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Introduction: The hot water chemical flooding technology effectively improves the fluidity ratio and enhances the horizontal and vertical oil displacement efficiency of the reservoir through the synergistic effect of thermal energy and chemicals, which can further enhance the recovery rate on the basis of throughput thermal recovery.Methods: Based on the geological reservoir parameters of Bohai B oilfield, an oil recovery system evaluation experiment and scheme design study were carried out. Injection parameters such as hot water temperature, chemical agent concentration, and chemical agent dosage that affect the oil recovery effect of hot water chemical flooding were optimized and designed. The development characteristics and effects of two thermal recovery technologies, namely multi thermal fluid throughput and hot water chemical flooding, were compared and analyzed.Results: The results show that with the increase of temperature, the effect of chemical agents on improving the water-oil mobility ratio and reducing the viscosity of crude oil is weakened, and the thermal energy plays a leading role in enhancing oil recovery, but when the temperature is higher than 115°C, the improvement of oil recovery is slowed down, and the comprehensive economic indicators decline rapidly. As the concentration of chemical agent increases, the enhanced oil recovery increases monotonously. When the concentration is 1500 mg/L, the comprehensive economic indicators reach the peak and then decline, indicating that the efficiency of chemical agent decreases. The total amount of chemical agent shall be controlled within 0.25 ~ 0.30 PV. The case calculation shows that hot water chemical flooding can expand the effective radius from 80 m to 400 m, more effectively use the reserves between injection and production wells, increase the oil recovery by 4.8 percentage points, and increase the oil yield by 31.7 m3/t per ton of agent.Discussion: It is suggested that Bohai B Oilfield can adopt hot water chemical flooding after the multiple thermal fluid huff and puff to continuously guarantee the oilfield production.

In subsurface energy extraction, permeability or conductivity is the vital parameter for quantifying fluid flow in porous media. Three-dimensional digital core technique is widely used to calculate flow parameters and to analyze the internal structure and properties of rocks. However, one major problem is its high computational cost associated with fine-scale simulation of porous media, especially for large and complex rock samples. In this study, we propose to use subvolume properties to increase computational efficiency. Specifically, we first construct digital cores of dune sand and sandstone by CT scanning technology, and divide the whole core into multiple subvolumes and calculate their permeabilities. Then, we reassemble the subvolumes and compute the permeability for the whole core. This approach may lead to underestimation as the connectivity between subvolumes could be lost. To address this issue, we divide the whole core into different-sized subvolumes, and then use curve fitting to deduce the permeability of whole rock sample via extrapolation. The results show that the proposed method has improved accuracy, and is significantly faster than simulating the whole digital core, since the computation on subvolumes can be easily parallelized. This approach provides new ideas for accurate and efficient permeability estimation for digital porous media. [ABSTRACT FROM AUTHOR]

Efficient thermoelectric power generation requires a large applicable temperature range and correlated materials with outstanding dimensionless figure of merit values. Lead chalcogenides, especially PbTe-based materials, play a pivotal role in building thermoelectric devices for applications at intermediate temperature. However, the use of earth-scarce Te and the obstacles of achieving a high power factor and low thermal conductivity have limited progress in this field. Here, earth-abundant PbSe-based materials have been made by a simultaneous approach of combining self-propagating synthesis (SHS) and SPS techniques with optimized morphology engineering. Based on excess Ag doping and an ultrafast synthesis process, materials with parallel connections arising from enormous Ag2Se nanofibers with high hole mobility and Ag-doped PbSe with a small effective mass have been created, resulting in enhanced electrical properties. Meanwhile, multi-sized pores which modify the morphology have been formed during the reaction, leading to Ag-doped materials with low lattice thermal conductivity by reducing both the sound velocity and phonon mean free paths. Ultimately, a high figure of merit (ZT) of ∼1.2 at 773 K, and an average value of ∼1.1 over a range from 523 K to 823 K have been achieved for the Pb0.99Ag0.01Se sample. These findings, combined with the energy- and time-saving fabrication process, highlight the prospective commercialization of PbSe-based thermoelectric materials in the future. [ABSTRACT FROM AUTHOR]

