Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However...Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However, wellbore instability, caused by the invasion of drilling fluids into shale formations, remains a significant challenge for the safe and efficient extraction of shale oil and gas. This work reports the preparation of mesoporous SiO2nanoparticles with low surface energy, utilized as multifunctional agents to enhance the performance of oil-based drilling fluids aimed at improving wellbore stability. The results indicate that the coating prepared from these nanoparticles exhibit excellent hydrophobicity and antifouling properties, increasing the water contact angle from 32°to 146°and oil contact angle from 24°to134.8°. Additionally, these nanoparticles exhibit exceptional chemical stability and thermal resistance.Incorporating these nanoparticles into oil-based drilling fluids reduced the surface energy of the mud cake from 34.99 to 8.17 m J·m-2and increased the roughness of shale from 0.26 to 2.39 μm. These modifications rendered the mud cake and shale surfaces amphiphobic, effectively mitigating capillary infiltration and delaying the long-term strength degradation of shale in oil-based drilling fluids. After 28days of immersion in oil-based drilling fluid, shale cores treated with MF-SiO2exhibited a 30.5% increase in compressive strength compared to untreated cores. Additionally, these nanoparticles demonstrated the ability to penetrate and seal rock pores, reducing the API filtration volume of the drilling fluid from11.2 to 7.6 m L. This study introduces a novel approach to enhance the development of shale gas and oil resources, offering a promising strategy for wellbore stabilization in oil-based drilling fluid systems.展开更多
Purpose: There have been many studies on the effects of different types of backpacks on posture from a biomechanical perspective and on the center of gravity. Considering the effects of autonomic nervous system activi...Purpose: There have been many studies on the effects of different types of backpacks on posture from a biomechanical perspective and on the center of gravity. Considering the effects of autonomic nervous system activity and mood associated with backpacks in mountaineering and hiking, research is also needed from a psychological perspective. In this study, the effects of adjusting the backpack shoulder stabilizer were preliminarily tested in terms of subjective fatigue and changes in autonomic nervous activity after hiking. Methods: The experimental 15 healthy participants hiked the mountain under two conditions: 1) without adjusting the stabilizer, a feature of the backpack (NAH condition), and 2) with the stabilizer adjusted (AH condition). First, all participants hiked the mountain in the NAH condition, and after a 30-minute break, they began the hike in the AH condition after confirming that a) their heart rate had recovered and b) they were in good physical condition. Results: HR was significantly lower after each hiking session than during the session. RMSSD was significantly lower pre-AH and post-AH than the NAH condition, but there was no significant difference between the NAH condition and either post-NAH or post-AH. Additionally, RMSSD was significantly lower in the AH condition than pre-AH or post-AH. The shoulders and back were significantly more burdened in the NAH condition than in the AH condition. The pleasure level was significantly higher in the AH condition than in the NAH condition. Conclusion: The results showed that also adjusting the position of the waist belt when adjusting the shoulder stabilizer, which is mainly used for the neck and shoulders, has a significant positive effect on the subjective burden on the upper body and parasympathetic nervous system activity after hiking.展开更多
Fiber is highly escapable in conventional slickwater,making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness.To solve these problems,a novel structure stabilizer(SS)is de...Fiber is highly escapable in conventional slickwater,making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness.To solve these problems,a novel structure stabilizer(SS)is developed.Through microscopic structural observations and performance evaluations in indoor experiments,the mechanism of proppant placement under the action of the SS and the effects of the SS on proppant placement dimensions and fracture conductivity were elucidated.The SS facilitates the formation of robust fiber-proppant agglomerates by polymer,fiber,and quartz sand.Compared to bare proppants,these agglomerates exhibit reduced density,increased volume,and enlarged contact area with the fluid during settlement,leading to heightened buoyancy and drag forces,ultimately resulting in slower settling velocities and enhanced transportability into deeper regions of the fracture.Co-injecting the fiber and the SS alongside the proppant into the reservoir effectively reduces the fiber escape rate,increases the proppant volume in the slickwater,and boosts the proppant placement height,conveyance distance and fracture conductivity,while also decreasing the proppant backflow.Experimental results indicate an optimal SS mass fraction of 0.3%.The application of this SS in over 80 wells targeting tight gas,shale oil,and shale gas reservoirs has substantiated its strong adaptability and general suitability for meeting the production enhancement,cost reduction,and sand control requirements of such wells.展开更多
