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Herein we report the design and synthesis of hypervalent trifluoromethylthio-iodine(III) reagent 1 and the elucidation of its structure by NMR spectroscopy and X-ray crystallography. The trifluoromethylthiolation reactions of 1 with various nucleophiles were explored, and this compound was found to be a versatile electrophilic reagent for the transfer of a trifluoromethylthio group (-SCF3). The hydrogen-bonding mode responsible for the activation of 1 by the solvent 1,1,1,3,3,3-hexafluoro-2-propanol was investigated both experimentally and computationally.

Lithium-ion batteries with nickel-rich layered oxide cathodes and graphite anodes have reached specific energies of 250-300 Wh kgsup-1/sup(refs.sup1,2/sup), and it is now possible to build a 90 kWh electric vehicle (EV) pack with a 300-mile cruise range. Unfortunately, using such massive batteries to alleviate range anxiety is ineffective for mainstream EV adoption owing to the limited raw resource supply and prohibitively high cost. Ten-minute fast charging enables downsizing of EV batteries for both affordability and sustainability, without causing range anxiety. However, fast charging of energy-dense batteries (more than 250 Wh kgsup-/supsup1/supor higher than 4 mAh cmsup-/supsup2/sup) remains a great challengesup3,4/sup. Here we combine a material-agnostic approach based on asymmetric temperature modulation with a thermally stable dual-salt electrolyte to achieve charging of a 265 Wh kgsup-/supsup1/supbattery to 75% (or 70%) state of charge in 12 (or 11) minutes for more than 900 (or 2,000) cycles. This is equivalent to a half million mile range in which every charge is a fast charge. Further, we build a digital twin of such a battery pack to assess its cooling and safety and demonstrate that thermally modulated 4C charging only requires air convection. This offers a compact and intrinsically safe route to cell-to-pack development. The rapid thermal modulation method to yield highly active electrochemical interfaces only during fast charging has important potential to realize both stability and fast charging of next-generation materials, including anodes like silicon and lithium metal.

Summary Adding a 200-mile range in 10 min, so-called extreme fast charging (XFC), is the key to mainstream adoption of battery electric vehicles (BEVs). Here, we present an asymmetric temperature modulation (ATM) method that, on one hand, charges a Li-ion cell at an elevated temperature of 60°C to eliminate Li plating and, on the other, limits the exposure time at 60°C to only ∼10 min per cycle, or 0.1% of the lifetime of a BEV, to prevent severe solid-electrolyte-interphase growth. The asymmetric temperature between charge and discharge opens a new path to enhance kinetics and transport during charging while still achieving long life. We show that a 9.5-Ah 170-Wh/kg cell sustained 1,700 XFC cycles (6 C charge to 80% state of charge) at 20% capacity loss with the ATM, compared to 60 cycles for a control cell, and that a 209-Wh/kg BEV cell retained 91.7% capacity after 2,500 XFC cycles.

Predicting the capacity-fade trajectory of a lithium-ion (Li-ion) battery cell is a critical task given its broad utility throughout the battery product life cycle. Even more useful is estimating a battery cell’s capacity-fade trajectory when this cell has not exhibited any noticeable capacity degradation. Accurately predicting the entire capacity-fade trajectory using early life data enables more efficient cell design, operation, maintenance, and evaluation for second-life use. To accomplish this challenging task, we propose an end-to-end learning framework combining empirical capacity fade models and data-driven machine learning models, in which the two types of models are closely coupled. First, we evaluate the accuracy of a library of relevant empirical models which have been shown to model the observed capacity fade of Li-ion cells with reasonable accuracy. After selecting a model, we formulate an end-to-end learning problem that simultaneously fits the chosen empirical model to estimate the capacity fade curve and trains a machine learning model to estimate the best-fit parameters of the empirical model. By solving this end-to-end learning problem, rather than sequentially executing the separate tasks of fitting the capacity fade model and training the machine learning model, we achieve a more optimal solution which is shown to better balance these two objectives. Our proposed end-to-end learning framework is evaluated using a publicly available battery dataset consisting of 124 lithium-iron-phosphate/graphite cells charged with various fast-charging protocols. This dataset was split into training, primary test, and secondary test datasets. Our method performs on par with existing early prediction methods in terms of cycle life prediction, attaining root-mean-square errors of 84 cycles and 169 cycles for primary and secondary test datasets, respectively. In addition to the cycle life prediction, our method possesses a unique ability to predict the entire capacity-fade trajectory.

