MikaStars39/nano-eval huggingface dataset:
The temperature inside a certain compressed air storage tank changes with the ambient temperature. If the average temperature is 2°C in winter and 20°C in summer, the pressure inside the storage tank remains constant. If a nozzle connected to this air source produces high-speed airflow, try calculating the ratio of the nozzle exit velocities in summer and winter.

Options:
A. 0.672
B. 0.969
C. 1.454
D. 1.058
E. 0.756
F. 0.811
G. 0.922
H. 0.889
I. 1.200
J. 1.325
Answer: B
Moist air with a pressure of \( $p_{1} = 0.1 \ \text{MPa}$ \), temperature \( $t_{1}$ = $30 \ \text{°C}$ \), and relative humidity \( $\varphi_{1} = 0.7$ \) undergoes reversible polytropic compression in the compressor to \( $p_{2} = 0.8 \ \text{MPa}$ \) and is then input into a storage tank, where it cools to \( $t_{3} = 35 \ \text{°C}$ \). Given the polytropic exponent \( $n = 1.25$ \), determine: the relative humidity \( $\varphi_{3}$ \) and the moisture content \( $d_{3}$ \) of the moist air in the storage tank is().

Options:
A. 85%
7.01 × 10⁻³ kg (water vapor) per kg (thousand air)
B. 60%
5.17 × 10^-3 kg (water vapor) per kg (thousand air)
C. 100%
6.56 × 10⁻³ kg (water vapor)/kg (dry air)
D. 70%
6.98 × 10⁻³ kg (water vapor) per kg (dry air)
E. 90%
3.22 × 10⁻³ kg (water vapor) per kg (dry air)
F. 75%
5.89 × 10⁻³ kg (water vapor)/kg (dry air)
G. 50%
4.46 × 10⁻³ kg (water vapor)/kg (dry air)
H. 95%
6.38 × 10⁻³ kg (water vapor)/kg (thousand air)
I. 90%
8.32 × 10^-3 kg (water vapor)/kg (dry air)
J. 8.0%
7.24 × 10^-3 kg (water vapor) per kg (thousand air)
Answer: C
In the cylinder-piston system, there are 2 kg of $\mathrm{CO}_{2}$ at a pressure of 500 kPa and a temperature of 400°C. The gas in the cylinder is cooled to 40°C. Due to the action of the external spring on the piston, the pressure inside the cylinder changes linearly with the volume: $p=kV$. If the pressure at the final state is 300 kPa, calculate the heat exchange during the process. It is known that the thermodynamic energy of $\mathrm{CO}_{2}$ is only a function of temperature, $U=c_{V}T$, and the specific heat capacity of $\mathrm{CO}_{2}$ can be considered constant, with $R_{\mathrm{g}}=0.189 \, \mathrm{~kJ/(kg \cdot K)}$, $c_{V}=0.866 \mathrm{kJ}/(\mathrm{kg} \cdot \mathrm{K})$.

Options:
A. $$
- 6 6 0. 9 \ \mathrm{k J}
$$
B. $$
- 7 0 1. 3 \ \mathrm{k J}
$$
C. $$
- 6 8 5. 5 \ \mathrm{k J}
$$
D. $$
- 6 5 6. 8 \ \mathrm{k J}
$$
E. $$
- 6 6 9. 1 \ \mathrm{k J}
$$
F. $$
- 6 5 8. 7 \ \mathrm{k J}
$$
G. $$
- 6 9 0. 2 \ \mathrm{k J}
$$
H. $$
- 7 1 0. 4 \ \mathrm{k J}
$$
I. $$
- 6 7 2. 4 \ \mathrm{k J}
$$
J. $$
- 7 2 5. 8 \ \mathrm{k J}
$$
Answer: E
An ejector is a compression device that uses a high-pressure airflow to draw in a low-pressure airflow, thus increasing its pressure. There is an ejector in which the high-pressure airflow enters through inlet 1 and the entrained low-pressure airflow enters through inlet 2. The two airflows mix and exit through outlet 3. Given that $t_{1}=20 \; \mathrm{^\circ C}$, $p_{1}=0.6 \; \mathrm{MPa}$, $t_{2}=20 \; \mathrm{^\circ C}$, $p_{2}=0.1 \; \mathrm{MPa}$, and $p_{3}=0.3 \; \mathrm{MPa}$, assume the flow is steady and adiabatic, and the kinetic energy of the airflow at the inlet and outlet sections can be neglected. Treat the air as an ideal gas with a constant specific heat capacity, gas constant $R_{\mathrm{g}}=287 \mathrm{J/(kg\cdot K)}$, and $c_{p}=1004 \mathrm{J/(kg\cdot K)}$. Find the maximum attainable entrainment ratio $\frac{m_{2}}{m_{1}}$.

Options:
A. 0.528
B. 0.769
C. 0.495
D. 0.756
E. 0.413
F. 0.692
G. 0.549
H. 0.631
I. 0.874
J. 0.587
Answer: H
The volume of the cylindrical thick-walled test container is 0.1 L, containing water in a critical state. Allow it to cool to room temperature, 20 °C, and determine the amount of heat released by the water in the process is(). (Given that the critical pressure of water $p_{cr}$ = $22064 kPa$) .

Options:
A. $$
- 8 3. 4 \ \mathrm{k J}
$$
B. $$
- 6 2. 3 \ \mathrm{k J}
$$
C. $$
- 5 0. 8 \ \mathrm{k J}
$$
D. $$
- 7 4. 1 \ \mathrm{k J}
$$
E. $$
- 6 9. 9 \ \mathrm{k J}
$$
F. $$
- 5 9. 6 \ \mathrm{k J}
$$
G. $$
- 6 0. 0 \ \mathrm{k J}
$$
H. $$
- 7 8. 5 \ \mathrm{k J}
$$
I. $$
- 8 0. 0 \ \mathrm{k J}
$$
J. $$
- 5 5. 2 \ \mathrm{k J}
$$
Answer: B
The radical polymerization of 1,3-butadiene is known to have $\Delta H^{-} = -73 \mathrm{~kJ \cdot mol^{-1} ~}$ and $\Delta S^{-} = -89.0 \mathrm{~J \cdot~ mol^{-1} \cdot~ K^{-1} ~}$. Here, $\Delta H^{-}$ and $\Delta S^{-}$ refer to the changes in enthalpy and entropy, respectively, when the equilibrium monomer concentration is $1 \mathrm{~mol \cdot L^{-1}}$. What are the equilibrium monomer concentrations at $27^\circ \mathrm{C}$, $77^\circ \mathrm{C}$, and $127^\circ \mathrm{C}$?

Options:
A. $$
8 \times1 0^{-9} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 5. 2 \times1 0^{-7} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 9. 5 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
B. $$
8 \times1 0^{-9} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 7. 0 \times1 0^{-6} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 1. 1 \times1 0^{-4} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
C. $$
2 \times1 0^{-8} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 5. 9 \times1 0^{-7} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 2. 3 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
D. $$
9 \times1 0^{-8} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 6. 2 \times1 0^{-6} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 1. 5 \times1 0^{-4} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
E. $$
5 \times1 0^{-8} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 4. 3 \times1 0^{-6} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 9. 9 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
F. $$
1 \times1 0^{-8} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 4. 7 \times1 0^{-6} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 2. 0 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
G. $$
3 \times1 0^{-9} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 6. 5 \times1 0^{-7} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 1. 8 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
H. $$
8 \times1 0^{-9} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 5. 7 \times1 0^{-7} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 1. 3 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
I. $$
7 \times1 0^{-9} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 3. 4 \times1 0^{-7} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 1. 2 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
J. $$
6 \times1 0^{-8} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 5. 1 \times1 0^{-6} \mathrm{~ m o l ~ \cdot~ L^{-1} ~},\ 3. 1 \times1 0^{-5} \mathrm{~ m o l ~ \cdot~ L^{-1} ~}
$$
Answer: H
Using BPO as the initiator, a study on the kinetics of styrene polymerization was conducted at 60°C, with the data as follows: $\big[ \mathrm{M} \big]= 8.53 \mathrm{~mol} \cdot\mathrm{L}^{-1}, [ I ]=4.0 \times 10^{-3} \mathrm{~mol} \cdot\mathrm{L}^{-1} , \, f=0.80, k_{d}=3.27 \times 10^{-4} \, \mathrm{s}^{-1} , k_{p}=1.76 \times 10^{2} \mathrm{L} \cdot\mathrm{mol}^{-1} \cdot\mathrm{s}^{-1} , k_{t}=3.58 \times 10^{7} \mathrm{L} \cdot\mathrm{mol}^{-1} \cdot\mathrm{s}^{-1} .$ What are the average degree of polymerization and the lifetime of the free radicals ?

