
咸寧建筑雅士白大理石廠這便是(shi)(shi)飾(shi)面板巖(yan)不(bu)能(neng)(neng)做瓦(wa)板巖(yan)的理(li)由(you),同理(li),瓦(wa)板巖(yan)能(neng)(neng)夠(gou)作飾(shi)面板巖(yan)的理(li)由(you)就(jiu)很簡略理(li)解(jie)了(le),只要(yao)把瓦(wa)板巖(yan)劈分的厚一點就(jiu)能(neng)(neng)夠(gou)滿意飾(shi)面板巖(yan)的悉(xi)數需要(yao)了(le)。石材(cai)加(jia)(jia)(jia)工(gong)工(gong)具的現狀(zhuang)石材(cai)是(shi)(shi)具有高(gao)(gao)硬度、高(gao)(gao)脆性特點的材(cai)料。隨(sui)著科(ke)學技(ji)術和現代工(gong)業的發(fa)展(zhan),石材(cai)的應用領(ling)域日益擴展(zhan),石材(cai)開采量(liang)(liang)(liang)逐年增(zeng)(zeng)加(jia)(jia)(jia),如(ru)圖(tu)1—1所示。我國(guo)石材(cai)行業經(jing)過近20年的高(gao)(gao)速(su)發(fa)展(zhan),一躍成為在(zai)石材(cai)產(chan)(chan)量(liang)(liang)(liang)、消費(fei)量(liang)(liang)(liang)、貿易量(liang)(liang)(liang)均位于世界首位的石材(cai)工(gong)業大(da)(da)國(guo)。2008年石材(cai)產(chan)(chan)量(liang)(liang)(liang)達2.23億平方千(qian)米,比(bi)2007年同比(bi)增(zeng)(zeng)加(jia)(jia)(jia)了(le)27%。2005年以來,石材(cai)的產(chan)(chan)量(liang)(liang)(liang)以穩定的速(su)度增(zeng)(zeng)長,其產(chan)(chan)品、工(gong)藝、設備(bei)技(ji)術含量(liang)(liang)(liang)極大(da)(da)提高(gao)(gao),大(da)(da)中型石材(cai)企業不(bu)斷涌現,行業呈(cheng)現強勁的發(fa)展(zhan)勢(shi)(shi)頭,中國(guo)已成為名(ming)副其實的世界石材(cai)加(jia)(jia)(jia)工(gong)廠(chang),重慶石材(cai)加(jia)(jia)(jia)工(gong)發(fa)展(zhan)趨勢(shi)(shi)和前景(jing)看好。

噪(zao)(zao)(zao)音所產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)(de)(de)危害是比較(jiao)大的(de)(de)(de)(de)(de)(de),尤(you)其是表現在(zai)如(ru)下(xia)幾個(ge)方(fang)(fang)(fang)面:1、長期在(zai)強烈(lie)的(de)(de)(de)(de)(de)(de)噪(zao)(zao)(zao)音環境中(zhong)工(gong)作(zuo),可以使人(ren)產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)噪(zao)(zao)(zao)聲性耳聾。2、影響(xiang)人(ren)們的(de)(de)(de)(de)(de)(de)正(zheng)(zheng)(zheng)常工(gong)作(zuo)、學(xue)習及日常生(sheng)(sheng)(sheng)(sheng)(sheng)活。那么(me)石(shi)材(cai)加(jia)工(gong)過程中(zhong)噪(zao)(zao)(zao)音是怎樣產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)(de)(de)呢(ni)?它(ta)主(zhu)要來自齒(chi)(chi)尖(jian)噪(zao)(zao)(zao)聲,鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)振(zhen)動及物(wu)料摩擦聲。