To quantitatively assess the satisfaction degree of precipitation on water requirement of table grape in the main producing areas in China, we analyzed the temporal and spatial variations of precipitation, water requirement and water deficit in different growth stages of table grape based on the 1981-2016 daily meteorological data from 429 meteorological stations in the study region (Jinlin and Liaoning of Northeast China; Shanxi and Hebei of North China; Xinjiang, Gansu, Ningxia and Shaanxi of Northwest China; Sichuan, Guizhou and Yunnan of Southwest China; Jiangsu, Shandong, Zhejiang, Anhui, Fujian, Henan, Hubei, Hunan and Guangxi of Southeast China). Results showed that precipitation in each growth stage showed an increasing trend from north to south and from west to east in the study period. The precipitation in germination-flowering stage was the lowest and showed a decreasing trend. The precipitation in maturation-defoliation stage showed a decreasing trend, while that in flowering-veraison and veraison-maturation stage exhibited an increasing trend. Water requirement of grape exhibited an increasing trend in each growth stage in the study region. Water requirement of grape in Xinjiang and the northern of Gansu Province was the highest. The precipitation could not meet water requirement of grape in Xinjiang, northern Gansu, Ningxia, northern Shaanxi, northern Shanxi, northern Hebei, western Liaoning and western Jilin in each growth stage, as well as northern Yunnan and southern Sichuan during germination-flowering stage. In constrast, water surplus was obvious in the other areas, especially in the southeast and southwest of China. The water deficit of grape showed an increasing trend during the germination-flowering and maturation-defoliation stage, while that during flowering-veraison and veraison-maturation stage showed a decreasing trend.为了定量评估我国鲜食葡萄主产区降水量对葡萄生长发育过程需水量的满足程度,本研究基于研究区域内(东北地区的吉林和辽宁,华北地区的山西和河北,西北地区的甘肃、宁夏和陕西,西南地区的四川、贵州和云南以及东南地区的江苏、山东、浙江、安徽、福建、河南、湖北、湖南和广西)1981—2016年429个气象站逐日气象数据,分析葡萄不同生育阶段降水量、需水量和水分亏缺量时空分布特征。结果表明: 研究期间,葡萄各生育阶段降水量整体由北向南、由西向东增加;萌芽-开花阶段的降水量最少且呈下降趋势,成熟-落叶阶段也呈下降趋势,开花-着色和着色-成熟阶段呈上升趋势。研究区各生育阶段的葡萄需水量均呈上升趋势,新疆和甘肃省北部的葡萄需水量最高。新疆、甘肃省北部、宁夏、陕西省北部、山西省北部、河北省、辽宁省西部和吉林省西部各生育阶段以及云南省北部、四川省南部萌芽-开花生育阶段的降水量无法满足葡萄需水量,其他地区,特别是我国东南和西南部部分地区水分盈余明显;萌芽-开花和成熟-落叶阶段的葡萄水分亏缺量呈上升趋势,开花-着色和着色-成熟阶段呈下降趋势。.

This study is to obtain precise data on iron physiological requirements in Chinese children using single stable isotope tracer technique.Thirty boys (10.6 ± 0.2 years) and 27 girls (10.4 ± 0.2 years) were received oral 6 mgThe iron physiological requirement was significantly lower in boys than those values in girls (16.88 ± 7.12This study indicate that iron physiological requirement could require more daily iron intake in girls as compare with the values in boys having the same body weight. These findings would be facilitate to the new revised dietary reference intakes.

The year 2017 was when electric vehicles (EVs) came of age. EV sales, according to Macquarie Bank, climbed from 740,000 vehicles in 2016 to 1.1 million, an increase of 51%. In terms of market shares, EVs accounted for 1.7% of new car sales in 2017, up from 1.1% in 2016. Although still small in the grand scheme of things, the growth rate was exceptional. All market movers are now taking EVs seriously, as evidenced by a flurry of announcements last year about the plans of major automakers for the EV market. Should these plans come to fruition, we are foreseeing roughly 400 models and 25 million sales of EVs by 2025.

We report on significantly enhanced performances of 1.3 μm InAs/GaAs quantum dot (QD) lasers by spatially separated dual-doping, including p-type modulation doping in barrier layers and n-type direct doping in QDs simultaneously. The QD lasers are a ridge waveguide of 6 × 1000 μm2 with uncoated facets, whose active region consists of eight stacked InAs QD layers. Compared with the conventional single p-type modulation doped ( p-doped) QD laser, the dually doped QD laser achieves a reduced threshold current from 51.07 to 43 mA, an increased single-sided slope efficiency from 0.18 to 0.25 W/A at 25 °C, and an increased characteristic temperature T0 from 654 to 7917 K between 15 and 85 °C. Furthermore, the continuous wave output power of the dually doped QD laser exceeds 20 mW without any attenuation at 85 °C, whereas that of the p-doped one appears to be saturated at 14.08 mW. The results presented here have important implications for realizing high-performance QD lasers emitting at 1.3 μm to various applications.