In the chemical flooding process, the premature breakthrough of chemical agents in production wells results in a large waste of chemical agents and increases the volume and processing difficulty of the produced fluids. The early warning method of chemical agent channeling can predict the strength of agent channeling in advance. The practice of chemical flooding shows that the production performance can be used for early warning of chemical agent channeling. In this paper, we analyze the relationship between cumulative oil production and cumulative polymer production of production wells in polymer–surfactant flooding. Three types of curves according to the enhanced oil production characteristics of chemical flooding, including convex type, S‐type, and concave type. We use the drop speed of the water–oil ratio and the rapid‐decline speed of water cut as early warning indicators to predict the channeling coefficient. A Latin hypercube experimental design method is used to design a polymer–surfactant flooding scheme with the main control factors of the channeling coefficient and early warning indicators. Numerical simulation is used to calculate samples of the channeling coefficient and early warning indicators under various conditions. The drop speed of the water–oil ratio reference value model and the rapid‐decline speed of the water cut reference value model are determined with a multiple regression method. A prediction model for the chemical agent channeling coefficient is established using the deviation coefficient of an early warning index. The method is applied in the Ng54‐61 polymer–surfactant flooding pilot area in the west of the Gudong Seventh District, Shengli Oilfield, China, and the error between the predicted result and the actual value is less than 10%. This research is helpful in taking effective antichanneling measures and improving the oil recovery degree of chemical flooding reservoirs. [ABSTRACT FROM AUTHOR]

In the DC-6 GHz band, low-insertion-loss packaging materials were investigated to effectively reduce the heat generated during the working process of the attenuation chip. Based on the working principle of the attenuation chip, when the signal passes through the attenuation chip resistor network, it results in energy loss. This means that the insertion loss of the chip generates heat, which leads to an uneven heat dissipation of the chip and thus functional failure. The microwave characteristics of the packaged joints were investigated using different packaging techniques. The results show that the S21 and S11 of the attenuation chip after nano-silver and Au80Sn20 packaging are optimal in the frequency band of DC-6 GHz, and the insertion loss is low compared with the commonly used packaging materials Sn60Pb40 and Sn96.5Ag3.5, which reduces the heat loss and improves the reliability of the attenuation chip packaging. [ABSTRACT FROM AUTHOR]

T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients with t(8;14)(q24;q11)/TCRA/D::MYC translocation represent a rare subgroup, with an aggressive course. In our retrospective analysis of 14 patients, all were identified during refractory or relapsed stages (5 primary tumor, 9 relapse). Notably, extramedullary invasion was detected in most patients. Four exhibited STIL::TAL1 translocation, and six demonstrated CDKN2A/B gene loss. The therapeutic outcomes were notably poor for all seven patients who received only chemotherapy or allogeneic hematopoietic stem cell transplantation (HSCT); all eventually succumbed to the disease with a median OS of 3 months. In the application of CD7 CAR-T therapy in six patients, five achieved CR. Of the four patients who underwent HSCT following CAR-T therapy, all have remained disease-free. The prognosis for T-ALL/LBL patients with t(8;14) translocation remains bleak, but interventions involving CD7 CAR-T may offer a potential pathway to CR. HSCT following CAR-T could be a viable strategy for long-term survival. [ABSTRACT FROM AUTHOR]

Bi2Te3-based materials can be assembled into promising thermoelectric generators (TEGs) used for room temperature applications, yet their regulation for a wide range of applications, like the Internet of Things (IoTs), is limited by the small open circuit voltage, poor output power and large energy loss resulting from parasitic depletion to some extent. In this work, we have fabricated high-density thermoelectric generators (HD-TEGs) to compensate for these shortages, and the boosted voltage could reduce the energy loss simultaneously. To integrate HD-TEGs, the fabrication processes manipulate electrode deposition and reflow soldering techniques of delivering micro- and bulk-TEGs. Subsequently, a normalized power density of ∼13.7 μW cm−2 K−2, along with an open circuit voltage of ∼1.9 V, calculated contact depletion of ∼36% and experimental circuit depletion of ∼5% at ΔT of 13 K, has been achieved in a HD-TEG with 338 thermocouples (Tcs). Upon increasing ΔT to 73 K, the open circuit voltage and maximum output power are ∼10.1 V and 843.2 mW, which exceed those of the 50-Tcs TEG with packing fraction (f) of 5% and 34%, as well as the 200-Tcs TEG (f = 20%). These conversion properties are even much better than those of most commercial TEGs. Further, the finite-element simulation data indicate that output power and open circuit voltage could be further optimized to ∼68.5 mW (25.4 μW cm−2 K−2) and ∼2.9 V at ΔT of 13 K, by further increasing the density of thermoelectric elements and reducing contact loss. Moreover, our study elucidates that fabricating TEGs by using a high-density approach, i.e., optimizing packing fraction by increasing the quantity of thermocouples, could be an effective avenue for achieving high output performance with superior critical voltage and small energy loss. [ABSTRACT FROM AUTHOR]