The response of roots and the rhizosphere environment to integrative cultivation practices in paddy rice

Integrative cultivation practices(ICPs)are essential for enhancing cereal yield and resource use efficiency.However,the effects of ICP on the rhizosphere environment and roots of paddy rice are still poorly understood.In this study,four rice varieties were produced in the field.Each variety was treated with six different cultivation techniques,including zero nitrogen application(0 N),local farmers’practice(LFP),nitrogen reduction(NR),and three progressive ICP techniques comprised of enhanced fertilizer N practice and increased plant density(ICP1),a treatment similar to ICP1 but with alternate wetting and moderate drying instead of continuous flooding(ICP2),and the same practices as ICP2 with the application of organic fertilizer(ICP3).The ICPs had greater grain production and nitrogen use efficiency than the other three methods.Root length,dry weight,root diameter,activity of root oxidation,root bleeding rate,zeatin and zeatin riboside compositions,and total organic acids in root exudates were elevated with the introduction of the successive cultivation practices.ICPs enhanced nitrate nitrogen,the activities of urease and invertase,and the diversity of microbes(bacteria)in rhizosphere and non-rhizosphere soil,while reducing the ammonium nitrogen content.The nutrient contents(ammonium nitrogen,total nitrogen,total potassium,total phosphorus,nitrate,and available phosphorus)and urease activity in rhizosphere soil were reduced in all treatments in comparison with the non-rhizosphere soil,but the invertase activity and bacterial diversity were greater.The main root morphology and physiology,and the ammonium nitrogen contents in rhizosphere soil at the primary stages were closely correlated with grain yield and internal nitrogen use efficiency.These findings suggest that the coordinated enhancement of the root system and the environment of the rhizosphere under integrative cultivation approaches may lead to higher rice production.

基于信道短化和圆球译码的水声通信迭代序列检测

The demand for high-data-rate underwater acoustic communications(UACs)in marine development is increasing;however,severe multipaths make demodulation a challenge.The decision feedback equalizer(DFE)is one of the most popular equalizers in UAC;however,it is not the optimal algorithm.Although maximum likelihood sequence estimation(MLSE)is the optimal algorithm,its complexity increases exponentially with the number of channel taps,making it challenging to apply to UAC.Therefore,this paper proposes a complexity-reduced MLSE to improve the bit error rate(BER)performance in multipath channels.In the proposed algorithm,the original channel is first shortened using a channel-shortening method,and several dominant channel taps are selected for MLSE.Subsequently,sphere decoding(SD)is performed in the following MLSE.Iterations are applied to eliminate inter-symbol interference caused by weak channel taps.The simulation and sea experiment demonstrate the superiority of the proposed algorithm.The simulation results show that channel shortening combined with SD can drastically reduce computational complexity,and iterative SD performs better than DFE based on recursive least squares(RLS-DFE),DFE based on improved proportionate normalized least mean squares(IPNLMS-DFE),and channel estimation-based DFE(CE-DFE).Moreover,the sea experimental results at Zhairuoshan Island in Zhoushan show that the proposed receiver scheme has improved BER performance over RLSDFE,IPNLMS-DFE,and CE-DFE.Compared with the RLS-DFE,the BER,after five iterations,is reduced from 0.0076 to 0.0037 in the 8–12 k Hz band and from 0.1516 to 0.1145 in the 13–17 k Hz band at a distance of 2000 m.Thus,the proposed algorithm makes it possible to apply MLSE in UAC in practical scenarios.

