【導讀】1．多余約束是體系中不需要的約束。2．如果體系的計算自由度大于零，那么體系一定是幾何可變體系。3．兩根鏈桿的約束作用相當于一個單鉸。5．兩剛片用三鏈桿相聯(lián)，且三鏈桿平行不等長，則構(gòu)成瞬變體系。6．圖示兩個單跨梁，同跨度同荷載。但橫截面形狀不同，故其內(nèi)力也不相同。7．三鉸拱的矢高f越大，水平推力也越大。8．求桁架內(nèi)力時截面法所截取的隔離體包含兩個或兩個以上的結(jié)點。9．某荷載作用下桁架可能存在零桿，它不受內(nèi)力，因此在實際結(jié)構(gòu)中可以將其去掉。10．試判斷下列彎矩圖是否正確。4．解：由三剛片規(guī)則，可知體系是無多余約束的幾何不變體系。1．靜定結(jié)構(gòu)由于支座移動引起的位移與剛度無關(guān)。2．反力互等定理僅對超靜定結(jié)構(gòu)才有使用價值。4．同一結(jié)構(gòu)的力法基本體系不是唯一的。六、求圖示桁架結(jié)點B的豎向位移，已知桁架各桿的EA=21×104kN。

　　

【正文】 h EIhEIk ???? 專業(yè)好文檔 專業(yè)好文檔 Winger TuivasaSheck, who scored two tries in the Kiwis39。 2018 semifinal win over England, has been passed fit after a lowerleg injury, while Slater has been named at fullback but is still recovering from a knee injury aggravated against USA. Both sides boast 100% records heading into the encounter but Australia have not conceded a try since Josh Charnley39。s effort in their first pool match against England on the opening day. Aussie winger Jarryd Hayne is the petition39。s top try scorer with nine, closely followed by TuivasaSheck with eight. But it is recently named Rugby League International Federation player of the year Sonny Bill Williams who has attracted the most interest in the tournament so far. The Kiwi with a tournament high 17 offloads has the chance of being the first player to win the World Cup in both rugby league and rugby union after triumphing with the All Blacks in 2020. I39。d give every award back in a heartbeat just to get across the line this weekend, said (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s antiracism taskforce, is in London for the Football Association39。s 150th anniversary celebrations and will attend City39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s 21 win. Michel Platini, president of European football39。s governing body, has also ordered an immediate investigation into the referee39。s actions. CSKA said they were surprised and disappointed by Toure39。s plaint. In a statement the Russian side added: We found no ra cist insults from fans of CSKA. Baumgartner the disappointing news: Mission aborted. The supersonic descent could happen as early as Sunda. The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere ) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. The balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform. They blew it in 2020 when they got caught cold in the final and they will not make the same mist ake against the Kiwis in Manchester. Five ye ars ago they cruised through to the final and so far history has repeated itself here the last try the y conceded was scored by England39。s Josh Charnley in the opening game of the tournament. That could be classed as a weakness, a team undercooked but I have been impressed by the Kangaroos39。 focus in their games since then. 專業(yè)好文檔 They have been concentrating on the sort of stuff that wins you tough, even contests strong defence, especially on their own goalline, pleting sets and a good kickchase. They39。ve been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team mates. It is as though their entire tournament has been preparation for the final. In Johnathan Thurston, Cooper Cronk, Cameron Smith and either Billy Slater or Greg Inglis at full back they have a spine that is unmatched in rugby league. They have played in so many highpressure games a priceless asset going into Saturday. The Kiwis are a lot less experienced but winning a dramatic match like their semifinal against England will do wonders for their confidence. They defeated Australia in the Four Nations final in 2020 and the last World Cup, and know they can rise to the big occasion.