An efficient method for constructing a random insertional mutant library for forward genetics in Nannochloropsis oceanica

Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.

Enhancing Data Forwarding Efficiency in SIoT with Multidimensional Social Relations

Effective data communication is a crucial aspect of the Social Internet of Things(SIoT)and continues to be a significant research focus.This paper proposes a data forwarding algorithm based on Multidimensional Social Relations(MSRR)in SIoT to solve this problem.The proposed algorithm separates message forwarding into intra-and cross-community forwarding by analyzing interest traits and social connections among nodes.Three new metrics are defined:the intensity of node social relationships,node activity,and community connectivity.Within the community,messages are sent by determining which node is most similar to the sender by weighing the strength of social connections and node activity.When a node performs cross-community forwarding,the message is forwarded to the most reasonable relay community by measuring the node activity and the connection between communities.The proposed algorithm was compared to three existing routing algorithms in simulation experiments.Results indicate that the proposed algorithmsubstantially improves message delivery efficiency while lessening network overhead and enhancing connectivity and coordination in the SIoT context.

A fast forward computational method for nuclear measurement using volumetric detection constraints

Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation models.Among the various detection tools that use nuclear sources,the detector response can reflect various types of information of the medium.The Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex environments.However,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response results.Therefore,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is proposed.First,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo simulation.Then,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion model.The environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection volume.Finally,the method is applied to a neutron porosity tool for verification.In various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 p.u.In field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method.

Estimation of Displacement and Extension due to Reverse Drag of Normal Faults: Forward Method

In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. There are three sub-cases of basal detachment for the rigid body model: horizontal detachment, antithetic detachment and synthetic detachment. For the rigid body model, the established equations indicate that the total displacement on the synthetic base (Dt2) is the largest, that on the horizontal base (Dt1) is moderate, and that on the antithetic base (Dt3) is the smallest. On the other hand, the value of (Dt1) is larger than the displacement for the vertical shear (Dt4). The value of (Dt1) is larger than or less than the displacement for the inclined shear (Dt5) depending on the original fault dip δ0, bedding angle θ, and the angle of shear direction β. For all original parameters, the value of Dt5 is less than the value of Dt4. Also, by comparing three rotation mechanisms, we find that the inclined shear produces largest extension, the rigid body model with horizontal detachment produces the smallest extension, and the vertical shear model produces moderate extension.

Exploring the Relationship Between Patent Forward Citation and Stock Return Rate Using Empirical Data of China Stock Market

A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than two thousand of A-shares from 2017 to 2020 were selected.The effect of the traditional patent forward citation and the price-citation for discriminating the stock return rate was thoroughly analyzed via ANOVA.The A-shares of forward citation counts above the average showed higher stock return rate means than the A-shares having patents but receiving no forward citations.The price-citation,combining both the financial and patent attributes,defined as the multiplication of the current stock price and the currently receiving forward citation count,showed its excellence in discriminating the stock return rate.The A-shares of higher price-citation showed significantly higher stock return rate means while the A-shares of lower price-citation showed significantly lowest stock return rate means.The price-citation effect had not been changed by COVID-19 though COVID-19 affected the social and economic environment to a considerable extent in 2020.

Application Strategy of BIM Technology in the Forward Design of Bridges

Bridge engineering is highly specialized and has spatial characteristics,which puts forward higher requirements for design work.The advancement of information technology has provided ample tools to facilitate bridge design work,with building information modeling(BIM)technology being one of them.BIM technology ensures the efficiency and quality of the forward design of bridges,while also reducing construction costs.This article starts with defining the concept of BIM technology,followed by a discussion on its advantages in bridge design and application process,which serves as a reference for other bridge designers.

Forward stagewise regression with multilevel memristor for sparse coding

Sparse coding is a prevalent method for image inpainting and feature extraction,which can repair corrupted images or improve data processing efficiency,and has numerous applications in computer vision and signal processing.Recently,sev-eral memristor-based in-memory computing systems have been proposed to enhance the efficiency of sparse coding remark-ably.However,the variations and low precision of the devices will deteriorate the dictionary,causing inevitable degradation in the accuracy and reliability of the application.In this work,a digital-analog hybrid memristive sparse coding system is pro-posed utilizing a multilevel Pt/Al_(2)O_(3)/AlO_(x)/W memristor,which employs the forward stagewise regression algorithm:The approxi-mate cosine distance calculation is conducted in the analog part to speed up the computation,followed by high-precision coeffi-cient updates performed in the digital portion.We determine that four states of the aforementioned memristor are sufficient for the processing of natural images.Furthermore,through dynamic adjustment of the mapping ratio,the precision require-ment for the digit-to-analog converters can be reduced to 4 bits.Compared to the previous system,our system achieves higher image reconstruction quality of the 38 dB peak-signal-to-noise ratio.Moreover,in the context of image inpainting,images containing 50%missing pixels can be restored with a reconstruction error of 0.0424 root-mean-squared error.