Single-electron transport in H_(2)O@C_(60) single-molecule transistors

Single-molecule transistors(SMTs) based on fullerenes and their derivatives have been recognized as a long-sought platform for studying the single-electron transport properties.H_(2)O@C_(60) is a combination of fullerene and H_(2)O,a typical light molecule.Here we use the 'molecular surgery' technique to synthesize the H_(2)O@C_(60) molecule and then construct the H_(2)O@C_(60) SMTs,together with the C_(60) SMTs.Evidences for single-electron transport have been obtained in our measurements,including explicit Coulomb blockade and Coulomb oscillations.We then calculate the detailed parameters of the H_(2)O@C_(60) and C_(60) SMTs using a capacitance model derived from the Coulomb diamond feature,which gives a capacitance ratio of 1:5.05:8.52 for the H_(2)O@C_(60) SMT and 1:29.5:74.8 for the C_(60) SMT.Moreover,the gate efficiency factor a turns out to be 0.0686 in the H_(2)O@C_(60) SMT,about ten times larger than that in the C_(60) SMT.We propose that the enhanced gate efficiency in H_(2)O@C_(60) SMT may be induced by the closer attachment of molecular orbital electron clouds to the gate substrate due to polarization effects of H_(2)O.

Electrical spin polarization through spin-momentum locking in topological-insulator nanostructures

Recently, spin-momentum-locked topological surface states（SSs） have attracted significant attention in spintronics.Owing to spin-momentum locking, the direction of the spin is locked at right angles with respect to the carrier momentum.In this paper, we briefly review the exotic transport properties induced by topological SSs in topological-insulator（TI）nanostructures, which have larger surface-to-volume ratios than those of bulk TI materials. We discuss the electrical spin generation in TIs and its effect on the transport properties. A current flow can generate a pure in-plane spin polarization on the surface, leading to a current-direction-dependent magnetoresistance in spin valve devices based on TI nanostructures.A relative momentum shift of two coupled topological SSs also generates net spin polarization and induces an in-plane anisotropic negative magnetoresistance. Therefore, the spin-momentum locking can enable the broad tuning of the spin transport properties of topological devices for spintronic applications.

Effect of body mass index on the operation time and postoperative hospital stay of retroperitoneal laparoscopic renal cyst decortication

Objective:To investigate the effect of body mass index(BMI)on the operation time and postoperative hospital stay for patients who underwent retroperitoneal laparoscopic decortication for a single simple renal cyst.Methods:A retrospective cohort study was conducted among 81 patients with single simple renal cyst who had undergone retroperitoneal laparoscopic cyst decortication from January 2017 to December 2019 in Wuxi Xishan People's Hospital.All patients were divided into three groups according to BMI:normal group(BMI<25 kg/m^(2),n=44),overweight group(BMI=25-30 kg/m^(2),n=21),and obese group(BMI>30 kg/m^(2),n=16).Multiple linear regression was conducted to investigate the correlation.Results:The three groups were comparable in terms of age,gender,maximum diameter of cyst,and cyst location.In the aspect of operation time,only the patients in obese group had longer duration when compared with those in the normal group(59.1±15.7 min vs.45.2±12.8 min,p=0.001).And the patients in the obese group had significantly longer hospital stay compared with those in the normal group(6.2±1.9 d vs.5.2±0.5 d,p=0.002)and overweight group(6.2±1.9 d vs.5.0±1.0d,p=0.001).In the analysis of multiple linear regression,it was found that operation time is significantly affected by BMI and location 2,with coefficients of 1.299 and -8.646 respectively.The influence of BMI was greater than location 2(0.335 vs.-0.289).For hospital stay,only BMI had an effect on it,with a coefficient of 0.110.Conclusion:BMI was a major factor that associated with longer operation time and hospital stay in patients with retroperitoneal laparoscopic renal cyst decortication.

Pyrochlore-based high-entropy ceramics for capacitive energy storage

High-performance dielectrics are widely used in high-power systems,electric vehicles,and aerospace,as key materials for capacitor devices.Such application scenarios under these extreme conditions require ultra-high stability and reliability of the dielectrics.Herein,a novel pyrochlore component with high-entropy design of Bi1.5Zn_(0.75)Mg_(0.25)Nb_(0.75)Ta_(0.75)O_(7)(BZMNT)bulk endows an excellent energy storage performance of Wrec≈2.72 J/cm3 together with an ultra-high energy efficiency of 91%at a significant enhanced electric field Eb of 650 kV/cm.Meanwhile,the temperature coefficient(TCC)of BZMNT(~−220 ppm/℃)is also found to be greatly improved compared with that of the pure Bi1.5ZnNb1.5O7(BZN)(~−300 ppm/℃),demonstrating its potential application in temperature-reliable conditions.The high-entropy design results in lattice distortion that contributes to the polarization,while the retardation effect results in a reduction of grain size to submicron scale which enhances the Eb.The high-entropy design provides a new strategy for improving the high energy storage performance of ceramic materials.

