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Laminar burning velocity, Markstein length, and critical flame radius of an H2/O2 flame with different diluents, He, Ar, N2 and CO2, were measured under elevated pressure with different diluent concentrations. The effects of pressures, diluents, and dilution and equivalence ratios were studied by comparing calculated and experimental results. The laminar burning velocity showed non-monotonic behavior with pressure when the dilution ratio was low. The reason is the radical pool reduced with increasing pressure and leads to the decrease of overall reaction order from larger than 2 to smaller than 2, and further leads to this non-monotonic phenomenon. A modified empirical equation was presented to capture the relationship between active radicals and laminar burning velocity. Critical radii and Markstein lengths both decrease with initial pressure and increase with equivalence ratio and dilution ratio. The calculated critical radii indicate that the Peclet number and flame thickness control the change of Rcr. It can be found that Leeff has a significant influence on Peclet number and leads to the decrease of critical flame radii of Ar, N2, and CO2 diluted mixture. Interestingly, the CO2 diluted mixture has the lowest Markstein length under stoichiometric conditions and a high value under fuel-rich conditions, consistent as the flame instability observed on the flame images. The reason is that the Leeff of CO2 diluted mixture increased rapidly with the equivalence ratio.

Magnetic Resonance (MR) imaging plays an important role in medical diagnosis and biomedical research. Due to the high in-slice resolution and low through-slice resolution nature of MR imaging, the usefulness of the reconstruction highly depends on the positioning of the slice group. Traditional clinical workflow relies on time-consuming manual adjustment that cannot be easily reproduced. Automation of this task can therefore bring important benefits in terms of accuracy, speed and reproducibility. Current auto-slice-positioning methods rely on automatically detected landmarks to derive the positioning, and previous studies suggest that a large, redundant set of landmarks are required to achieve robust results. However, a costly data curation procedure is needed to generate training labels for those landmarks, and the results can still be highly sensitive to landmark detection errors. More importantly, a set of anatomical landmark locations are not naturally produced during the standard clinical workflow, which makes online learning impossible. To address these limitations, we propose a novel framework for auto-slice-positioning that focuses on localizing the canonical planes within a 3D volume. The proposed framework consists of two major steps. A multi-resolution region proposal network is first used to extract a volume-of-interest, after which a V-net-like segmentation network is applied to segment the orientation planes. Importantly, our algorithm also includes a Performance Measurement Index as an indication of the algorithm's confidence. We evaluate the proposed framework on both knee and shoulder MR scans. Our method outperforms state-of-the-art automatic positioning algorithms in terms of accuracy and robustness.

The numerous drawbacks hindering the practical take-off of the lithium–sulfur technology requires significant breakthrough in designing novel sulfur host. Herein, bipyramidal sulfur/graphene oxide composite cathode with sulfur content of 92% is obtained via a room-temperature bottom-up approach with the aid of polyvinylpyrrolidone. Material characterization reveals the uniform coating of each individual sulfur particle by a thin wall of graphene oxide and residual polyvinylpyrrolidone molecules. The robustness and close proximity of the protective graphene oxide shell not only facilitates electron and ion transportation but also restrains the diffusion of polysulfides through interfacial chemical interaction. As a result, the cathode manifests a high initial reversible capacity of 1301 mAh g−1 at 0.2 C, outstanding capacity retention of 86.4% at 1 C after 115 cycles and long cycle life of 250 cycles with 360.6 mAh g−1 remaining capacity at 2 C. The present work provides an affordable and sustainable approach of confining sulfur at high content which is essential for high-energy density lithium–sulfur battery.

A novel partial bio-based molecular design platform for high performance polymer (HPP) namely diamine-adenine-monomer platform (DAAMP) was suggested and discussed in this paper. Aimed at introducing the adenine moiety into backbone of HPP and endowing great wide molecular tailorability, DAAMP was synthesized via a nucleophilic displacement between 6-chloropurine and various diamines. Phthalonitrile (PN) resin is a typical class of HPP. To verify the feasibility of DAAMP for HPP design, two new phthalonitrile monomers based on two different diamine namely DAAMP-PN were synthesized. The chemical structures of synthesized monomers were confirmed by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The two new DAAMP-PNs based on different diamines showed an obvious difference in thermal polymerization behavior. Multiple hydrogen bonding was exhibited in DAAMP-PN system. And the prepared DAAMP-PN polymer showed high glass transition temperature, excellent thermal and thermo-oxidative stabilities. The results demonstrated that DAAMP is a promising building-block for HPP design with flexible molecular tailorability.

