hundred.v=smallHundred.v}|DsmallHundred{hundred.v=5+smallHundred.v}|CM{hundred.v=9}smallHundred-＞C{smallHundred.v=1}|CC{smallHundred.v=2}|CCC{smallHundred.v=3}|ε{hundred.v=0}ten-＞smallTen{ten.v=smallTen.v}|XL{ten.v=4}|LsmallTen{ten.v=5+smallTen.v}|XC{ten.v=9}smallTen-＞X{smallTen.v=1}|XX{smallTen.v=2}|XXX{smallTen.v=3}|ε{smallTen.v=0}digit-＞smallDigit{digit.v=smallDigit.v}|IV{digit.v=4}|VsmallDigit{digit.v=5+smallDigit.v}|IX{digit.v=9}smallDigit-＞I{smallDigit.v=1}|II{smallDigit.v=2}|III{smallDigit.v=3}|ε{smallDigit.v=0}2.3.5Constructasyntax-directedtranslationschemethattranslatespostfixarithmeticexpressionsintoequivalentprefixarithmeticexpressions.answerproduction:expr-＞exprexprop|digittranslationscheme:expr-＞{print(op)}exprexprop|digit{print(digit)}ExercisesforSection2.42.4.1Constructrecursive-descentparsers,startingwiththefollowinggrammars:S-＞+SS|-SS|aS-＞S(S)S|εS-＞0S1|01Answer1）S-＞+SS|-SS|avoidS(){switch(lookahead){case"+":match("+");S();S();break;case"-":match("-");S();S();break;case"a":match("a");break;default:thrownewSyntaxException();}}voidmatch(Terminalt){if(lookahead=t){lookahead=nextTerminal();}else{thrownewSyntaxException()}}2）S-＞S(S)S|εvoidS(){if(lookahead=="("){S();match("(");S();match(")");S();}}3）S-＞0S1|01voidS(){switch(lookahead){case"0":match("0");S();match("1");break;case"1"://match(epsilon);break;default:thrownewSyntaxException();}}ExercisesforSection2.62.6.1ExtendthelexicalanalyzerinSection2.6.5toremovecomments,definedasfollows:Acommentbeginswith//andincludesallcharactersuntiltheendofthatline.Acommentbeginswith/*andincludesallcharactersthroughthenextoccurrenceofthecharactersequence*/.2.6.2ExtendthelexicalanalyzerinSection2.6.5torecognizetherelationaloperators.2.6.3ExtendthelexicalanalyzerinSection2.6.5torecognizefloatingpointnumberssuchas2.,3.14,and.5.AnswerSourcecode:commit8dd1a9aCodesnippet(src/lexer/Lexer.java)：publicTokenscan()throwsIOException,SyntaxException{for(;;peek=(char)stream.read()){if(peek==''||peek=='\t'){continue;}elseif(peek=='\n'){line=line+1;}else{break;}}//handlecommentif(peek=='/'){peek=(char)stream.read();if(peek=='/'){//singlelinecommentfor(;;peek=(char)stream.read()){if(peek=='\n'){break;}}}elseif(peek=='*'){//blockcommentcharprevPeek='';for(;;prevPeek=peek,peek=(char)stream.read()){if(prevPeek=='*'&&peek=='/'){break;}}}else{thrownewSyntaxException();}}//handlerelationsignif("".indexOf(peek)＞-1){StringBufferb=newStringBuffer();b.append(peek);peek=(char)stream.read();if(peek=='='){b.append(peek);}returnnewRel(b.toString());}//handlenumber,notypesensitiveif(Character.isDigit(peek)||peek=='.'){BooleanisDotExist=false;StringBufferb=newStringBuffer();do{if(peek=='.'){isDotExist=true;}b.append(peek);peek=(char)stream.read();}while(isDotExist==true?Character.isDigit(peek):Character.isDigit(peek)||peek=='.');returnnewNum(newFloat(b.toString()));}//handlewordif(Character.isLetter(peek)){StringBufferb=newStringBuffer();do{b.append(peek);peek=(char)stream.read();}while(Character.isLetterOrDigit(peek));Strings=b.toString();Wordw=words.get(s);if(w==null){w=newWord(Tag.ID,s);words.put(s,w);}returnw;}Tokent=newToken(peek);peek='';returnt;}ExercisesforSection2.82.8.1For-statementsinCandJavahavetheform:for(exprl;expr2;expr3)stmtThefirstexpressionisexecutedbeforetheloop;itistypicallyusedforinitializingtheloopindex.Thesecondexpressionisatestmadebeforeeachiterationoftheloop;theloopisexitediftheexpressionbecomesO.Theloopitselfcanbethoughtofasthestatement{stmtexpr3;}.Thethirdexpressionisexecutedattheendofeachiteration;itistypicallyusedtoincrementtheloopindex.Themeaningofthefor-statementissimilartoexpr1;while(expr2){stmtexpr3;}DefineaclassForforfor-statements,similartoclassIfinFig.2.43.AnswerclassForextendsStmt{ExprE1;ExprE2;ExprE3;StmtS;publicFor(Exprexpr1,Exprexpr2,Exprexpr3,Stmtstmt){E1=expr1;E2=expr2;E3=expr3;S=stmt;}publicvoidgen(){E1.gen();Labelstart=newLable();Lalelend=newLable();emit("ifFalse"+E2.rvalue().toString()+"goto"+end);S.gen();E3.gen();emit("goto"+start);emit(end+":")}}2.8.2TheprogramminglanguageCdoesnothaveabooleantype.ShowhowaCcompilermighttranslateanif-statementintothree-addresscode.AnswerReplaceemit("isFalse"+E.rvalue().toString()+"goto"+after);withemit("ifNotEqual"+E.rvalue().toString()+"0goto"+after);oremit("isNotEqualZero"+E.rvalue().toString()+"goto"+after);
2025/11/27 8:37:48
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树莓派超声波测距代码Python，有兴趣的看看。
importRPi.GPIOasgpioimporttime超声波测距部分Python代码defdistance(measure='cm'):gpio.setmode(gpio.BOARD)gpio.setup(12,gpio.OUT)gpio.setup(16,gpio.IN)gpio.output(12,False)whilegpio.input(16)==0:nosig=time.time()whilegpio.input(16)==1:sig=time.time()
importRPi.GPIOasgpioimporttime超声波测距部分Python代码defdistance(measure='cm'):gpio.setmode(gpio.BOARD)gpio.setup(12,gpio.OUT)gpio.setup(16,gpio.IN)gpio.output(12,False)whilegpio.input(16)==0:nosig=time.time()whilegpio.input(16)==1:sig=time.time()
2025/11/15 14:44:23
636B
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根据磁光材料的非互易特性和波导光栅的滤波特性,介绍了一种磁光波导光栅的非互易滤波特性及其应用。
该磁光波导光栅采用法拉第旋转系数为4800°/cm的掺铈钇铁石榴石(Ce:YIG)材料、单模的脊型补偿墙截面结构和cosine型变迹光栅结构的设计。
利用有限差分法和等效折射率法模拟该磁光波导光栅非互易效应的大小,同时结合耦合模理论和转移矩阵法对该磁光波导光栅的非互易滤波特性进行分析。
结果表明,对于TE模和1550nm波段,该磁光波导光栅正反向传输的中心波长偏移0.8nm,带宽0.4nm(-20dB)。
这种非互易滤波特性可以用来实现波长选择光隔离器和光分插复用器(OADM)等集成光学器件。
该磁光波导光栅采用法拉第旋转系数为4800°/cm的掺铈钇铁石榴石(Ce:YIG)材料、单模的脊型补偿墙截面结构和cosine型变迹光栅结构的设计。
利用有限差分法和等效折射率法模拟该磁光波导光栅非互易效应的大小,同时结合耦合模理论和转移矩阵法对该磁光波导光栅的非互易滤波特性进行分析。
结果表明,对于TE模和1550nm波段,该磁光波导光栅正反向传输的中心波长偏移0.8nm,带宽0.4nm(-20dB)。
这种非互易滤波特性可以用来实现波长选择光隔离器和光分插复用器(OADM)等集成光学器件。
2025/11/4 3:53:12
1.35MB
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Silage,Dennis.DigitalcommunicationsystemsusingSystemVue/DennisSilage.p.cm.Includesindex.ISBN1-58450-850-7(alk.paper)1.Digitalcommunications.I.Title.TK5103.7.S492005621.382--dc222005031785
2025/11/2 6:53:42
10.33MB
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Handbookofmultisensordatafusion:theoryandpractice/editors,MartinE.Liggins,DavidL.Hall,JamesLlinas.--2nded.p.cm.--(Electricalengineeringandappliedsignalprocessingseries;no.22)Includesbibliographicalreferencesandindex.ISBN978-1-4200-5308-1(hbk.:alk.paper)1.Multisensordatafusion--Handbooks,manuals,etc.I.Hall,DavidL.(DavidLee),1946-II.Liggins,MartinE.III.Hall,DavidL.IV.Llinas,James.V.Title.VI.Series.
