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With the development of the oil industry and the exhaustion of shallow oil resources， recent oil and gas exploration has tended to focus on the drilling technology for deep and ultra-deep wells. However， the high temperatures at the bottom of deep wells will lead to the dispersion， aggregation and passivation of the drilling fluid， which will increase its viscosity and reduce its fluidity. This has resulted in great technical challenges in deep well drilling operations.Anti-high temperature viscosity reducers can reduce the viscosity and adjust the rheology of drilling fluids， which can play an important role in maintaining their stability and efficiency.Synthetic polymer viscosity reducers have the advantages of strong tailorability of molecular structure and excellent high temperature resistance， and are widely used in high temperature drilling fluids. In this paper， recent research progress in the use of synthetic polymer viscosity reducers in high temperature drilling fluids is reviewed， and the high temperature resistance and the mechanisms of viscosity reduction for carboxylic acids， sulfonic acids， carboxylic acid-sulfonic acids and zwitterionic viscosity reducers are compared. This study provides a reference for the design of new anti-high temperature viscosity reducers.
As an important chemical raw material， formic acid is widely used in many fields.In many industrial processes， a large amount of low-concentration formic acid solution is produced and cannot be used directly. If it is discharged into the environment， it will lead to a serious waste of resources and environmental pollution.Therefore， it is of great practical significance to concentrate and reuse formic acid aqueous solutions.This paper reviews the current methods for the concentration of formic acid aqueous solutions， including distillation， extraction， membrane distillation， electrodialysis， dehydrating agent concentration and freeze concentration.The underlying principles and application examples of various concentration methods are introduced， and their advantages and disadvantages are summarized. Finally， possible further advances in technology for the concentration of formic acid aqueous solutions are discussed.
A self-excited hydrodynamic cavitation jet reactor combined with ozone oxidation has been used to treat salicylic acid wastewater， and the degradations of salicylic acid by hydrodynamic cavitation， ozone oxidation and their combination were compared.The results show that the maximum salicylic acid removal rate is only 3.89% when the salicylic acid wastewater is treated by hydrodynamic cavitation for 60 min under different working conditions. Under the same conditions， the maximum removal rates of salicylic acid by ozonation alone and the combined treatment of the two methods were 61.47% and 70.63%， respectively.At an ozone flow rate of 0.6-1.0 L/min， the synergistic coefficient of the combined treatment was greater than 1， indicating that the combined system had a synergistic effect.When the ozone flow rate was 0.8 L/min， the synergistic coefficient of the combined system reached a maximum （1.306）， and the removal rates of salicylic acid and total organic carbon （TOC） were 58.51% and 29.94%， respectively， after combined treatment for 60 min.When the ozone flow rate was greater than 0.8 L/min， the synergy coefficient decreased， indicating that too much ozone might weaken cavitation and ozone mass transfer.
Butylenediol ether trisiloxane （BEOTSS） has been synthesized from butynediol ethoxylate （BEO） and 1，1，1，3，5，5，5-heptamethyltrisiloxane （MDHM） by a hydrosilylation reaction using a ruthenium catalyst. The structure of BEOTSS was characterized by infrared spectroscopy （FT-IR） and nuclear magnetic resonance （1H-NMR） spectroscopy.The effects of varying the reaction temperature， reaction time， raw material ratio and catalyst dosage on the conversion of MDHM were investigated， and the catalytic reaction conditions were optimized by orthogonal tests. The optimum conditions were as follows： a catalyst dosage of 30 mg/kg， an n（BEO）∶n（MDHM） ratio of 1.05∶1， a reaction time of 6.0 h， and a reaction temperature of 100 °C. Under these conditions， the conversion rate of MDHM could reach 99%.The interfacial properties of BEOTSS were measured. The results show that the surface tension of a 0.1% BEOTSS aqueous solution is 22.5 mN/m at 25 °C， and the critical micelle concentration （CMC） is 4.9×10-5 mol/L， indicating that BEOTSS can significantly reduce the surface tension of water at low concentration and has excellent surface activity.