Heteroatom doping porous carbon material possess a variety of attractive functionality such as electrical properties, catalytic properties and adsorptive capability. As an important building block of DNA, adenine has following characteristics: 1. Heterocyclic structure 2. Potential interaction modes 3. Flexible structure tailor ability 4. Available from biomass. In this study, adenine-containing polyimide (API) foam has been prepared by freeze-drying, and is used as polymer precursor of nitrogen doping carbon foam (ACF). The carbon foam (PCF) prepared by adenine-free PI foam (PMDA ODA PI) is used as a comparison. The results show that the nitrogen content of ACF after carbonization at 1000 °C (ACF-1000) is as high as 4.35%, which is about twice higher than PCF-1000 (1.90%). The conductivity of ACF-1000 is 7.11 × 10−1 s cm−1, which is 38.06% larger than PCF-1000 (5.15 × 10−1 s cm−1). The electromagnetic interference shielding effectiveness (EMI SE) of ACF-1000 is 41.1 dB, which is 26.85% higher than PCF-1000 (32.4 dB). The SSE/d (defined as the SE divided by the thickness and density of the shielding material) of ACF-1000 is 13569 dB cm2/g, which is 66.41% higher than PCF-1000 (8154 dB cm2/g). This work shows that adenine is a promising nitrogen-doping building block for polymer-derived carbon materials. The introduction of adenine structure into the polymer is helpful for improving the EMI shielding performance of carbonized products.

The effects of the addition of primary alcohol fuels (methanol, ethanol, and n-butanol) on the combustion characteristics and performance of natural gas engines are examined by experimentation with a dual-fuel test engine, followed by a comparative analysis of the test results. The test engine was operated under a light load, at a fixed speed of 1600 rpm, and with a brake mean effective pressure of 0.387 MPa. The air-fuel ratio was held constant at the stoichiometric equivalent ratio. The engine performance was analyzed for different natural gas/alcohol fuel mixtures by using four alcohol fuel energy substitute ratios (AESRs): 0% (pure natural gas), 19%, 44%, and 60%. The experimental results indicate that faster burning rates can be obtained by mixing any of the three alcohol fuels with natural gas, compared with pure natural gas. Further, by increasing the AESR, faster flame development and flame propagation times can be obtained, and the crank angle when 50% of the mass is burned approaches the top dead center position. These outcomes lead to an advance in combustion phasing. The addition of primary alcohol fuels in the dual-fuel mode can also reduce total hydrocarbon and nitrogen oxide emissions. Moreover, the brake thermal efficiency of natural gas can be improved significantly by adding methanol, whereas negligible improvements in this aspect are obtained by adding ethanol and n-butanol. The comparative analysis indicates that methanol addition has advantages over ethanol and n-butanol additions in increasing the brake thermal efficiency and reducing the regulated emissions of natural gas engines.

Ischemic post-conditioning (IPO) activates Akt signaling to confer cardioprotection. The responsiveness of diabetic hearts to IPO is impaired. We hypothesized that decreased cardiac SIRT1, a positive regulator of Akt, may be responsible for the impaired responsiveness of diabetic hearts to IPO-mediated cardioprotection. High-fat diet and streptozotocin-induced diabetic mice were subjected to myocardial ischemia/reperfusion (MI/R, 30 min ischemia and 180 min reperfusion) or IPO (three cycles of 10 s of reperfusion and ischemia at the onset of reperfusion). Adenoviral vectors encoding GFP or SIRT1 (Ad-SIRT1) were administered by direct injection into the left ventricular. Our results showed that IPO activated the Akt signaling pathway and reduced MI/R injury in non-diabetic hearts but not in diabetic hearts, in which reduced expression of SIRT1 and increased Akt acetylation were observed. Delivery of Ad-SIRT1 into the diabetic hearts reduced Akt acetylation and restored the cardioprotective effects of IPO by modulating Akt signaling pathway. In contrast, cardiac-specific SIRT1 knockout increased Akt acetylation and blunted the cardioprotective effects of IPO. In in vitro study, transfection with wild-type SIRT1 but not inactive mutant SIRT1 reduced the expression of Akt acetylation and restored the protective effects of hypoxic post-conditioning in high glucose-incubated cardiomyocytes. Moreover, the cardiomyocytes transfected with constitutive Akt acetylation showed repressed Akt phosphorylation and blunted protective effects against hypoxia/reoxygenation injury. These findings demonstrate that the reduction of SIRT1 blunts the protective effects of IPO by impairing Akt signaling pathway and that SIRT1 up-regulation restores IPO-mediated cardioprotection in diabetic mice via deacetylation-dependent activation of Akt signaling pathway.