Finite-element analysis for surface discharge on polyimide insulation in air at atmospheric pressure under pulsed electrical stress

A surface discharge non-equilibrium plasma model of air–polyimide under pulsed electrical stress is established, byconsidering the reaction of charged particles on the dielectric surface and the secondary electron emission caused by thecondition that high-energy particles bombard the material surface. The model defines the chemical reaction of air discharge byusing simplified set of reactions, which greatly reduces the complexity of the model. To avoid the negative value of particledensity in the process of solution, the logarithmic finite-element method is used to solve the model established, so as toimplement the dynamic simulation of the surface discharge process. Also, the temporal and spatial evolution of themicroparameters such as charge and electric field distribution during discharge are obtained, and the reliability of the model isverified by experiments in terms of discharge development pattern and surface charge accumulation. By comparing thedevelopment process of surface discharge under single pulse and repetitive pulses, it can be seen that surface dischargedevelops from needle electrode to ground electrode under both repetitive pulses and single pulse stress, but the relationshipbetween the discharge propagation time under repetitive pulses and pulse repetition rate is a ‘u’ curve, and the inflection pointmoves to higher repetition rate region with the increase of voltage.

Micro‐mechanism study on synergistic degradation of the oil‐paper insulation with dibenzyl disulfide,hexadecyl mercaptan and benzothiophene

In recent years,there have been many cases of transformer failures caused by corrosive sulfides.At present,research mainly focuses on the single sulfide dibenzyl disulphide,but few research on multiple sulphur or the oil‐paper hybrid insulation.In this study,three typical sulfides dibenzyl disulfide,hexadecyl mercaptan and benzothiophene were selected to form seven sulfide‐oil‐paper models.Then relaxation calculations were carried out,and through molecular dynamics simulation,the synergistic effect of different sulfides on the properties of insulating paper and insulating oil was discussed.Results show that the coexistence of the three sulfides has the most severe weakening on the mechanical properties of cellulose,and it also causes great damage to hydrogen bonds.Hexadecyl mercaptan has a weaker effect on hydrogen bond destruction,but it will greatly aggravate the cellulose chain movement.The viscosity of insulating oil is generally increased by the influence of sulfide.Hexadecyl mercaptan is the main factor affecting the viscosity.Thiophene has little effect on the viscosity,ctive protection technology on sulphur corrosion.

伴腹膜后浆细胞瘤的多发性骨髓瘤一例

患者女性,72岁,因"体检行CT检查发现左肾上腺区肿物1周"于2020年6月9日入院。患者1周前体检行胸部CT检查,发现左肾上腺区占位(31 mm×23 mm);平素无头痛头晕,无视物模糊,无胸闷气急,无恶心呕吐,无腹痛腹泻,无四肢乏力。既往有高血压病史,血压控制平稳。查体无明显异常。

Transport evidence of 3D topological nodal-line semimetal phase in ZrSiS

Topological nodal-line semimetal is a new emerging material, which is viewed as a three-dimensional （3D） analog of graphene with the conduction and valence bands crossing at Dirac nodes, resulting in a range of exotic transport properties. Herein, we report on the direct quantum transport evidence of the 3D topological nodal-line semimetal phase of ZrSiS with angular-dependent magnetoresistance （MR） and the combined de Hass-van Alphen （dHvA） and Shubnikov-de Hass （SdH） oscillations. Through fitting by a two-band model, the MR results demonstrate high topological nodal-line fermion densities of approximately 6 × 10^21 cm^-3 and a perfect electron/hole compensation ratio of 0.94, which is consis- tent with the semi-classical expression fitting of Hall conductance Gxy and the theoretical calculation. Both the SdH and dHvA oscillations provide clear evidence of 3D topological nodal-line semimetal characteristic.