Focusing on the balance between damping performance and resilience of ethylene-propylene-diene monomer （EPDM） rubber composites， this work mainly studied the influence of butyl rubber （IIR）， carbon black （CB） content and CB types on the microstructure including chemical crosslinking and filler network， and properties of IIR/EPDM composites. The results showed that the increase in IIR content increased the molecule saturation degree， and the content of side methyl groups in the IIR/EPDM compound. The degree of entanglement of rubber molecular chains was also increased. IIR also increased the shearing modulus，and damping properties， but lowered the resilience of IIR/EPDM composites. Furthermore， the decrease in CB content and the introduction of CB with larger particle size in IIR/EPDM composites lowered the filler network， increased the filler dispersion of the composites， and the mobilities of rubber molecules， leading to high damping and resilience properties of IIR/EPDM composites. Therefore， when introducing a proper mass ratio of EPDM/butyl rubber （80/20），CB （N550） with large particle size， and less CB content （45 phr） in the EPDM composite， the composites with good damping performance and resilience were obtained.
The hot corrosion behavior of Super304H （S30432） steel and a new type of Fe-Cr-Ni （FCN） steel optimized for melting the composition of S30432 steel in mixed molten salts of 15% KCl+15% K2SO4+70% Na2SO4 （wt.%） has been investigated at two temperatures， 650 ℃ and 700 ℃. The samples were completely corroded in the mixed salt melt， and their weights were measured intermittently to obtain hot corrosion kinetic curves. X⁃ray diffraction， scanning electron microscopy （SEM）， and energy⁃dispersive X⁃ray spectrometry （EDS） were used to analyze the physical phase composition， morphology， and composition of the corrosion products. At 650 ℃， both S30432 and FCN steels increase， with S30432 steel losing approximately twice as much weight as FCN steel. At 700 ℃， S30432 steel experienced severe corrosion， resulting in spalling of corrosion products. FCN steel exhibited a ‘weight loss-weight gain-weight loss’ trend， with a lower degree of corrosion compared to S30432 steel. In contrast to FCN steel， S30432 steel showed serious intergranular corrosion. The corrosion products of S30432 steel mainly consisted of Fe3O4， Fe2O3， and FeCr2O4， while those of FCN steel included Fe3O4， Fe2O3， FeCr2O4， Cr2O3， and a small amount of FeS. In the mixed molten salt， FCN steel exhibits greater corrosion resistance than S30432 steel. The corrosion product layer is susceptible to erosion by composite sulfate and other corrosive media， leading to erosion of both the corrosion layer and substrate. The sulfur partial pressure required for the predominant sulfurization reaction to occur was calculated from a thermodynamic perspective.Internal oxidation and internal sulfidation may occur， and Cr2O3 can easily dissolve in chloride salts， generating the volatile compound CrO2Cl2 that accelerates corrosion.
Natural rubber （NR）/chlorinated butyl rubber （CIIR） composites have been prepared by mechanical blending and molding. The vulcanization properties， mechanical properties， uniaxial tensile orientation properties， strain-induced crystallization （SIC） and damping behavior of the composites were analyzed. Transmission electron microscopy （TEM） showed that CIIR components had an island structure distribution in the blends， and the boundaries were clear. With the increasing CIIR content， the compressive stress-strain properties were similar to those of pure NR， but the tensile strength decreased significantly compared with pure NR. Infrared dichroism analysis showed that the orientation behavior is mainly due to the NR component. Synchrotron radiation wide-angle X-ray diffraction （WAXD） analysis showed that the higher the proportion of CIIR， the weaker the SIC behavior. NR/CIIR blends with the characteristics of both precursors can be prepared by mechanical blending. The loss factor at 30 Hz increases from 0.1 for NR pure rubber to 0.18 for a 50/50 NR/CIIR blend， with an increase of 80%. This work provides new ideas for the preparation of rubber composite materials for shock insulation.