Options:
A. $$
4. 7 1 {\times} 1 0^{3},\ 1.32\ \mathrm{s}
$$
B. $$
2. 1 6 {\times} 1 0^{3},\ 0.57\ \mathrm{s}
$$
C. $$
1. 2 4 {\times} 1 0^{3},\ 0.65\ \mathrm{s}
$$
D. $$
2. 9 8 {\times} 1 0^{3},\ 0.94\ \mathrm{s}
$$
E. $$
1. 8 5 {\times} 1 0^{3},\ 0.74\ \mathrm{s}
$$
F. $$
3. 2 9 {\times} 1 0^{3},\ 1.08\ \mathrm{s}
$$
G. $$
0. 8 9 {\times} 1 0^{3},\ 0.47\ \mathrm{s}
$$
H. $$
2. 4 6 {\times} 1 0^{3},\ 0.82\ \mathrm{s}
$$
I. $$
4. 0 3 {\times} 1 0^{3},\ 1.25\ \mathrm{s}
$$
J. $$
3. 5 7 {\times} 1 0^{3},\ 1.15\ \mathrm{s}
$$
Answer: H
Methyl methacrylate undergoes bulk polymerization at 60°C using azobisisobutyronitrile as the initiator, with disproportionation termination accounting for 90% of the kinetic termination. $k_{d} = 1.16 \times 10^{-5} \, \text{s}^{-1}$, $k_{p} = 3700 \, \text{L} \cdot \text{mol}^{-1} \cdot \text{s}^{-1}$, $k_{t} = 7.4 \times 10^{7} \, \text{L} \cdot \text{mol}^{-1} \cdot \text{s}^{-1}$, with an initiator efficiency of 1.0. The monomer concentration is $10.86 \, \text{mol} \cdot \text{L}^{-1}$, and the initiator concentration is $0.206 \times 10^{-3} \, \text{mol} \cdot \text{L}^{-1}$. What is the number-average degree of polymerization of the resulting polymer?

Options:
A. $$
2. 8 1 \times1 0^{4}
$$
B. $$
4. 2 6 \times1 0^{4}
$$
C. $$
9. 7 2 \times1 0^{4}
$$
D. $$
8. 3 7 \times1 0^{4}
$$
E. $$
5. 0 3 \times1 0^{4}
$$
F. $$
0. 3 4 \times1 0^{4}
$$
G. $$
6. 5 9 \times1 0^{4}
$$
H. $$
7. 0 4 \times1 0^{4}
$$
I. $$
3. 1 8 \times1 0^{4}
$$
J. $$
1. 9 4 \times1 0^{4}
$$
Answer: E
When calculating, use the following data and conditions: $C_{\mathrm{M}} = 8.0 \times 10^{-5}$, $C_{I} = 3.2 \times 10^{-4}$, $C_{S} = 2.3 \times 10^{-6}$. The density of styrene at $0.887 \ \mathrm{g} \cdot \mathrm{mL}^{-1}$, and at 60 $^\circ C$, the density of benzene is $0.839 \ \mathrm{g} \cdot \mathrm{mL}^{-1}$. Assume the styrene-benzene system is an ideal solution. The relative molecular mass of $n$-butanethiol is 90. Using di-tert-butyl peroxide as an initiator, study the bulk polymerization of styrene at 60 $^\circ C$. The concentration of styrene solution is $1.0 \ \mathrm{mol} \cdot \mathrm{L}^{-1}$, and the concentration of peroxide is $0.01 \ \mathrm{mol} \cdot \mathrm{L}^{-1}$. The initial rates of initiation and polymerization are $4.0 \times 10^{-11} \ \mathrm{mol} \cdot \mathrm{L}^{-1} \cdot \mathrm{s}^{-1}$ and $1.5 \times 10^{-7} \ \mathrm{mol} \cdot \mathrm{L}^{-1} \cdot \mathrm{s}^{-1}$, respectively. To achieve polystyrene with a relative molecular mass of 85,000, how much $n$-butanethiol (given $C_{\mathrm{s}}^{\prime} = 21$) is needed?

Options:
A. $$
4. 5 7 \times1 0^{-4} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
B. $$
4. 0 1 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
C. $$
3. 9 8 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
D. $$
4. 9 9 \times1 0^{-2} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
E. $$
5. 0 0 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
F. $$
3. 6 3 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
G. $$
4. 2 3 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
H. $$
4. 1 1 \times1 0^{-2} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
I. $$
5. 1 5 \times1 0^{-3} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
J. $$
3. 7 2 \times1 0^{-4} \ \mathrm{g} \cdot\mathrm{L}^{-1}
$$
Answer: G
If the chain termination reaction of a free radical polymerization is entirely through coupling termination, what is the relative molecular weight distribution index of the polymer obtained at low conversion rates?

Options:
A. $2.5$
B. $1.8$
C. $0.7$
D. $1.5$
E. $2.1$
F. $1.3$
G. $0.9$
H. $1.0$
I. $2.0$
J. $3.0$
Answer: D
Vinyl chloride $( \mathbf{M}_{1} )$ - vinyl acetate $( \mathrm{M}_{2} )$ radical copolymerization at $60 \mathrm{~°C}$, with $r_{1} = 1.68$ and $r_{2} = 0.23$. What is the copolymer composition $F_{1}$ when the concentration of vinyl acetate is 15% (by mass fraction)?

Options:
A. $0.213$
B. $0.854$
C. $0.045$
D. $0.319$
E. $0.789$
F. $0.126$
G. $0.678$
H. $0.562$
I. $0.475$
J. $0.932$
Answer: J
When the initial monomer composition is $f_{1}=50$%, monomers $\mathbf{M}_{1}$ and $\mathbf{M}_{2}$ undergo copolymerization, with $r_{1}=0$ and $r_{2}=0.5$. If $F_{1}$ varies by no more than 5%, what should be the maximum value of the conversion rate controlled ?

Options:
A. $42.1\%$
B. $41.2\%$
C. $46.5\%$
D. $39.3\%$
E. $48.7\%$
F. $44.6\%$
G. $37.8\%$
H. $50.9\%$
I. $49.2\%$
J. $43.4\%$
Answer: B
Styrene $( \mathbf{M}_{1} )$ copolymerizes with methyl methacrylate $( \mathbf{M}_{2} )$. During free radical copolymerization at 60°C, the reactivity ratios are $r_{1}=0.52$ and $r_{2}=0.46$. If $f_{1}=0.2$, what is the mole fraction of styrene in the polymer at low conversion rates?

Options:
A. $0.150$
B. $0.240$
C. $0.275$
D. $0.420$
E. $0.315$
F. $0.375$
G. $0.195$
H. $0.285$
I. $0.330$
J. $0.255$
Answer: H
Dissolve $1.0 \times 10^{-3} \mathrm{~mol~ RLi}$ in THF, then quickly add 2.4 mol of styrene. The total volume of the solution is 1 L. Assuming the monomer mixes uniformly immediately, after 2000 seconds of reaction, half of the monomer has polymerized. What is the degree of polymerization of polystyrene after 2000 seconds of polymerization?

