逆出蚕发生的原因及孵化方式的初步研究

针对生产上出现“逆出蚕”这一情况 ,通过催青实验调查发生逆出蚕的原因及其孵化方式。实验采用碧波×洞庭、春蕾×镇珠 2个蚕品种 ,分别在常温、高温与RH 70 %、RH 80 %、RH90 %组合的 6个条件下 ,进行两段式催青至孵化。通过对孵化率、逆出蚕率的调查 ,发现影响同一品种逆出蚕的主要原因是湿度 ,实验还观察到了逆出蚕的孵化方式。这些为今后进一步研究逆出蚕和减少逆出蚕的发生有着积极作用和现实意义。

逆出蚕发生原因与防治措施探讨

逆出蚕发生原因与防治措施探讨曲阜市丝绸公司李钦凯，胡玉生，徐明波山东农业大学养蚕教研室王洪利由于平附种改为散卵，收蚁时顶壳蚕有所增加，一年四季均有发生，特别是春季更普遍，为解决这一问题做了如下试验。一、材料与方法试验材料莆松×皓月一代杂交种。试验方法...

对逆出卵产生原因的探讨

蚕种在孵化期间处在冷风直吹、不停振动,或两者共同作用,以及处于高浓度CO2和缺氧的闷热环境中时,且时间较长条件下,才会产生逆出卵。

逆出蚁的发生与调查

最近两年本场安排了晚秋丝茧育生产,其散卵普通种的催青方法与原种相同,为了达到一日收蚁足量而适当提高了催青积温.收蚁当日凌晨散卵从黑暗室取出发种时,已有部分孵化的苗蚁,然后从散卵盒中倒出散卵及苗蚁一起感光,收蚁时发现有逆出蚁发生,且两年晚秋都有发生.而平附原种在类似的情况下,从未明显发生过逆出蚁.这种逆出蚁(俗称戴帽子蚕)外观上看,蚁蚕腹部和尾部在卵壳外,而头胸部在卵壳内,顶着卵壳无法脱落,因无法食桑而死亡.为此,笔者对逆出蚁的发生进行初步试验性调查.

如何防止逆出蚕的发生

逆出蚕在生产上发生普遍,危害较大。如我县1994年在夏季收蚁期间正值高温干燥季节,约有400张蚕种不同程度发生逆出蚕,轻者达2%,重者达20%,严重影响了实用孵化率和张产。究其原因:一是补催青忽略补湿,室内过于干燥,干湿差高达4—5℃;二是剧烈振动,特别有的蚕农超容量装收蚁袋,因不附着而剧烈振荡,造成蚁体移位。生产上,只要做到两点:一是加强补催青过程中的补湿,保证干湿差1—

逆出蚁发生的调查与分析

通过试验设置4个不同处理来调查逆出蚁发生的原因。

温阳益气活血法联合西医常规治疗在心衰后汗出厥逆患者的应用探讨

本文旨在分析暖阳增气促进血液循环疗法与西方医学标准疗法结合应用于心脏衰竭所致汗泄逆冲症状患者的疗效成果。方法 依采取随机数字抽样技术,选取本医院2022年1月至同年12月期间收治的40位心力衰竭并发自汗症状的患者进行了分组,共分为两个组别,分别是实验组(20例)和对照组(20例)。实验组在接受西医标准疗法的同时,额外施以温阳补气和促进血液循环的中医治疗方案,而对照组患者则只接受了西医的常规治疗措施。接着对两批病人所接受治疗的效果、心脏作用能力、血清中的生物标志物浓度以及六分钟步行测试的成绩等多项指标进行了对比分析。结果 观察组病人的整体疗效显著达到95%,相较之下,对照组仅展现出70%的有效反应,这种显著性差别是有统计学支持的,具有明显的数据价值(P值小于0.05)。另外,通过比较发现,观察组成员在心脏功能、血清生化指标以及六分钟步行测试的表现均超过了对照组,这种差距在统计上也是显著的(P值小于0.05)。结论 融合温阳益气与活血手法与传统西药治疗策略,形成的一体化治疗方案,对于心功能衰竭引发的汗液异常和冷逆现象的患者来说,能有效缓解其临床表现,并提升心脏功能指标,同时减少血清中的生物标志物含量,其实践应用具有较高的推广价值。