齒(chi)(chi)尖(jian)噪(zao)(zao)(zao)聲:是當(dang)鋸(ju)片(pian)(pian)(pian)高(gao)(gao)速(su)(su)(su)運(yun)轉(zhuan)(zhuan)時(shi),鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)鋸(ju)齒(chi)(chi)與(yu)(yu)周(zhou)圍的(de)(de)(de)(de)(de)(de)空氣(qi)(qi)(qi)(qi)(qi)(qi)相互作(zuo)用,引起空氣(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)壓(ya)(ya)力(li)脈動而(er)產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)(de)(de)噪(zao)(zao)(zao)聲。齒(chi)(chi)尖(jian)噪(zao)(zao)(zao)聲的(de)(de)(de)(de)(de)(de)聲功(gong)率與(yu)(yu)鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)直徑、鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)線(xian)速(su)(su)(su)度(du)(du)的(de)(de)(de)(de)(de)(de)三次(ci)方(fang)(fang)(fang)成(cheng)(cheng)正(zheng)(zheng)(zheng)比,當(dang)轉(zhuan)(zhuan)速(su)(su)(su)越低時(shi),與(yu)(yu)其線(xian)速(su)(su)(su)度(du)(du)三次(ci)方(fang)(fang)(fang)成(cheng)(cheng)正(zheng)(zheng)(zheng)比,齒(chi)(chi)尖(jian)噪(zao)(zao)(zao)聲的(de)(de)(de)(de)(de)(de)頻(pin)(pin)率可由下(xia)式(shi)計算(suan):式(shi)中(zhong):fi—齒(chi)(chi)尖(jian)噪(zao)(zao)(zao)聲頻(pin)(pin)率,即(ji)鋸(ju)齒(chi)(chi)每秒打空氣(qi)(qi)(qi)(qi)(qi)(qi)質點的(de)(de)(de)(de)(de)(de)次(ci)數,(HZ)z—鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)齒(chi)(chi)數(個(ge))n—鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)軸(zhou)的(de)(de)(de)(de)(de)(de)轉(zhuan)(zhuan)速(su)(su)(su)(r/min)i—諧波(bo)序(xu)號i=1、2、3……鋸(ju)片(pian)(pian)(pian)旋轉(zhuan)(zhuan)時(shi),每個(ge)齒(chi)(chi)尖(jian)產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)單極輻射流(liu),并(bing)周(zhou)期地(di)通過工(gong)作(zuo)臺的(de)(de)(de)(de)(de)(de)鋸(ju)縫向外排(pai)(pai)出,由于氣(qi)(qi)(qi)(qi)(qi)(qi)流(liu)壓(ya)(ya)力(li)發(fa)生(sheng)(sheng)(sheng)(sheng)(sheng)激烈(lie)變化,隨(sui)(sui)之(zhi)產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)排(pai)(pai)氣(qi)(qi)(qi)(qi)(qi)(qi)噪(zao)(zao)(zao)聲,排(pai)(pai)氣(qi)(qi)(qi)(qi)(qi)(qi)噪(zao)(zao)(zao)聲的(de)(de)(de)(de)(de)(de)升(sheng)功(gong)率也隨(sui)(sui)著鋸(ju)片(pian)(pian)(pian)線(xian)速(su)(su)(su)度(du)(du)增大而(er)急(ji)劇(ju)增加(jia),它(ta)與(yu)(yu)氣(qi)(qi)(qi)(qi)(qi)(qi)流(liu)速(su)(su)(su)度(du)(du)的(de)(de)(de)(de)(de)(