Options:
A. $$
1. 2 \times1 0^{3}
$$
B. $$
1. 7 \times1 0^{3}
$$
C. $$
1. 9 \times1 0^{2}
$$
D. $$
1. 3 \times1 0^{3}
$$
E. $$
1. 5 \times1 0^{3}
$$
F. $$
1. 1 \times1 0^{3}
$$
G. $$
1. 4 \times1 0^{3}
$$
H. $$
1. 6 \times1 0^{2}
$$
I. $$
1. 8 \times1 0^{3}
$$
J. $$
1. 0 \times1 0^{3}
$$
Answer: A
The linear polycondensation of hydroxy acid $\mathrm{HO}(\mathrm{CH}_2)_4\mathrm{COOH}$ was performed, and the weight-average relative molecular mass of the product was measured to be 18,400. What are the percentage of esterified hydroxyl groups, the number-average relative molecular mass, and the number of structural units $X_n$?

Options:
A. $98.9\%,\ 9251,\ 92.51$
B. $97.8\%,\ 9000,\ 90.00$
C. $92.5\%,\ 8600,\ 86.00$
D. $96.6\%,\ 8800,\ 88.00$
E. $99.1\%,\ 9200,\ 92.00$
F. $95.0\%,\ 8051,\ 80.51$
G. $97.3\%,\ 8900,\ 89.00$
H. $94.7\%,\ 8400,\ 84.00$
I. $96.0\%,\ 8950,\ 89.50$
J. $93.9\%,\ 8150,\ 81.50$
Answer: A
In the polyvinyl alcohol (PVA) solution, add $\mathrm{HIO}_{4}$, assuming the entire 1,2-glycol structure reacts with $\mathrm{HIO}_{4}$ causing the molecular chain to break. The number average molecular weight of PVA measured before joining is 35,000, and it is 2,200 after the effect. What is the percentage of head-to-head linkage structures in PVA (the number of head-to-head structures per 100 structural units)?

Options:
A. $3.65\%$
B. $0.75\%$
C. $1.33\%$
D. $0.99\%$
E. $2.05\%$
F. $2.22\%$
G. $4.01\%$
H. $0.58\%$
I. $3.15\%$
J. $1.88\%$
Answer: J
Assuming it is an equivalent freely jointed chain, the segment length is 18.5 $\mathrm{C-C}$ bonds. What is the root mean square end-to-end distance of a polyethylene chain with $M = 250,000 \ \mathrm{g \cdot mol}^{-1}$?

Options:
A. $$
7 2. 4 {\mathrm{~ n m}}
$$
B. $$
9 5. 6 {\mathrm{~ n m}}
$$
C. $$
1 0 2. 3 {\mathrm{~ n m}}
$$
D. $$
5 4. 2 {\mathrm{~ n m}}
$$
E. $$
6 9. 0 {\mathrm{~ n m}}
$$
F. $$
8 0. 2 {\mathrm{~ n m}}
$$
G. $$
8 8. 5 {\mathrm{~ n m}}
$$
H. $$
5 8. 7 {\mathrm{~ n m}}
$$
I. $$
4 9. 8 {\mathrm{~ n m}}
$$
J. $$
6 3. 1 {\mathrm{~ n m}}
$$
Answer: A
In an asynchronous serial transmission system, the character format is: 1 start bit, 8 data bits, 1 parity bit, and 2 stop bits. If it requires transmitting 120 characters per second, calculate the bit rate for transmission is ().

Options:
A. 1080bps
B. 1100bps
C. 960bps
D. 880bps
E. 1000bps
F. 940bps
G. 9600bps
H. 1220bps
I. 900bps
J. 840bps
Answer: C
Using a serial method to transmit characters, when a signal transmits only one bit of data, the total number of bits transmitted per second is often referred to as the baud rate. The bit rate indicates the number of effective characters transmitted per second. Here, assuming the data transmission rate is 120 characters/second, with each character format prescribed to include 11 bits (1 start bit, 8 data bits, one parity bit, and 1 stop bit), what is the bit rate?

Options:
A. 88 bit/s
B. 9600 bit/s
C. 960 kbit/s
D. 96 bit/s
E. 4800 bit/s
F. 100 bit/s
G. 11 bit/s
H. 960bit/s
I. 8 bit/s
J. 120 bit/s
Answer: H
Given the effective information as 110, use the generator polynomial G(x) = 11011 to encode it into a cyclic redundancy check (CRC) code is ().

Options:
A. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=0 1 1 0 1
$$
B. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=0 1 0 1 1
$$
C. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 0 0 0 1
$$
D. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 1 0 1 1
$$
E. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=0 0 1 1 1
$$
F. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 1 0 0 1
$$
G. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 0 0 1 1
$$
H. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=0 1 1 1 0
$$
I. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 0 1 1 0
$$
J. $$
\mathsf{M} \left( \mathbf{x} \right) \mathbf{\cdot x}^{3}+\mathsf{R} \left( \mathbf{x} \right)=1 1 1 0 0
$$
Answer: D
If a cache system has a main memory capacity of 12MB and a cache capacity of 400KB, what is the total capacity of this storage system?

Options:
A. 12.1MB
B. 12.4MB
C. 13MB
D. 11.8MB
E. 400KB
F. 11MB
G. 11.6MB
H. 12.9MB
I. 12.3MB
J. 12MB
Answer: J
The rotational speed of a certain disk drive is n revolutions per minute, with a total of 4 recording surfaces. Each track records m bytes of information, with a total of 256 tracks. What is the average wait time?

Options:
A. 30s
B. 15s
C. 40s
D. 45s
E. 55s
F. 25s
G. 60s
H. 50s
I. 35s
J. 20s
Answer: A
If dual sign bits are used, what are the values of the dual sign bits when the addition of two positive numbers results in an overflow?

Options:
A. 10
B. 11
C. 00
D. 01
Answer: D
In the instruction format, the purpose of adopting an extended opcode design scheme is to keep the instruction word length unchanged. What changes should be made to the number of instruction operations?

Options:
A. Enhance the complexity of command operations
B. Simplify the number of command operations
C. Limit the number of command operations
D. Decrease the number of command operations
E. Increase the number of command operations
F. Stabilize the number of command operations
G. Maintain the number of command operations
H. Minimize the variety of command operations
I. Consolidate the number of command operations
J. Optimize the number of command operations
Answer: E
Why is the basicity of amines stronger than that of alcohols or phenols?

Options:
A. Amines have lower activation energy to form alcohols, which directly influences their inherent basicity.
B. The electronegativity of a nitrogen atom is less than that of an oxygen atom. The bonding ability on the amino nitrogen atom is stronger.
C. Structural variations in amino groups increase hydrogen bonding, unlike hydroxyl groups in alcohol.
D. Alcohols have strong covalent bonds that limit their ability to donate electrons, impacting their basicity.
E. Amines have a polar C-N bond, while alcohols form stable hydrogen bonds in water. This factor reduces basicity.
F. Nitrogen in amines can acquire a positive charge, making it more acidic compared to alcoholic protons.
G. The presence of hydroxyl groups vastly improves the capacity of alcohols to sustain resonance than amines.
H. The presence of lone pairs in oxygen reduces the likelihood of forming bonds, affecting alcohol basicity.
I. The aromatic nature of phenols significantly enhances the electron-withdrawing effect from hydroxyl oxygen.
J. The hydroxyl group in alcohols stabilizes the oxygen atom through resonance. The interaction weakens basicity.
Answer: B
When phenol is mixed with acyl chloride and heated in the presence of a Lewis acid or Brønsted acid, this reaction first produces ____, followed by ____ rearrangement.

Options:
A. Aliphatic ester,Finkelstein
B. Carboxylate ester,Baeyer-Villiger
C. Alcohol ester,Lindlar
D. Aryl ketone,Reimer-Tiemann
E. Aryl ester,Wittig
F. Alkyl ketone,Friedel-Crafts
G. Alkene ester,Hofmann
H. Phenol ester,Fries
I. Vinyl ester,Schotten-Baumann
J. Aryl amide,Esterification
Answer: H
A man with blood type AB married a woman with blood type A. If the woman's father has blood type O, what genotypes can be expected for their children?

