Response optimization of a three-axis sensitive SERF magnetometer for closed-loop operation

Most triaxial-vectorial magnetic field measurements with spin-exchange relaxation free(SERF)atomic magnetometer(AM)are based on the quasi-steady-state solution of the Bloch equation.However,the responding speed of these methods is greatly limited because the frequency of the modulation signal should be slow enough to ensure the validity of the quasi-steady-state solution.In this work,a new model to describe the response of the three-axis sensitive SERF AM with high modulation frequency is presented and verified.The response of alkali-atomic spin to high-frequency modulation field is further investigated by solving the Bloch equation in a modulation-frequency-dependence manner.This solution is well verified by our experiments and can offer a reference for selection of modulation frequencies.The result shows a potential to achieve a SERF AM operating in a geomagnetic field without heavy aluminum shielding when the modulation frequencies are selected properly.

Prokaryotic diversity and community composition in the surface sediments of the Changjiang River Estuary in summer

Microorganisms are fundamental for the functioning of marine ecosystems and are involved in the decomposition of organic matter, transformation of nutrients and circulation of biologically-important chemicals. Based on the complexity of the natural geographic characteristics of the Changjiang River Estuary, the geographic distribution of sedimentary microorganisms and the causes of this distribution are largely unexplored. In this work, the surface sediment samples from the adjacent sea area of the Changjiang River Estuary were collected. Their prokaryotic diversity was examined by high-throughput sequencing technology, and the environmental factors of the bacterial community were investigated. The results indicated that the distribution of prokaryotic communities in the sediments of the study areas showed obvious spatial heterogeneity. The sampling sequences divided the sample regions into three distinct clusters. Each geographic region had a unique community structure, although Proteobacteria, Bacteroidota, Desulfobacterota, Acidobacteriota, and Actinobacteriota all existed in these three branches. Canonical correspondence analysis demonstrated that prokaryotic diversity and community distribution were significantly correlated with the geographic location of sediment, seawater depth, and in particular, nutrient content(e.g., total phosphorus, total organic carbon and dissolved oxygen). Moreover, it was found for the first time that the metal ions obviously affected the composition and distribution of the prokaryotic community in this area. In general, this work provides new insights into the structural characteristics and driving factors of prokaryotic communities under the background of the ever-changing Changjiang River Estuary.

Workability and Durability of Concrete Incorporating Waste Tire Rubber:A Review

Environmental problems caused by waste tires are becoming increasingly prominent.There is an urgent need to find a green way to dispose of waste tires,and scholars have made considerable efforts in this regard.In the construction industry,rubber extracted from waste tires can be added to concrete to alleviate environmental problems to a certain extent.As a new building material,rubber concrete has superior properties compared to ordinary concrete and has been widely used in many fields.Numerous studies have been conducted worldwide to investigate the effect of waste tire rubber on the performance of concrete.It has been reported that the addition of waste tire rubber has a significant influence on the performance of concrete.Workability influences the hardened performance of rubber concrete,especially the durability.Based on the current research results,the workability and durability of concrete manufactured with waste tire rubber,including water absorption and permeability,carbonation resistance,chloride ion permeability resistance,and freeze-thaw resistance,are summarized in this paper.It is concluded that the addition of waste tires has a negative effect on the workability of concrete.In terms of durability,concrete exhibits better chloride ion penetration resistance and frost resistance,with a higher water absorption rate,and lower anti-permeability and carbonation resistance owing to the addition of waste tire rubber.

Development of a Regional Regression Model for Estimating Annual Runoff in the Hailar River Basin of China

The Hailar River, a first-grade tributary of the Erguna River that borders China and Russia, is the main water source for the local industry and agriculture. However, because there are only 11 flow gauging stations and those stations cannot monitor all runoff paths, it is hard to directly use the existing flow data to estimate the annual runoffs from all subbasins of interest although such estimation is needed for utilization and protection of the water resources in the Hailar River. Thus, this study implemented an indirect approach (i.e., regional regression model) by correlating annual runoff with annual rainfall and water surface evaporation as well as hydrologic characteristics of the 11 subbasins monitored by the gauging stations. The study used 51 years (from 1956 to 2006) data. The results indicated a significant correlation (R2 > 0.87) between annual runoff and the selected subbasin characteristics and showed the model to be robust because the predicted runoffs for the validation period are compatible with the corresponding observed values. In addition, this model was used to estimate the annual runoffs for the subbasins that are not monitored by the 11 flow gauging stations, which adds new information to existing literature.