威斯康星大学发展战略规划2020 Forward专项考察

基于美国威斯康星大学2020 Forward专项的考察结果显示:实施大学发展战略规划在价值逻辑层面呈现校园文化传统、绩效管理工具和危机应对方案三重意蕴;在行动要素层面有赖于目标体系、主体网络和保障机制的协同增效;在反馈闭环层面应形成“目标回溯-措施谋划-评价措施-行动成果-评估成效”的系统耦合。威斯康星2020 Forward的实践经验表明,战略思维、目标分解、全员参与和有效评估是大学发展战略规划精准落地、高效实施的四个关键原则。

3D forward modeling and response characteristics of low-resistivity overburden of the CFS-PML absorbing boundary for ground-well transient electromagnetic method

This study used the stable and convergent Dufort-Frankel method to differentially discretize the diffusion equation of the ground-well transient electromagnetic secondary field.The absorption boundary condition of complex frequency-shifted perfectly matched layer(CFS-PML)was used for truncation so that the low-frequency electromagnetic wave can be better absorbed at the model boundary.A typical three-dimensional(3D)homogeneous half-space model was established and a low-resistivity cube model was analyzed under the half-space condition.The response patterns and drivers of the low-resistivity cube model were discussed under the influence of a low-resistivity overburden.The absorption boundary conditions of CFS-PML significantly affected the low-frequency electromagnetic waves.For a low-resistivity cube around the borehole,its response curve exhibited a single-peak,and the extreme point of the curve corresponded to the center of the low-resistivity body.When the low-resistivity cube was directly below the borehole,the response curve showed three extreme values(two high and one low),with the low corresponding to the center of the low-resistivity body.The total field response of the low-resistivity overburden was stronger than that of the uniform half-space model due to the low-resistivity shielding effect of electromagnetic waves.When the receiving-transmitting distance gradually increased,the effect of the low-resistivity overburden was gradually weakened,and the response of the low-resistivity cube was strengthened.It was affected by the ratio of the overburden resistivity to the resistivity of the low-resistivity body.

THE REGULARIZED SOLUTION APPROXIMATION OF FORWARD/BACKWARD PROBLEMS FOR A FRACTIONAL PSEUDO-PARABOLIC EQUATION WITH RANDOM NOISE

This paper deals with the forward and backward problems for the nonlinear fractional pseudo-parabolic equation ut+(-Δ)^(s1)ut+β(-Δ)^(s2)u=F(u,x,t)subject o random Gaussian white noise for initial and final data.Under the suitable assumptions s1,s2andβ,we first show the ill-posedness of mild solutions for forward and backward problems in the sense of Hadamard,which are mainly driven by random noise.Moreover,we propose the Fourier truncation method for stabilizing the above ill-posed problems.We derive an error estimate between the exact solution and its regularized solution in an E‖·‖Hs22norm,and give some numerical examples illustrating the effect of above method.

Entry-Level Forward Surgical Team Training Is Associated with Increased Confidence of Primary Combat Surgeons

Background: In recent years, we have established an entry-level Forward Surgical Team (FST) training program in a Chinese military medical university for the 5th grade undergraduates, who would be deployed to different military medical services as primary combat surgeons. This study aimed to assess the role of this pre-service training in improving their confidence with combat medical skills, after several years since they received the training. Methods: We conducted a nationwide survey of 239 primary combat surgeons who have ever participated in an entry-level FST training program before deployment between June 2016 and June 2020, which was for evaluating on a 5-point Likert scale the benefits of entry-level FST training and conventional surgery training in improving their confidence with combat medical skills. The difference in scores was compared using the student t-test. Significance was considered as P Results: The total score was significantly higher for entry-level FST training than that for conventional surgery training (30.76 ± 4.33 vs. 28.95 ± 4.80, P There was no significant difference between the training for surgical skills confidence scores (18.03 ± 8.04 vs. 17.51 ± 8.30, P = 0.098), but for non-technical skills, the score of entry-level FST training was significantly higher than that of conventional surgery training (12.73 ± 5.39 vs. 11.44 ± 5.62, P The distributions of confidence scores were different under various subgroups by demographics. There were no significant differences in scores between the two training in all specific surgical skill sets except “life-saving surgery” (P = 0.011). Scores of all 4 non-technical skill sets were significantly higher for entry-level FST than those for conventional surgery training (P Conclusions: The training should be considered as an essential strategy to improve confidence in combat medical skills, especially life-saving surgery and non-technical skills, for primary combat surgeons.