Exploring scalable and cost-effective material preparation route is critical for achieving the commercialization of lithium–sulfur batteries. Herein, nitrogen and sulfur codoped carbon dots/reduced graphene oxide (N,S-CDs/rGO) composites are facilely fabricated via hydrothermal and annealing treatment of a mixture of graphene oxide and egg-white without additional reactants. The egg-white, not only act as heteroatoms source, but also produce carbon dots. The as-prepared material possesses a porous architecture with N,S-codoping into both graphene and carbon dots. Benefiting from combined advantages of each constituent, such as superior electrical conductivity, abundant edges and doping sites, N,S-CDs/rGO cathodes (with 65 wt% and 76 wt% sulfur content) exhibits enhanced performances characterize by a higher rate capability and high sulfur utilization. For instance, N,S-CDs/rGO@S65 cathode exhibits a capacity of 1550 mAh g−1 at 0.5 C and still kept high capacities of 1038, 861.1 and 783.6 mAh g−1 at 1, 3, and 5 C respectively. Even at an ultra high rate of 7 C, a capacity of 740.8 mAh g−1 is sustained. Moreover the cathode retains 427.9 mAh g−1 reversible capacity after 600 cycles at 5 C. This work provides a new route toward the simple design of cathode for advanced Li–S cells.

In this paper, an adenine-derived fluorescent chromophore (HCC-APA) was synthesized to detect its interaction with iron ions. The results showed that a large stokes shift (υ = 10981.5 cm−1) fluorescence of the HCC-APA was appeared. The fluorescence quantum yields of HCC-APA in DMF and THF were 3.49% and 17.54%, respectively, demonstrating its higher fluorescence performance than unmodified adenine. Besides, the fluorescence quenching of HCC-APA with iron ions was further detected. Fluorescence titration experiments confirmed that the detection limit of HCC-APA for Fe3+ was 3.69 μM. The interaction between iron ions and HCC-APA was investigated by continuous variable method, indicating that the binding ratio is 1:1. And the interaction site was deeply explored by 1H NMR and molecular simulation.

Lithium–sulfur (Li–S) batteries have attracted an increasing attention for advanced energy storage devices, because of their high energy density, low cost and lower environmental impacts. However, their commercial applications are still hampered with the low conductivity and sulfur utilization, the low sulfur loading and the serious capacity fading at a high current rate. Herein, we prepared flower-like molybdenum disulfide and carbon nanotubes (MoS2/CNTs) composites with mesoporous structures for high sulfur utilization cathodes. The flower-like MoS2 can immobilize sulfur and obstruct the solubility of polysulfide within the structures. The MoS2/CNTs-S cathode with 2.6 mg cm−2 sulfur loading and capacity per area of 3.83 mA h cm−2 delivers an initial specific discharge capacity of 1473 mA h g−1 with 88.0% sulfur utilization and maintains a reversible capacity of 855.5 mA h g−1 with coulombic efficiency up to 96.6% after 50 cycles at the current rate of 0.2 C (335.0 mA g−1). Impressively, the MoS2/CNTs-S cathode at 5 C shows the high specific capacity of 1254 mA h g−1 with 76.0% sulfur utilization and maintains 384.0 mA h g−1 with an average coulombic efficiency of 91% after 200 cycles. The MoS2/CNTs-S cathode could be a good candidate for high-performance Li–S battery.

This study aims to evaluate the performance, emissions, and combustion characteristics of a methanol/natural gas dual-fuel spark-ignition engine by conducting several experiments. A heavy-duty natural gas engine is modified by adding a methanol port-injection system to accelerate the burning rate, increase the thermal efficiency, and reduce the hydrocarbon emission. The effects of the methanol energy substitution ratio (MSR) on the brake thermal efficiency, heat release rate, peak cylinder temperature, flame development period, flame propagation period, and emissions are investigated under light, medium, and heavy loads (brake mean effective pressures of 0.387, 0.775, and 1.163 MPa, respectively) at an engine speed of 1600 rpm and a relative air/fuel ratio of 1.3. The results show that the peak cylinder pressure, peak cylinder temperature, and heat release rate increase with an increase in the MSR. A larger MSR leads to a shorter flame development period and flame propagation period as well as earlier combustion phasing. In addition, the brake thermal efficiency increases and the equivalent brake specific fuel consumption decreases significantly with methanol enrichment under the three engine load conditions. For exhaust emissions, the brake specific total hydrocarbon emission decreases while the brake specific nitrogen oxide emission increases slightly with an increase in the MSR. For cycle-by-cycle variation, the coefficient of variation in the indicated mean effective pressure increases slightly with an increase in the MSR. In addition, the peak ringing/knocking intensity is found to be 2.05 MW/m2 that is much less than the critical knocking point (5 MW/m2). Therefore, there was no knocking throughout the entire experiment.