Influences of landform as a confounding variable on SOM-NDVI association in semiarid Ordos Plateau

Soil organic matter （SOM） plays an important role in maintaining vegetation cover and thus mitigating land erosion of fragile terrestrial ecosystems such as in the Northern Ordos Plateau of China （NOPC）. However, little information is available on whether and how SOM varies spatially as an intrinsic characteristic of landform in NOPC. The objective of this study was to examine the spatial associations of SOM with landform and vegetation cover. The study was conducted in a 23,000-km2 area within NOPC because this area has landforms of mobile dunes （MD）, flat dunes （FD）, grassy sandy land （GSL）, flat sandy bedrocks （FSB）, and swamps and salt lakes （SW）, which are typical landforms in semiarid ecosystems. SOM was determined using a standard laboratory analysis method for 5 cm topsoil samples collected at 72 locations across the study area. In addition, the 250 m Multitem- poral Moderate Resolution Imaging Spectroradiometer （MODIS） imageries taken in the period from August 2006 to August 2010 were used to extract Normalized Difference Vegetation Index （NDVI） which in turn was used as the surrogate of vegetation cover. Classic and geostatistical methods were used to compare SOM concentration across different landforms. The results indicated that an area with a greater value for NDVI （i.e. better vegetation cover） tended to have a higher SOM concentration regardless of the landform types. However, the association between SOM and NDVI varied from one landform to another. The SW and GSL had a highest SOM concentration, while MD had a lowest concentration. For the study area as a whole and the FD, GSL, and MD, SOM was found to be the sole function of NDVI, whereas, for the FSB, SOM was influenced by several intrinsic variables, namely ground surface altitude, slope, and aspect, as well as NDVI. SOM for the SW landform was found to be a function of NDVI. Furthermore, SOM and NDVI exhibited a consistent spatial pattern of increasing from north to south and from west to east. The highest SOM concentration of 3.5% occurred along an east-westward belt, which is adjacent to water pathways, in the mid part of the study area.

Inductive effect of hydroxyl safflower yellow-A on apoptosis in abnormal HUVEC via the mitochondrial pathway

Objective:To investigate the mechanism by which hydroxyl safflower yellow A,an active component of safflower (Carthamus tinctorius L.),promotes apoptosis in abnormal human umbilical vein endothelial cells (HUVECs).Methods:Supernatant of BGC-823 was used to stimulate HUVECs to establish a model of abnormal proliferation of HUVECs.After determining an ideal concentration of HSYA by MTT assay,apoptosis was detected with flow cytometry and TUNEL assay.Mechanism of apoptosis was assessed using quantitative real-time polymerase chain reaction,Western blot,and ELISA.Results:A range of concentrations of HSYA inhibited proliferation and promoted apoptosis of abnormal HUVECs.As the rate of apoptosis increased,mRNA expression of caspase-3 increased while expression of mutant p53 decreased.HSYA had no effect on Fas gene expression.Analogously,protein expression of Bax was increased while those of Bcl-2,Fas,and Fas-L were decreased.Conclusions:HSYA appears to induce apoptosis of HUVECs with the stimulation of the supematant of tumor cells.The mechanism of apoptosis by HSYA may involve activation of the mitochondrial apoptotic pathway and regulation of the expressions of Bcl-2,Bax,and p53.

Fibroadenoma of the Ectopic Axillary Breast Tissue: Sonographic Appearances

Ectopic breast tissue is reported to occur in 0.4% - 6% of women. Breast neoplasms may develop in ectopic breast tissue, as in eutopic breast tissue. The most frequent condition in ectopic breast is breast cancer. Fibroadenomas of ectopic breast tissue have been reported, but are rare. We report two cases of fibroadenomas of ectopic axillary breast tissues. The sonographic appearance of the nodules was spherical and hypoechoic. We found the component of breast tissue near the nodule. It is important to diagnose fibroadenomas of ectopic breast tissue before a histologic examination.