A boy, aged 2 years and 4 months, had a sudden onset of blepharoptosis of the right eyelid, accompanied by the mouth deviated to the right side, drinking cough, nystagmus, and developmental regression. Cranial MRI showed softening lesions formed after infarction of the right dorsolateral medulla oblongata, while head CT angiography showed no imaging of the proximal part of the V4 segment of the right vertebral artery. The child was diagnosed with dorsolateral medulla oblongata syndrome and was treated with gamma globulin to regulate immune function, with mannitol to reduce neuronal edema, with low-molecular-weight heparin sodium to improve local hypercoagulation of occluded blood vessels, with hyperbaric oxygen to improve local ischemia and hypoxia and promote the recovery of brain function, and with neuromuscular electrical stimulation to promote the recovery of neuromuscular function. Before discharge, only mild right ataxia and Horner syndrome remained. This article reports the first case of infantile dorsolateral medulla oblongata syndrome and provides experience for the diagnosis and treatment of the disease.

Recent studies have shown that monoamine oxidase A (MAOA) is significantly expressed in malignant prostate cancer (PCa) and plays an important role in tumorigenesis indicating its potential to serve as a target for PCa treatment. Here, we choose the small molecule isoniazid as the MAOA inhibition functionality and incorporated it in the tumor-targeting moiety of heptamethine carbocyanine dyes

Based on daily meteorological data and agro-meteorological data in three provinces of Northeast China during 1981-2017, combined with chilling injury indices, we analyzed the spatial-temporal distribution characteristics of solar, heat, precipitation resources and sterile-type chilling injury in rice growing season, especially in the booting and flowering stages. In 1981-2017, agriculture climatic resources in rice growing season showed a warming, drying and darkening trend. Accumulated temperature (≥10 ℃) and sunshine hours increased with a rate of 73.5 ℃·d·(10 a)基于东北三省1981—2017年逐日地面观测资料和农业气象观测站水稻生育期资料,结合水稻障碍型冷害指标,分析东北三省水稻生长季特别是孕穗-开花期光、温、降水资源以及障碍型冷害的时空分布特征。结果表明: 1981—2017年,东北三省水稻生长季农业气候资源呈暖干变暗趋势,≥10 ℃活动积温和日照时数增幅分别为73.5 ℃·d·(10 a)

Increasing energy density of Li-ion batteries (LiBs) along with fast charging capability are two key approaches to eliminate range anxiety and boost mainstream adoption of electric vehicles (EVs). Either the increase of energy density or of charge rate, however, heightens the risk of lithium plating and thus deteriorates cell life. The trilemma of fast charging, energy density and cycle life are studied systematically in this work utilizing a physics-based aging model with incorporation of both lithium plating and solid-electrolyte-interphase (SEI) growth. The model is able to capture the key feature of temperature-dependent aging behavior of LiBs, or more specifically, the existence of an optimal temperature with the longest cycle life. We demonstrate that this optimal temperature is a result of competition between SEI growth and lithium plating. Further, it is revealed that either the increase of charge rate or of energy density accelerates lithium plating induced aging. As such, the optimal temperature for cell life increases from ∼20 °C for a high-power cell at 1C charge to ∼35–45 °C with the increase of charge rate and/or energy density. It would be beneficial to further increase the charge temperature in order to enable robust fast charging of high energy EV cells.

Voltage plateau during relaxation or discharge after charging is a distinct signal associated with stripping of deposited Li metal and hence a feasible tool for online detection of Li plating in Li-ion batteries. Here, we present a physics-based model with incorporation of Li plating and stripping to gain a fundamental understanding of the voltage plateau behavior. Specifically, we focus on the internal cell characteristics when voltage plateau occurs and on key factors affecting the shape and duration of voltage plateau. Furthermore, the validity of using the duration of voltage plateau for estimating Li plating amount is assessed. It is found that the duration of voltage plateau depends on the rate of Li stripping, while the stripping rate is restricted by the capability of Li+ intercalation into graphite. Parameters like intercalation kinetics, solid-state diffusivity of graphite and cell temperature can substantially influence the voltage curves even with the same amount of Li plating. Further, we report an interesting phenomenon that during Li stripping one part of anode near the separator has net oxidation current (local stripping rate > intercalation rate), providing Li+ ions and electrons to the other part of anode near the foil which has net reduction current.