de)6次(ci)方(fang)(fang)(fang)成(cheng)(cheng)正(zheng)(zheng)(zheng)比,在(zai)線(xian)速(su)(su)(su)度(du)(du)較(jiao)小時(shi),與(yu)(yu)其5次(ci)方(fang)(fang)(fang)成(cheng)(cheng)正(zheng)(zheng)(zheng)比,則排(pai)(pai)氣(qi)(qi)(qi)(qi)(qi)(qi)噪(zao)(zao)(zao)聲頻(pin)(pin)率為:式(shi)中(zhong):fi—排(pai)(pai)氣(qi)(qi)(qi)(qi)(qi)(qi)噪(zao)(zao)(zao)聲頻(pin)(pin)率,(HZ)z—鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)齒(chi)(chi)數(個(ge))n—鋸(ju)片(pian)(pian)(pian)軸(zhou)的(de)(de)(de)(de)(de)(de)轉(zhuan)(zhuan)速(su)(su)(su)(r/min)i—諧波(bo)序(xu)號i=1、2、3……在(zai)鋸(ju)片(pian)(pian)(pian)高(gao)(gao)速(su)(su)(su)旋轉(zhuan)(zhuan)時(shi),每當(dang)渦流(liu)分離的(de)(de)(de)(de)(de)(de)頻(pin)(pin)率與(yu)(yu)鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)固有(you)頻(pin)(pin)率相近時(shi),就發(fa)生(sheng)(sheng)(sheng)(sheng)(sheng)共振(zhen),便發(fa)出“尖(jian)叫聲”,其頻(pin)(pin)率為:f=z fr式(shi)中(zhong):z—鋸(ju)片(pian)(pian)(pian)的(de)(de)(de)(de)(de)(de)齒(chi)(chi)數(個(ge))fr—軸(zhou)回轉(zhuan)(zhuan)頻(pin)(pin)率(HZ)鋸(ju)片(pian)(pian)(pian)屬于薄壁件(jian),其剛(gang)性一般較(jiao)差,在(zai)外力(li)的(de)(de)(de)(de)(de)(de)作(zuo)用下(xia)很容(rong)易產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)振(zhen)動,由于振(zhen)動便容(rong)易產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)料的(de)(de)(de)(de)(de)(de)摩擦,因此該類(lei)的(de)(de)(de)(de)(de)(de)噪(zao)(zao)(zao)音也就隨(sui)(sui)之(zhi)產(chan)(chan)生(sheng)(sheng)(sheng)(sheng)(sheng)。

通常情況(kuang)下圓形的(de)(de)(de)刀(dao)具因為切開(kai)半徑比(bi)照小,所以(yi)重(zhong)慶(qing)石(shi)(shi)(shi)(shi)材(cai)(cai)加(jia)工(gong)廠的(de)(de)(de)石(shi)(shi)(shi)(shi)材(cai)(cai)在(zai)受力的(de)(de)(de)進(jin)程中(zhong)比(bi)照安穩,一(yi)同切開(kai)進(jin)程的(de)(de)(de)好(hao)壞直接決(jue)議著(zhu)石(shi)(shi)(shi)(shi)材(cai)(cai)的(de)(de)(de)運(yun)用(yong)壽數。因此(ci)加(jia)工(gong)東(dong)西的(de)(de)(de)翻開(kai)將會不(bu)斷(duan)跋涉。同樣(yang)是修(xiu)建板(ban)石(shi)(shi)(shi)(shi)類,瓦(wa)(wa)(wa)板(ban)巖(yan)能(neng)夠(gou)做(zuo)飾面(mian)板(ban)巖(yan),而飾面(mian)板(ban)巖(yan)不(bu)能(neng)做(zuo)瓦(wa)(wa)(wa)板(ban)巖(yan),這是啥理由呢?