Bacterial cellulose-chloramphenicol （BC-Chl） composite membranes have been prepared using an impregnation-recrystallization method by loading chloramphenicol on bacterial cellulose.The morphology and structure of the composite membranes were characterized by scanning electron microscopy （SEM）， Fourier transform infrared spectroscopy （FT-IR） and X-ray diffraction （XRD）.The results show that the BC-Chl composite membrane maintains the porous three‑dimensional network structure of bacterial cellulose. The loading of chloramphenicol did not change the crystal form of the bacterial cellulose， but the loading process did destroy the crystalline region of the cellulose to a certain extent.After swelling for 12 h， the swelling ratio of the BC-Chl composite membrane was above 400%， showing its good water retention capacity.In vitro drug release experiments showed that the drug concentration peak time of the BC-Chl composite membrane was extended to about 2 h compared with 45 min for the chloramphenicol raw material， confirming a delayed drug release effect.Inhibition zone tests showed that when the drug loading was about 200 μg/mg， the inhibition zone diameter rates of the BC-Chl composite membrane against Corynebacterium glutamicum and Escherichia coli were 5.8 and 5.1， respectively.After SH-SY5Y cells were treated with the BC-Chl composite membrane with a drug loading of about 200 μg/mg for 24 h， the cell activity remained above 75%， indicating that the BC-Chl composite membrane had low cytotoxicity and good biocompatibility.
The amplitude domain characteristics of wind power generation signals cannot comprehensively characterize long-term fluctuations and local rapid changes in the construction of new power systems. To address this issue， a stochastic time series model of wind power signals was first established； Secondly， a bimodal model of the metastability term and the dynamic term of the current amplitude signal was established， and five characteristic parameters and two characteristic functions were constructed in the run range domain； Finally， 24 typical waveform modes in the run range domain were extracted， and a sample library of wind power typical waveforms was constructed to extract typical features of the voltage and current signals of wind power generation. The results provide a comprehensive characterization of the complex features of wind power generation energy signals.
Metallurgical cranes operate under complex and continuous lifting conditions， leading to large volumes of structural stress monitoring data over extended periods. Conventional stress spectrum analysis methods often result in the accumulation of residual waves， reducing accuracy. To address this issue， a novel online analysis method for fatigue damage assessment of metallurgical cranes is proposed. Initially， a step-type rainflow counting method is employed to segment and count real-time generated random stress data， providing real-time output of random stress spectra. When the cumulative residual waves reach a certain threshold during cyclic segmentation counting， a secondary fusion counting of the residual waves is performed. The results are then incorporated into the random stress spectra to correct the real-time counting， thus improving counting accuracy of subsequent fatigue damage assessments. Using S-N curves combined with Miner's damage theory， the step-type rainflow counting is applied to analyze the real-time generated stress spectra and calculate fatigue life， forming an online analysis method tailored for fatigue damage assessment. Simulation experiments are conducted using both four-point rainflow counting and step-type rainflow counting methods on random stress spectrum data. The results show that the accuracy of step-type rainflow counting reaches 99% of conventional rainflow counting. This online analysis method can be applied to analyze stress data from a measurement point at the connection of the sub-main beam of a metallurgical crane. The effective fatigue life at this measurement point is calculated. The results demonstrate that this online analysis method effectively enhances the real-time assessment of metallurgical crane fatigue， providing reasonable evaluation results and a timely reliable basis for long-term crane maintenance.
In practical engineering， a T-junction has large size and strict parameter conditions， so it is necessary to model the actual working conditions in order to conduct experimental research. A vertical T-junction model was established with the momentum ratio as the main similarity criterion and high temperature heat-conducting oil as the medium to ensure the thermal similarity between the prototype and the model in terms of temperature difference， velocity ratio and diameter ratio. Large Eddy Simulation was used to validate the prototype and the model， and the time distributions of temperature and velocity were compared. The results show that the flow field and temperature field of the prototype and model T-junction are similar， and it is therefore feasible to use heat transfer oil as the medium and the momentum ratio similarity to model the mixed cold and hot fluids in a T-junction.