Options:
A. $1I^{A}I^{B}:1I^{B}i:1I^{B}I^{B}:1I^{O}i$
B. $1I^{O}i:1I^{A}i:1I^{B}I^{B}:1I^{A}I^{B}$
C. $1I^{A}i:1i^{i}:1I^{B}i:1I^{O}i$
D. $1I^{A}I^{B}:1I^{B}i:1I^{A}i:1I^{B}I^{B}$
E. $1I^{A}I^{O}:1i^{i}:1I^{A}I^{B}:1I^{B}I^{B}$
F. $1I^{O}I^{A}:1I^{O}i:1I^{B}I^{B}:1I^{A}I^{B}$
G. $1I^{A}i:1I^{A}I^{A}:1I^{B}I^{B}:1I^{B}i$
H. $1I^{A}I^{A}:1I^{A}I^{B}:1I^{B}i:1I^{O}I^{A}$
I. $1I^{B}i:1I^{A}I^{A}:1I^{A}I^{B}:1I^{O}i$
J. $1I^{A}I^{A}:1I^{A}i:1I^{A}I^{B}:1I^{B}i$
Answer: J
The color of corn kernels is determined by three dominant genes A, C, and R. The kernels are colored when the genotype is A_CR_; all other genotypes are colorless. A corn plant with colored kernels is crossed with an accRR plant, resulting in 50% colored kernels; crossed with an aaCCrr plant, resulting in 25% colored kernels; and crossed with an AAccrr plant, resulting in 50% colored kernels. Write out the genotype of this corn plant is().

Options:
A. AaCCrr
B. aaCCRR
C. AaCCRr
D. AaCcRR
E. AaCcRr
F. aaccRR
G. AAccRR
H. AaccRR
I. AAcrrr
J. AACCrr
Answer: C
A polled bull mated with three cows: mating with horned cow A produced a polled calf, mating with horned cow B produced a horned calf, and mating with polled cow C produced a horned calf. Assuming the polled allele P is dominant over the horned allele H, what are the genotypes of these four cattle?

Options:
A. A:Pp, B:Pp, C:Hh, D(Bull):Hh
B. A:PP, B:PP, C:Pp, D (bull):Pp
C. A:PP, B:Hh, C:PP, D(Bull):HH
D. A:HH, B:HH, C:PP, D (Bull):HH
E. A: PP, B: Pp, C: HH, D (Bull): HH
F. A: HH, B: PP, C: Hh, D (Bull): Pp
G. A: Pp, B: Pp, C: PP, D (Bull): PP
H. A: PP, B: Hh, C: Pp, D (Bull): Hh
I. A: Hh, B: PP, C: Pp, D (Bull): Hh
J. A: Hh, B: Hh, C: PP, D (Bull): PP
Answer: B
In pea plants, long tendrils (T) are dominant over short tendrils (t), green peas (G) are dominant over yellow peas (g), and round seeds (R) are dominant over wrinkled seeds (r). A cross between plants with long tendrils, yellow round seeds and plants with short tendrils, green round seeds produced the following offspring: 51 long tendril, green round seeds; 61 long tendril, yellow round seeds; 62 short tendril, green round seeds; 59 short tendril, yellow round seeds; 21 short tendril, green wrinkled seeds; and 20 short tendril, yellow wrinkled seeds. Write the genotype for the tendril length, pea color, and seed shape of the parents is().

Options:
A. $$
T t G G r r \times t t g g R r
$$
B. $$
t t G g R r \times T t g g r r
$$
C. $$
t t g g R R \times T t G G R r
$$
D. $$
t t G g R r \times T T g g R R
$$
E. $$
T t G g R R \times T T g g R r
$$
F. $$
t t g g R r \times T t G g R R
$$
G. $$
T T g g r r \times t t G G R r
$$
H. $$
T t g g R r \times t t G g R r
$$
I. $$
T T g g R r \times t t G g r r
$$
J. $$
T T G g R R \times T t g g R r
$$
Answer: H
In fruit flies, the allele b results in black body color for the fly, while 6 represents the wild-type body color. Another gene, wz (wazy), causes the wings to be waxy, with wz" representing wild-type normal wings. The third gene, cn, results in vermilion eyes, whereas cn* refers to wild-type red eyes. Heterozygous females for these three genes were test-crossed, yielding 1,000 offspring with the following phenotypes and quantities: 5 wild-type; 6 black body, waxy wings, and vermilion eyes; 69 waxy wings and vermilion eyes; 67 black body; 382 vermilion eyes; 379 black body and waxy wings; 48 waxy wings; 44 black body and vermilion eyes. (Note: In the offspring phenotypes, unless mentioned otherwise, they are wild-type.) Calculate chromosome interference and coincidence coefficient.

Options:
A. $I=1-(9/16.11)=31.3%$
B. $I=1-(7/13.88)=32.6%$
C. $I=1-(12/17.34)=26.7%$
D. $I=1-(13/14.89)=29.9%$
E. $I=1-(5/12.76)=36.2%$
F. $I=1-(8/14.25)=29.4%$
G. $I=1-(10/15.96)=28.8%$
H. $I=1-(14/18.45)=24.1%$
I. $I=1-(11/15.14)=27.4%$
J. $I=1-(6/11.58)=33.5%$
Answer: I
In a particular animal species, a beautiful (G) wild-type female individual mates with an unattractive (g) mutant male individual, and all their offspring are beautiful males and unattractive females. Give the genotypes of the parents is().

Options:
A. The female is G_, and the male is Gg.
B. The female is Gg, and the male is Gg.
C. The female is GG, and the male is GG.
D. The female is gg, and the male is gg.
E. The female is G_, and the male is gg.
F. The female is gg, and the male is G_.
G. The female is gg, and the male is GG.
H. The female is GG, and the male is Gg.
I. The female is G_, and the male is GG.
J. The female is Gg, and the male is gg.
Answer: E
The streptomycin-resistant ($Str^{r}$) F strain with the genotype $gal^{-} thr^{-} azi^{r} lac \ \ Ton^{r} mal^{-} xyl^{-} leu^{-}$ was crossed with a prototrophic $\mathrm{Hfr}$ strain having opposite traits. After mating for 60 minutes, the samples were transferred to a minimal medium containing streptomycin. The original mixture contained $2 \times 10^{7}$ Hfr cells and $4 \times 10^{7}$ F cells. The percentages of gene transfer in the Hfr strain were 72% $ton^{s}$, 0% $mal^{+}$, 27% $gal^{+}$, 91% $azi^{s}$, 0% $xyl^{+}$, and 48% $lac^{+}$. In the original mixture, how many $F$ cells were present for each Hfr cell?

Options:
A. 19
B. 20
C. 25
D. 21
E. 15
F. 18
G. 22
H. 24
I. 17
J. 13
Answer: B
There is a type of pumpkin that weighs an average of 2.5 kg, and another variety that weighs an average of 1 kg. The hybrid offspring (F1) of these two varieties have an average weight of 1.75 kg. When F1 are crossbred, they produce 200 F2, with weights ranging from 1 to 2.5 kg. Among them, approximately 3 weigh around 2.5 kg, and another 3 weigh around 1 kg. How many pairs of genes control the weight of these two types of pumpkins?

Options:
A. 10
B. 5
C. 8
D. 4
E. 9
F. 1
G. 7
H. 2
I. 6
J. 3
Answer: J
The vertical acceleration of a certain solid-fuel rocket is given by $a=ke^{-bt} - cv - g$, where $k$, $b$, and $c$ are constants, and $v$ is the velocity. While flying in the atmosphere, the gravitational acceleration $g$ can be considered constant. The first term in the equation represents the effect of rocket thrust, and the second term represents the effect of air resistance. If the initial velocity is zero, find the velocity of the rocket after $t$ seconds.