This paper aimed to study the effects of spark timing and methanol addition on the combustion characteristics and emissions of a natural gas/methanol dual-fuel engine. The engine speed is maintained at 1600 rpm and the brake mean effective pressure (BMEP) is maintained at 0.387 MPa with an excess air/fuel ratio of 1.3. The methanol energy substitution ratio (MSR) is set to 0%, 7.5%, and 14.5%. The spark timings are varied from 18 °CA to 38 °CA before the top dead centre, in intervals of 4 °CA. The results demonstrate that for a specific spark timing, the methanol addition increases the peak cylinder pressure, the maximum of the heat release rate, and the peak cylinder mean temperature. Concurrently, it decreases the flame development period (CA0-10) and the flame propagation period (CA10-90) with an increase in the MSR. An improvement in the brake thermal efficiency (BTE), a reduction in the total hydrocarbon (THC) emission, and an increase in the nitrogen oxide (NOX) emission are achieved using methanol enrichment. In addition, the effect of these trends is more pronounced with an increase in MSR. In contrast, for a specific MSR, a spark timing advance increases the peak cylinder pressure and temperature, while decreasing the exhaust temperature under an identical BMEP. Moreover, the spark timing at the maximum BTE retards as MSR increases.

Accurately modeling the kinetics of the pyrolysis reaction of phthalonitrile resin was helpful to investigate the pyrolysis mechanisms. To study the pyrolysis kinetics, phthalonitrile resin was measured by thermogravimetric analysis (TGA) at different heating rates in flowing nitrogen. The results indicated that there were two consecutive and overlapping stages in the pyrolysis process. The overlapped peaks were separated by multi-peak fitting method. Two models, namely, Kissinger, Kissinger-Akahira-Sunose (KAS), were employed to calculate activation energy at various stages of pyrolysis process. Kinetic models were determined using the differential method and Coats-Redfern method. Based on the attained kinetic models and activation energy values, the pre-exponential factor values were determined by KAS method. According to the calculated apparent activation energies, the most probable kinetic mechanism functions and pre-exponential factors, the simulated data agreed well with the experimental data.

Methanol is a competitive low-carbon fuel for spark ignition engines. Though it has higher knock resistance than gasoline fuel, knocking combustion is still an obstacle for the application of methanol in spark ignition engines with relatively higher compression ratios. In this work, experimental investigations into knocking combustion and suppression were conducted on a single-cylinder, naturally aspirated, SI engine with a compression ratio of 15. Firstly, the knocking characteristics of the methanol engine with stoichiometric mixture under port fuel injection mode were evaluated. Results showed that knocking combustion occurred under medium and high loads. Especially, under the condition of indicated mean effective pressure (IMEP) = 0.7 MPa, some random heavy knock cycles with ultra-high knock intensity were observed. The frequency of heavy knock was 2.5% and the highest maximum amplitude of pressure oscillations reached 2.39 MPa. This heavy knock was similar to the super-knock phenomenon in boosted direct injection gasoline engines, and it can not be eliminated by retarding spark timing or adopting fuel-lean combustion. Then, the mechanism of the heavy knock was studied by thermodynamic condition analysis. Results showed that the heavy knock was triggered by pre-ignition which was induced by some hot spots in the combustion chamber. Finally, to make the best use of the charge cooling effect, the methanol direct injection strategy was applied to suppress the knocking combustion. When the engine worked with full opening throttle and adopt a single injection, the maximum knock intensity decreased to 0.43 MPa×°CA at −350 °CA ATDC start of injection which was 5.1% of the maximum value during port fuel injection mode. With the co-optimization of the start of injection and spark timing, the engine with a stoichiometric mixture could operate within the knock intensity limit at full load. Under this operating condition, the crank angle of 50% mass fraction burned located at 12 °CA ATDC and IMEP = 1.05 MPa was achieved. What’s more, adopting the optimal split injection instead of a single injection, the knock intensity was further reduced by 14.3% with a slight reduction of 0.02 MPa in IMEP.