Electric vehicles (EVs) driven in cold weather experience two major drawbacks of Li-ion batteries: drastic power loss (up to 10-fold at −30 °C) and restriction of regenerative braking at temperatures below 5–10 °C. Both factors greatly reduce cruise range, exacerbating drivers' range anxiety in winter. While preheating the battery before driving is a practice widely adopted to maintain battery power and EV drivability, it is time-consuming (on the order of 40 min) and prohibits instantaneous mobility. Here we reveal a control strategy that can rapidly restore EV battery power and permit full regeneration while driving at temperatures as low as −40 °C. The strategy involves heating the battery internally during regenerative braking and rest periods of driving. We show that this technique fully restores room-temperature battery power and regeneration in 13, 33, 46, 56 and 112 s into uninterrupted driving in 0, −10, −20, −30 and −40 °C environments, respectively. Correspondingly, the strategy significantly increases cruise range of a vehicle operated at cold temperatures, e.g. 49% at −40 °C in simulated US06 driving cycle tests. The present work suggests that smart batteries with embedded sensing/actuation can leapfrog in performance.

Battery thermal management systems (BTMSs) are expected to keep the battery temperature at a moderate level (∼30 °C) to minimize the thermally exacerbated degradation. However, during fast charging, a strong cooling system is required to restrict the temperature rise of Li-ion batteries (LiBs), which significantly increases the cost and weight of battery packs, and induces a large temperature variation inside the battery. In this work we find that all these drawbacks could be relieved by allowing LiBs to charge at higher temperatures. Since the fast charging of a LiB only takes a tiny fraction of its lifetime, the aging rate is limited even at a charging temperature of 60 °C. Three types of thermal environments are proposed: kept constant at 30 °C, preheated to 60 °C, and adiabatic fast charging. With an experimentally validated electrochemical-thermal (ECT) coupled model, we explore the interplay between thermal management and the fast-charging performance. It is found that a gradually increasing temperature profile is the best option to balance the lithium plating and thermal management of the battery. Combining adiabatic fast charging with a preheating step, we can achieve minimal cooling need, perfect temperature uniformity within a battery, and fast-charging capability simultaneously.

We demonstrate that an energy-dense, 288 Wh kg−1 lithium-ion battery can provide 152 Wh kg−1 energy and 1056 W kg−1 power at ultralow temperatures such as −40 or −50 °C, contrary to virtually no performance expected under two simultaneous extremes: 4.04 mAh cm−2 cathode loading and −40 °C. Unleashing this huge potential of current battery materials is achieved through a self-heating structure by embedding a micron-thin nickel foil in the electrochemical energy storage cell. The heating process from −40 to 10 °C consumes only 5.1% of battery energy and takes 77 s. Further, based on the chemistry agnostic nature of self-heating, we present a generic chart to transform rate capability of lithium-ion and lithium metal batteries. These illustrative examples point to a new era of battery structure innovation, significantly broadening the performance envelopes of existing and emerging battery materials for electrified transportation.

A physics-based Li-ion battery (LIB) aging model accounting for both lithium plating and solid electrolyte interphase (SEI) growth is presented, and is applied to study the aging behavior of a cell undergoing prolonged cycling at moderate operating conditions. Cell aging is found to be linear in the early stage of cycling but highly nonlinear in the end with rapid capacity drop and resistance rise. The linear aging stage is found to be dominated by SEI growth, while the transition from linear to nonlinear aging is attributed to the sharp rise of lithium plating rate. Lithium plating starts to occur in a narrow portion of the anode near the separator after a certain number of cycles. The onset of lithium plating is attributed to the drop of anode porosity associated with SEI growth, which aggravates the local electrolyte potential gradient in the anode. The presence of lithium metal accelerates the porosity reduction, further promoting lithium plating. This positive feedback leads to exponential increase of lithium plating rate in the late stage of cycling, as well as local pore clogging near the anode/separator interface which in turn leads to a sharp resistance rise.

