已知化合物：① $\rm CaCO_3(s)$的分解温度为897 ℃；②$\rm MnCO_3(s)$的分解温度为525 ℃，则它们在298K下分解反应的平衡常数$K^\ominus$关系为 A: $K_1^\ominus >K_2^\ominus$ B: $K_1^\ominus < K_2^\ominus$ C: $K_1^\ominus = K_2^\ominus$ D: 无法比较

已知反应$\rm H_2(s)\ +\ S(s)\ \longrightarrow\ H_2S(g)$ 的平衡常数为$K^\ominus_1$ ；$\rm O_2(s)\ +\ S(s)\ \longrightarrow\ SO_2(g)$ 的平衡常数为$K^\ominus_2$ 的平衡常数为 ；则反应 的平衡常数为 A: $\frac{K^\ominus_2}{K^\ominus_1}$ B: $K^\ominus_2 - K^\ominus_1$ C: ${K^\ominus_1}{K^\ominus_2}$ D: $\frac{K^\ominus_1}{K^\ominus_2}$

电池$\rm Zn(s) \ |\ ZnCl_2(0.555\ mol\cdot kg^{-1}\ |\ AgCl(s)\ |\ Ag(s)$的能斯特方程表达式正确的是 A: $E=E^\ominus +\frac{RT}{zF}\ln a_{_\pm}^3$ B: $E=E^\ominus +\frac{RT}{zF}\ln a_\rm{Zn^{2+}}a^2_{Cl^-}$ C: $E=E^\ominus -\frac{RT}{zF}\ln a_\rm{Zn^{2+}}a^2_{Cl^-}$ D: $E=E^\ominus -\frac{RT}{zF}\ln a_\rm{ZnCl_2}$

已知20 ℃时，水的表面张力$72.8\ mN\cdot m^{-1} $，此温度和$p\ominus$压力下将水的表面积可逆地增大$10\rm\ cm^2$时，体系的 $\Delta G$（单位：J）为（ A ） A: $7.28\times 10^{-5}$ B: $-7.28\times 10^{-5}$ C: $7.28\times 10^{-1}$ D: $-7.28\times 10^{-1}$

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。