用高锰酸钾测定[tex=2.071x1.214]+bDmnWn+YhPCXvTygs1ZBA==[/tex]时通常选用硫酸锰、硫酸及磷酸的混合液作介质。试说明三种物质的主要作用各是什么?可否用盐酸或硝酸代替硫酸，为什么? 

玻璃的组成是13mol%[tex=2.214x1.214]Wuiuvx2jfTYPx196+y/ZbA==[/tex]、13mol%Ca0、74mol%[tex=1.857x1.214]m01XwMMesRHsPZSPgkITFA==[/tex]，计算非桥氧分数。有两种不同配比的玻璃，其组成如下：[img=611x114]17db947db80dcff.png[/img]试用玻璃结构参数说明两种玻璃高温下粘度的大小。

已知[tex=42.0x1.571]415UJxNb83DWaELlfi/xFTKIAPqUFkVXjBqV31K6ntDqLR/BlzHvrEtxQDLOX7BcaHE2nS3VQJnFhXvvMakIJhpB3BiBb9UQ8GY30Bl71XjJ+anNI/s8ldDdqRlcTqA+jHAE4vH0/5S2QP7OzW0/vaF+D2gZVnAx8yf0YnsiViZLDshM0i658viijZToXMVbwDV9WSAe9D6Sh8fXSiCOQg8yvKZGX6PlaSKP+KCAgBuynIXCliuockswN/iDTxJ5VhU21+WN66jLe1BZtvxy6uoTyFgfie9jGbPQ2USY/6Y=[/tex],标准状态时,在[tex=2.357x1.214]Zvm+LBJt3x+5uf/RH3+l4w==[/tex]酸性溶液中加人适量[tex=2.071x1.214]+bDmnWn+YhPCXvTygs1ZBA==[/tex],生成的产物可能是A.[tex=2.5x1.214]o4/3WgPY6RPjrhpyuWLGCQ==[/tex]B.[tex=3.5x1.429]NJxvwLvFudhhrMNGAuoKg6/Zo9VNpmQfPDG0ePu8F/Q=[/tex]C.[tex=3.357x1.214]DupqhsqJ1cT/ogUQzjaJXA==[/tex]D.[tex=4.286x1.429]2SeL8z9HelygHXSjPzOAc2f9D+OGQ7ZxOoD5TE4RaNI=[/tex]

for i in range(b.max_row): for j in range(b.max_column): print(b.cell(row=i,column=j).value)上面语句运行的结果是：__________。 A: 1 1 1 1 1 1 1 1 1 1 B: 1111111111 C: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D: 出现异常

【单选题】CDMA通信的基站,假定基站A的码片序列是+1 +1 +1 -1 -1 +1 -1 -1,基站发射bit为101时,实际发射的信号是 A. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 B. +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 +1 +1 +1 -1 -1 +1 -1 -1 C. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 D. –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1

for i in range(1,11): for j in range(1,11): b.cell(row=i,column=j).value=1 #b是一个工作表对象for i in range(1,11): for j in range(1,11): print(b.cell(row=i,column=j).value,end=" ") print()上面程序代码运行的结果是（）。 A: 1 B: 1 1 1 1 1 1 1 1 1 1 C: 1111111111 D: 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1

下列哪个码片序列不能用于CDMA通信 A: ( -1 -1 -1 +1 +1 -1 +1 +1 ) B: ( -1 -1 +1 -1 +1 +1 +1 -1 ) C: ( -1 +1 -1 +1 +1 -1 -1 -1 ) D: ( -1 +1 -1 -1 -1 -1 +1 -1 )

请仔细观察下面行列式的计算过程，如果四个等号都理解了，请选择A，否则请选择B。 | a 1 1 1 1 | |a＋4 a＋4 a＋4 a＋4 a＋4| | 1 a 1 1 1 | | 1 a 1 1 1 | | 1 1 a 1 1 |= | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 a | | 1 1 1 1 1 | | 1 a 1 1 1 | =(a＋4) | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 1 | | 0 a–1 0 0 0 | =(a＋4) | 0 0 a–1 0 0 | | 0 0 0 a–1 0 | | 0 0 0 0 a–1 | =(a＋4)(a–1)^4

共有4个站进行码分多址通信。4个站的码片序列为：a：（-1 -1 -1 +1 +1 -1 +1 +1） b：（-1 -1 +1 -1 +1 +1 +1 -1） c：（-1 +1 -1 +1 +1 +1 -1 -1） d：（-1 +1 -1 -1 -1 -1 +1 -1） 现收到这样的码片序列：（-1 +1 -3 +1 -1 -3 +1 +1），则（ ）发送1。

共有四个站进行CDMA通信，现收到这样的码片序列（-3 +1 -1 -1 +1 +1 +1 -3），则下列站点发送了数据1的是（ ） A: （-1 -1 -1 +1 +1 -1 +1 +1） B: （-1 -1 +1 -1 +1 +1 +1 -1） C: （-1 +1 -1 +1 +1 +1 -1 -1） D: （-1 +1 -1 -1 -1 -1 +1 -1）