A microstructure-based modeling method is developed to predict the mechanical behaviors of lithium-ion battery separators. Existing battery separator modeling methods cannot capture the structural features on the microscale. To overcome this issue, we propose an image-based microstructure Representative Volume Element (RVE) modeling method, which facilitates the understanding of the separators' complex macro mechanical behaviors from the perspective of microstructural features. A generic image processing workflow is developed to identify different phases in the microscopic image. The processed RVE image supplies microstructural information to the Finite Element Analysis (FEA). Both mechanical behavior and microstructure evolution are obtained from the simulation. The evolution of microstructure features is quantified using the stochastic microstructure characterization methods. The proposed method successfully captures the anisotropic behavior of the separator under tensile test, and provides insights into the microstructure deformation, such as the growth of voids. We apply the proposed method to a commercially available separator as the demonstration. The analysis results are validated using experimental testing results that are reported in literature.

Automotive Li-ion cells are becoming much larger and thicker in order to reduce the cell count and increase battery reliability, posing a new challenge to battery heating from the cold ambient due to poor through-plane heat transfer across a cell's multiple layers of electrodes and separators. In this work, widely used heating methods, including internal heating using the cell's resistance and external heating by resistive heaters, are compared with the recently developed self-heating Li-ion battery (SHLB) with special attention to the heating speed and maximum local temperature critical to battery safety. Both conventional methods are found to be slow due to low heating power required to maintain battery safety. The heating power in the external heating method is limited by the risk of local over-heating, in particular for thick cells. As a result, the external heating method is restricted to ∼20 min slow heating for a 30 °C temperature rise. In contrast, the SHLB is demonstrated to reach a heating speed of 1–2 °C/sec, ∼40 times faster for large-size thick cells, with nearly 100% heating efficiency and spatially uniform heating free from safety concerns.

This study aimed to measure the basal energy expenditure (BEE) of Chinese healthy adults and establish an accurate predictive equation for this population.In total, 470 Chinese healthy adults had their BEE measured using the Cosmed K4bThere was a significant difference in BEE between males and females, with 5,954 kJ/d and 5,089 kJ/d, respectively. People living in rural areas expended significantly higher BEE (5,885 kJ/d) than those in urban areas (5,279 kJ/d). Previous equations developed by Henry, Schofield, Harris-Benedict (H-B), and Liu overestimated the BEE of Chinese healthy adults. The new equations derived from the present study displayed the smallest average bias and RMSE from the measured basal energy expenditure (mBEE). The CCC of the new equations was higher than other predictive equations, but it was lower than 0.8. There was no significant difference in the accuracy rate among all predictive equations.Sex and regional differences in BEE were observed in Chinese healthy adults. Neither the widely used previous predictive equations nor the one derived in the present study were accurate enough for estimating the BEE of Chinese healthy adults. Further study is required to develop more accurate equations for predicting the BEE of Chinese healthy adults aged between 20-45 years.

Tumor plasticity refers to tumor cell's inherent property of transforming one type of cell to different types of cells. Tumor plasticity is the main cause of tumor relapse, metastasis and drug resistance. Cancer stem cell (CSC) model embodies the trait of tumor plasticity. During carcinoma progression, epithelial-mesenchymal transition (EMT) plays crucial role in the formation of CSCs and vasculogenic mimicry (VM) based on epithelial-mesenchymal plasticity. And the unique tumor microenvironment (TME) not only provides suitable niche for CSCs but promotes the building of CSCs and VM that nourishes tumor tissue together with neoplasm metabolism by affecting tumor plasticity. Therapeutic strategies targeting tumor plasticity are promising ways to treat malignant tumor. In this article, we discuss the recent developments of potential drug targets related to CSCs, EMT, TME, VM, and metabolic pathways and summarize drugs that target these areas in clinical trials.

We present a new battery with high safety and performance, overcoming the materials-based conflict of reactivity versus stability., We present a novel concept to achieve high performance and high safety simultaneously by passivating a Li-ion cell and then self-heating before use. By adding a small amount of triallyl phosphate in conventional electrolytes, we show that resistances of the passivated cells can increase by ~5×, thereby ensuring high safety and thermal stability. High power before battery operation is delivered by self-heating to an elevated temperature such as 60°C within tens of seconds. The present approach of building a resistive cell with highly stable materials and then delivering high power on demand through rapid thermal stimulation leads to a revolutionary route to high safety when batteries are not in use and high battery performance upon operation.

