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Shengli Oilfield has abundant low-permeability oil reservoirs with proven reserves of 1.18 billion tons， presenting a good prospect for development. However， there is a problem of inability to inject and produce during the development process of the oil reservoirs due to the low porosity， poor permeability， and strong heterogeneity of the low-permeability oil reservoir. A systematic review was conducted on the prediction and analysis methods for low-permeability oil reservoirs in Shengli Oilfield to achieve efficient development of low-permeability oil reservoirs， as well as efficient development technologies， and the advantages and disadvantages of existing technologies were analyzed to provide an outlook for the development technologies of low-permeability oil reservoirs. Based on research and practice， the following conclusions are drawn： ① Shengli Oilfield has developed fine reservoir characterization technologies such as reservoir prediction， in-situ stress prediction， and evaluation of reservoir heterogeneity. ② Based on theoretical and technological innovation， the physical limit of reserve production was constantly broken， forming differential development technology series， such as water injection development technology of horizontal wells in ultra-low permeability oil reservoirs， long well section multi-stage fracturing development technology of horizontal wells in tight oil reservoirs， well pattern adaptation technology for enhanced oil recovery of general low-permeability oil reservoirs， pressure flooding technology in low-permeability tight oil reservoirs， and viscous emulsion-surfactant flooding technology. Good development results have been achieved. ③ Combined with the actual needs of high-quality development and speed and efficiency improvement development of low-permeability oil reservoirs in Shengli Oilfield， the well pattern reconstruction technology of dual control streamline variation， CCUS technology， and nanobubble flooding technology were proposed， pointing out the development direction for improving oil recovery of low-permeability oil reservoirs.

Due to long-term alternating load, engineering thin-walled structures will produce fatigue cracks, and most of them are penetrative cracks, which will lead to difficult repair and irreplaceable problems in engineering. Therefore, a coating technology is proposed to repair and crack arrest thin-walled structures. Thin plate test pieces related to practical engineering were made, and cracks were preset. The test piece was going to be subjected to the first-order bending resonance state and the excitation test with the foundation excitation of 10g on the vibration test bench until cracks appear. Two kinds of coatings, NiCrAl coating and NiCrAl transition layer + ZrO2 functional layer composite coating, were applied to the test piece by double-sided spraying method to repair the crack, and the excitation test was repeated. Comparing the crack propagation time and propagation rate of the test piece before and after coating, the influence of NiCrAl coating and ZrO2 coating on the crack propagation of the thin-walled plate test piece was analyzed. The crack arrest effect of the coating on the thin-walled plate is verified.

Mimicking natural botanical/zoological systems has revolutionarily inspired four-dimensional (4D) hydrogel robotics, interactive actuators/machines, automatic biomedical devices, and self-adaptive photonics. The controllable high-freedom shape reconfiguration holds the key to satisfying the ever-increasing demands. However, miniaturized biocompatible 4D hydrogels remain rigorously stifled due to current approach/material limits. In this research, we spatiotemporally program micro/nano (μ/n) hydrogels through a heterojunction geometric strategy in femtosecond laser direct writing (fsLDW). Polyethylene incorporated N-isopropylacrylamide as programmable interactive materials here. Dynamic chiral torsion, site-specific mutation, anisotropic deformation, selective structural coloration of hydrogel nanowire, and spontaneous self-repairing as reusable μ/n robotics were identified. Hydrogel-materialized monolayer nanowires operate as the most fundamental block at nanometric accuracy to promise high freedom reconfiguration and high force-to-weight ratio/bending curvature under tight topological control. Taking use of this biomimetic fsLDW, we spatiotemporally constructed several in/out-plane self-driven hydrogel grippers, diverse 2D-to-3D transforming from the same monolayer shape, responsive photonic crystal, and self-clenched fists at μ/n scale. Predictably, the geometry-modulable hydrogels would open new access to massively-reproducible robotics, actuators/sensors for microenvironments, or lab-on-chip devices.

Rapid fabricating and harnessing stimuli-responsive behaviors of microscale bio-compatible hydrogels are of great interest to the emerging micro-mechanics, drug delivery, artificial scaffolds, nano-robotics, and lab chips. Herein, we demonstrate a novel femtosecond laser additive manufacturing process with smart materials for soft interactive hydrogel micro-machines. Bio-compatible hyaluronic acid methacryloyl was polymerized with hydrophilic diacrylate into an absorbent hydrogel matrix under a tight topological control through a 532 nm green femtosecond laser beam. The proposed hetero-scanning strategy modifies the hierarchical polymeric degrees inside the hydrogel matrix, leading to a controllable surface tension mismatch. Strikingly, these programmable stimuli-responsive matrices mechanized hydrogels into robotic applications at the micro/nanoscale (

Desalinating seawater is a crucial method for addressing the shortage of freshwater resources. High-efficiency, low-cost, and environmentally friendly desalination technologies are key issues that urgently need to be addressed. This work used Populus tomentosa Carr. as a matrix material and prepared Populus tomentosa Carr.@Fe-GA through a complexation reaction to enhance the water evaporation rate and photothermal conversion efficiency of seawater desalination. The concentration of the impregnation solution was further refined, and the bonding mechanism along with the thermal stability of the composite photothermal material was investigated, including an assessment of their photothermal conversion efficiency. The research results indicate that the evaporation rate of water in a 3.5% NaCl solution for Populus tomentosa Carr.@Fe-GA under light intensity conditions of one sun reached 1.72 kg·m−2·h−1, which was an increase of 44.5% compared to untreated Populus tomentosa Carr. It achieved a photothermal conversion efficiency of 95.1%, an improvement of 53.6% over untreated Populus tomentosa Carr., and maintained stability and high evaporation performance (95.4%) even after prolonged rinsing. This work realizes the functional utilization of seawater desalination with Populus tomentosa Carr. and offers a novel approach for the development and use of wood-derived photothermal material. [ABSTRACT FROM AUTHOR]