定向 定点 定练--浅谈习作单元教学读写融和教学策略

统编教材从三年级开始,每个学期都安排了一个习作单元,六个板块紧紧围绕单元习作能力训练“点”,前后勾连、层层推进、“读写融和”,形成严谨的习作训练体系链。在教学时,要围绕语文要素明确方向,精准定位读写目标,找准适切的读写融和点,进行有层次、有梯度的系统的读写融和实践训练,这样才能使语文习作要素真正落地,切实提高学生的习作能力。

Golay Pair Aided Timing Synchronization Algorithm for Distributed MIMO-OFDM System

In order to solve the problem of inaccurate synchronization for distributed multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) system in both multipath and low signal to noise ratio(SNR) channels, a golay pair aided timing synchronization(GPATS) method is proposed in this paper. A new synchronous training sequence based on the golay pair with guard interval is designed in GPATS method. By utilizing the unique properties of the new training sequence, the different timing point and the inter-transmitter delays(ITD) are obtained at the receiver. Simulation results show that, compared with the traditional synchronization approaches, the proposed algorithm can provide high accuracy in detecting different time offsets caused by the distributed transmitters of the MIMO-OFDM system, especially over multipath and low SNR channels.

Effects of core stability exercise on rehabilitation in stroke patients with hemiplegia： a meta-analysis

Objective： To evaluate the effects of core stability exercise （CST） on rehabilitation in stroke patients with hemiplegia. Methods： Randomly controlled trials about the effects of CST on rehabilitation in stroke patients with hemiplegia were searched in the database, including PubMed, Embase, Web of Science, Cochrane Library, CNKI, Wanfang, CBM and VIP. Search terms include “core stability training / core stability exercise / core stabilization training / core stabilization exercise/ core strength training / core strength exercise” and “stroke / brain ischemia / cerebral infarction / cerebral hemorrhage / intracranial thrombosis / brain hemorrhage / cerebrovascular disorder /cerebrovascular accident, cerebrovascular disease / hemiplegia / hemiparesis/ stroke rehabilitation”. Study screening, data extraction and quality assessment were conducted by two researchers independently. Data was analyzed using RevMan 5.3 software. Results： Totally 11 studies and 704 patients were included with 352 patients in experiment group and 352 in control group. Results of meta-analysis showed that combination of CST and conventional rehabilitation had better effects on trunk control [MD = 10.44, 95% CI （8.83-12.04）, P 〈 0.001], banlace [MD = 5.6, 95% CI （4.81-6.39）, P 〈 0.001], activities of daily living [MD = 12.06, 95% CI （7.65-16.46）, P 〈 0.001], ambulation functional [MD = 0.72, 95% CI （0.32-1.12）, P 〈 0.001] and walking speed [MD = 3.39, 95% CI （2.03-4.76）, P 〈 0.001] than conventional rehabilitation, but there is no clear difference on walking stride [MD = 2.52, 95% CI （-0.25-5.29）, P = 0.07] between two groups. Conclusion： CST together with conventional rehabilitation can better improve trunk control, banlace, activities of daily living, ambulation functional and walking speed in stroke patients compared with conventional rehabilitation, but can not make the walking stride better significantly. However, since the conclusion of this meta-analysis was drawn based on middle quality RCTs, future high quality researchs should be conducted to confirm its positive intervention effects.

Athletes who train on unstable compared to stable surfaces exhibit unique postural control strategies in response to balance perturbations

Background:Athletes have been shown to exhibit better balance compared to non-athletes(NON).However,few studies have investigated how the surface on which athletes train affects the strategies adopted to maintain balance.Two distinct athlete groups who experience different types of sport-specific balance training are stable surface athletes(SSA) such as basketball players and those who train on unstable surfaces(USA) such as surfers.The purpose of this study was to investigate the effects of training surface on dynamic balance in athletes compared to NON.Methods:Eight NON,eight SSA,and eight USA performed five 20-s trials in each of five experimental conditions including a static condition and four dynamic conditions in which the support surface translated in the anteroposterior(AP) or mediolateral(ML) planes using positive or negative feedback paradigms.Approximate entropy(Ap En) and root mean square distance(RMS) of the center of pressure(Co P) were calculated for the AP and ML directions.Four 3 × 5(group × condition) repeated measures ANOVAs were used to determine significant effects of group and condition on variables of interest.Results:USA exhibited smaller Ap En values than SSA in the AP signals while no significant differences were observed in the ML Co P signals.Generally,the negative feedback conditions were associated with significantly greater RMS values than the positive feedback conditions.Conclusion:USA exhibit unique postural strategies compared to SSA.These unique strategies seemingly exhibit a direction-specific attribute and may be associated with divergent motor control strategies.