To analyze the rate of erythrocyte iron incorporation and provided guidance for the iron nutrition for prepubertal children.Fifty-seven prepubertal children of Beijing were involved in this study and each subject was orally administered 3 mg ofThe percentage of erythrocyteThe oral administration of

Background and objective: Anterior cruciate ligament tibial eminence avulsion fractures are repaired via early open reduction. Choosing the best fixation method in accordance with the bone size can effectively promote restoration of the cruciate ligament to its normal anatomical position and achieve bone healing. The use of absorbable screws for internal fixation of anterior cruciate ligament tibial eminence avulsion fractures reportedly promotes fracture healing, but the efficacy and safety need further clarification. The present study aims to observe the efficacy and safety of open reduction and internal fixation with absorbable screws through a small incision in the repair of anterior cruciate ligament tibial eminence avulsion fracture. Participants and methods: This prospective, single-center, self-controlled trial will include 72 patients with anterior cruciate ligament tibial eminence avulsion fractures. Open reduction and internal fixation with absorbable screws will be performed through a small incision. All patients will be followed up at 3, 6, and 12 months postoperatively. This study was approved by the Medical Ethics Committee of No. 1 Hospital of Longnan City, China in December 2014 (approval number: S2014-064-02). Protocol version is 1.0. Written informed consent regarding the study protocol and surgery procedure will be obtained from the participants’ family members or the participants themselves. Results: The primary outcome measure is the recovery of knee function assessed by the Lysholm Knee Scoring Scale score at 12 months postoperatively. Secondary outcome measures are the Lysholm Knee Scoring Scale scores preoperatively and 3 and 6 months postoperatively, the International Knee Documentation Committee scores, knee range of motion, knee morphology on radiographs and magnetic resonance images preoperatively and 3, 6, and 12 months postoperatively, and the incidences of adverse reactions 3, 6, and 12 months postoperatively. In our pilot study involving 50 patients with anterior cruciate ligament tibial eminence avulsion fractures (50 knees) from October 2015 to January 2018, no patient had joint stiffness or fracture redisplacement on radiography 3 months postoperatively. The mean knee range of motion was significantly larger at 6 months postoperatively compared with preoperatively (P Conclusion: This trial will assess the efficacy and safety of open reduction and internal fixation with absorbable screws through a small incision to restore knee function in patients with anterior cruciate ligament tibial eminence avulsion fracture. Trial registration: This study was registered with the Chinese Clinical Trial Registry on March 13, 2019 (registration number: ChiCTR1900021865).

Capacity variation among battery cells can occur due to inconsistent manufacturing processes and operating conditions, such as uneven temperature distribution. For a battery string made of parallel-connected cells with only one voltage and one current sensor, the lack of independent current sensors makes it difficult to detect or control the degradation variation. In order to investigate the progression mechanism of cell-to-cell capacity variation, this paper adopts an electric aging model and analytically determines the relationship between variation progression and cell degradation characteristics. Assuming all cells have similar temperatures, the capacity variation will decrease over time for cells with a convex or linear degradation curve (i.e., the most common case), providing a self-balancing mechanism for parallel-connected cells. Compared to battery strings with uniform cell capacities, battery strings with an initial cell-to-cell variation will degrade slightly faster. State-of-charge imbalance and uneven heat generation are analyzed using a thermal model. Assuming the same coefficient of heat transfer (i.e., same cooling condition), simulation results further verify the self-balancing mechanism for a parallel battery string consisting of 5 LiFePO4 battery cells.

Urban air mobility (UAM) demands batteries with high energy density, long cycle life, and fast rechargeability. Here, we demonstrate an energy-dense lithium-ion battery (LiB) with ultralong cycle life under ultrafast charging. By using the asymmetric temperature modulation (ATM) method, i.e., charging at an elevated temperature and discharging around the ambient temperature, it is experimentally shown that the 209 Wh/kg LiB is charged to 88% state of charge (SOC) in ∼5 min under UAM cycling while retaining 97.7% capacity after 1,000 cycles. Moreover, an experimentally validated electrochemical-thermal (ECT) model is developed to elucidate the fast charging process and the degradation mode of UAM batteries, quantitatively capturing lithium plating during fast charging. We find that the LiBs for UAM applications are most prone to lithium plating due to their higher initial SOC required as the reserve for safety; nevertheless, the ATM method is effective in minimizing or preventing lithium plating in the high SOC range of 30-90%. In addition to slowing down capacity fade, the ATM method also raises the usable capacity by 10%, which boosts the battery energy density and ensures the battery to perform full UAM cycles even at the end of life.

This paper aims to validate a viscoplastic constitutive model and investigate the local and the full-field strain of notched specimen. A high temperature digital image correlation (DIC)-based test system was constructed to measure the full-field surface deformation. Surface strain fields of notched DZ125 specimens were measured under monotonic tensile loadings at 20 °C, 650 °C, 760 °C, and 850 °C. Taking the effect of anisotropy, applied stress, and temperature into account, numerical simulations were conducted using a developed viscoplastic constitutive model. DIC-based measurements agreed well with the simulated strains, with the minimum correlation coefficient of 95.47%. Both the numerical and experimental results show that the area of notch plasticity increases with temperature and applied stress, and the high strain zone nearly remains constant under various tensile loadings. For a given notch geometry, the strain mutation in high strain zone nearly remains constant no matter how the temperature and the applied stress change.