The synergistic stabilization effect of different metal lanolin fatty acids as natural-based thermal stabilizers for poly（vinyl chloride） （PVC） including calcium lanolin fatty acid （Calan2）,zinc lanolin fatty ac...The synergistic stabilization effect of different metal lanolin fatty acids as natural-based thermal stabilizers for poly（vinyl chloride） （PVC） including calcium lanolin fatty acid （Calan2）,zinc lanolin fatty acid （Znlan2） and lanthanum lanolin fatty acid （Lalan3） were studied through Congo red testing,color measurements,FTIR analyses and thermal behavior in this paper. The results showed that Lalan3/Calan2/Znlan2 stabilizers exhibited more excellent thermal stabilization efficiency to PVC than Calan2/Znlan2 thermal stabilizers,and the optimal mass ratio of Lalan3/Calan2/Znlan2 was 8：9：3. At last,the effect of degradation mechanism on PVC and synergistic stabilization was also investigated by FTIR analyses and thermal behavior.展开更多
The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-m...The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs.展开更多
Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The sta...Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The stabilizer plays a key role because it can affect the physical stability and even the oral bioavailability of NCs.However,how stabilizers affect the bioavailability of NCs remains unknown.In this study,F68,F127,HPMC,and PVP were each used as a stabilizer to formulate naringenin NCs.The NCs formulated with PVP exhibited excellent release behaviors,cellular uptake,permeability,oral bioavailability,and anti-inflammatory effects.The underlying mechanism is that PVP effectively inhibits the formation of naringenin dimer,which in turn improves the physical stability of the supersaturated solution generated when NC is dissolved.This finding provides insights into the effects of stabilizers on the in vivo performances of NCs and supplies valuable knowledge for the development of poorly water-soluble drugs.展开更多
Fin stabilizers with fin-lift feedback control can shield the mapping error of calculation between the fin angle and fin lift force,which is in the fin stabilizer with fin-angle feedback control.In practice,there are ...Fin stabilizers with fin-lift feedback control can shield the mapping error of calculation between the fin angle and fin lift force,which is in the fin stabilizer with fin-angle feedback control.In practice,there are some technical difficulties in lift fin stabilizers,such as lift force detection and lift force sensor installation,so it cannot achieve the good antirolling performance.Therefore,a fin stabilizer system with fin-lift/fin-angle integrated control is brought forward.Data fusion based on wavelet denoising technology is employed in the system,which combines lift with fin angle local information from two sensors with different frequency ranges in order to eliminate redundant and contradictory information,and using complementary information to obtain the relative integrity of the lift force signal.The system model is established in this paper,and the fusion signal and the antirolling performance of this model are simulated respectively.The result shows that the control system can meet the antirolling need in different sea situations.展开更多
The influences ofphosphite and epoxy soybean oil in combination with liquid calcium/zinc isocaprylates on the thermal stability of flexible poly(vinyl chloride)were studied.The stabilizing effect of poly(vinyl chlorid...The influences ofphosphite and epoxy soybean oil in combination with liquid calcium/zinc isocaprylates on the thermal stability of flexible poly(vinyl chloride)were studied.The stabilizing effect of poly(vinyl chloride)was evaluated by Congo red method,thermoaging test and Thermogravimetric-differential Scanning Calorimetry(TG-DSC).The results showed that the addition of the phosphite or epoxy soybean oil improved the thermal stability of PVC with the calcium/zinc isocaprylates stabilizing system,especially epoxidied soybean oil exhibited a remarkable effect,and the synergism on PVC thermal stability for 3:2 phenyl dioctyl phosphite to epoxidized soybean oil weight ratio was acquired.Accordingly,the rapid mass loss in TG curve occured between 258.9℃and 334.4℃,which corresponded to the enthalpy of the pyrogenation of 609.2 J/g.It was also found that the stabilized PVC of the best ratio gave better mechanical and processing properties.展开更多
In this study, thermo-adapted （Ta） PPR vaccines were assessed for their stability at 25, 37, 40, 42 and 45℃ in lyophilized form using two extrinsic stabilizers {lactalbumin hydrolysate-sucrose （LS） and stabilizer...In this study, thermo-adapted （Ta） PPR vaccines were assessed for their stability at 25, 37, 40, 42 and 45℃ in lyophilized form using two extrinsic stabilizers {lactalbumin hydrolysate-sucrose （LS） and stabilizer E} and in reconstituted form with the diluents （1 mol/L MgSO4 or 0.85% NaC1）. The lyophilized vaccines showed an expiry period of 24-26 days at 25℃, 7-8 days at 37℃ and 3-4 days at 40℃. LS stabilizer was superior at 42℃ with a shelf-life of 44 h, whereas in stabilizer E, a 40 h shelf-life with a comparable half-life was observed. At 45 ℃, the half-life in stabilizer E was better than LS and lasted for 1 day. Furthermore, the reconstituted vaccine maintained the titre for 48 h both at 4℃ and 25℃ and for 24-30 h at 37℃. As both the stabilizers performed equally well with regard to shelf-life and half-life, the present study suggests LS as stabilizer as a choice for lyophilization with 0.85% NaCldiluent, because it has better performance at higher temperature. These Ta vaccines can be used as alternatives to existing vaccines for the control of the disease in tropical countries as they are effective in avoiding vaccination failure due to the breakdown in cold-chain maintenance, as this vaccine is considerably more stable at ambient temperatures.展开更多