Prior expectations play an important role in the process of perception. In real life, facial expressions always appear within a scene, which enables individuals to generate predictions that affect facial expression judgments. In the present study, using event-related potentials, we investigated the influence of scene-based expectation on facial expression processing. In addition, we used a cognitive task to manipulate cognitive load to interfere with scene-based expectation. Results showed that under the condition of sufficient cognitive resources, faces elicited more negative N170 amplitudes and more positive N400 amplitudes when the emotional valence of the scenes and faces was congruent. However, in the condition of cognitive load, no such difference was observed. The findings suggested that the effect of expectation on facial expression recognition emerges during both the early and late stages of facial expression processing, and the effect is weakened when cognitive resources are occupied by unrelated tasks.

Cooled exhaust gas recirculation (EGR) is one of the most effective methods in spark ignition (SI) natural gas (NG) engines to improve the fuel economy and reduce the nitrogen oxides (NOx) emissions. The objective of this study is to anatomize the EGR rate and temperature impact on the combustion and emissions characteristics by the experiments in a heavy duty (HD) NG engine under various spark timings. The results showed that the increasing EGR rate reduced the burning rate and extended the combustion duration. Spark timing should be optimized to copy with the retarded combustion phase. Under high EGR rate, the combustion performance could be optimized with the increase of EGR temperature. There exists a proper EGR rate in real application for the fuel consumption of the engine. Higher EGR temperature plays positive effects on fuel economy, owing to the higher combustion efficiency and lower throttle losses, and the decreasing amplitude of BSFC is 1.25% between the EGR temperatures of 333 K and 373 K. With the increase of EGR rate from 5% to 25%, NOx emissions are reduced by up to 76%, the unburned hydrocarbon (HC) and carbon monoxide (CO) emissions are increased by 34.6% and 12.9% respectively. Higher EGR temperature could alleviate the increase of HC and CO emissions, but sacrificing the NOx emissions, and the increase extent of NOx emissions is 35.3%. The results provide an insight into the quantitative comparisons of EGR rate and temperature on the NG engine performance and emissions, which promotes the utilizing EGR strategy in SI NG engines.

The fuel economy of natural gas (NG) spark ignition (SI) engine could improve significantly when using high exhaust gas recirculation (EGR) dilution. However, the combustion processes become instability and even occur misfire at higher EGR rate. In this paper, the high energy ignition system, which was the technology of variable spark, was utilized to extend the EGR tolerance of a SI engine. Extensive experimental tests were conducted to investigate the effects of spark discharge current and duration on combustion and emissions characteristics at low load condition. The results showed that the fuel economy was improved with the spark discharge energy at the high EGR rate of 30%. The increase amplitude of fuel economy was 1.32% when the spark discharge energy increased from 210 to 320 mJ. The effective spark discharge energy was existed in consideration of the fuel economy. The ignition delay (CA0-5) and the flame propagation period (CA10-90) shortened with an increase in spark discharge energy. Besides, NOx emissions were more sensitive to the spark discharge energy than that of HC and CO emissions. As the spark discharge energy increased, the increase extent of NOx emissions was 26.9%, while HC and CO emissions decrease slightly.

Background Intracerebral hemorrhage (ICH) is a common neurological emergency with higher mortality and disability rate than cerebral ischemia. Although diverse therapeutic interventions have been explored for potential neuroprotection from ICH, no effective drugs until now are available for improvement of survival rate or the life quality of survivors after ICH. Just like cerebral ischemia, inflammatory mechanism is highly thought to play a vital role in hemorrhagic brain injury. Ligustilide (LIG) has potent anti-inflammatory effects, which were shown to be closely related to its neuroprotective effects against ischemic brain injury. Senkyunolide H (SH) and senkyunolide I (SI) are natural degradation products of LIG, which contain the mother nucleus structure of LIG as that of phthalide. However, no reports have been retrieved about the neuroprotective effects of the three phthalide compounds on ICH, especially from the perspectives of inflammatory pathways. Accordingly, this study investigated the neuroprotective potentials and mechanisms of LIG, SH and SI on experimental ICH in mice. Methods ICH was induced in adult male CD-1 mice by intracerebral injection of autologous blood. LIG, SH and SI, respectively, was administrated after ICH induction. Neurological deficits, brain edema, injury volume, the number of surviving/dying neurons and inflammatory gene expression were evaluated at 3 days after ICH. Results Neurological deficits, brain edema, neuronal injury, microglia and astrocytes activation as well as peripheral immune cells infiltration were all significantly improved by LIG and SH, yet SI not. Moreover, the expression of TLR4, p-NF-kB p65, TNF-α and IL-6, was significantly downregulated by LIG and SH treatment. So was Prx1 expression and release. Conclusions LIG and SH provide the potent neuroprotective effects against hemorrhagic stroke by inhibiting Prx1/TLR4/NF-kB signaling and the subsequent immune and neuroinflammation lesions.