Options:
A. $$
\begin{array} {l} {{{e^{-d \, t} \left\{\left[ {\frac{k} {b-c}} \cdot e^{( d-b ) \, t}-{\frac{g} {d}} \cdot e^{d \, t} \right]-\left[ {\frac{k} {b-c}}-{\frac{g} {d}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
B. $$
\begin{array} {l} {{{e^{-c \, t} \left\{\left[ {\frac{k} {c-b}} \cdot e^{( c-b ) \, t}-{\frac{g} {c}} \cdot e^{c \, t} \right]-\left[ {\frac{k} {c-b}}-{\frac{g} {c}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
C. $$
\begin{array} {l} {{{e^{-a \, t} \left\{\left[ {\frac{k} {b-c}} \cdot e^{( c-a ) \, t}-{\frac{g} {b}} \cdot e^{b \, t} \right]-\left[ {\frac{k} {b-c}}-{\frac{g} {b}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
D. $$
\begin{array} {l} {{{e^{b \, t} \left\{\left[ {\frac{k} {c-b}} \cdot e^{( c-b ) \, t}-{\frac{g} {a}} \cdot e^{a \, t} \right]-\left[ {\frac{k} {c-b}}-{\frac{g} {a}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
E. $$
\begin{array} {l} {{{e^{-e \, t} \left\{\left[ {\frac{k} {c-b}} \cdot e^{( e-c ) \, t}-{\frac{g} {e}} \cdot e^{e \, t} \right]-\left[ {\frac{k} {c-b}}-{\frac{g} {e}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
F. $$
\begin{array} {l} {{{e^{-f \, t} \left\{\left[ {\frac{k} {c-a}} \cdot e^{( f-a ) \, t}-{\frac{g} {f}} \cdot e^{f \, t} \right]-\left[ {\frac{k} {c-a}}-{\frac{g} {f}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
G. $$
\begin{array} {l} {{{e^{-b \, t} \left\{\left[ {\frac{k} {c-b}} \cdot e^{( b-c ) \, t}-{\frac{a} {c}} \cdot e^{c \, t} \right]-\left[ {\frac{k} {c-b}}-{\frac{a} {c}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
H. $$
\begin{array} {l} {{{e^{c \, t} \left\{\left[ {\frac{k} {b-c}} \cdot e^{( b-c ) \, t}-{\frac{g} {b}} \cdot e^{b \, t} \right]-\left[ {\frac{k} {b-c}}-{\frac{g} {b}} \right] \right\}}}}{{{-D}}} \\ \end{array}
$$
I. $$
\begin{array} {l} {{{e^{g \, t} \left\{\left[ {\frac{k} {a-b}} \cdot e^{( g-b ) \, t}-{\frac{g} {a}} \cdot e^{g \, t} \right]-\left[ {\frac{k} {a-b}}-{\frac{g} {a}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
J. $$
\begin{array} {l} {{{e^{-a \, t} \left\{\left[ {\frac{g} {c-b}} \cdot e^{( b-c ) \, t}-{\frac{k} {c}} \cdot e^{c \, t} \right]-\left[ {\frac{g} {c-b}}-{\frac{k} {c}} \right] \right\}}}}{{{+D}}} \\ \end{array}
$$
Answer: B
If air resistance is neglected, a rocket flying at a certain altitude above Earth experiences a gravitational acceleration of $g = 7.32 \, \text{m/s}^2$. Due to the thrust, the rocket also generates another acceleration $a_{\mathrm{t}} = 7.62 \, \text{m/s}^2$, which is tangential to its trajectory and forms a 30° angle with the instantaneous vertical line. If the instantaneous speed of the rocket is 40,000 km/h, find the radius of curvature $\rho$ of its trajectory at that moment and the tangential acceleration $a_{\tau_0}$.

Options:
A. $3.90\times10^{4} \mathrm{km}$
$g\sin60^{\circ}$
B. $4.00\times10^{4} \mathrm{km}$
$g\cos45^{\circ}$
C. $2.75\times10^{4} \mathrm{km}$
$g\sin45^{\circ}$
D. $3.00\times10^{4} \mathrm{km}$
$g\sin15^{\circ}$
E. $4.25\times10^{4} \mathrm{km}$
$g\cos30^{\circ}$
F. $3.37\times10^{4} \mathrm{km}$
$g\sin30^{\circ}$
G. $2.50\times10^{4} \mathrm{km}$
$g\sin75^{\circ}$
H. $3.50\times10^{4} \mathrm{km}$
$g\tan30^{\circ}$
I. $3.80\times10^{4} \mathrm{km}$
$2g\sin30^{\circ}$
J. $3.60\times10^{4} \mathrm{km}$
$g\tan45^{\circ}$
Answer: F
The initial velocity of a projectile is $460 m/s$ with an elevation angle of $30°$. Find the radius
of curvature ${\rho}$ of the trajectory 10 seconds after launch, ignoring the effect of air resistance.

Options:
A. $$
2 2. 3 9 \mathrm{k m}
$$
B. $$
1 7. 3 4 \mathrm{k m}
$$
C. $$
1 4. 4 7 \mathrm{k m}
$$
D. $$
1 5. 6 8 \mathrm{k m}
$$
E. $$
1 9. 4 5 \mathrm{k m}
$$
F. $$
2 3. 5 1 \mathrm{k m}
$$
G. $$
2 0. 7 6 \mathrm{k m}
$$
H. $$
2 1. 8 8 \mathrm{k m}
$$
I. $$
1 8. 9 3 \mathrm{k m}
$$
J. $$
1 6. 0 2 \mathrm{k m}
$$
Answer: I
If the speed of an artificial satellite at point A on the semi-major axis is $v = 17970$ km/h, and the acceleration due to Earth's gravity is $a = a_{r} = -1.556$ m/s² .
What are the rates of change $a_{\tau}$ and $\ddot{r}$ of the satellite's velocity when it passes through point A?

Options:
A. $$
- 0. 6 2 2 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 2 7 4 \mathrm{m / s^{2}}
$$
B. $$
- 0. 4 7 8 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 6 5 0 \mathrm{m / s^{2}}
$$
C. $$
- 0. 7 7 8 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 3 8 8 \mathrm{m / s^{2}}
$$
D. $$
- 0. 1 8 8 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 8 5 4 \mathrm{m / s^{2}}
$$
E. $$
- 0. 3 3 5 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 5 7 8 \mathrm{m / s^{2}}
$$
F. $$
- 0. 2 4 4 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 7 6 6 \mathrm{m / s^{2}}
$$
G. $$
- 0. 9 0 1 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 4 5 9 \mathrm{m / s^{2}}
$$
H. $$
- 0. 8 9 0 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 1 9 2 \mathrm{m / s^{2}}
$$
I. $$
- 0. 5 6 7 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 4 9 9 \mathrm{m / s^{2}}
$$
J. $$
- 0. 5 0 1 \mathrm{m} / {\bf s}^{2}
$$
$$
- 0. 2 2 9 \mathrm{m / s^{2}}
$$
Answer: C
The blade $OP$ is $0.6 \mathrm{m}$ long, rotating uniformly around the center $O$. The center $O$ moves to the right along a horizontal groove with an acceleration of $\boldsymbol{a}_{\mathrm{o}}=2 \mathrm{m/s}^{2}$. It is known that the acceleration of the endpoint $\boldsymbol{P}$ of the blade is $a_{p}=3 \ \mathrm{m/s}^2$. Find the magnitude of the angular velocity $w$ of $OP$ rotating about the central axis $O$.