One method for eliminating oscillations in power systems is using stabilizers.By applying an appropriate control signal in the excitation system of a generator,a power system stabilizer improves the dynamic stability ...One method for eliminating oscillations in power systems is using stabilizers.By applying an appropriate control signal in the excitation system of a generator,a power system stabilizer improves the dynamic stability of power systems.However,the issue that is of high importance is the correct design of these stabilizers.These stabilizers must be designed to have proper performance when operating conditions change.When designed incorrectly,not only they do not improve the stability margin,but also increase the oscillations.In this paper,the robust design of power system stabilizers on a four-machine power system has been performed.For this purpose,the differential evolution algorithm has been used.The studies have been repeated as three scenarios by producing different loading conditions for the generators.The performances of the conventional stabilizer and the optimized one have been compared.Simulation results indicate that the designed robust stabilizer outperforms other stabilizers in different conditions and has damped the interarea and intra-area oscillation modes in the shortest time with minimum amplitude.展开更多
Influences of lanthanum stearate （LaSt3） and calcium stearate/zinc stearate （Ca/Zn） stabilizers on stabilization efficiency of dibutyltin dilaurate （DBTDL） to polyvinyl chloride （PVC） in air were investigated....Influences of lanthanum stearate （LaSt3） and calcium stearate/zinc stearate （Ca/Zn） stabilizers on stabilization efficiency of dibutyltin dilaurate （DBTDL） to polyvinyl chloride （PVC） in air were investigated. The results revealed that the stabilization effect of DBTDL could be achieved by the La/Sn stabilizers with a ratio of 8/2. Addition of DBTDL could enhance thermal property and reduce dynamic storage modulus （G＇） at 180℃ for PVC containing LaSt3 or Ca/Zn stabilizers. On the other hand, incorporation of LaSh did not influence the stabilization efficiency of DBTDL markedly; while addition of Ca/Zn stabilizers could significantly decrease thermal property for the DBTDL stabilized PVC. Furthermore, the effects of LaSt3 and Ca/Zn stabilizers on the stabilization efficiency of DBTDL were explained in the framework of ionization potential.展开更多
Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of environment noise. The double-dot setup de...Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of environment noise. The double-dot setup design allows accounting for the full multiple tunneling process between the dots through the Majorana island, within a master equation approach. In the co-tunneling regime, which results in a Majorana-mediated effective coupling between the dots, the master equation approach allows us to obtain analytic solutions for the measurement currents. The measurement quality,characterized by figures of merit such as the visibility of measurement signals, is carried out in regard to the unusual decoherence effect rather than ‘which-path’ dephasing. The results obtained in this work are expected to be useful for future experiments of Majorana qubit and stabilizer measurements.展开更多
There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can b...There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can be involved for all kinds of dyes. To enhance the photostability of the commonly used disperse dyes, a series of tests on the ef-fect of variable stabilizers on the photodegradation rate of nine representative disperse dyes werecarried out both in ethyl acetate solution and on cellulose acetate film. A moderate light sourceemitting above 300 nm was adopted in this study to simulate the photofading under practical appli-cations. The results show that, in solution, 2,2,6,6-tetramethyl-piperidine is the most effectivegeneral stabilizer for all the tested dyes, but on cellulose film, nickel diethyl-dithiocarbamateshows the greatest general protecting effect, and a synergistic effect is observed for special combina-tions of stabilizers.展开更多
The objective of this study was to assess the clinical evidence for or against mood stabilizers as a treatment for Alzheimer’s disease (AD).We searched 5 databases from their inception to January 2010.Five randomized...The objective of this study was to assess the clinical evidence for or against mood stabilizers as a treatment for Alzheimer’s disease (AD).We searched 5 databases from their inception to January 2010.Five randomized clinical trials of mood stabilizers to treat human patients suffering from AD were included.These trials assessed the effectiveness of mood stabilizers as an adjunct treatment to conventional anti-dementia drugs on behavioral and psychological symptoms, especially on agitation.Methodological quality was assessed using the Jadad score.The results suggested a significant effect in favor of placebo on the Mini-Mental Status Examination [n=270, weight mean difference (WMD), -0.89; 95% confidence intervals (CIs) -1.69 to -0.09, P=0.03] and on the Neuropsychiatric Inventory total (NPI total) (n=51, WMD, 3.71; 95% CIs 0.15 to 7.26, P=0.04).There were no significant differences in change scores on total Brief Psychiatric Rating Scale (BPRS total), NPI/BPRS agitation, Cohen-Mansfield Agitation Inventory total and Physical Self Maintenance Scale between mood stabilizers and placebo.Only one of these studies was free of methodological limittions (Jadad score=5).In conclusion, based on the existing evidence, mood stabilizers are ineffective or even harmful as a treatment for AD.展开更多
A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The res...A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.展开更多
Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stab...Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.展开更多
Geophysical inversion under different stabilizers has different descriptions of the target body boundary,especially in complex geological structures.In this paper,we present an extremum boundary inversion algorithm ba...Geophysical inversion under different stabilizers has different descriptions of the target body boundary,especially in complex geological structures.In this paper,we present an extremum boundary inversion algorithm based on different stabilizers for electrical interface recognition.Firstly,we use the smoothest and minimum-support stabilizing functional to study the applicability of adaptive regularization inversion algorithm.Then,an electrical interface recognition method based on different stabilizers is developed by introducing extremum boundary inversion algorithm.The testing shows that the adaptive regularization inversion method does work for different stabilizers and has a low dependence on the initial models.The ratio of the smooth and focusing upper and lower boundaries obtained using the extremum boundary inversion algorithm can clearly demarcate electrical interfaces.We apply the inversion algorithm to the magnetotelluric(MT)data collected from a preselected area of a high-level-waste clay-rock repository site in the Tamusu area.We recognized regional structures with smooth inversion and the local details with focusing inversion and determined the thickness of the target layer combined with the geological and drilling information,which meets the requirement for the site of the high-level waste clay-rock repository.展开更多
To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose(NC)/nitroglycerine(NG),we synthesized N-(...To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose(NC)/nitroglycerine(NG),we synthesized N-(4-methoxy)phenylpyrrolidine-C_(60) and four different of bis(N-(4-methoxy)phenylpyrrolidine)-C_(60) compounds through Prato reaction.Their structures were characterized by UVevis,^(1)H NMR,^(13)C NMR,high-resolution mass spectroscopy,and single-crystal X-ray diffraction.Their stabilization effect to NC/NG were investigated using differential scanning calorimetry,methyl violet,vacuum stabilization effect,weight loss,and accelerating rate calorimeter tests.The results indicated these compounds had excellent stabilization effect to NC/NG.The stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C_(60).Moreover,the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different,and its stabilization effect to NC is also different.The stabilization effect order of different bisadduct isomers to nitrocellulose is as follows:e-edge>trans-2>cis-2>trans-3.Electron paramagnetic resonance(EPR)and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/NG.The EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide,and their ability is better than that of the monoadduct and C_(60),which is consistent with the results of stabilization effect performance test.展开更多
Circulating fluidized bed combustion（CFBC） fly ash was mixed with cement or lime at a different ratio as a stabilizer to stabilize lake sludge.In order to understand the influences of stabilizers on the lake sludge ...Circulating fluidized bed combustion（CFBC） fly ash was mixed with cement or lime at a different ratio as a stabilizer to stabilize lake sludge.In order to understand the influences of stabilizers on the lake sludge properties,tests unconfined compressive strength,water stability and SEM observation were performed.The experimental results show that with the increase of the curing time,the strength of all the stabilized specimens increase,especially the samples containing cement.The strength of the specimens is decreased with the increasing of the CFBC fly ash/cement ratio,the optimum ratio between CFBC fly ash and cement is 2：3.The water stability of CFBC fly ash-cement based stabilizers is higher than those of cement and lime.Moreover,the lake sludge stabilization mechanism of CFBC fly ash-cement based stabilizers includes gelation and filling of the hydration products,i e,C-S-H gel and the AFt crystal,which act as benders to solidify those particles together and fill in the packing void of the aggregates.展开更多
A phosphogypsum-based subgrade stabilizer(PBSS)was formulated using industrial by-product phosphogypsum(PG),mixed with slag and calcium-silicon-rich active material(GSR).The active powder(AP)was used to modify PBSS,an...A phosphogypsum-based subgrade stabilizer(PBSS)was formulated using industrial by-product phosphogypsum(PG),mixed with slag and calcium-silicon-rich active material(GSR).The active powder(AP)was used to modify PBSS,and PBSS-AP was obtained.PBSS and PBSS-AP were each mixed with 10%silty soil,and cement and lime(CAL:5%lime+2%cement)were used as the traditional material for comparative experiments.Samples were cured under standard conditions,and tested for unconfined compressive strength(UCS),water stability,volume expansion,and leachate,to explore the stabilization effect of the three solidified materials on silty soil.The results showed that the comprehensive performance of sility soil mixed with 12%PBSS-AP was the best.The CaO,SiO_(2)and Al_(2)O_(3)provided by PG,Slag and GSR will react with water to form a stable C-S-H gel,which is conducive to stabilizing the soil.Field application results showed that the compaction exceeded 95%,the deflection was 144.9 mm,and UCS was 2.5 MPa after 28 days.These findings indicated that PBSS-AP is an effective stabilizer for subgrade soils.展开更多
基金support from the National Natural:Science Foundation of China(NO.52174014)the National Natural Science Foundation Basic Science Center(NO.52288101).