首(shou)要要知道(dao)優(you)質的(de)(de)(de)板(ban)石(shi)(shi)(shi)(shi)有(you)(you)(you)必要具有(you)(you)(you)的(de)(de)(de)特征(zheng):劈(pi)分功用(yong)好(hao)、平(ping)整度(du)(du)(du)好(hao)、色(se)差小、黑度(du)(du)(du)高(其他色(se)彩同理)、曲折強(qiang)度(du)(du)(du)高、含鈣鐵硫量低,燒失(shi)量低,耐酸(suan)堿功用(yong)好(hao),吸水率低,耐候(hou)性好(hao)。重(zhong)慶(qing)石(shi)(shi)(shi)(shi)材(cai)(cai)加(jia)工(gong)廠的(de)(de)(de)青石(shi)(shi)(shi)(shi)板(ban)材(cai)(cai)不(bu)具有(you)(you)(you)超(chao)卓的(de)(de)(de)劈(pi)分功用(yong),根柢沒(mei)(mei)有(you)(you)(you)方法(fa)把石(shi)(shi)(shi)(shi)板(ban)瓦(wa)(wa)(wa)劈(pi)分到(dao)5~7mm的(de)(de)(de)規范厚度(du)(du)(du);沒(mei)(mei)有(you)(you)(you)超(chao)卓的(de)(de)(de)曲折強(qiang)度(du)(du)(du),在(zai)這一(yi)厚度(du)(du)(du)下就無(wu)法(fa)抵達蓋(gai)瓦(wa)(wa)(wa)的(de)(de)(de)運(yun)用(yong)需要;平(ping)整度(du)(du)(du)差,根柢不(bu)能(neng)滿意規整穩妥的(de)(de)(de)掛(gua)瓦(wa)(wa)(wa)施工(gong)需要;沒(mei)(mei)有(you)(you)(you)超(chao)卓的(de)(de)(de)材(cai)(cai)料特征(zheng),就不(bu)能(neng)夠(gou)經久不(bu)褪色(se)、不(bu)風化、不(bu)生(sheng)銹而堅持100年以(yi)上的(de)(de)(de)運(yun)用(yong)壽數。

燒(shao)毛(mao)加(jia)工(gong)(gong)燒(shao)毛(mao)加(jia)工(gong)(gong)又(you)稱火燒(shao)加(jia)工(gong)(gong)、噴(pen)燒(shao)加(jia)工(gong)(gong),是利(li)用組(zu)成花崗石(shi)(shi)的(de)不同礦(kuang)物顆粒(li)熱(re)脹(zhang)系數(shu)的(de)差異,用火焰噴(pen)燒(shao)使其表面(mian)部(bu)分顆粒(li)熱(re)脹(zhang)破裂脫(tuo)落,形成起(qi)伏(fu)有(you)(you)序(xu)的(de)粗(cu)面(mian)紋(wen)飾(shi)(shi)。這種(zhong)粗(cu)面(mian)花崗石(shi)(shi)板材,非(fei)常(chang)的(de)適(shi)合于濕滑場所(suo)的(de)地面(mian)裝飾(shi)(shi)和戶外的(de)墻(qiang)面(mian)裝飾(shi)(shi)。主要(yao)(yao)設備是花崗石(shi)(shi)自(zi)動燒(shao)毛(mao)機(ji)(ji)。6、輔(fu)助加(jia)工(gong)(gong)輔(fu)助加(jia)工(gong)(gong)是將已切齊(qi)、磨(mo)光的(de)石(shi)(shi)材按需(xu)要(yao)(yao)磨(mo)邊、倒角、開孔洞(dong)、鉆(zhan)眼、銑(xian)槽、銑(xian)邊等(deng)。主要(yao)(yao)的(de)加(jia)工(gong)(gong)設備有(you)(you)自(zi)動磨(mo)邊倒角機(ji)(ji)、仿形銑(xian)機(ji)(ji)、薄壁(bi)鉆(zhan)孔機(ji)(ji)、手持金剛石(shi)(shi)圓鋸、手持磨(mo)光拋光機(ji)(ji)等(deng)。7、檢驗(yan)修補天然花崗石(shi)(shi)難免(mian)有(you)(you)裂縫、孔洞(dong)等(deng)瑕疵,而且在加(jia)工(gong)(gong)過程(cheng)也難免(mian)會(hui)有(you)(you)一些磕碰,出(chu)現(xian)一些小缺陷。所(suo)以在加(jia)工(gong)(gong)完成后所(suo)有(you)(you)的(de)花崗巖板材都需(xu)要(yao)(yao)檢驗(yan),首先要(yao)(yao)通過清洗,重慶石(shi)(shi)材加(jia)工(gong)(gong)然后是吹(chui)干檢驗(yan),合格(ge)品包裝入庫(ku),而不合格(ge)產品則應先挑出(chu)來。

