【題組】⑵傳統汽油引擎採用真空提前機構,試說明在 1000 rpm、節流閥部分開啟(partthrottle)狀況下之點火正時該如何設定?(6 分)
【題組】⑶在某些狀況下點火正時會採用較 MBT 正時延遲之點火正時角度,試舉兩個例子說明之。(7 分)
三、引擎常使用廢氣再循環(exhaust gas recirculation, EGR)以降低 NOx 廢氣排放。試說明:【題組】⑴焰後區 NO 生成之化學反應機構與主要影響因素。(7 分)
【題組】⑵ NO2生成之化學反應機構,並針對汽油引擎與柴油引擎比較 NO2占 NOx 排放之比例。(6 分)
【題組】⑶使用 EGR 降低 NOx 廢氣排放時,EGR 比例太高時汽油引擎未燃碳氫化合物(UHC)排放升高之原因。(7 分)
四、汽油引擎之廢氣排放,常使用觸媒轉化器進行後處理,以降低廢氣之排放濃度。試說明:【題組】⑴觸媒轉化效率(catalytic conversion efficiency)之定義。(5 分)
【題組】⑵何謂觸媒啟用溫度(light-off temperature)?並敘述汽油引擎排氣系統暖機時間長短對於廢氣排放之影響。(8 分)
【題組】⑶影響觸媒轉化器轉化效率耐久性之因素。(7 分)
五、直噴(direct injection)柴油引擎之未燃碳氫化合物(UHC)生成原因可分為三大項。試說明:【題組】⑴過度貧油區域之 UHC 生成原因。(7 分)
【題組】⑵燃料噴嘴囊部體積(sac volume)所造成之 UHC 生成原因。(6 分)
【題組】⑶缸壁焠熄(wall quenching)所造成之 UHC 生成原因。(7 分)
六、 文意字彙 10%【題組】41. What? You w n first prize in the singing contest? Good for you!
【題組】42. We can see the moon clearly through b rs.
【題組】43. Thanks for giving us so many books and toys. You're g s.
【題組】44. Of all the s ts, I love Chinese most.
【題組】45. On Moon Festival, children usually wear p o hats.
【題組】46. David loves to play v l with his classmates after school.
【題組】47. Bill's birthday is coming. Let's give him a s e party.
【題組】48. Students, you can raise your hand to ask if you have any q ns.
【題組】49. Dad, I need a new p r of glasses. I can't see well.
【題組】50. Honey, you did so well on the exam. I have something s l for you.
七、依提示作答 10%【題組】51. I lost the swimming race because I had a stomachache then. ( 依畫線部分造原問句 )
【題組】52. Mike bought his kids a cool toy robot. ( 把兩畫線部分皆改成代名詞 )
【題組】53. What did Mia do yesterday afternoon? ( 用 『完成一張學習單並和 Judy 去看電影』回答 )
【題組】54. We ate so much ice cream because it was too hot. ( 用 so 改寫 )