文摘Oil-based drilling fluids possess excellent properties such as shale inhibition, cuttings suspension, and superior lubrication, making them essential in the development of unconventional oil and gas reservoirs.However, wellbore instability, caused by the invasion of drilling fluids into shale formations, remains a significant challenge for the safe and efficient extraction of shale oil and gas. This work reports the preparation of mesoporous SiO2nanoparticles with low surface energy, utilized as multifunctional agents to enhance the performance of oil-based drilling fluids aimed at improving wellbore stability. The results indicate that the coating prepared from these nanoparticles exhibit excellent hydrophobicity and antifouling properties, increasing the water contact angle from 32°to 146°and oil contact angle from 24°to134.8°. Additionally, these nanoparticles exhibit exceptional chemical stability and thermal resistance.Incorporating these nanoparticles into oil-based drilling fluids reduced the surface energy of the mud cake from 34.99 to 8.17 m J·m-2and increased the roughness of shale from 0.26 to 2.39 μm. These modifications rendered the mud cake and shale surfaces amphiphobic, effectively mitigating capillary infiltration and delaying the long-term strength degradation of shale in oil-based drilling fluids. After 28days of immersion in oil-based drilling fluid, shale cores treated with MF-SiO2exhibited a 30.5% increase in compressive strength compared to untreated cores. Additionally, these nanoparticles demonstrated the ability to penetrate and seal rock pores, reducing the API filtration volume of the drilling fluid from11.2 to 7.6 m L. This study introduces a novel approach to enhance the development of shale gas and oil resources, offering a promising strategy for wellbore stabilization in oil-based drilling fluid systems.
文摘Purpose: There have been many studies on the effects of different types of backpacks on posture from a biomechanical perspective and on the center of gravity. Considering the effects of autonomic nervous system activity and mood associated with backpacks in mountaineering and hiking, research is also needed from a psychological perspective. In this study, the effects of adjusting the backpack shoulder stabilizer were preliminarily tested in terms of subjective fatigue and changes in autonomic nervous activity after hiking. Methods: The experimental 15 healthy participants hiked the mountain under two conditions: 1) without adjusting the stabilizer, a feature of the backpack (NAH condition), and 2) with the stabilizer adjusted (AH condition). First, all participants hiked the mountain in the NAH condition, and after a 30-minute break, they began the hike in the AH condition after confirming that a) their heart rate had recovered and b) they were in good physical condition. Results: HR was significantly lower after each hiking session than during the session. RMSSD was significantly lower pre-AH and post-AH than the NAH condition, but there was no significant difference between the NAH condition and either post-NAH or post-AH. Additionally, RMSSD was significantly lower in the AH condition than pre-AH or post-AH. The shoulders and back were significantly more burdened in the NAH condition than in the AH condition. The pleasure level was significantly higher in the AH condition than in the NAH condition. Conclusion: The results showed that also adjusting the position of the waist belt when adjusting the shoulder stabilizer, which is mainly used for the neck and shoulders, has a significant positive effect on the subjective burden on the upper body and parasympathetic nervous system activity after hiking.
文摘Fiber is highly escapable in conventional slickwater,making it difficult to form fiber-proppant agglomerate with proppant and exhibit limited effectiveness.To solve these problems,a novel structure stabilizer(SS)is developed.Through microscopic structural observations and performance evaluations in indoor experiments,the mechanism of proppant placement under the action of the SS and the effects of the SS on proppant placement dimensions and fracture conductivity were elucidated.The SS facilitates the formation of robust fiber-proppant agglomerates by polymer,fiber,and quartz sand.Compared to bare proppants,these agglomerates exhibit reduced density,increased volume,and enlarged contact area with the fluid during settlement,leading to heightened buoyancy and drag forces,ultimately resulting in slower settling velocities and enhanced transportability into deeper regions of the fracture.Co-injecting the fiber and the SS alongside the proppant into the reservoir effectively reduces the fiber escape rate,increases the proppant volume in the slickwater,and boosts the proppant placement height,conveyance distance and fracture conductivity,while also decreasing the proppant backflow.Experimental results indicate an optimal SS mass fraction of 0.3%.The application of this SS in over 80 wells targeting tight gas,shale oil,and shale gas reservoirs has substantiated its strong adaptability and general suitability for meeting the production enhancement,cost reduction,and sand control requirements of such wells.
基金Project supported by the Natural Science Foundation of Fujian Province (2007HZ0001-2)
文摘The synergistic stabilization effect of different metal lanolin fatty acids as natural-based thermal stabilizers for poly（vinyl chloride） （PVC） including calcium lanolin fatty acid （Calan2）,zinc lanolin fatty acid （Znlan2） and lanthanum lanolin fatty acid （Lalan3） were studied through Congo red testing,color measurements,FTIR analyses and thermal behavior in this paper. The results showed that Lalan3/Calan2/Znlan2 stabilizers exhibited more excellent thermal stabilization efficiency to PVC than Calan2/Znlan2 thermal stabilizers,and the optimal mass ratio of Lalan3/Calan2/Znlan2 was 8：9：3. At last,the effect of degradation mechanism on PVC and synergistic stabilization was also investigated by FTIR analyses and thermal behavior.