天(tian)然(ran)石(shi)(shi)(shi)材(cai)硬(ying)度(du)大,脆性(xing)(xing)大,不(bu)(bu)耐(nai)撞擊,易破碎,耐(nai)沖擊性(xing)(xing)比天(tian)然(ran)石(shi)(shi)(shi)材(cai)好。(4)加(jia)(jia)工(gong)(gong)制作(zuo)(zuo)方便。人(ren)造(zao)石(shi)(shi)(shi)的(de)(de)硬(ying)度(du)和(he)(he)韌性(xing)(xing)已調整到一(yi)定范圍。可(ke)(ke)以(yi)像做硬(ying)木一(yi)樣加(jia)(jia)工(gong)(gong),凡是(shi)木工(gong)(gong)用(yong)的(de)(de)工(gong)(gong)具和(he)(he)機械(xie)設備(bei)(bei)都可(ke)(ke)以(yi)用(yong)于(yu)人(ren)造(zao)石(shi)(shi)(shi)材(cai)的(de)(de)制作(zuo)(zuo)加(jia)(jia)工(gong)(gong),可(ke)(ke)粘接(利用(yong)專用(yong)膠水(shui),各(ge)種(zhong)臺(tai)面(mian)(mian)均可(ke)(ke)接得“天(tian)衣無(wu)(wu)縫”),可(ke)(ke)彎曲(qu),可(ke)(ke)加(jia)(jia)工(gong)(gong)成各(ge)種(zhong)形(xing)狀,這是(shi)天(tian)然(ran)石(shi)(shi)(shi)材(cai)無(wu)(wu)法比擬的(de)(de)。(5)結構致密(mi),清潔衛生(sheng)(sheng)(sheng),天(tian)然(ran)石(shi)(shi)(shi)材(cai)存(cun)在(zai)(zai)著天(tian)然(ran)微孔(kong),在(zai)(zai)做櫥柜的(de)(de)臺(tai)面(mian)(mian)時,菜湯等(deng)營(ying)養物質(zhi)(zhi)易滲(shen)入其內,滋(zi)生(sheng)(sheng)(sheng)細(xi)菌;而人(ren)造(zao)石(shi)(shi)(shi)材(cai)結構致密(mi),無(wu)(wu)微孔(kong),液體物質(zhi)(zhi)不(bu)(bu)能(neng)滲(shen)入,細(xi)菌不(bu)(bu)能(neng)在(zai)(zai)其中(zhong)生(sheng)(sheng)(sheng)長(chang),故(gu)有(you)些商(shang)家把人(ren)造(zao)石(shi)(shi)(shi)炒作(zuo)(zuo)為“抗菌石(shi)(shi)(shi)”也(ye)有(you)其道(dao)理(li)。人(ren)造(zao)石(shi)(shi)(shi)材(cai)從誕生(sheng)(sheng)(sheng)至今經歷幾十年的(de)(de)研究、開發和(he)(he)創新,使(shi)人(ren)造(zao)石(shi)(shi)(shi)材(cai)能(neng)開發多種(zhong)材(cai)料(liao)廣(guang)泛應(ying)用(yong)與(yu)商(shang)業、住(zhu)宅、甚至軍事領(ling)域等(deng)。在(zai)(zai)商(shang)業用(yong)途上,人(ren)造(zao)石(shi)(shi)(shi)材(cai)的(de)(de)使(shi)用(yong)幾乎不(bu)(bu)受限制。根(gen)(gen)據(ju)產品的(de)(de)適應(ying)性(xing)(xing),它(ta)可(ke)(ke)用(yong)于(yu)健康(kang)中(zhong)心(xin)、醫療機構、公共寫(xie)字樓(lou)、廠礦公司(si)、購物中(zhong)心(xin)等(deng)空(kong)間里的(de)(de)設備(bei)(bei)設施。