When there is a difference in the rigidity of a rotor support， the vibration vector is affected by the mounting angle of the sensor， resulting in a difference in the dynamic balancing effect. By separating the time-domain data collected by two sensors in the direction orthogonal to the measurement point， the forward and backward precession components of the rotor vibration signal can be separated based on the Hilbert transform， and the amplitude and phase of the forward component can be extracted by using the cross-correlation method， so as to realize the measurement of the rotor imbalance vector. Based on this method， different rotors have been analyzed and the results verified by numerical simulation and experimental analysis. The simulation results show that the residual vibration at the bearing support position within the balanced speed range with our new method using multi⁃plane and multi⁃speed dynamic balancing is lower than that obtained after balancing with a single-direction sensor. The experimental results for a flexible rotor indicate that after using our new method for dynamic balancing， the residual vibration at critical speed is lower than that after using a single direction sensor for dynamic balancing. The results of the rigid rotor experiment show that after using this method for dynamic balancing and removing the influence of slow rolling vector， the vibration amplitude of the test rotor measurement point mainly due to imbalance decreases by at least 54.17%， while the corresponding measurement point amplitudes at single X and single Y direction measurement points decrease by 37.50% and 33.33%， respectively， after dynamic balancing. In summary， the proposed method can improve the accuracy of dynamic balancing and should have valuable engineering applications.
Human-object interation （HOI） plays a crucial role in understanding complex scenes. Recently， contrastive language image pre‑training has shown great potential in providing prior knowledge about interactions in HOI detectors through knowledge extraction. However， this method typically relies on large‑scale training data， and most methods directly map parameter interaction queries to a set of HOI predictions in a one‑stage manner. This leads to a lack of sufficient exploration and utilization of the rich interaction structures. The use of multimodal data allows more dimensional information to be extracted and offers a more comprehensive understanding of the interaction behavior between human and object. In this study we designed a Transformer style HOI detector. This process scheme first retrieves comparative language image pre‑training （CLIP） knowledge based on queries， then performs interactive suggestion generation， and finally converts non‑parametric interactive suggestions into HOI predictions through a structure aware network. Structural awareness networks improve the accuracy of prediction results by encoding the overall semantic structure and local spatial structure with additional encoding. The accuracy of this model on the public dataset V‑COCO reached 64.83%， and the accuracy on HICO-DET reached 28.78%. Compared with existing HOI detection algorithms， this algorithm exhibits superior performance， demonstrating its effectiveness.
China has proposed the “30-60” dual-carbon targets along with corresponding policies， and the significance of carbon footprint as a metric for measuring greenhouse gas emissions is increasing. To better understand the research hotspots， trends， and future developments in this field， the CiteSpace literature measurement software was used in a visual analysis of 1 287 documents on carbon footprint research from the CNKI core database， collected between 2010 and 2023. This study systematically summarises the research progress in this field at different time points， the main journals that published key authors， and the focal research points. The findings of the study indicate that： （1） The concept of green development and the proposal of dual-carbon targets have greatly bolstered research on China’s carbon footprint； （2） Cross-regional， cross-institutional， and interdisciplinary scientific research cooperation have all had a significant impact on the advancement of research on China’s carbon footprint； （3） Carbon footprint management， assessment， and certification have emerged as hot research areas that could propel China towards achieving the “30-60” dual-carbon targets.
The ring resonator is the basic functional unit in a photonic crystal wavelength-division multiplexer （WDM）. It can realize the separation and multiplexing of optical signals of different wavelengths. Optical signal transmission can be simultaneously enhanced both in capacity and efficiency by using WDMs. A 2D-3D heterostructure is used as the basis of this work， which allows dense wavelength-division multiplexing. A ring resonator is introduced into the two-dimensional photonic crystal plane. Wavelength-division multiplexing is then realized by changing the cavity length of the resonator and the number of internal dielectric columns.