基金financial support from the National Basic Research Program of China(973 Program,No.2009CB930300)
文摘The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs.
基金by the National Natural Science Foundation of China(No.82173765)the Science Foundation for Outstanding Youth of Liaoning Province(2021-YQ-08)+5 种基金Ningxia Key Research and Invention Program(No.2021BEG02039)Basic Research Projects of Liaoning Provincial Department of Education(2020LFW01)the Career Development Program for Young Teachers in Shenyang Pharmaceutical University(ZQN2019003)the Outstanding Youth Lifting Program in Shenyang Pharmaceutical University(YQ202115)the Natural Science Foundation of Liaoning Province(2020-MS-074)Open Fund of Key Laboratory of Biotechnology and Bioresources Utilization(Dalian Minzu University),Ministry of Education(KF2022005),China.
文摘Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The stabilizer plays a key role because it can affect the physical stability and even the oral bioavailability of NCs.However,how stabilizers affect the bioavailability of NCs remains unknown.In this study,F68,F127,HPMC,and PVP were each used as a stabilizer to formulate naringenin NCs.The NCs formulated with PVP exhibited excellent release behaviors,cellular uptake,permeability,oral bioavailability,and anti-inflammatory effects.The underlying mechanism is that PVP effectively inhibits the formation of naringenin dimer,which in turn improves the physical stability of the supersaturated solution generated when NC is dissolved.This finding provides insights into the effects of stabilizers on the in vivo performances of NCs and supplies valuable knowledge for the development of poorly water-soluble drugs.
基金supported by the "Ship Control Engineering" Emphasis Project of 211 Engineering in the Tenth Five-Year Plan
文摘Fin stabilizers with fin-lift feedback control can shield the mapping error of calculation between the fin angle and fin lift force,which is in the fin stabilizer with fin-angle feedback control.In practice,there are some technical difficulties in lift fin stabilizers,such as lift force detection and lift force sensor installation,so it cannot achieve the good antirolling performance.Therefore,a fin stabilizer system with fin-lift/fin-angle integrated control is brought forward.Data fusion based on wavelet denoising technology is employed in the system,which combines lift with fin angle local information from two sensors with different frequency ranges in order to eliminate redundant and contradictory information,and using complementary information to obtain the relative integrity of the lift force signal.The system model is established in this paper,and the fusion signal and the antirolling performance of this model are simulated respectively.The result shows that the control system can meet the antirolling need in different sea situations.
文摘The influences ofphosphite and epoxy soybean oil in combination with liquid calcium/zinc isocaprylates on the thermal stability of flexible poly(vinyl chloride)were studied.The stabilizing effect of poly(vinyl chloride)was evaluated by Congo red method,thermoaging test and Thermogravimetric-differential Scanning Calorimetry(TG-DSC).The results showed that the addition of the phosphite or epoxy soybean oil improved the thermal stability of PVC with the calcium/zinc isocaprylates stabilizing system,especially epoxidied soybean oil exhibited a remarkable effect,and the synergism on PVC thermal stability for 3:2 phenyl dioctyl phosphite to epoxidized soybean oil weight ratio was acquired.Accordingly,the rapid mass loss in TG curve occured between 258.9℃and 334.4℃,which corresponded to the enthalpy of the pyrogenation of 609.2 J/g.It was also found that the stabilized PVC of the best ratio gave better mechanical and processing properties.
基金Supported by grants from Indian Council of Agricultural Research,Ministry of Agriculture,Government of India,New Delhi,under the Ad-hoc Scheme(F.No.11-3/2007-GA-II and1-1/2007-ASR-IV)
文摘In this study, thermo-adapted （Ta） PPR vaccines were assessed for their stability at 25, 37, 40, 42 and 45℃ in lyophilized form using two extrinsic stabilizers {lactalbumin hydrolysate-sucrose （LS） and stabilizer E} and in reconstituted form with the diluents （1 mol/L MgSO4 or 0.85% NaC1）. The lyophilized vaccines showed an expiry period of 24-26 days at 25℃, 7-8 days at 37℃ and 3-4 days at 40℃. LS stabilizer was superior at 42℃ with a shelf-life of 44 h, whereas in stabilizer E, a 40 h shelf-life with a comparable half-life was observed. At 45 ℃, the half-life in stabilizer E was better than LS and lasted for 1 day. Furthermore, the reconstituted vaccine maintained the titre for 48 h both at 4℃ and 25℃ and for 24-30 h at 37℃. As both the stabilizers performed equally well with regard to shelf-life and half-life, the present study suggests LS as stabilizer as a choice for lyophilization with 0.85% NaCldiluent, because it has better performance at higher temperature. These Ta vaccines can be used as alternatives to existing vaccines for the control of the disease in tropical countries as they are effective in avoiding vaccination failure due to the breakdown in cold-chain maintenance, as this vaccine is considerably more stable at ambient temperatures.