异构计算系统任务调度的遗传算法及改进

提出一种新的染色体编码方法——逆排序消出结点法RSEEN,确保染色体对应的任务分配调度为合理调度,不必在遗传操作过程中不断地验证和调整基因以保证染色体的有效性,简化了遗传操作,使优良基因更易保全并传递给后代,种群的进化过程更接近自然的进化法则。另外,还采用了启发式变异方法,加速了算法的收敛性。同时,构造本算法是以异构计算系统模型为基础的,充分考虑了任务间数据交换的开销和处理机间的差异,算法的应用更有普遍意义。

发生“带帽蚕”原因的探讨

对蚕种孵化时发生带帽蚕(逆出蚕)的原因,有的认为与蚕的品种性状有关;有的认为与上一代的体质有关;为了探讨发生带帽蚕的原因,我们做了不同品种、不同湿度环境及转青卵冷藏的蚕种催青孵化实验:(一)蚕品种新月×新松,为青州蚕场春制种,第7批;9月6日出库,张种卵重14克,张种良卵27440粒,一克良卵1960粒,不良卵率1.2%(1)催青后期温度25.5℃、干湿差1—1.5℃。第一天孵化26879头,孵化率98%;第二天孵化552头、孵化率1.97%,迟孵化卵9粒、迟孵化率0.03%;带帽蚁蚕11头、带帽蚁率0.04%。(2)

Micro-nanostructural designs of bifunctional electrocatalysts for metal-air batteries

Water-based rechargeable metal-air batteries play an important role in the storage and conversion of renewable electric energy.However,the sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)have limited the practical application of rechargeable metal-air batteries.Most of reviews were focused on single functional electrocatalysts while few on bifunctional electrocatalysts.It is indispensable but challenging to design a bifunctional electrocatalyst that is active and stable to the two reactions.Recently,attempts to develop high active bifunctional electrocatalysts for both ORR and OER increase rapidly.Much work is focused on the micro-nano design of advanced structures to improve the performance of bifunctional electrocatalyst.Transition-metal materials,carbon materials and composite materials,and the methods developed to prepare micro-nano structures,such as electrochemical methods,chemical vapor deposition,hydrothermal methods and template methods are reported in literatures.Additionally,many strategies,such as adjustments of electronic structures,oxygen defects,metal-oxygen bonds,interfacial strain,nano composites,heteroatom doping etc.,have been used extensively to design bifunctional electrocatalysts.To well understand the achievements in the recent literatures,this review focuses on the micro-nano structural design of materials,and the related methods and strategies are classed into two groups for the improvement of intrinsic and apparent activities.The fine adjustment of nano structures and an in-depth understanding of the reaction mechanism are also discussed briefly.

Spectral Calculation of the Output Voltage of an Inverter with Bipolar Pulse Width Modulation

Converters with pulse width modulation are used for connections between the direct current （DC） and alternating current （AC） networks, e.g., in uninterrupted power supply systems, AC electromotor drives, for powering induction furnaces, in audio technique. Spectrum of signals sampled by pulse amplitude modulation and output voltage spectrum of the converter with pulse width modulation have similar properties. Spectrum of signals sampled by pulse amplitude modulation contains a harmonic of frequency equal to the frequency of the modulating signal and the harmonics of frequencies equal to the sum of frequency of the modulating signal and multiples of the sampling frequency. The output voltage spectrum of the converter with bipolar pulse width modulation contains harmonic of frequency equal to the frequency of the modulating signal and harmonics of frequencies equal to sum of the frequency of the modulating signal and multiples of the frequency of the carrier signal. It also contains harmonics of frequencies equal to the sum of the multiples of the frequency of the modulating signal and the multiples of the carrier signal. The comparison analysis was carried out for the harmonics of the output voltage of the converter with bipolar pulse width modulation in time domain. The dependency of the amplitudes and frequency spectrum on the wave forms of the carrier signal and modulating signal was shown. Similarity of the output voltage spectrum of the converter and signal spectrum sampled by the pulse width modulation was also shown. Key words： Output voltage converter with bipolar pulse width modulation, spectral analysis, Fourier series, carrier signal, reference signal.