Options:
A. $$ 1. 2 8 \mathrm{r a d} / \mathrm{s} $$
B. $$
1. 9 3 \mathrm{r a d} / \mathrm{s}
$$
C. $$ 2. 5 0 \mathrm{r a d} / \mathrm{s} $$
D. $$ 1. 5 6 \mathrm{r a d} / \mathrm{s} $$
E. $$ 3. 6 1 \mathrm{r a d} / \mathrm{s} $$
F. $$ 0. 7 4 \mathrm{r a d} / \mathrm{s} $$
G. $$ 0. 8 7 \mathrm{r a d} / \mathrm{s} $$
H. $$ 2. 9 3 \mathrm{r a d} / \mathrm{s} $$
I. $$ 1. 1 9 \mathrm{r a d} / \mathrm{s} $$
J. $$ 4. 2 9 \mathrm{r a d} / \mathrm{s} $$
Answer: B
Calculate the moment of inertia of a cylindrical brass shaft with a diameter of $75mm$ and a length of $3m$ about its geometric axis of rotation is(). The density can be taken as $8500kg/m³$.

Options:
A. $$
0. 0 8 8 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
B. $$
0. 1 5 6 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
C. $$
1. 0 3 5 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
D. $$
0. 0 9 6 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
E. $$
0. 1 2 3 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
F. $$
0. 3 4 7 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
G. $$
0. 1 0 2 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
H. $$
0. 0 7 9 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
I. $$
0. 0 5 4 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
J. $$
0. 2 1 8 \quad\mathrm{k g} \cdot\mathrm{m}^{2}
$$
Answer: H
A car with a mass of 1275 $\mathrm{kg}$ is brought to a stop from a speed of 60,000 m/h by braking, reducing its speed to 20,000 m/h. Assume that during the braking process, the $0.5 \mathrm{kg}$ brake pad and the $4 \mathrm{kg}$ steel brake drum are uniformly heated, but no heat is transferred to the outside. Given that the specific heat capacities of the brake pad and the steel brake drum are $1.1 \mathrm{kJ} / (\mathrm{kg} \cdot \mathrm{K})$ and $0.46 \mathrm{kJ} / (\mathrm{kg} \cdot \mathrm{K})$ respectively, calculate the temperature increase of the brake pad and the brake drum.

Options:
A. $$
76.8 \mathrm{~ C}
$$
B. $$
88.9 \mathrm{~ C}
$$
C. $$
90.5 \mathrm{~ C}
$$
D. $$
58.1 \mathrm{~ C}
$$
E. $$
65.9 \mathrm{~ C}
$$
F. $$
81.4 \mathrm{~ C}
$$
G. $$
72.3 \mathrm{~ C}
$$
H. $$
61.7 \mathrm{~ C}
$$
I. $$
53.2 \mathrm{~ C}
$$
J. $$
49.6 \mathrm{~ C}
$$
Answer: E
The air in a certain compressor is compressed, and the parameters of the air before compression are: $p_{\text{i}} = 0.1 \text{MPa}, \nu_{\text{i}} = 0.845 \, \text{m}^{3} \big/ \text{kg}$. The parameters after compression are $p_{2} = 0.1 \text{MPa}$, $\nu_{2} = 0.175 \, \text{m}^{3} / \text{kg}$. Assume that during the compression process, the thermodynamic energy of the air per kg increases by 139.0 kJ while 50 kJ of heat is released externally. The compressor produces 10 kg of compressed air per minute. Find: the work (technical work) required to produce 1 kg of compressed air?

Options:
A. $$
150.2 \mathrm{kJ}
$$
B. $$
260.1 \mathrm{kJ}
$$
C. $$
185.9 \mathrm{kJ}
$$
D. $$
175.6 \mathrm{kJ}
$$
E. $$
270.5 \mathrm{kJ}
$$
F. $$
199.3 \mathrm{kJ}
$$
G. $$
220.7 \mathrm{kJ}
$$
H. $$
314.8 \mathrm{kJ}
$$
I. $$
289.4 \mathrm{kJ}
$$
J. $$
244.5 \mathrm{kJ}
$$
Answer: J
A rigid adiabatic container with a volume of $V = 0.028 \, \mathrm{m}^3$ initially contains air at a pressure of 0.1 MPa and a temperature of 21°C. Now, the valve of the gas pipeline connected to this container is opened to fill the container with more gas. Assume the state parameters of the gas in the pipeline remain constant at $p = 0.7 \, \mathrm{MPa}, \; \; t = 21^{\circ}\mathrm{C}$. When the pressure in the container reaches 0.2 MPa, the valve is closed. Find the temperature of the gas inside the container when equilibrium is reached. Assume that air can be regarded as an ideal gas, with its thermodynamic energy related to temperature by $\left\{ u \right\}_{\mathrm{kJ/kg}} = 0.72 \left\{ T \right\}_{\mathrm{K}}$ and enthalpy related to temperature by $\left\{ h \right\}_{\mathrm{kJ/kg}} = 1.005 \left\{ T \right\}_{\mathrm{K}}$.

Options:
A. $$
0.0482kg,315.47K
$$
B. $$
0.0458kg,300.50K
$$
C. $$
0.0625kg,310.32K
$$
D. $$
0.0571kg,342.69K
$$
E. $$
0.0504kg,330.21K
$$
F. $$
0.0557kg,335.92K
$$
G. $$
0.0519kg,305.74K
$$
H. $$
0.0593kg,340.12K
$$
I. $$
0.0631kg,325.69K
$$
J. $$
0.0469kg,320.13K
$$
Answer: D
Some medium and large diesel engines use compressed air to start. If the air bottle used to start the diesel engine has a volume of $V=0.3 \ \mathbf{m}^{3}$ and contains compressed air at $p_{1}=8 \mathrm{MPa}$ and $T_{1}=303 \mathrm{K}$, after starting, the air pressure in the bottle decreases to $p_{2}=0.46 \mathrm{MPa}$ and $T_{2}=303 \mathrm{K}$. Find the mass of the air used.

Options:
A. $$
16.05 kg
$$
B. $$
8.34 kg
$$
C. $$
15.23 kg
$$
D. $$
14.62 kg
$$
E. $$
11.73 kg
$$
F. $$
12.47 kg
$$
G. $$
10.29 kg
$$
H. $$
7.68 kg
$$
I. $$
13.91 kg
$$
J. $$
9.85 kg
$$
Answer: E
Initial state: $p_{1}=0.1 \mathrm{~MPa}$ and $t_{1}=27^\circ \mathrm{C}$ for $\mathrm{CO_{2}}$, with $V_{2}=0.8 \ \mathrm{m}^{3}$, undergoes a certain state change process, with an entropy change $\Delta S=0.242 \ \mathrm{kJ/K}$ (exact value). Final pressure $p_{2}=0.1 \mathrm{~MPa}$. Find the final temperature $t_{2}$.

Options:
A. $$
180.25 {\mathrm{~ C}}
$$
B. $$
150.35 {\mathrm{~ C}}
$$
C. $$
300.12 {\mathrm{~ C}}
$$
D. $$
227.47 {\mathrm{~ C}}
$$
E. $$
240.75 {\mathrm{~ C}}
$$
F. $$
200.00 {\mathrm{~ C}}
$$
G. $$
275.89 {\mathrm{~ C}}
$$
H. $$
250.00 {\mathrm{~ C}}
$$
I. $$
320.15 {\mathrm{~ C}}
$$
J. $$
190.45 {\mathrm{~ C}}
$$
Answer: D
Inside the container, there is 1 kg of superheated Freon 134a vapor, with parameters at $300 \mathrm{~kPa, ~} 100 \mathrm{~^\circ C}$. It is cooled at constant pressure to become a two-phase mixture with a quality of 0.75. Calculate the change in the thermodynamic energy of Freon 134a during this process.