Feed-Forward Neural Network Based Petroleum Wells Equipment Failure Prediction

In the oil industry, the productivity of oil wells depends on the performance of the sub-surface equipment system. These systems often have problems stemming from sand, corrosion, internal pressure variation, or other factors. In order to ensure high equipment performance and avoid high-cost losses, it is essential to identify the source of possible failures in the early stage. However, this requires additional maintenance fees and human power. Moreover, the losses caused by these problems may lead to interruptions in the whole production process. In order to minimize maintenance costs, in this paper, we introduce a model for predicting equipment failure based on processing the historical data collected from multiple sensors. The state of the system is predicted by a Feed-Forward Neural Network (FFNN) with an SGD and Backpropagation algorithm is applied in the training process. Our model’s primary goal is to identify potential malfunctions at an early stage to ensure the production process’ continued high performance. We also evaluated the effectiveness of our model against other solutions currently available in the industry. The results of our study show that the FFNN can attain an accuracy score of 97% on the given dataset, which exceeds the performance of the models provided.

Looking Forward To Oil

China is playing a major role in Uganda’s oil industry development Although oil in Uganda was first discovered in 1925 during the colonial era,it was not until recently that its exploration and plans to exploit the black gold commercially began in earnest.In November 2022,the country’s Minister of Energy and Mineral Development Ruth Nankabirwa Ssentamu said at a conference in Abu Dhabi,“I hope that by April 2025,we shall see the first oil.”

一种星载高效率电源的样机研制

针对星载合成孔径雷达电源高效率抗辐射的需求,对适用于星载领域的各种电源拓朴结构进行了对比分析,提出一种同步整流正激变换器拓扑方案。该方案采用单管栅极电荷保持驱动拓扑,解决了变压器死区时间续流管驱动问题,并对电路原理以及抗辐射加固方法进行详细说明,给出电路组成、关键器件和参数计算方法。根据所提方案制作了一台输入50 V~70 V、输出5 V/6 A的样机。实验结果表明:该电源具有高效率和抗辐射的特点,验证了技术方案的准确性,可以满足星载电源的需求。

高速列车顶层设计指标分解研究现状与展望

顶层设计指标分解是决定高速列车正向设计周期长短和成功与否的首要环节.首先,在阐述运输能力、安全舒适、绿色环保、经济性等高速列车顶层设计指标的基础上,从系统结构组成、运行边界条件以及大系统耦合作用等角度提出高速列车顶层设计指标分解所面临的技术挑战;然后,论述设计指标分解方法、设计指标分解关联模型和设计指标分解协调策略3个方面研究现状,并分析现有方法的不足与新需求;最后,展望群落生态学在高速列车顶层设计指标分解中的适用性,剖析基于群落生态学的高速列车顶层设计指标分解将会面临的关键问题,并给出相应的解决技术路线,以期为高速列车顶层设计指标分解的深入研究和实践提供参考.

基于2.5D有限元的高密度电法不同装置勘探效果研究

高密度电法是一种适用性广泛的电阻率勘探方法,拥有多种电极排列装置选择。不同装置由于电极分布方式的差异,在针对不同地质目标和测区环境时往往表现出明显不同的探测能力。为探究各排列装置的特点及其适用情况,推导了2.5D电位的变分问题,采用Delaunay三角化算法实现了非结构化网格剖分,进而实现了有限元正演模拟。结合实践,对常见地质情况进行建模,分别使用温纳α、温纳β、施伦贝谢尔、偶极-偶极4种装置开展正反演对比研究。研究发现:(1)在探测未知区域单个异常体时,温纳β、施伦贝谢尔2种排列的效果更好;(2)在探测相邻较近的多个异常体时,应优先采用具有更高水平分辨率的施伦贝谢尔和偶极-偶极排列;(3)对于低阻破碎带的勘探,温纳β和偶极-偶极排列更为适用;(4)当地层具有较好分层界限时,4种排列均可体现良好的分层效果。因此,高密度电法勘探实践中应综合考虑不同排列装置的特点,根据具体情况选用合适的多种排列方式进行测量,并对采集数据进行综合对比分析,以获得更为准确的解释结果。