“Real People” is the Core View of the Materialization of the Object of Patriotic Education

The object of patriotism education is the people,who are the creators of the spirit of patriotism and constantly add new connotations to it.Historical activities are the activities of the masses,with the deepening of historical activities,it will be the expansion of the masses.Patriotism education is an important part of ideological and political education activities,and it is the stage that cannot be crossed to realize the real community.

Synthesis of amorphous Pd-based nanocatalysts for efficient alcoholysis of styrene oxide and electrochemical hydrogen evolution

Amorphous nanomaterials with long-range disordered structures could possess distinct properties and promising applications,especially in catalysis,as compared with their conventional crystalline counterparts.It is imperative to achieve the controlled preparation of amorphous noble metal-based nanomaterials for the exploration of their phase-dependent applications.Here,we report a facile wet-chemical reduction strategy to synthesize various amorphous multimetallic Pd-based nanomaterials,including PdRu,PdRh,and PdRuRh.The phase-dependent catalytic performances of distinct Pd-based nanomaterials towards diverse catalytic applications have been demonstrated.Specifically,the usage of PdRu nanocatalysts with amorphous and crystalline face-centered cubic(fcc)phases can efficiently switch the ring-opening route of styrene oxide to obtain different products with high selectivity through alcoholysis reaction and hydrogenation reaction,respectively.Moreover,when used as an electrocatalyst for hydrogen evolution reaction(HER),the synthesized amorphous PdRh nanocatalyst exhibits low overpotential and high turnover frequency values,outperforming its crystalline fcc counterpart and most of the reported Pd-based HER electrocatalysts.

A real-world study of immune checkpoint inhibitors in advanced triple-negative breast cancer

Background:Triple-negative breast cancer(TNBC)is the most aggressive type of breast cancer.Immune checkpoint inhibitors(ICIs)have been widely used to treat various tumors and have changed the landscape of tumor management,but the data from real-world studies of ICIs for TNBC treatment remain limited.The aim of this study was to evaluate the efficacy of ICIs in the treatment of patients with advanced TNBC in a real-world setting and to explore possible correlates.Methods:The clinical data of advanced TNBC patients who received ICI treatment in the Chinese People's Liberation Army(PLA)General Hospital were collected.Treatment responses,outcomes and adverse events(AEs)were assessed.Results:Eighty-one patients were included in the study.The confirmed objective response rate(ORR)was 32.1%,and the disease control rate(DCR)was 64.2%.The median progression-free survival(PFS)was 4.2 months,and the median overall survival(OS)was 11.0 months.PFS and OS were longer in patients who achieved clinical benefit from ICIs and shorter in patients who received later-line ICIs and higher levels of inflammation;specifically,patients with higher TILs had longer PFS.Overall AEs were tolerable.Conclusions:ICIs are effective in the treatment of advanced TNBC,and the adverse reactions are tolerable.A panel of biomarkers including LDH,ALP,and bNLR were identified to predict the efficacies of ICIs in TNBC treatment.

煤与高岭石表面性质对凝聚过程的影响机制

煤泥水中含大量高岭石等黏土矿物,为其絮凝沉降带来较大的困难。为明确矿物性质对凝聚过程的影响机制,在应用扩展的DLVO理论计算煤和高岭石颗粒间作用力的基础上,采用聚焦光束反射测量仪监测了CaCl2用量为4.50 mmol/L时20 g/L的煤和高岭石的悬浮液在60,100和150 r/min的搅拌转速下的凝聚过程。结果表明,颗粒间的静电作用力在颗粒表面间距2~200 nm范围内起主导作用,高岭石的电负性较大,在凝聚过程中更难发生靠近和碰撞;较高的转速可为颗粒提供较大的动量,有利于提高碰撞频率,缩短完成凝聚所需时间,实验条件下,煤和高岭石的凝聚时间分别由74和123 s缩短至47和89 s。疏水性作用力在颗粒表面间距小于2 nm的范围内起主导作用,决定了颗粒的黏附效率;煤因强疏水性,在碰撞后更易黏附,且能抵抗更高的流体剪切作用,可由19.32μm凝聚形成100μm的大凝聚体,而高岭石则因其亲水性难以得到较大粒度的凝聚体,均小于30μm。