In this study, a boron-doped microporous carbon (BMC)/sulfur nanocomposite is synthesized and applied as a novel cathode material for advanced Li-S batteries. The cell with this cathode exhibits an ultrahigh cycling stability and rate capability. After activation, a capacity of 749.5 mAh/g was obtained on the 54th cycle at a discharge current of 3.2 A/g. After 500 cycles, capacity of 561.8 mAh/g remained (74.96% retention), with only a very small average capacity decay of 0.056%. The excellent reversibility and stability of the novel sulfur cathode can be attributed to the ability of the boron-doped microporous carbon host to both physically confine polysulfides and chemically bind these species on the host surface. Theoretical calculations confirm that boron-doped carbon is capable of significantly stronger interactions with the polysulfide species than undoped carbon, most likely as a result of the lower electronegativity of boron. We believe that this doping strategy can be extended to other metal-air batteries and fuel cells, and that it has promising potential for many different applications.

The recently discovered self-heating lithium-ion battery structure provided a practical solution to the poor performance at subzero temperatures that has hampered battery technology for decades. Here we report an improved self-heating lithium-ion battery (SHLB) that heats from −20 °C to 0 °C in 12.5 seconds, or 56% more rapidly, while consuming 24% less energy than that reported previously. We reveal that a nickel foil heating element embedded inside a SHLB cell plays a dominant role in self-heating and we experimentally demonstrate that a 2-sheet design can achieve dramatically accelerated self-heating due to more uniform internal temperature distribution. We also report, for the first time, that this embedded nickel foil can simultaneously perform as an internal temperature sensor (ITS) due to the perfectly linear relationship between the foil’s electrical resistance and temperature.

The recently discovered self-heating lithium ion battery has shown rapid self-heating from subzero temperatures and superior power thereafter, delivering a practical solution to poor battery performance at low temperatures. Here, we describe and validate an electrochemical-thermal coupled model developed specifically for computational design and improvement of the self-heating Li-ion battery (SHLB) where nickel foils are embedded in its structure. Predicting internal cell characteristics, such as current, temperature and Li-concentration distributions, the model is used to discover key design factors affecting the time and energy needed for self-heating and to explore advanced cell designs with the highest self-heating efficiency. It is found that ohmic heat generated in the nickel foil accounts for the majority of internal heat generation, resulting in a large internal temperature gradient from the nickel foil toward the outer cell surface. The large through-plane temperature gradient leads to highly non-uniform current distribution, and more importantly, is found to be the decisive factor affecting the heating time and energy consumption. A multi-sheet cell design is thus proposed and demonstrated to substantially minimize the temperature gradient, achieving 30% more rapid self-heating with 27% less energy consumption than those reported in the literature.

Ni-based superalloys are used as turbine blade material in which creep-fatigue is an important damage mechanism. Simulation and experiment methods are used to investigate and predicte the failure mechanism of the first stage high pressure turbine blades of an aeroengine after 600 hours service. The high pressure turbine blades were made of Ni-base superalloy DZ4, fabricated by DS investment casting. The largest stress point was obtained by finite element analysis. During the fatigue test, the high temperature and low cycle fatigue/creep load simulating the real working condition were applied on the blades until they fractured. And then several examinations were carried out to identify the fracture’s main cause, such as visual examination, SEM fractography and microstructural characterization. In conclusion, the fracture of the high pressure turbine blades was mainly caused by the interaction of the fatigue and creep. Besides, the oxidation accelerated the blades fracture.

Mechanical breakdown of graphite materials due to diffusion-induced stress (DIS) is a key aging mechanism of lithium-ion batteries. In this work, electrochemical-thermal coupled model along with a DIS model is developed to study the DIS distribution across the anode thickness. Special attention is paid to the evolution behavior of surface tangential stress (STS) in the discharge process for graphite at different locations of the anode. For the first time, we report that the evolution of STS, as well as local current, at all locations of the anode, evolve like sinusoidal waves in the discharge process with several crests and troughs. The staging behavior of graphite active material, in particular the sharp change of open-circuit potential (OCP) of graphite in the region between two plateaus, is found to be the root cause for the sinusoidal patterns of current and stress evolution. Furthermore, the effects of various parameters, such as starting state of charge, discharge C-rate and electrode thickness on the current and stress evolutions are investigated.