當它(ta)作(zuo)(zuo)用(yong)于(yu)柜臺(tai)、墻體、水(shui)槽、展示架(jia)、家具、電梯等(deng)器物時,色彩紋理(li)設計獨特(te)的(de)(de)人(ren)造(zao)石(shi)(shi)(shi)材(cai)無(wu)(wu)不(bu)(bu)顯(xian)示其體貼、溫暖、可(ke)(ke)塑(su)性(xing)(xing)強、可(ke)(ke)自由切裁、彎曲(qu)、研磨、接合耐(nai)久等(deng)卓越性(xing)(xing)能(neng),產品的(de)(de)這些特(te)點,是(shi)消費者在(zai)(zai)使(shi)用(yong)時可(ke)(ke)以(yi)大膽創作(zuo)(zuo),保持美(mei)感。人(ren)造(zao)石(shi)(shi)(shi)材(cai)可(ke)(ke)以(yi)根(gen)(gen)據(ju)使(shi)用(yong)的(de)(de)需要做成各(ge)種(zhong)應(ying)用(yong)等(deng)級的(de)(de)材(cai)料(liao),是(shi)衛生(sheng)(sheng)(sheng)環保材(cai)料(liao),實心(xin)無(wu)(wu)孔(kong),毫無(wu)(wu)隱污納垢的(de)(de)空(kong)洞或縫隙(xi)。其表面(mian)(mian)接縫非常緊(jin)密(mi),不(bu)(bu)會被水(shui)滲(shen)透(tou)。

不銹鋼(gang)石(shi)(shi)材(cai)(cai)(cai)掛件鋼(gang)號為(wei)202以(yi)上,或根據(ju)項目實際(ji)需要(yao)(yao)采(cai)用(yong)304鋼(gang)號連接(jie)配件。(2)石(shi)(shi)材(cai)(cai)(cai)厚度(du)要(yao)(yao)求在(zai)20mm以(yi)上,2500mm高以(yi)內(nei)的(de)墻(qiang)體,豎向(xiang)(xiang)需采(cai)用(yong)5#槽鋼(gang),橫(heng)(heng)向(xiang)(xiang)采(cai)用(yong)40mmx40mm型角鋼(gang),間(jian)距根據(ju)石(shi)(shi)材(cai)(cai)(cai)的(de)橫(heng)(heng)縫(feng)排版確(que)(que)定(ding),2500mm高以(yi)上的(de)墻(qiang)體,豎向(xiang)(xiang)需采(cai)用(yong)8#槽鋼(gang),橫(heng)(heng)向(xiang)(xiang)采(cai)50mmx50mm型角鋼(gang),間(jian)距根據(ju)石(shi)(shi)材(cai)(cai)(cai)的(de)恒豐排版確(que)(que)定(ding)。3、膠粘(zhan)劑粘(zhan)貼(tie)施工(gong)(gong)工(gong)(gong)藝木基層面(mian)粘(zhan)貼(tie)石(shi)(shi)材(cai)(cai)(cai)工(gong)(gong)藝,適用(yong)于小(xiao)面(mian)積、小(xiao)塊面(mian)材(cai)(cai)(cai)料(liao)施工(gong)(gong)范圍(如(ru)文化石(shi)(shi)、裝(zhuang)飾線、踢腳線),須(xu)用(yong)AB膠結合不銹鋼(gang)自(zi)攻螺釘粘(zhan)接(jie)固定(ding),石(shi)(shi)材(cai)(cai)(cai)背面(mian)應挖成倒八字型孔,要(yao)(yao)做好防腐(fu)處理。三、墻(qiang)面(mian)石(shi)(shi)材(cai)(cai)(cai)細(xi)部收口(kou)要(yao)(yao)點1、石(shi)(shi)材(cai)(cai)(cai)墻(qiang)面(mian)橫(heng)(heng)縫(feng),需根據(ju)人(ren)體的(de)視線高度(du)排布,施工(gong)(gong)時需廠(chang)家定(ding)加工(gong)(gong),現場安裝(zhuang)。2、墻(qiang)面(mian)石(shi)(shi)材(cai)(cai)(cai)陽(yang)角收口(kou)均需45度(du)拼接(jie)對角處理;待墻(qiang)面(mian)石(shi)(shi)材(cai)(cai)(cai)全部鋪(pu)貼(tie)完成后,須(xu)調制與石(shi)(shi)材(cai)(cai)(cai)同色的(de)云(yun)石(shi)(shi)膠作勾縫(feng)處理,勾縫(feng)必(bi)須(xu)嚴密。