Norton equivalent circuit for current control loop of grid-connected system

Modeling method for the current control loop of a grid-connected PWM inverter with the LCL output filter was discussed.Firstly,the current control loop with the LCL inverter-side current as feedback was established.Then,parameters of PI controller were calculated on the basis of an equivalent controlled object.Finally,Norton equivalent circuit for the current control loop of grid-connected system was derived by integrating one control equation,which connected the PWM inverter output voltage and the LCL inverter-side current,with two circuit equations,separately using the LCL inverter-side current and the injected current as loop currents.With the induced Norton equivalent circuit,system-level resonant and unstable issues on real grid-connected system applied in weak distributed power systems can be easily analyzed.The validity of substituting Norton equivalent circuit for grid-connected system is verified by simulation and experiment.

Regularized Inverse Covariance Estimation for Longitudinal Data with Informative Dropout

This paper proposes a novel method for estimating the sparse inverse covariance matrixfor longitudinal data with informative dropouts. Based on the modified Cholesky decomposition,the sparse inverse covariance matrix is modelled by the autoregressive regression model,which guarantees the positive definiteness of the covariance matrix. To account for the informativedropouts, we then propose a penalized estimating equation method using the inverse probabilityweighting approach. The informative dropout propensity parameters are estimated by the generalizedmethod of moments. The asymptotic properties are investigated for the resulting estimators.Finally, we illustrate the effectiveness and feasibility of the proposed method through Monte Carlosimulations and a practical application.

Work entransy and its applications

The entransy theory has been applied to the analyses of heat-work conversion systems. The physical meaning and the applications of work entransy are analyzed and discussed in this paper. Work entransy, which is clarified to be a process dependent quantity, is not the entransy of work, but the system entransy change accompanying work transfer. The relationship between the work entransy and the output work is set up. When the application preconditions are satisfied, larger work entransy leads to larger output work. Entransy loss, which was proposed and applied to heat work conversion processes with irreversible heat transfer, is the net entransy flow into the system and the summation of work entransy and entransy dissipation. The application preconditions of entransy loss are also discussed.

Analyses of thermodynamic performance for the endoreversible Otto cycle with the concepts of entropy generation and entransy

In this paper, the endoreversible Otto cycle is analyzed with the entropy generation minimization and the entransy theory. The output power and the heat-work conversion efficiency are taken as the optimization objectives, and the relationships of the output power, the heat-work conversion efficiency, the entropy generation rate, the entropy generation numbers, the entransy loss rate, the entransy loss coefficient, the entransy dissipation rate and the entransy variation rate associated with work are discussed. The applicability of the entropy generation minimization and the entransy theory to the analyses is also analyzed. It is found that smaller entropy generation rate does not always lead to larger output power, while smaller entropy generation numbers do not always lead to larger heat-work conversion efficiency, either. In our calculations, both larger entransy loss rate and larger entransy variation rate associated with work correspond to larger output power, while larger entransy loss coefficient results in larger heat-work conversion efficiency. It is also found that the concept of entransy dissipation is not always suitable for the analyses because it was developed for heat transfer.

Entransy analyses of the thermodynamic cycle in a turbojet engine

The analysis and the design of turbojet engines are of great importance to the improvement of the system performance.Many researchers focus on these topics,and many important and interesting results have been obtained.In this paper,the thermodynamic cycle in a turbojet engine is analyzed with the entransy theory and the T-Q diagram.The ideal thermodynamic cycle in which there is no inner irreversibility is analyzed,as well as the influences from some inner irreversible factors,such as the heat transfer process,the change of the component of the working fluid and the viscosity of the working fluid.For the discussed cases,it is shown that larger entransy loss rate always results in larger output power,while smaller entropy generation rate does not always.The corresponding T-Q diagrams are also presented,with which the change tendencies of the entransy loss rate and the output power can be shown very intuitively.It is shown that the entransy theory is applicable for analyzing the inner irreversible thermodynamic cycles discussed in this paper.Compared with the concept of entropy generation,the concept of entransy loss and the corresponding T-Q diagram are more suitable for describing the change of the output power of the analyzed turbojet engine no matter if the inner irreversible factors are considered.

Reduction of nonreciprocal errors in a differential interferometric fiber optical gyroscope using optically differential processing

The bias stability of differential interferometric fiber optical gyroscope is analyzed.Thermal error causing long-term bias drift are reduced by putting the 90°splice in the middle of the fiber coil and applying a wide spectrum light source.Also,a kind of novel optical differential processing,which is much more precise than the electronic differential processing,is proposed for reducing the residual nonreciprocal error in the final differential output.An experimental setup based on optical differential processing was built.An^100 fold reduction in the long-term bias drift is demonstrated experimentally compared with the primary differential interferometric fiber optical gyroscope.