文摘One method for eliminating oscillations in power systems is using stabilizers.By applying an appropriate control signal in the excitation system of a generator,a power system stabilizer improves the dynamic stability of power systems.However,the issue that is of high importance is the correct design of these stabilizers.These stabilizers must be designed to have proper performance when operating conditions change.When designed incorrectly,not only they do not improve the stability margin,but also increase the oscillations.In this paper,the robust design of power system stabilizers on a four-machine power system has been performed.For this purpose,the differential evolution algorithm has been used.The studies have been repeated as three scenarios by producing different loading conditions for the generators.The performances of the conventional stabilizer and the optimized one have been compared.Simulation results indicate that the designed robust stabilizer outperforms other stabilizers in different conditions and has damped the interarea and intra-area oscillation modes in the shortest time with minimum amplitude.
基金supported by Key Projects in the National Science & Technology Pillar Program(No. 2007BAE10B04)
文摘Influences of lanthanum stearate （LaSt3） and calcium stearate/zinc stearate （Ca/Zn） stabilizers on stabilization efficiency of dibutyltin dilaurate （DBTDL） to polyvinyl chloride （PVC） in air were investigated. The results revealed that the stabilization effect of DBTDL could be achieved by the La/Sn stabilizers with a ratio of 8/2. Addition of DBTDL could enhance thermal property and reduce dynamic storage modulus （G＇） at 180℃ for PVC containing LaSt3 or Ca/Zn stabilizers. On the other hand, incorporation of LaSh did not influence the stabilization efficiency of DBTDL markedly; while addition of Ca/Zn stabilizers could significantly decrease thermal property for the DBTDL stabilized PVC. Furthermore, the effects of LaSt3 and Ca/Zn stabilizers on the stabilization efficiency of DBTDL were explained in the framework of ionization potential.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0303304)the National Natural Science Foundation of China (Grant Nos. 11675016, 11974011, and 61905174)。
文摘Motivated by the need of quantum measurement of Majorana qubits and surface-code stabilizers, we analyze the performance of a double-dot interferometer under the influence of environment noise. The double-dot setup design allows accounting for the full multiple tunneling process between the dots through the Majorana island, within a master equation approach. In the co-tunneling regime, which results in a Majorana-mediated effective coupling between the dots, the master equation approach allows us to obtain analytic solutions for the measurement currents. The measurement quality,characterized by figures of merit such as the visibility of measurement signals, is carried out in regard to the unusual decoherence effect rather than ‘which-path’ dephasing. The results obtained in this work are expected to be useful for future experiments of Majorana qubit and stabilizer measurements.
文摘There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can be involved for all kinds of dyes. To enhance the photostability of the commonly used disperse dyes, a series of tests on the ef-fect of variable stabilizers on the photodegradation rate of nine representative disperse dyes werecarried out both in ethyl acetate solution and on cellulose acetate film. A moderate light sourceemitting above 300 nm was adopted in this study to simulate the photofading under practical appli-cations. The results show that, in solution, 2,2,6,6-tetramethyl-piperidine is the most effectivegeneral stabilizer for all the tested dyes, but on cellulose film, nickel diethyl-dithiocarbamateshows the greatest general protecting effect, and a synergistic effect is observed for special combina-tions of stabilizers.
基金supported by a grant from the Wuhan Bureau of Science and Technology, Hubei,China (No.200960-323132)
文摘The objective of this study was to assess the clinical evidence for or against mood stabilizers as a treatment for Alzheimer’s disease (AD).We searched 5 databases from their inception to January 2010.Five randomized clinical trials of mood stabilizers to treat human patients suffering from AD were included.These trials assessed the effectiveness of mood stabilizers as an adjunct treatment to conventional anti-dementia drugs on behavioral and psychological symptoms, especially on agitation.Methodological quality was assessed using the Jadad score.The results suggested a significant effect in favor of placebo on the Mini-Mental Status Examination [n=270, weight mean difference (WMD), -0.89; 95% confidence intervals (CIs) -1.69 to -0.09, P=0.03] and on the Neuropsychiatric Inventory total (NPI total) (n=51, WMD, 3.71; 95% CIs 0.15 to 7.26, P=0.04).There were no significant differences in change scores on total Brief Psychiatric Rating Scale (BPRS total), NPI/BPRS agitation, Cohen-Mansfield Agitation Inventory total and Physical Self Maintenance Scale between mood stabilizers and placebo.Only one of these studies was free of methodological limittions (Jadad score=5).In conclusion, based on the existing evidence, mood stabilizers are ineffective or even harmful as a treatment for AD.
文摘A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.
基金The work cited in this review was supported by the National Natural Science Foundation of China (No, 928700801 and No 2880201)
文摘Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.