Options:
A. $$ -19.77 kJ $$
B. $$
-15.06 kJ
$$
C. $$ -16.58 kJ $$
D. $$ -17.23 kJ $$
E. $$ -14.89 kJ $$
F. $$ -20.65 kJ $$
G. $$ -11.34 kJ $$
H. $$ -18.32 kJ $$
I. $$ -13.67 kJ $$
J. $$ -12.45 kJ $$
Answer: B
Oxygen is compressed from $t_{1}=40 ^{\circ} \mathrm{C}, \ p_{1}=0.1 \mathrm{~MPa}$ to $p_{2}=0.4 \mathrm{~MPa}$. Calculate the technical work consumed in compressing $\mathbf{1kg}$ of oxygen. Assuming adiabatic compression, consider a constant specific heat capacity.

Options:
A. $$
-145.50 \mathrm{k J} / \mathrm{k g}
$$
B. $$
-155.60 \mathrm{k J} / \mathrm{k g}
$$
C. $$
-138.34 \mathrm{k J} / \mathrm{k g}
$$
D. $$
-135.67 \mathrm{k J} / \mathrm{k g}
$$
E. $$
-148.75 \mathrm{k J} / \mathrm{k g}
$$
F. $$
-120.00 \mathrm{k J} / \mathrm{k g}
$$
G. $$
-132.80 \mathrm{k J} / \mathrm{k g}
$$
H. $$
-140.25 \mathrm{k J} / \mathrm{k g}
$$
I. $$
-130.10 \mathrm{k J} / \mathrm{k g}
$$
J. $$
-125.90 \mathrm{k J} / \mathrm{k g}
$$
Answer: C
The gas passes through a gas turbine, adiabatically expanding from 0.8 MPa, 420°C to $0.1 \mathrm{~MPa}$, $130 \mathrm{~°C}$. Given that the specific heat capacity of the gas is $c_{p}=1.01 \mathrm{kJ}/(\mathrm{kg} \cdot \mathrm{K})$, $c_{\gamma}=0.732 \mathrm{kJ}/(\mathrm{kg} \cdot \mathrm{K})$, calculate the technical work $w_{\mathrm{t}}$ produced by $1 \mathrm{kg}$ of gas, assuming that the kinetic energy differences and potential energy differences at the gas inlet and outlet are negligible.

Options:
A. $$
305.6 \mathrm{k J} / \mathrm{k g}
$$
B. $$
292.9 \mathrm{k J} / \mathrm{k g}
$$
C. $$
310.7 \mathrm{k J} / \mathrm{k g}
$$
D. $$
295.3 \mathrm{k J} / \mathrm{k g}
$$
E. $$
270.4 \mathrm{k J} / \mathrm{k g}
$$
F. $$
275.9 \mathrm{k J} / \mathrm{k g}
$$
G. $$
280.5 \mathrm{k J} / \mathrm{k g}
$$
H. $$
289.1 \mathrm{k J} / \mathrm{k g}
$$
I. $$
265.2 \mathrm{k J} / \mathrm{k g}
$$
J. $$
300.0 \mathrm{k J} / \mathrm{k g}
$$
Answer: B
The container with a volume of $0.425 \mathrm{m}^{3}$ is filled with nitrogen gas at a pressure of $16.21 \mathrm{MPa}$ and a temperature of 189 K. Use the Van der Waals equation to calculate the mass of the nitrogen gas in the container.

Options:
A. $$
147.0 \mathrm{k g}
$$
B. $$
139.8 \mathrm{k g}
$$
C. $$
144.3 \mathrm{k g}
$$
D. $$
170.9 \mathrm{k g}
$$
E. $$
152.7 \mathrm{k g}
$$
F. $$
132.4 \mathrm{k g}
$$
G. $$
160.2 \mathrm{k g}
$$
H. $$
125.6 \mathrm{k g}
$$
I. $$
155.5 \mathrm{k g}
$$
J. $$
130.1 \mathrm{k g}
$$
Answer: A
A single-stage piston compressor intakes air at a volume of $V_{1}=140 \, \mathrm{m}^{3}/\mathrm{h}$ per hour. The intake air's state parameters are $p_{1}=0.1 \, \mathrm{MPa}$, $t_{1}=27^{\circ}\mathrm{C}$. The output air pressure is $p_{2}=0.6 \, \mathrm{MPa}$. Calculate the ideal power required for the compressor (expressed in $\mathrm{kW}$) under the following three conditions: polytropic compression (assuming $n=1.2$)

Options:
A. $$
10.05kW
$$
B. $$
7.50kW
$$
C. $$
6.89kW
$$
D. $$
8.12kW
$$
E. $$
11.57kW
$$
F. $$
9.78kW
$$
G. $$
9.45kW
$$
H. $$
10.23kW
$$
I. $$
7.95kW
$$
J. $$
12.30kW
$$
Answer: D
A mixture of 1 mol of gaseous ethylene and 3 mol of oxygen reacts in a rigid container at 25°C. Determine the amount of heat released by the system when the products are cooled to 600 K.

Options:
A. $$
1308927 J
$$
B. $$
1223450 J
$$
C. $$
1426739 J
$$
D. $$
1357821 J
$$
E. $$
1401122 J
$$
F. $$
1286386 J
$$
G. $$
1219500 J
$$
H. $$
1265005 J
$$
I. $$
1298860 J
$$
J. $$
1372283 J
$$
Answer: F
Water is being heated on the outside of a horizontal pipe with an outer diameter of 76 mm. If the ambient water temperature and the average temperature of the outer pipe wall are 25°C and 45°C, respectively. What is the heat transfer coefficient for natural convection?

Options:
A. $815W\cdot m^{-2}\cdot K^{-1}$
B. $759W\cdot m^{-2}\cdot K^{-1}$
C. $732W\cdot m^{-2}\cdot K^{-1}$
D. $674W\cdot m^{-2}\cdot K^{-1}$
E. $681W\cdot m^{-2}\cdot K^{-1}$
F. $698W\cdot m^{-2}\cdot K^{-1}$
G. $745W\cdot m^{-2}\cdot K^{-1}$
H. $712W\cdot m^{-2}\cdot K^{-1}$
I. $699W\cdot m^{-2}\cdot K^{-1}$
J. $723W\cdot m^{-2}\cdot K^{-1}$
Answer: J
The temperature of a certain humid air is 40°C, with a total pressure of 101.33 kPa and a moisture content of $2.0×10^{-2}kg·m^{-3}$. What is the temperature to which the humid air should be raised in order to reduce its relative humidity to 10%?

Options:
A. 67.8°C
B. 79.3°C
C. 60.2°C
D. 48.9°C
E. 75.2°C
F. 50.1°C
G. 62.4°C
H. 55.6°C
I. 42.0°C
J. 70.5°C
Answer: A
In the laboratory, to obtain kinetic data, experiments were conducted using a piston flow reactor filled with 1.6L of catalyst. The reaction takes place at $573K, 2000kPa$. Pure gaseous reactant A is fed, and on the catalyst, the reaction A→R occurs with a rate of $e^{-1}$. The initial volumetric flow rate $q_{V, 0}= 0.5 L \cdot \mathrm{s}^{-1}$, and the conversion rate is 65%. The kinetic equation is $r_A=kc_A^2$.
Now, based on the experimental results for scale-up design, if the operation continues under the original conditions and the conversion rate remains 65%.What is the amount of catalyst to be loaded into the piston flow reactor when $q_{V,0}$ is increased to 25 $L \cdot s^{-1}$?

Options:
A. 120L
B. 60L
C. 40L
D. 70L
E. 110L
F. 50L
G. 100L
H. 90L
I. 80L
J. 30L
Answer: I
The train ascends a straight sloped track with a gradient of 0.008 at a constant speed. Excluding the electric locomotive, the train weighs 12,000 kN. Assume the resistance encountered by the train is equal to 0.005 times the pressure on the track. What is the tractive force of this electric locomotive ?