特拉敖包矿产地氧化还原过渡带磁异常特征及产生机理探讨

鄂尔多斯盆地北缘是我国重要的砂岩型铀矿床基地,近几年地质勘查发现特拉敖包地区有很大的找矿潜力,定位氧化还原过渡带是圈定有利成矿地区的关键。前人针对砂岩型铀矿开展的磁法研究大多只是直接对矿床的磁异常进行简单分析,很少研究不同环境磁化率差异,也未考虑深部基底磁性的影响。文章统计了研究区不同砂体磁化率参数,计算了理论模型正演响应,并开展磁法测量,获得了磁异常特征并求取剩余磁异常,其结果与氧化还原过渡带位置,以及三价铁与二价铁比值有一定的对应关系。认为研究区氧化还原过渡带上方表现为微弱高异常特征,与传统层间氧化带型磁异常形态有区别,原因是后期油气还原作用使局部铁元素价态发生变化,引起局部磁异常升高。

一种基于太赫兹成像的复杂地形自适应定高方法

针对现有近感探测器难以适应复杂地形情况下的精确定高问题,提出一种基于成像的图像域自适应对地高度估计方法。该方法将多普勒锐化成像原理应用到前下视场景,利用太赫兹频段分辨力高、孔径合成长度短的优势,采用太赫兹前下视成像实现地形感知,将传统近感探测器的一维距离测量扩展为二维成像测量,实现对运动轨迹前下方地形地貌的精确感知。在获得地面目标图像后,利用地面图像特征,采用图像域特征拟合方法实现对地高度估计。对前下视多普勒锐化成像的参数设计和成像算法进行了理论分析和仿真验证,开发了一套工作于220 GHz频段的太赫兹近感探测系统,并开展了无人机挂载试验。试验表明,该方法能有效感知地表目标环境,排除角反、树木等其他目标对地面高度测量的干扰,测高精确度达0.5 m,证明了该基于太赫兹成像的对地高度估计方法的可行性,为基于图像域特征提升近感探测器对复杂地形适应能力和感知能力奠定了工作基础。

任意起伏地形下重力异常三维正演及并行计算

为了进一步提高空间-波数域三维重力异常正演算法的适用范围和计算效率,本文采用任意傅里叶变换算法实现了空间-波数域三维重力异常正演,且在NVIDIA CUDA平台上进行CPU-GPU并行加速.任意傅里叶变换算法的基本思想是将二维傅里叶变换转化为两个一维傅里叶变换,一维傅里叶变换积分离散为多个单元积分累加和,离散单元中原函数采用二次插值形函数拟合,求出单元积分的解析表达式.相比现有的傅里叶变换算法,新方法具有采样灵活、积分精度高、计算速度快和傅里叶变换的截断效应小等优势.利用空间-波数域算法的高度并行性,采用CPU并行求解常微分方程,GPU并行计算任意傅里叶变换,实现了CPU-GPU并行加速方案,进一步提升了本文算法效率.利用常密度模型,对比数值解和解析解,结果表明本文算法正确;利用变密度模型对比了任意傅里叶变换算法与高斯快速傅里叶变换算法的计算效率与精度,在相近的数值精度下,本文算法波数选取少,效率高;测试CPU-GPU并行效果,结果表明相比CPU串行算法,CPU-GPU并行算法的计算效率大大提升,千万数量级节点数模型正演仅耗时数秒.最后利用实际地形数据进行三维重力异常场数值模拟,证明了新方法的高效性与实用性,对实现大规模复杂条件下重力异常精细化反演成像与综合解释有重要意义.

新工科背景下“正/逆向设计加工”课程实践体系的探索与实践

阐述了长安大学现代工程训练中心建立的“正/逆向设计加工”课程实践体系的主要内容和实施效果。体系以教学融合+创新实践的方法进行构建,融合“CAD”“3D打印”“逆向工程”“CNC数控加工”等知识内容,采用递进式教学打破课程孤岛,鼓励学生自主创造,坚持全贯穿式教学实践环境。为培养新工科背景下的智能制造复合型人才提供了新型教学思路,对推动高校工程训练教学改革具有一定的借鉴意义。