基金supported by the National Natural Science Foundation of China(Nos.41604104,41674077 and 41404057)PRC High-level Radioactive Waste Geological Disposal Project([2014] No.1578)+2 种基金Open Fund of State Key Laboratory of Marine Geology(Tongji University)(MGK1704)Jiangxi Province Youth Science Fund(No.20171BAB213031)Scientific Research Starting Foundation for Doctors of East China University of Technology(DHBK201403)
文摘Geophysical inversion under different stabilizers has different descriptions of the target body boundary,especially in complex geological structures.In this paper,we present an extremum boundary inversion algorithm based on different stabilizers for electrical interface recognition.Firstly,we use the smoothest and minimum-support stabilizing functional to study the applicability of adaptive regularization inversion algorithm.Then,an electrical interface recognition method based on different stabilizers is developed by introducing extremum boundary inversion algorithm.The testing shows that the adaptive regularization inversion method does work for different stabilizers and has a low dependence on the initial models.The ratio of the smooth and focusing upper and lower boundaries obtained using the extremum boundary inversion algorithm can clearly demarcate electrical interfaces.We apply the inversion algorithm to the magnetotelluric(MT)data collected from a preselected area of a high-level-waste clay-rock repository site in the Tamusu area.We recognized regional structures with smooth inversion and the local details with focusing inversion and determined the thickness of the target layer combined with the geological and drilling information,which meets the requirement for the site of the high-level waste clay-rock repository.
基金This work was supported by National Natural Science Foundation of China(51972278)Outstanding Youth Science and Technology Talents Program of Sichuan(no.19JCQN0085)Open Project of State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology(No.19fksy04).
文摘To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose(NC)/nitroglycerine(NG),we synthesized N-(4-methoxy)phenylpyrrolidine-C_(60) and four different of bis(N-(4-methoxy)phenylpyrrolidine)-C_(60) compounds through Prato reaction.Their structures were characterized by UVevis,^(1)H NMR,^(13)C NMR,high-resolution mass spectroscopy,and single-crystal X-ray diffraction.Their stabilization effect to NC/NG were investigated using differential scanning calorimetry,methyl violet,vacuum stabilization effect,weight loss,and accelerating rate calorimeter tests.The results indicated these compounds had excellent stabilization effect to NC/NG.The stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C_(60).Moreover,the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different,and its stabilization effect to NC is also different.The stabilization effect order of different bisadduct isomers to nitrocellulose is as follows:e-edge>trans-2>cis-2>trans-3.Electron paramagnetic resonance(EPR)and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/NG.The EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide,and their ability is better than that of the monoadduct and C_(60),which is consistent with the results of stabilization effect performance test.
基金Funded by the High-Tech Research and Development Program of China(863 Program)(No.2009AA11Z106)
文摘Circulating fluidized bed combustion（CFBC） fly ash was mixed with cement or lime at a different ratio as a stabilizer to stabilize lake sludge.In order to understand the influences of stabilizers on the lake sludge properties,tests unconfined compressive strength,water stability and SEM observation were performed.The experimental results show that with the increase of the curing time,the strength of all the stabilized specimens increase,especially the samples containing cement.The strength of the specimens is decreased with the increasing of the CFBC fly ash/cement ratio,the optimum ratio between CFBC fly ash and cement is 2：3.The water stability of CFBC fly ash-cement based stabilizers is higher than those of cement and lime.Moreover,the lake sludge stabilization mechanism of CFBC fly ash-cement based stabilizers includes gelation and filling of the hydration products,i e,C-S-H gel and the AFt crystal,which act as benders to solidify those particles together and fill in the packing void of the aggregates.
基金the Jiangsu Provincial Science and Technology Department’s Social Development-Major Science and Technology Demonstration Project(Grant No.BE2018697)the Jiangsu Provincial Science and Technology Department Social Development Project(Grant No.BE2017704)the Scientific Research Project of the Suqian Municipal Transportation Bureau.
文摘A phosphogypsum-based subgrade stabilizer(PBSS)was formulated using industrial by-product phosphogypsum(PG),mixed with slag and calcium-silicon-rich active material(GSR).The active powder(AP)was used to modify PBSS,and PBSS-AP was obtained.PBSS and PBSS-AP were each mixed with 10%silty soil,and cement and lime(CAL:5%lime+2%cement)were used as the traditional material for comparative experiments.Samples were cured under standard conditions,and tested for unconfined compressive strength(UCS),water stability,volume expansion,and leachate,to explore the stabilization effect of the three solidified materials on silty soil.The results showed that the comprehensive performance of sility soil mixed with 12%PBSS-AP was the best.The CaO,SiO_(2)and Al_(2)O_(3)provided by PG,Slag and GSR will react with water to form a stable C-S-H gel,which is conducive to stabilizing the soil.Field application results showed that the compaction exceeded 95%,the deflection was 144.9 mm,and UCS was 2.5 MPa after 28 days.These findings indicated that PBSS-AP is an effective stabilizer for subgrade soils.