长链脂肪族二元酸的合成及其在缩聚反应中的应用

长链脂肪族二元酸一般是指含有10个或以上碳原子的饱和直链二元酸,其两端带有羧基官能团,可用于合成香料、特种尼龙工程塑料、热熔胶、涂料、增塑剂、高级润滑油等众多化工产品;由于其链段中含有长烷烃链段,具有优于短链二元酸的性质,使得相应的合成材料具有优越的性能,因此广泛应用于化工、轻工、国防、汽车工业、工程材料等领域;同时,还可用于开发新的聚合物产品。长链脂肪族二元酸在自然界中不单独存在,目前工业上主要通过化学合成法和生物发酵法生产。本文主要对长链脂肪族二元酸的合成方法进行综述,包括传统有机合成、生物技术转化、烯烃复分解、异构化-氢氧羰基化及聚乙烯端基功能化等,并简要概述长链脂肪族二元酸在缩聚反应(聚酯和聚酰胺)中的应用。最后,对合成方法待解决的问题进行了总结,并对未来发展方向进行了展望。

Confinedly implanted NiFe2O4-rGO： Cluster tailoring and highly tunable electromagnetic properties for selective-frequency microwave absorption

Lightweight and high-efficiency microwave absorption materials with tunable electromagnetic properties is a highly sought-after goal and a great challenge for researchers. In this work, a simple strategy of confinedly implanting small NiFe204 clusters on reduced graphene oxide is demonstrated, wherein the magnetic clusters are tailored, and more significantly, the electromagnetic properties are highly tuned. The microwave absorption was efficiently optimized yielding a maximum reflection loss of -58 dB and - 12 times broadening of the bandwidth （at -10 dB）. Furthermore, tailoring of the implanted magnetic clusters successfully realized the selective-frequency microwave absorption, and the absorption peak could shift from 4.6 to 16 GHz covering 72% of the measured frequency range. The fascinating performances eventuate from the appropriately tailored clusters, which provide optimal synergistic effects of the dielectric and magnetic loss caused by multi-relaxation, conductance, and resonances. These findings open new avenues for designing microwave absorption materials in future, and the well-tailored NiFe204-rGO can be readily applied as a multi-functional microwave absorption material in various fields ranging from civil and commerce to military and aerospace.

Preparation and performance analysis of Pt-IPMC for driving bionic tulip

Based on the biological characteristics of tulip,the low driving voltage and fast response of ionic polymer metal composite(IPMC),we analyzed the fabrication,morphology and performance of the platinum IPMC(Pt-IPMC)and selected the right IPMC for driving bionic tulip.The preparation and performance of IPMC was analyzed first in this paper such as blocking force,output displacement and bending angle of IPMC under the different directed current voltage(DC).The optimal IPMC sample size and driving voltage were selected based on tulip blooming angles and the strain energy density of IPMC,which completed the blooming process of bionic tulip.The feasibility of IPMC used in driving bionic field was fully proved in this paper,which laid a foundation for the application of IPMC in driving biomimetic biological robots.

Effects of hydrological and climatic variables on cyanobacterial blooms in four large shallow lakes fed by the Yangtze River

Shallow lakes,one of the most widespread water bodies in the world,are easily shifted to a new trophic state due to external interferences.Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms(CyanoHABs)in shallow lakes,which pose serious threats to ecological integrity and human health.This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes(Lake Dongting and Poyang)and isolated lakes(Lake Chao and Tai).The results show that(i)chlorophyll-a(Chl-a)concentration tends to decrease exponentially with increasing relative lake level fluctuations(RLLF)and precipitation,but to increase linearly with increasing wind speed and air temperature;(ii)Chl-a concentrations in lakes were significantly higher when RLLF<100,precipitation<2.6 mm,wind speed>2.6 ms^(-1),or air temperature>17.8℃;(iii)the Chl-a concentration of Yangtze-isolated lakes was more significantly affected by water level amplitude,precipitation,wind speed and air temperature than the Yangtze-connected lakes;(iv)the RLLF and the ratio of wind speed to mean water depth could be innovative coupling factors to examine variation characteristics of Chl-a in shallow lakes with greater correlation than single factors.