Hybrid electric vehicles (HEVs) have become increasingly popular due to their high fuel economy performance. HEVs typically fall into three categories according to their powertrain configuration, namely serial, parallel, and power-split hybrid. All these configurations use small internal combustion engines (ICEs), which can suffer from high torque fluctuations detrimental for noise, vibration and harshness performance. This paper introduces a novel architecture of hybrid electric powertrain systems (patent pending) which suppresses torque fluctuations and carries out the functionality of hybrid driving. This new hybrid architecture conceptually lies between a serial and a power-split. The new system uses an ICE and two electric machines, including one with a rotating stator, and has the functionalities of existing hybrid powertrains, including transmission, boost, regenerative braking. The paper presents a model for this new powertrain, and a unique controller implemented in MATLAB Simulink®. A specially designed ruled-based multi-state controller is included in the model to achieve control and enhance fuel economy. Results of drive cycle simulations show the systems performance including torque fluctuation suppression and great fuel economy.

Objectives Partial androgen deficiency of the aging male (PADAM) is characterised by a deficiency in serum androgen levels. Both electroacupuncture (EA) and mild moxibustion (MM) can raise serum testosterone levels in PADAM. We investigated the mechanisms underlying the use of EA and MM in a rodent model of PADAM. Methods Fifty rats received cyclophosphamide injection over 5 consecutive days to induce PADAM, which was verified by comparing total testosterone (TT) and free testosterone (FT) levels with 10 non-PADAM healthy control rats (CON). Successful modelling was confirmed in 43 of 50 rats, 40 of which were randomly divided into untreated (PADAM), EA-treated (PADAM+EA), MM-treated (PADAM+MM), and androlin (AD)-treated (PADAM+AD) groups (n=10 each). EA and MM were administered at BL23 and CV4 acupuncture points for 8 weeks, and no treatment was given to rats in the PADAM and CON groups. Serum levels of luteinising hormone (LH) and follicle-stimulating hormone (FSH), mRNA expression of cytochrome P450c17 (P450c17) and 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1), and protein levels of cytochrome P450 side chain cleavage (P450scc), 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) and steroidogenic factor 1 (SF-1) were evaluated after 8 weeks. Results Both EA and mild MM significantly increased serum TT and FT levels with MM displaying superiority. P450scc, 17β-HSD3 and SF-1 protein expression, and P450c17 and 3β-HSD1 mRNA expression, were significantly increased and serum LH and FSH levels were significantly decreased in PADAM+EA and PADAM+MM relative to PADAM rats. Moreover, serum LH and FSH levels were significantly lower and 17β-HSD3 protein expression significantly higher in PADAM+MM relative to PADAM+EA rats. Conclusions EA and MM at the BL23 and CV4 acupuncture points appear to be effective treatments for PADAM, and MM displays superior efficacy to EA.

Lithium-ion batteries suffer severe power loss at temperatures below zero degrees Celsius, limiting their use in applications such as electric cars in cold climates and high-altitude drones. The practical consequences of such power loss are the need for larger, more expensive battery packs to perform engine cold cranking, slow charging in cold weather, restricted regenerative braking, and reduction of vehicle cruise range by as much as 40 per cent. Previous attempts to improve the low-temperature performance of lithium-ion batteries have focused on developing additives to improve the low-temperature behaviour of electrolytes, and on externally heating and insulating the cells. Here we report a lithium-ion battery structure, the 'all-climate battery' cell, that heats itself up from below zero degrees Celsius without requiring external heating devices or electrolyte additives. The self-heating mechanism creates an electrochemical interface that is favourable for high discharge/charge power. We show that the internal warm-up of such a cell to zero degrees Celsius occurs within 20 seconds at minus 20 degrees Celsius and within 30 seconds at minus 30 degrees Celsius, consuming only 3.8 per cent and 5.5 per cent of cell capacity, respectively. The self-heated all-climate battery cell yields a discharge/regeneration power of 1,061/1,425 watts per kilogram at a 50 per cent state of charge and at minus 30 degrees Celsius, delivering 6.4-12.3 times the power of state-of-the-art lithium-ion cells. We expect the all-climate battery to enable engine stop-start technology capable of saving 5-10 per cent of the fuel for 80 million new vehicles manufactured every year. Given that only a small fraction of the battery energy is used for self-heating, we envisage that the all-climate battery cell may also prove useful for plug-in electric vehicles, robotics and space exploration applications.