Options:
A. $$
1 5 6 \ \mathrm{k N}
$$
B. $$
2 3 0 \ \mathrm{k N}
$$
C. $$
1 5 3 \ \mathrm{k N}
$$
D. $$
1 5 0 \ \mathrm{k N}
$$
E. $$
1 3 9 \ \mathrm{k N}
$$
F. $$
1 6 0 \ \mathrm{k N}
$$
G. $$
1 7 5 \ \mathrm{k N}
$$
H. $$
1 6 5 \ \mathrm{k N}
$$
I. $$
2 0 0 \ \mathrm{k N}
$$
J. $$
1 4 8 \ \mathrm{k N}
$$
Answer: A
Given that the side length of square $ABDC$ is $a$, try to find a point $E$ such that after removing the isosceles triangle $AEB$ from the square, point $E$ becomes the centroid of the remaining area . So where is the position of point E ?

Options:
A. $$
\frac{a} {2}, 0. 8 3 4 a
$$
B. $$
\frac{a} {7}, 0. 6 4 1 a
$$
C. $$
\frac{a} {2}, 0. 6 9 2 a
$$
D. $$
\frac{a} {3}, 0. 5 7 8 a
$$
E. $$
\frac{a} {6}, 0. 7 3 4 a
$$
F. $$
\frac{a} {4}, 0. 7 6 2 a
$$
G. $$
\frac{a} {2}, 0. 6 3 4 a
$$
H. $$
\frac{a} {5}, 0. 6 3 4 a
$$
I. $$
\frac{a} {2}, 0. 6 5 8 a
$$
J. $$
\frac{a} {2}, 0. 5 9 6 a
$$
Answer: G
A circular disk with a radius of $r=20$ cm moves within the vertical plane $xy$. The motion equation for the center of the disk, point $C$, is given by $x_{C}=10t$ and $y_{C}=100-4.9t^{2}$, where $x_{C}$ and $y_{C}$ are measured in meters. The disk rotates with a constant angular velocity of $\omega=\frac{\pi}{2}$ rad/s around a horizontal axis $C$ that is perpendicular to the disk's surface. What is the acceleration of a point $A$ on the edge of the disk at time $t=0$ ? ( Assume the position of point $A$ on the disk is determined by the angle $\varphi=\omega t$, with $\varphi$ measured counterclockwise from the vertical line.)

Options:
A. $$2. 9 4 \ \mathrm{m / s^{2}}$$
B. $$9. 3 1 \ \mathrm{m / s^{2}}$$
C. $$5. 5 6 \ \mathrm{m / s^{2}}$$
D. $$7. 5 9 \ \mathrm{m / s^{2}}$$
E. $$6. 8 0 \ \mathrm{m / s^{2}}$$
F. $$0. 8 7 \ \mathrm{m / s^{2}}$$
G. $$3. 7 1 \ \mathrm{m / s^{2}}$$
H. $$4. 2 3 \ \mathrm{m / s^{2}}$$
I. $$1. 6 5 \ \mathrm{m / s^{2}}$$
J. $$8. 4 2 \ \mathrm{m / s^{2}}$$
Answer: B
The two banks of the river are parallel to each other. A small boat departs from point $A$, heading in a direction perpendicular to the bank. After setting off, it reaches the opposite bank in 10 minutes, at which time the boat's position $C$ is 120 meters downstream from point $A$. To make the boat, with the same original relative speed, travel from point $A$ to directly opposite point $B$, it must head upstream at a certain angle to $AB$. In this scenario, the boat reaches the opposite bank in 12.5 minutes. What are the width of the river $l$, the speed of the boat relative to the water $u$, and the speed of the current $v$ ?

Options:
A. $$170m,24m/min, 10m/min$$
B. $$230m,19m/min, 15m/min$$
C. $$250m,15m/min, 10m/min$$
D. $$220m,18m/min, 11m/min$$
E. $$240m,17m/min, 13m/min$$
F. $$200m,20m/min, 12m/min$$
G. $$180m,25m/min, 14m/min$$
H. $$190m,22m/min, 13m/min$$
I. $$210m,21m/min, 9m/min$$
J. $$160m,23m/min, 11m/min$$
Answer: F
A flywheel with a diameter of 50 cm is mounted on a shaft with a diameter of 60 mm, and the flywheel rotates at a speed of 180 r/min. It is known that the flywheel stops after making 90 revolutions once the machine is turned off. Assume that the mass of the flywheel is uniformly distributed along the rim and the mass of the shaft can be neglected. What is the coefficient of sliding friction $f$ between the shaft and the bearing ?

Options:
A. $$0. 0 8$$
B. $$0. 1 2$$
C. $$0. 0 3$$
D. $$0. 1 0$$
E. $$0. 0 7$$
F. $$0. 0 9$$
G. $$0. 1 1$$
H. $$0. 0 5$$
I. $$0. 0 6$$
J. $$0. 0 4$$
Answer: E
The airplane flies in a straight line from the starting point, with this line having a deviation angle $\psi$ relative to a given straight flight path. For different flights, the angle $\psi$ can have various values. Assume that the angle $\psi$ is a Gaussian-distributed random variable, with its expected value equal to zero and a mean square error of $\sigma_{\psi}=2^{\circ}$. What are the probabilities that the lateral deviation of the airplane from the given flight path does not exceed 5 km for three flight distances: $L=50, 100, 200 \mathrm{~km}$ ?

Options:
A. $$
0. 8 9 9, 0. 7 6, 0. 5 4
$$
B. $$
0. 9 3 2, 0. 7 8, 0. 4 5
$$
C. $$
0. 9 5 4, 0. 8 6, 0. 4 8
$$
D. $$
0. 9 6 5, 0. 5 4, 0. 4 9
$$
E. $$
0. 9 9 7, 0. 8 6, 0. 5 2
$$
F. $$
0. 9 8 7, 0. 8 7, 0. 5 1
$$
G. $$
0. 9 4 3, 0. 7 7, 0. 5 3
$$
H. $$
0. 9 9 8, 0. 7 6, 0. 4 4
$$
I. $$
0. 8 8 8, 0. 8 5, 0. 6 2
$$
J. $$
0. 9 7 6, 0. 8 5, 0. 6 3
$$
Answer: E
Given the irrotational velocity potential $\varphi=V_{∞} \! \left( r+\frac{a^{2}} {r} \right) \cos \varepsilon+\frac{\Gamma} {2 \pi} \varepsilon$ for a known incompressible plane flow, the stream function $\phi$ is ().

Options:
A. $$
\psi=V_{∞} \Big( r+\frac{a^{2}} {r} \Big) \mathrm{c o s} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
B. $$
\psi=V_{∞} \Big( r-\frac{a^{2}} {r} \Big) \mathrm{c o s} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} \varepsilon+\mathrm{c o n s t}
$$
C. $$
\psi=V_{∞} \Big( r+\frac{a^{3}} {r} \Big) \mathrm{c o s} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
D. $$
\psi=V_{∞} \Big( r-\frac{a^{3}} {r} \Big) \mathrm{s i n} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} \varepsilon+\mathrm{c o n s t}
$$
E. $$
\psi=V_{∞} \Big( r+\frac{a^{2}} {r} \Big) \mathrm{s i n} \varepsilon+\frac{\Gamma} {2 \pi} \mathrm{l n} \varepsilon+\mathrm{c o n s t}
$$
F. $$
\psi=V_{∞} \Big( r-\frac{a^{4}} {r^{2}} \Big) \mathrm{s i n} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
G. $$
\psi=V_{∞} \Big( r-\frac{a^{2}} {r^{2}} \Big) \mathrm{s i n} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
H. $$
\psi=V_{∞} \Big( r-\frac{a^{2}} {r} \Big) \mathrm{c o s} \varepsilon+\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
I. $$
\psi=V_{∞} \Big( r-\frac{a^{2}} {r} \Big) \mathrm{s i n} \varepsilon-\frac{\Gamma} {2 \pi} \mathrm{l n} r+\mathrm{c o n s t}
$$
J. $$
\psi=V_{∞} \Big( r-\frac{a^{2}} {r} \Big) \mathrm{s i n} \varepsilon+\frac{\Gamma} {2 \pi} \mathrm{l n} \varepsilon+\mathrm{c o n s t}
$$
Answer: I