Considering the drawbacks of a diesel/natural gas dual-fuel combustion at low load usually is relative to undesirable natural gas-air-diesel mixture distributions in-cylinder and natural gas supply method and pilot diesel injection strategy are believed to play a critical role in the process of mixture formation in the cylinder. So an experimental study has been conducted to explore the effects of natural gas injection timing and split pilot injection strategy on the combustion performance and emissions characteristics in a diesel/natural gas dual-fuel engine. In this study, the effects of natural gas injection timing under a constant split pilot injection strategy and a varying first pilot injection timing under an optimized natural gas injection timing on combustion performance and emissions are evaluated. The cylinder pressure, Heat Release Rate (HRR), Pressure Rise Rate (PRR), ignition delay, flame development duration, CA50 and combustion duration as well as THC, CO, NOx emissions are analyzed for the purpose. The experimental results indicated that natural gas injection timing and split injection strategy have a significant influence on the combustion performance and emissions characteristics in the dual-fuel engine. The natural gas premixed combustion stage can be enhanced with retarded natural gas injection timing. The pilot diesel combustion stage is weakened under the split injection strategy and the combustion process can be improved by reasonably advanced first pilot injection timing. Moreover, combined variation natural gas injection timing and split pilot injection strategy is a potential way to optimize the performance of the diesel/natural gas dual-fuel engine.

The influence on the seismic behavior of RC shear walls by axial loads is evaluated and the observed damage in the earthquake damage investigation of RC shear walls is reproduced in this paper. Six RC shear walls with aspect ratio of 2 were analyzed by the method of nonlinear finite element under different axial load ratios, and the suggested modeling techniques and the accuracy of the numerical method were verified. The seismic performance of shear walls including load–displacement responses, ductility performance, stiffness degradation and energy dissipation capacity were discussed. The analysis results indicate that axial load has a significant effect on the seismic performance of RC shear walls. On the basis of this, the qualitative and quantitative relationships between the development of material damage and the deterioration of component performance were analyzed. It realizes the cross-scale conversion of damage information about structural components of RC shear wall from the local material scale to the component scale. Then the cross-scale refinement model of damage evolution of RC shear walls in the whole process was established, simplified and verified. The results show that, the refinement model can explain the development and distribution of damage evolution of RC shear walls in the whole process quickly and easily. The research results can provide a reference for the refinement of seismic design, damage assessment and reinforcement of RC shear walls.

A series of PIs (APIs) containing naturally occurring adenine moiety in polymer backbone has been prepared from adenine-containing diamine (p-APA) and commercial dianhydrides by a two-step polymerization process. FTIR study confirmed the structures of APIs. The hydrogen-bonding interactions of APIs were studied by FTIR, in-situ FTIR and theoretical methods. The crystalline behavior of APIs were studied by XRD, and the results showed that the APIs have relatively high degree of crystalline. Birefringence and polarized ATR FTIR studies showed that the groups and chains in API films could be simultaneously self-arranged in the in-plane direction without any further stretching. Molecular simulation methods were introduced to study the relationship between self-arranged in-plane orientation and hydrogen-bonding interactions. Thermogravimetric analysis (TGA) showed that the 5% weight loss of APIs (T5) are in the range of 511–569 °C in nitrogen, and the char yields (CR) of APIs are in the range of 55–67% under nitrogen condition. Dynamic mechanical analysis showed that the glass-transition temperature (Tg) are in the range of 315–400 °C. The mechanical properties were studied by universal strength tester, and the results showed that the tensile modulus of API films were in the range of 4.43–9.21 GPa, and the tensile strength of API films were in the range of 124.9–162.9 MPa. Thermal mechanical analysis showed that the in-plane CTE of APIs are in the range of −5.85–37.82 ppm/°C.