2025/8/11 13:54:28
15.23MB
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共1页。
找了几天CM-R湿敏电阻的资料，基本都只有性能指标，即工作电压这些，而没有阻值和湿度的关系表。
而艰难找到的这个文件也只有曲线。
HR202的资料还是比较容易找到的，和HR202湿敏电阻的阻值-湿度关系表对照了一下，应该是差不多的。
理论上可以参考HR202的阻值湿度关系，待画板写程序验证。
找了几天CM-R湿敏电阻的资料，基本都只有性能指标，即工作电压这些，而没有阻值和湿度的关系表。
而艰难找到的这个文件也只有曲线。
HR202的资料还是比较容易找到的，和HR202湿敏电阻的阻值-湿度关系表对照了一下，应该是差不多的。
理论上可以参考HR202的阻值湿度关系，待画板写程序验证。
2025/7/3 9:26:58
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ASTM B250 - 铜合金线的通用要求规范ASTM B250 是美国材料和试验协会（ASTM）发布的一份规范，旨在规定铜合金线的通用要求。
该规范涵盖了铜合金线的化学成分、物理和机械性能等方面的要求，并为铜合金线的生产和应用提供了统一的标准。
1. 范围ASTM B250 适用于铜合金线的生产和应用，包括自由切割黄铜棒、柱、形状的生产，以及 Copper-Silicon 合金线、磷磷铜合金线、铜贝リル合金线、铜镍锌合金线等各种铜合金线的生产。
2. 引用文件ASTM B250 规范引用了多个 ASTM 规范，包括 B 16/B 16M、B 99/B 99M、B 134/B 134M、B 159/B 159M、B 193、B 194、B 197/B 197M、B 206/B 206M 等，涵盖了铜合金线的化学成分、物理和机械性能等方面的要求。
3. 化学成分ASTM B250 规范规定了铜合金线的化学成分，包括铜的含量、杂质的含量、合金元素的含量等。
例如，自由切割黄铜棒、柱、形状的化学成分要求为 Cu+Ag 58.5% min、Pb 1.5% max、Fe 0.10% max 等。
4. 物理性能ASTM B250 规范规定了铜合金线的物理性能，包括 密度、电阻率、热导率、热膨胀系数等。
例如，铜合金线的密度要求为 8.94 g/cm³ min。
5. 机械性能ASTM B250 规范规定了铜合金线的机械性能，包括抗拉强度、抗压强度、延伸率、硬度等。
例如，铜合金线的抗拉强度要求为 450 MPa min。
6. 单位ASTM B250 规范规定了两种单位系统：SI 单位系统和英制单位系统。
例如，铜合金线的尺寸可以用 mm 或英寸表示。
7. 编辑记录ASTM B250 规范的编辑记录包括了所有的编辑变化和修订记录，以便用户了解规范的变化和发展。
ASTM B250 规范为铜合金线的生产和应用提供了统一的标准，涵盖了化学成分、物理和机械性能等方面的要求，为铜合金线的生产和应用提供了重要的指导作用。
2025/6/19 16:46:52
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介绍了以单片机STC12C5A60S2为微控制器的低成本、高精度、微型化的汽车倒车防撞预警系统。
文章分析了倒车防撞系统的设计原理，较详细的介绍了超声波传感器测距系统，结合超声波测距的工作原理和系统构成，给出了软件控制流程，并在数据处理中采用了温度补偿法修正测量精度，经过测试，系统工作稳定，测距范围为30-500cm，系统精度可达到2mm。
文章分析了倒车防撞系统的设计原理，较详细的介绍了超声波传感器测距系统，结合超声波测距的工作原理和系统构成，给出了软件控制流程，并在数据处理中采用了温度补偿法修正测量精度，经过测试，系统工作稳定，测距范围为30-500cm，系统精度可达到2mm。
2025/6/10 21:57:49
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在日常工作中，钉钉打卡成了我生活中不可或缺的一部分。然而，有时候这个看似简单的任务却给我带来了不少烦恼。
每天早晚，我总是得牢记打开钉钉应用，点击"工作台"，再找到"考勤打卡"进行签到。有时候因为工作忙碌，会忘记打卡，导致考勤异常，影响当月的工作评价。而且，由于我使用的是苹果手机，有时候系统更新后，钉钉的某些功能会出现异常，使得打卡变得更加麻烦。
另外，我的家人使用的是安卓手机，他们也经常抱怨钉钉打卡的繁琐。尤其是对于那些不太熟悉手机操作的长辈来说，每次打卡都是一次挑战。他们总是担心自己会操作失误，导致打卡失败。
为了解决这些烦恼，我开始思考是否可以通过编写一个全自动化脚本来实现钉钉打卡。经过一段时间的摸索和学习，我终于成功编写出了一个适用于苹果和安卓系统的钉钉打卡脚本。
2024-04-09 15:03
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